Recommended
More Related Content
More from AngelDelacruz900577
More from AngelDelacruz900577 (20)
Recently uploaded
Recently uploaded (20)
Lanthanide.docx
- 1. Lanthanide From Wikipedia,the free encyclopedia Jumpto navigationJumptosearch Lanthanidesinthe periodictable Hydrogen Helium Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon Potassium Calcium Scandium Titanium Vanadium Chromium
- 5. Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson Part of a seriesonthe Periodictable Periodictable forms Periodictable history Setsof elements By periodictable structure By metallicclassification Metals alkalialkaline earth transitionpost-transition lanthanideactinide (superactinide) Metalloids dividingmetalsandnonmetals Nonmetals unclassifiednonmetal halogennoblegas By othercharacteristics Elements List of chemical elements Propertiesof elements Data pagesfor elements CategoryChemistryPortal vte
- 6. The lanthanide (/ˈlænθənaɪd/) orlanthanoid(/ˈlænθənɔɪd/) seriesof chemical elements[1] comprises the 15 metallicchemical elementswithatomicnumbers57–71, from lanthanumthrough lutetium.[2][3][4] These elements,alongwiththe chemicallysimilarelementsscandiumandyttrium,are oftencollectivelyknownasthe rare-earthelementsorrare-earthmetals. The informal chemical symbol Lnisused ingeneral discussionsof lanthanidechemistrytorefertoany lanthanide.Allbutone of the lanthanidesare f-blockelements,correspondingtothe fillingof the 4f electronshell.There issome disputeonwhetherlanthanumorlutetiumisad-blockelement,but lutetiumisusuallyconsideredsobythose whostudythe matter;[5][6] itisincludeddue toitschemical similaritieswiththe other14.[7] All lanthanide elementsformtrivalentcations,Ln3+,whose chemistry islargelydeterminedbythe ionicradius,whichdecreasessteadilyfromlanthanumtolutetium. These elementsare calledlanthanidesbecausethe elementsinthe seriesare chemicallysimilarto lanthanum.Since "lanthanide"means"likelanthanum",ithasbeenarguedthatlanthanumcannot logicallybe alanthanide,butthe International Unionof Pure andAppliedChemistry(IUPAC) acknowledgesitsinclusionbasedoncommonusage.[8] In presentationsof the periodictable,the f-blockelementsare customarilyshownastwoadditional rowsbelowthe mainbodyof the table,[2] Thisconventionisentirelyamatterof aestheticsand formattingpracticality;ararelyusedwide-formattedperiodictable insertsthe 4f and5f seriesintheir properplaces,asparts of the table'ssixthandseventhrows (periods). The 1985 IUPAC"RedBook"(p. 45) recommendsthat"lanthanoid"isusedratherthan"lanthanide",as the ending"-ide"normallyindicatesanegative ion.However,owingtowide currentuse,"lanthanide"is still allowed. vte Lanthanides Lan-thanum 57 La 138.91 Cerium 58
- 8. 158.93 Dyspro-sium 66 Dy 162.50 Hol-mium 67 Ho 164.93 Erbium 68 Er 167.26 Thulium 69 Tm 168.93 Ytter-bium 70 Yb 173.05 Lute-tium 71 Lu 174.97 Primordial From decay Synthetic Bordershowsnatural occurrence of the element Contents
- 9. 1 Etymology 2 Physical propertiesof the elements 3 Chemistryand compounds 3.1 Effectof 4f orbitals 3.2 Lanthanide oxidationstates 3.3 Separationof lanthanides 3.4 Coordinationchemistryandcatalysis 3.4.1 Ln(III) compounds 3.4.2 Ln(II) andLn(IV) compounds 3.4.3 Hydrides 3.4.4 Halides 3.4.5 Oxidesandhydroxides 3.4.6 Chalcogenides(S,Se,Te) 3.4.7 Pnictides(group15) 3.4.8 Carbides 3.4.9 Borides 3.4.10 Organometalliccompounds 4 Physical properties 4.1 Magneticand spectroscopic 5 Occurrence 6 Applications 6.1 Industrial 6.2 Life science 6.3 Possible medical uses 7 Biological effects 8 See also 9 References 10 Citedsources 11 External links
- 10. Etymology The term "lanthanide"wasintroducedbyVictorGoldschmidtin1925.[9][10] Despite theirabundance, the technical term"lanthanides"isinterpretedtoreflectasense of elusivenessonthe partof these elements,asitcomesfromthe Greekλανθανειν (lanthanein),"tolie hidden".[11] Ratherthan referringtotheirnatural abundance,the wordreflectstheirpropertyof "hiding"behind each otherinminerals.The termderivesfromlanthanum, firstdiscoveredin1838, at that time a so- callednewrare-earthelement"lyinghidden"or"escapingnotice"inaceriummineral,[12] anditis an ironythat lanthanumwaslateridentifiedasthe firstinan entire seriesof chemicallysimilarelements and gave itsname to the whole series. Togetherwiththe twoelementsatthe topof group 3, scandiumand yttrium, the trivial name "rare earths"issometimesusedtodescribe all the lanthanides;adefinitionof rare earthsincludingthe group 3, lanthanide,andactinide elementsisalsooccasionallyseen,andrarelySc+ Y + lanthanides+ thorium.[citationneeded] The "earth"inthe name "rare earths"arisesfromthe mineralsfromwhich theywere isolated,whichwere uncommonoxide-typeminerals.However,these elementsare neither rare inabundance nor "earths"(anobsolete termforwater-insoluble stronglybasicoxidesof electropositive metalsincapableof beingsmeltedintometal usinglate 18thcenturytechnology).Group 2 isknownas the alkaline earthelementsformuchthe same reason. The "rare" in the "rare earths"name hasmuch more to do withthe difficultyof separatingouteachof the individual lanthanide elementsthanscarcityof any of them.By wayof the Greek"dysprositos"for "hard to getat," element66,dysprosiumwassimilarlynamed;lanthanumitselfisnamedafteraword for "hidden."The elements57(La) to 71 (Lu) are verysimilarchemicallytoone anotherandfrequently occur togetherinnature,oftenanywhere fromthree toall 15 of the lanthanides(alongwithyttriumasa 16th) occur inmineralssuchassamarskite,monazite andmanyotherswhichcanalsocontainthe other twogroup 3 elementsaswell asthoriumandoccasionallyotheractinidesaswell.[13] A majorityof the rare earthswere discoveredatthe same mine inYtterby,Swedenandfourof themare named(yttrium, ytterbium,erbium,terbium) afterthe cityanda fifth*(holmium) afterStockholm;scandiumisnamed afterScandinavia,thuliumafterthe oldname Thule,andthe immediately-followinggroup4element (number72) hafniumisnamedforthe Latinname of the city of Copenhagen.[13] Samarskite (amineral whichisthe source of the name of the elementsamarium) andothersimilar mineralsinparticularalsohave these elementsinassociationwiththe nearbymetalstantalum, niobium, hafnium,zirconium,vanadium,andtitanium, fromgroup4and group 5 ofteninsimilaroxidationstates. Monazite isa phosphate of numerousgroup3 + lanthanide +actinide metalsandminedespeciallyfor the thoriumcontentandspecificrare earthsespeciallylanthanum,yttriumandcerium.Ceriumand lanthanumaswell asothermembersof the rare earthseriesare oftenproducedasa metal called mischmetal containingavariable mixtureof these elementswithceriumandlanthanumpredominating;
- 11. it hasdirectusessuch as lighterflintsandothersparksourceswhichdonotrequire extensive purificationof one of these metals.[13] There are alsorare earth-bearingmineralsbasedongroup2 elementssuchasyttrocalcite,yttrocerite, yttrofluorite whichvaryincontentof yttrium, cerium, andlanthanuminaparticularas well asvarying amountsof the others.[14] Otherlanthanide/rare earthmineralsincludebastnäsite,florencite, chernovite,perovskite,xenotime,cerite,gadolinite,lanthanite,fergusonite,polycrase,blomstrandine, håleniusite,miserite,loparite,lepersonnite,euxenite,all of whichhave arange of relative element concentrationandmayhave the symbol of a predominatingone suchasmonazite-ce;group3elements do notoccur as native elementmineralsinthe fashionof gold,silver,tantalumandmanyotherson earthbut may inlunarregolith.Veryrare cerium, lanthanum, andpresumablyotherlanthanide/group3 halides,feldsparsandgarnetsare alsoknowntoexist.[15] All of thisis the resultof the orderin whichthe electronshellsof these elementsare filled—the outermosthasthe same configurationforall of them, anda deepershellisprogressivelyfilledwith electronsasthe atomicnumberincreasesfrom57 towards71.[13] For manyyears,mixturesof more than one rare earthwere consideredtobe single elements,suchasneodymiumandpraseodymium beingthoughttobe the single elementdidymiumandsoon.[16] Verysmall differencesinsolubilityare usedinsolventandion-exchange purificationmethodsforthese elementswhichrequireagreatdeal of repeatingtogeta purifiedmetal.The refinedmetalsandtheircompoundshave subtle andstark differencesamongstthemselvesinelectronic,electrical,optical,andmagneticpropertieswhichaccount for theirmanyniche uses.[13] By wayof examplesof the termmeaningthe above considerationsratherthantheirscarcity,ceriumis the 26th mostabundantelementinthe Earth'scrust and more abundantthan copper,[13] neodymium ismore abundantthangold;thulium(the secondleastcommonnaturallyoccurringlanthanide)ismore abundantthan iodine,[17] whichisitself commonenoughforbiologytohave evolvedcritical usages thereof,andeventhe lone radioactive elementinthe series,promethium, ismore commonthanthe tworarest naturallyoccurringelements,franciumandastatine,combined. Physical propertiesof the elements Chemical element La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Atomicnumber57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 Image Lanthanum-2.jpg Cerium2.jpg Praseodymium.jpg Neodymium2.jpg Samarium-2.jpgEuropium.jpg Gadolinium-4.jpg Terbium-2.jpg Dy chips.jpg
- 12. Holmium2.jpg Erbium-crop.jpgThuliumsublimeddendriticand1cm3 cube.jpg Ytterbium-3.jpg Lutetiumsublimeddendriticand1cm3 cube.jpg Density(g/cm3)6.162 6.770 6.77 7.01 7.26 7.52 5.244 7.90 8.23 8.540 8.79 9.066 9.32 6.90 9.841 Meltingpoint(°C) 920 795 935 1024 1042 1072 826 1312 1356 1407 1461 1529 1545 824 1652 Boilingpoint(°C) 3464 3443 3520 3074 3000 1794 1529 3273 3230 2567 2720 2868 1950 1196 3402 Atomicelectronconfiguration (gasphase)* 5d1 4f15d1 4f3 4f4 4f5 4f6 4f7 4f75d1 4f9 4f10 4f11 4f12 4f13 4f14 4f145d1 Metal lattice (RT) dhcp fcc dhcp dhcp dhcp ** bcc hcp hcp hcp hcp hcp hcp fcc hcp Metallicradius(pm) 162 181.8 182.4 181.4 183.4 180.4 208.4 180.4 177.3 178.1 176.2 176.1 175.9 193.3 173.8 Resistivityat25 °C (μΩ·cm) 57–80 20 °C 73 68 64 88 90 134 114 57 87 87 79 29 79 Magneticsusceptibility χmol /10−6(cm3·mol−1)+95.9 +2500 (β) +5530(α) +5930 (α) +1278(α) +30900 +185000 (350 K) +170000 (α) +98000 +72900 +48000 +24700 +67 (β) +183 * BetweeninitialXe andfinal 6s2 electronicshells ** Sm has a close packedstructure like mostof the lanthanidesbuthasanunusual 9 layerrepeat GschneiderandDaane (1988) attribute the trendinmeltingpointwhichincreasesacrossthe series, (lanthanum(920 °C) – lutetium(1622 °C)) to the extentof hybridizationof the 6s,5d, and 4f orbitals. The hybridizationisbelievedtobe at itsgreatestforcerium, whichhasthe lowestmeltingpointof all, 795 °C.[18] The lanthanide metalsare soft;theirhardnessincreasesacrossthe series.[8] Europium standsout, as ithas the lowestdensityinthe seriesat5.24 g/cm3 and the largestmetallicradiusinthe seriesat208.4 pm.It can be comparedto barium, whichhasa metallicradiusof 222 pm.It is believed that the metal containsthe largerEu2+ ionand that there are onlytwoelectronsinthe conduction band.Ytterbiumalsohasa large metallicradius,andasimilarexplanationissuggested.[8] The resistivitiesof the lanthanidemetalsare relativelyhigh,rangingfrom29 to 134 μΩ·cm.These valuescan
- 13. be comparedto a good conductorsuch as aluminium, whichhasa resistivityof 2.655 μΩ·cm. Withthe exceptionsof La,Yb,and Lu (whichhave nounpairedf electrons),the lanthanidesare strongly paramagnetic,andthisisreflectedintheirmagneticsusceptibilities.Gadoliniumbecomesferromagnetic at below16 °C (Curie point).The otherheavierlanthanides –terbium, dysprosium,holmium, erbium, thulium,andytterbium –become ferromagneticatmuchlowertemperatures.[19] Chemistryandcompounds Chemical element La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Atomicnumber57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 Ln3+ electronconfiguration*[20] 4f0 4f1 4f2 4f3 4f4 4f5 4f6 4f7 4f8 4f9 4f10 4f11 4f12 4f13 4f14 Ln3+ radius(pm)[8] 103 102 99 98.3 97 95.8 94.7 93.8 92.3 91.2 90.1 89 88 86.8 86.1 Ln4+ ioncolor inaqueoussolution[21] — Orange-yellow Yellow Blue-violet — — — — Red-brown Orange-yellow — — — — — Ln3+ ioncolor inaqueoussolution[20] Colorless Colorless Green Violet Pink Pale yellow Colorless Colorless V.pale pink Pale yellow Yellow Rose Pale green Colorless Colorless Ln2+ ioncolor inaqueoussolution[8] — — — — — Bloodred Colorless — — — — — Violet-red Yellow-green — * Notincludinginitial [Xe] core f → f transitionsare symmetryforbidden(orLaporte-forbidden),whichisalsotrue of transitionmetals. However,transitionmetalsare able touse vibroniccouplingtobreakthisrule.The valence orbitalsin lanthanidesare almostentirelynon-bondingandassuch little effective vibroniccouplingtakes,hence the spectra fromf → f transitionsare muchweakerandnarrowerthan those fromd → d transitions.In general thismakesthe colorsof lanthanide complexesfarfainterthanthose of transitionmetal complexes. Approximate colorsof lanthanide ionsinaqueoussolution[8][22][23]
- 14. Oxidationstate 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 +2 Sm2+ Eu2+ Tm2+ Yb2+ +3 La3+ Ce3+ Pr3+ Nd3+ Pm3+ Sm3+ Eu3+ Gd3+ Tb3+ Dy3+ Ho3+ Er3+ Tm3+ Yb3+ Lu3+ +4 Ce4+ Pr4+ Nd4+ Tb4+ Dy4+ Effectof 4f orbitals Goingacross the lanthanidesinthe periodictable,the 4f orbitalsare usuallybeingfilled.The effectof the 4f orbitalson the chemistryof the lanthanidesisprofoundandisthe factorthat distinguishesthem fromthe transition metals.There are seven4f orbitals,andthere are twodifferentwaysinwhichthey are depicted:asa "cubicset"or as a general set.The cubicsetis fz3,fxz2,fyz2, fxyz,fz(x2−y2), fx(x2−3y2) andfy(3x2−y2).The 4f orbitalspenetrate the [Xe] core andare isolated,andthustheydonot participate inbonding.Thisexplainswhycrystal fieldeffectsare small andwhytheydonot formπ bonds.[20] Asthere are seven4f orbitals,the numberof unpairedelectronscanbe ashighas 7, which givesrise tothe large magneticmomentsobservedforlanthanidecompounds. Measuringthe magneticmomentcanbe usedto investigate the 4f electronconfiguration,andthisisa useful tool inprovidinganinsightintothe chemical bonding.[24] The lanthanide contraction,i.e.the reductioninsize of the Ln3+ ionfromLa3+ (103 pm) to Lu3+ (86.1 pm),is oftenexplainedbythe poor shieldingof the 5s and 5p electronsbythe 4f electrons.[20] Lanthanide oxides:clockwise fromtopcenter:praseodymium, cerium, lanthanum,neodymium, samariumand gadolinium. The electronicstructure of the lanthanide elements,withminorexceptions,is[Xe]6s24fn.The chemistry of the lanthanidesisdominatedbythe +3 oxidationstate,andinLnIIIcompoundsthe 6selectronsand (usually) one 4f electronare lostandthe ionshave the configuration[Xe]4fm.[25] All the lanthanide elementsexhibitthe oxidationstate +3.In addition,Ce3+can lose itssingle f electrontoformCe4+ with the stable electronicconfigurationof xenon.Also,Eu3+can gain an electrontoformEu2+ withthe f7 configurationthathasthe extrastabilityof a half-filledshell.OtherthanCe(IV) andEu(II),none of the lanthanidesare stable inoxidationstatesotherthan+3 in aqueoussolution. In termsof reductionpotentials,the Ln0/3+ couplesare nearlythe same forall lanthanides,ranging from−1.99 (forEu) to −2.35 V (forPr).Thus these metalsare highlyreducing,withreducingpower similartoalkaline earthmetalssuchasMg (−2.36 V).[8]
- 15. Lanthanide oxidationstates Ionizationenergiesandreductionpotentialsof the elements The ionizationenergiesforthe lanthanidescanbe comparedwithaluminium.Inaluminiumthe sumof the firstthree ionizationenergiesis5139 kJ·mol−1,whereasthe lanthanides fall inthe range 3455 – 4186 kJ·mol−1.Thiscorrelateswiththe highlyreactivenature of the lanthanides. The sum of the firsttwoionizationenergiesforeuropium,1632 kJ·mol−1can be comparedwiththatof barium1468.1 kJ·mol−1and europium'sthird ionizationenergyisthe highestof the lanthanides.The sumof the firsttwo ionizationenergiesforytterbiumare the secondlowestinthe seriesanditsthird ionizationenergyisthe secondhighest.The highthirdionizationenergyforEuand Yb correlate withthe half filling4f7andcomplete filling4f14 of the 4f subshell,andthe stabilityaffordedbysuch configurationsdue toexchange energy.[20] Europiumandytterbiumformsaltlike compoundswith Eu2+ and Yb2+, for example the saltlike dihydrides.[26] Botheuropiumandytterbiumdissolve inliquid ammoniaformingsolutionsof Ln2+(NH3)x againdemonstratingtheirsimilaritiestothe alkalineearth metals.[8] The relative ease withwhichthe 4thelectroncanbe removedinceriumand(toa lesser extent praseodymium)indicateswhyCe(IV)andPr(IV) compoundscanbe formed,forexample CeO2isformed rather thanCe2O3 whenceriumreactswithoxygen. Separationof lanthanides The similarityinionicradiusbetweenadjacentlanthanideelementsmakes itdifficulttoseparate them fromeach otherinnaturallyoccurringoresand othermixtures.Historically,the verylaboriousprocesses of cascadingand fractional crystallizationwere used.Because the lanthanideionshave slightlydifferent radii,the lattice energyof theirsaltsandhydrationenergiesof the ionswill be slightlydifferent,leading to a small difference insolubility.Saltsof the formulaLn(NO3)3·2NH4NO3·4H2Ocan be used. Industrially,the elementsare separatedfromeachotherbysolventextraction.Typicallyanaqueous solutionof nitratesisextractedintokerosenecontainingtri-n-butylphosphate.The strengthof the complexesformedincreasesasthe ionicradiusdecreases,sosolubilityinthe organicphase increases. Complete separationcanbe achievedcontinuouslybyuse of countercurrentexchangemethods.The elementscanalsobe separatedbyion-exchangechromatography,makinguse of the factthat the stabilityconstantforformationof EDTA complexesincreasesforlogK≈ 15.5 for[La(EDTA)]−to logK ≈ 19.8 for [Lu(EDTA)]−.[8][27] Coordinationchemistryandcatalysis
- 16. Wheninthe formof coordinationcomplexes,lanthanidesexistoverwhelminglyintheir+3oxidation state,althoughparticularlystable 4f configurationscanalso give +4 (Ce,Tb) or +2 (Eu, Yb) ions.All of these formsare stronglyelectropositive andthuslanthanide ionsare hardLewisacids.The oxidation statesare alsoverystable;withthe exceptionsof SmI2[28] andcerium(IV) salts,[29] lanthanidesare not usedforredox chemistry.4f electronshave ahighprobabilityof beingfoundclose tothe nucleusand are thusstronglyaffectedasthe nuclearcharge increasesacrossthe series;thisresultsina correspondingdecreaseinionicradii referredtoasthe lanthanide contraction. The lowprobabilityof the 4f electronsexistingatthe outerregionof the atom or ionpermitslittle effectiveoverlapbetweenthe orbitalsof alanthanide ionandanybindingligand.Thuslanthanide complexestypicallyhave little ornocovalentcharacterand are not influencedbyorbital geometries. The lack of orbital interactionalsomeansthatvaryingthe metal typicallyhaslittleeffectonthe complex (otherthansize),especiallywhencomparedtotransitionmetals.Complexes are heldtogetherby weakerelectrostaticforceswhichare omni-directionalandthusthe ligandsalone dictate the symmetry and coordinationof complexes.Stericfactorstherefore dominate,withcoordinative saturationof the metal beingbalancedagainst inter-ligandrepulsion.Thisresultsinadiverse range of coordination geometries,manyof whichare irregular,[30] andalsomanifestsitself inthe highlyfluxional nature of the complexes.Asthere isnoenergeticreasontobe lockedintoasingle geometry,rapidintramolecular and intermolecularligandexchangewilltake place.Thistypicallyresultsincomplexesthatrapidly fluctuate betweenall possible configurations. Many of these featuresmake lanthanidecomplexeseffectivecatalysts.HardLewis acidsare able to polarise bondsuponcoordinationandthusalterthe electrophilicityof compounds,withaclassic example beingthe Luche reduction.The large size of the ionscoupledwiththeirlabile ionicbonding allowsevenbulkycoordinatingspecies tobindanddissociate rapidly,resultinginveryhighturnover rates;thus excellentyieldscanoftenbe achievedwithloadingsof onlyafew mol%.[31] The lackof orbital interactionscombinedwiththe lanthanide contractionmeansthatthe lanthanideschange insize across the seriesbutthat theirchemistryremainsmuchthe same.Thisallowsforeasytuningof the stericenvironmentsandexamplesexistwhere thishasbeenusedtoimprove the catalyticactivityof the complex[32][33][34] andchange the nuclearityof metal clusters.[35][36] Despite this,the use of lanthanidecoordinationcomplexesashomogeneouscatalystsislargely restrictedtothe laboratoryand there are currentlyfew examplesthembeingusedonanindustrial scale.[37] Lanthanidesexistinmanyformsotherthancoordinationcomplexesandmanyof these are industriallyuseful.Inparticularlanthanidemetal oxidesare usedasheterogeneouscatalystsinvarious industrial processes. Ln(III) compounds
- 17. The trivalentlanthanidesmostlyformionicsalts.The trivalentionsare hardacceptorsand formmore stable complexeswithoxygen-donorligandsthanwithnitrogen-donorligands.The largerionsare 9- coordinate inaqueoussolution,[Ln(H2O)9]3+butthe smallerionsare 8-coordinate,[Ln(H2O)8]3+. There issome evidence thatthe laterlanthanideshave more watermoleculesinthe second coordinationsphere.[38] Complexationwithmonodentateligandsisgenerallyweakbecauseitis difficulttodisplace watermoleculesfromthe firstcoordinationsphere.Strongercomplexesare formed withchelatingligandsbecause of the chelate effect,suchasthe tetra-anionderivedfrom1,4,7,10- tetraazacyclododecane-1,4,7,10-tetraaceticacid(DOTA). Samplesof lanthanide nitratesintheirhexahydrateform.Fromlefttoright:La, Ce,Pr, Nd,Sm, Eu, Gd, Tb, Dy,Ho, Er, Tm,Yb, Lu. Ln(II) andLn(IV) compounds The most commondivalentderivativesof the lanthanidesare forEu(II),whichachievesafavorable f7 configuration.Divalenthalidederivativesare knownforall of the lanthanides.Theyare either conventional saltsorare Ln(III) "electride"-like salts.The simple saltsincludeYbI2,EuI2,and SmI2. The electride-like salts,describedasLn3+, 2I−, e−, include LaI2,CeI2 andGdI2. Many of the iodidesform soluble complexeswithethers,e.g.TmI2(dimethoxyethane)3.[39] Samarium(II) iodide isauseful reducingagent.Ln(II) complexescanbe synthesizedbytransmetalationreactions.The normal range of oxidationstatescanbe expandedviathe use of stericallybulkycyclopentadienyl ligands,inthisway manylanthanidescanbe isolatedasLn(II) compounds.[40] Ce(IV) incericammoniumnitrate isauseful oxidizingagent.The Ce(IV) isthe exceptionowingtothe tendencytoforman unfilledf shell.Otherwise tetravalentlanthanidesare rare.However,recently Tb(IV)[41][42][43] andPr(IV)[44] complexeshave beenshowntoexist. Hydrides Chemical element La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Lanthanide metalsreactexothermicallywithhydrogento formLnH2,dihydrides.[26] Withthe exception of Eu andYb, whichresemble the BaandCa hydrides(non-conducting,transparentsalt-like compounds),theyformblackpyrophoric,conductingcompounds[49] where the metalsub-lattice isface centredcubicand the H atomsoccupy tetrahedral sites.[26] Furtherhydrogenationproducesa trihydride whichisnon-stoichiometric,non-conducting,more saltlike.The formationof trihydride is associatedwithandincrease in8–10% volume andthisislinkedtogreaterlocalizationof charge onthe hydrogenatomswhichbecome more anionic(H−hydride anion) incharacter.[26]
- 18. Halides Lanthanide halides[8][50][51][49] The onlytetrahalidesknownare the tetrafluoridesof cerium, praseodymium,terbium, neodymiumand dysprosium,the lasttwoknownonlyundermatrix isolationconditions.[8][54] All of the lanthanides formtrihalideswithfluorine,chlorine,bromineandiodine.Theyare all highmeltingandpredominantly ionicinnature.[8] The fluoridesare onlyslightlysoluble inwaterandare not sensitive toair,andthis contrastswiththe other halideswhichare airsensitive,readilysoluble inwaterandreactat high temperature toformoxohalides.[55] The trihalideswere importantaspure metal can be preparedfromthem.[8] Inthe gas phase the trihalidesare planarorapproximatelyplanar,the lighterlanthanideshave alower% of dimers,the heavierlanthanidesahigherproportion.The dimershave asimilarstructure toAl2Cl6.[56] Some of the dihalidesare conducting while the restare insulators.The conductingformscanbe consideredasLnIIIelectridecompoundswhere the electronisdelocalisedintoaconductionband,Ln3+ (X−)2(e−).All of the diodideshave relativelyshortmetal-metalseparations.[50] The CuTi2structure of the lanthanum,ceriumandpraseodymiumdiodidesalongwithHP-NdI2contain44 netsof metal and iodine atomswithshortmetal-metal bonds(393-386 La-Pr).[50] these compoundsshouldbe considered to be two-dimensional metals(two-dimensional in the same waythatgraphite is).The salt-like dihalides include those of Eu,Dy,Tm, and Yb. The formationof a relativelystable+2oxidationstate forEu andYb isusuallyexplainedbythe stability(exchange energy) of half filled(f7) andfullyfilled f14.GdI2 possessesthe layeredMoS2structure,isferromagneticandexhibitscolossal magnetoresistance[50] The sesquihalidesLn2X3andthe Ln7I12 compoundslistedinthe table containmetal clusters,discrete Ln6I12 clustersinLn7I12 and condensedclustersformingchainsinthe sesquihalides.Scandiumformsa similarclustercompoundwithchlorine,Sc7Cl12[8] Unlike manytransitionmetal clustersthese lanthanide clustersdonothave strongmetal-metal interactionsandthisisdue to the low numberof valence electronsinvolved,butinsteadare stabilisedbythe surroundinghalogenatoms.[50] LaI is the onlyknownmonohalide.Preparedfromthe reactionof LaI3and La metal,ithasa NiAstype structure and can be formulatedLa3+ (I−)(e−)2.[53] Oxidesandhydroxides All of the lanthanidesformsesquioxides,Ln2O3.The lighter/largerlanthanidesadoptahexagonal 7- coordinate structure while the heavier/smalleronesadoptacubic6-coordinate "C-M2O3" structure.[51] All of the sesquioxidesare basic,and absorbwaterand carbon dioxide fromairtoformcarbonates, hydroxidesandhydroxycarbonates.[57] Theydissolve inacidstoformsalts.[20]
- 19. Ceriumformsa stoichiometricdioxide,CeO2,where ceriumhasanoxidationstate of +4. CeO2 isbasic and dissolveswithdifficultyinacidtoformCe4+ solutions,fromwhichCeIV saltscanbe isolated,for example the hydratednitrateCe(NO3)4.5H2O.CeO2isusedas an oxidationcatalystincatalytic converters.[20] Praseodymiumandterbiumformnon-stoichiometricoxidescontainingLnIV,[20] althoughmore extreme reactionconditionscanproduce stoichiometric(ornearstoichiometric) PrO2 and TbO2.[8] Europiumandytterbiumformsalt-like monoxides,EuOandYbO, whichhave a rock saltstructure.[20] EuO isferromagneticatlowtemperatures,[8] andisa semiconductorwithpossible applicationsin spintronics.[58] A mixedEuII/EuIIIoxide Eu3O4can be producedbyreducingEu2O3 in a streamof hydrogen.[57] Neodymiumandsamariumalsoformmonoxides,butthese are shiny conducting solids,[8] althoughthe existence of samariummonoxideisconsidereddubious.[57] All of the lanthanidesformhydroxides,Ln(OH)3.Withthe exceptionof lutetiumhydroxide,whichhasa cubic structure,theyhave the hexagonal UCl3structure.[57] The hydroxidescanbe precipitatedfrom solutionsof LnIII.[20] Theycanalsobe formedbythe reactionof the sesquioxide,Ln2O3,withwater, but althoughthisreactionisthermodynamicallyfavorable itiskineticallyslowforthe heaviermembers of the series.[57] Fajans'rulesindicate thatthe smallerLn3+ionswill be more polarizingandtheirsalts correspondinglylessionic.The hydroxidesof the heavierlanthanidesbecomelessbasic,forexample Yb(OH)3and Lu(OH)3 are still basichydroxidesbutwill dissolve inhotconcentratedNaOH.[8] Chalcogenides(S,Se,Te) All of the lanthanidesformLn2Q3 (Q=S, Se,Te).[20] The sesquisulfidescanbe producedbyreactionof the elementsor(withthe exceptionof Eu2S3) sulfidizingthe oxide(Ln2O3) withH2S.[20] The sesquisulfides,Ln2S3generallylosesulfurwhenheatedandcanforma range of compositionsbetween Ln2S3 and Ln3S4. The sesquisulfidesare insulatorsbutsome of the Ln3S4 are metallicconductors(e.g. Ce3S4) formulated(Ln3+)3(S2−)4(e−),while others(e.g.Eu3S4andSm3S4) are semiconductors.[20] Structurallythe sesquisulfidesadoptstructuresthatvaryaccordingto the size of the Ln metal.The lighterandlargerlanthanidesfavoring7-coordinatemetal atoms,the heaviestandsmallestlanthanides (Yb andLu) favoring6 coordinationandthe reststructureswitha mixture of 6 and 7 coordination.[20] Polymorphismiscommonamongstthe sesquisulfides.[59] The colorsof the sesquisulfidesvarymetal to metal anddependonthe polymorphicform. The colorsof the γ-sesquisulfidesare La2S3, white/yellow; Ce2S3, dark red;Pr2S3, green;Nd2S3, lightgreen;Gd2S3,sand; Tb2S3, lightyellow andDy2S3, orange.[60] The shade of γ-Ce2S3can be variedbydopingwithNaor Ca withhuesrangingfromdark redto yellow,[50][60] andCe2S3 basedpigmentsare usedcommerciallyandare seenaslow toxicity substitutesforcadmiumbasedpigments.[60]
- 20. All of the lanthanidesformmonochalcogenides,LnQ,(Q=S,Se,Te).[20] The majorityof the monochalcogenidesare conducting,indicatingaformulationLnIIIQ2−(e-) wherethe electronisin conductionbands.The exceptionsare SmQ,EuQ andYbQ whichare semiconductorsorinsulatorsbut exhibitapressure inducedtransitiontoa conductingstate.[59] CompoundsLnQ2are knownbutthese do notcontainLnIV butare LnIIIcompoundscontainingpolychalcogenide anions.[61] OxysulfidesLn2O2Sare well known,theyall have the same structure with7-coordinate Lnatoms,and3 sulfurand4 oxygenatomsasnear neighbours.[62] Dopingthese withotherlanthanide elements producesphosphors.Asanexample,gadoliniumoxysulfide,Gd2O2SdopedwithTb3+ producesvisible photonswhenirradiatedwithhighenergyX-raysandisusedasa scintillatorinflatpanel detectors.[63] Whenmischmetal,analloyof lanthanidemetals,isaddedtomoltensteel toremove oxygenandsulfur, stable oxysulfidesare producedthatformanimmiscible solid.[20] Pnictides(group15) All of the lanthanidesformamononitride,LnN,withthe rocksaltstructure.The mononitrideshave attractedinterestbecause of theirunusual physical properties.SmN andEuN are reportedasbeing"half metals".[50] NdN,GdN,TbN andDyN are ferromagnetic,SmN isantiferromagnetic.[64] Applicationsin the fieldof spintronics are beinginvestigated.[58] CeN isunusual asitis a metallicconductor, contrastingwiththe othernitridesalsowiththe otherceriumpnictides.A simple descriptionisCe4+N3− (e–) butthe interatomicdistancesare a bettermatchfor the trivalentstate ratherthanfor the tetravalentstate.A numberof differentexplanationshave beenoffered.[65] The nitridescanbe preparedbythe reactionof lanthanummetalswithnitrogen.Somenitrideisproducedalongwiththe oxide,whenlanthanummetalsare ignitedinair.[20] Alternativemethodsof synthesisare ahigh temperature reactionof lanthanide metalswithammoniaorthe decompositionof lanthanide amides, Ln(NH2)3.Achievingpure stoichiometriccompounds,andcrystalswithlow defectdensityhasproved difficult.[58] The lanthanidenitridesare sensitive toairandhydrolyse producingammonia.[49] The other pnictidesphosphorus,arsenic,antimonyandbismuthalsoreactwiththe lanthanidemetalsto formmonopnictides,LnQ.Additionallyarange of other compoundscan be producedwithvarying stoichiometries,suchasLnP2, LnP5, LnP7, Ln3As,Ln5As3 and LnAs2.[66] Carbides Carbidesof varyingstoichiometriesare knownforthe lanthanides.Non-stoichiometryiscommon.All of the lanthanidesformLnC2and Ln2C3 whichbothcontainC2 units.The dicarbideswithexceptionof EuC2, are metallicconductorswiththe calciumcarbide structure andcanbe formulatedasLn3+C22−(e– ).The C-Cbond lengthislongerthanthatin CaC2, whichcontainsthe C22− anion,indicatingthatthe antibondingorbitalsof the C22− anionare involvedinthe conductionband.These dicarbideshydrolyse
- 21. to formhydrogenanda mixture of hydrocarbons.[67] EuC2and to a lesserextentYbC2hydrolyse differentlyproducingahigherpercentage of acetylene(ethyne).[68] The sesquicarbides,Ln2C3can be formulatedasLn4(C2)3. These compoundsadoptthe Pu2C3 structure[50] whichhasbeendescribedashavingC22− anionsin bisphenoidholesformedbyeightnearLnneighbours.[69] The lengtheningof the C-Cbondisless markedinthe sesquicarbidesthaninthe dicarbides,withthe exceptionof Ce2C3.[67] Othercarbonrich stoichiometriesare knownforsome lanthanides.Ln3C4(Ho-Lu) containingC,C2 and C3 units;[70] Ln4C7 (Ho-Lu) containC atomsand C3 units[71] and Ln4C5 (Gd-Ho) containingCandC2 units.[72] Metal rich carbidescontaininterstitial Catomsandno C2 or C3 units.These are Ln4C3 (Tb andLu); Ln2C (Dy, Ho, Tm)[73][74] and Ln3C[50] (Sm-Lu). Borides All of the lanthanidesformanumber of borides.The "higher"borides(LnBx where x >12) are insulators/semiconductorswhereasthe lowerboridesare typicallyconducting.The lowerborideshave stoichiometriesof LnB2,LnB4, LnB6 and LnB12.[75] Applicationsinthe fieldof spintronicsare being investigated.[58] The range of boridesformedbythe lanthanidescanbe comparedto those formedby the transitionmetals.The boronrichboridesare typical of the lanthanides(andgroups1–3) whereasfor the transitionmetalstendtoformmetal rich,"lower"borides.[76] The lanthanideboridesare typically groupedtogetherwiththe group3 metalswithwhichtheyshare manysimilaritiesof reactivity, stoichiometryandstructure.Collectivelythese are thentermedthe rare earthborides.[75] Many methodsof producinglanthanide borideshave beenused,amongstthemare directreactionof the elements;the reductionof Ln2O3withboron; reductionof boronoxide,B2O3,andLn2O3 together withcarbon; reductionof metal oxide withboroncarbide,B4C.[75][76][77][78] Producinghighpurity sampleshasprovedtobe difficult.[78] Single crystalsof the higherborideshave beengrowninalow meltingmetal (e.g.Sn,Cu,Al).[75] Diborides,LnB2,have beenreportedforSm, Gd,Tb, Dy,Ho, Er, Tm, Yb andLu. All have the same,AlB2, structure containingagraphiticlayerof boron atoms.Low temperature ferromagnetictransitionsforTb, Dy, Ho and Er. TmB2 isferromagneticat7.2 K.[50] Tetraborides,LnB4have beenreportedforall of the lanthanidesexceptEuB4,all have the same UB4 structure.The structure has a boron sub-lattice consistsof chainsof octahedral B6 clusterslinkedby boronatoms.The unitcell decreasesinsize successivelyfromLaB4 to LuB4. The tetraboridesof the lighterlanthanidesmeltwithdecompositiontoLnB6.[78] Attemptstomake EuB4 have failed.[77] The LnB4 are good conductors[75] and typicallyantiferromagnetic.[50]
- 22. Hexaborides,LnB6have beenreportedforall of the lanthanides.Theyall have the CaB6structure, containingB6 clusters.Theyare non-stoichiometricdue tocationdefects.The hexaboridesof the lighter lanthanides(La–Sm) meltwithoutdecomposition,EuB6decomposestoboronandmetal and the heavierlanthanidesdecomposetoLnB4 withexceptionof YbB6 whichdecomposesformingYbB12.The stabilityhasinpart beencorrelatedtodifferencesinvolatilitybetweenthe lanthanide metals.[78] In EuB6 andYbB6 the metalshave an oxidationstate of +2 whereasinthe restof the lanthanide hexaboridesitis+3. Thisrationalisesthe differencesinconductivity,the extraelectronsinthe LnIII hexaboridesenteringconductionbands.EuB6isa semiconductorandthe restare good conductors.[50][78] LaB6 and CeB6 are thermionicemitters,used,forexample,inscanningelectron microscopes.[79] Dodecaborides,LnB12,are formedbythe heaviersmallerlanthanides,butnotbythe lighterlarger metals,La – Eu. Withthe exceptionYbB12(where Ybtakesan intermediate valenceandisa Kondo insulator),the dodecaboridesare all metalliccompounds.Theyall have the UB12 structure containinga 3 dimensional frameworkof cubooctahedral B12clusters.[75] The higherboride LnB66 is knownforall lanthanide metals.The compositionisapproximate asthe compoundsare non-stoichiometric.[75] Theyall have similarcomplex structure withover1600 atomsin the unitcell.The boroncubic sublattice containssupericosahedramade upof a central B12 icosahedra surroundedby12 others,B12(B12)12.[75] Othercomplex higherboridesLnB50(Tb,Dy, Ho Er Tm Lu) and LnB25 are known(Gd,Tb,Dy, Ho, Er) and these containboronicosahedrainthe boron framework.[75] Organometalliccompounds Lanthanide-carbonσbondsare well known;howeverasthe 4f electronshave alow probabilityof existingatthe outerregionof the atom there islittle effectiveorbital overlap,resultinginbondswith significantioniccharacter.Assuch organo-lanthanide compoundsexhibitcarbanion-like behavior,unlike the behaviorintransitionmetal organometalliccompounds.Because of theirlarge size,lanthanides tendto formmore stable organometallicderivativeswithbulkyligandstogive compoundssuchas Ln[CH(SiMe3)3].[80] Analoguesof uranoceneare derivedfromdilithiocyclooctatetraene,Li2C8H8. Organiclanthanide(II) compoundsare alsoknown,suchasCp*2Eu.[39] Physical properties Magneticand spectroscopic All the trivalentlanthanide ions,exceptlanthanumandlutetium,have unpairedf electrons.However, the magneticmomentsdeviateconsiderablyfromthe spin-onlyvaluesbecauseof strongspin-orbit coupling.The maximumnumberof unpairedelectronsis7,inGd3+, witha magneticmomentof 7.94 B.M., but the largestmagneticmoments,at10.4–10.7 B.M., are exhibitedbyDy3+ and Ho3+. However,
- 23. inGd3+ all the electronshave parallel spinandthispropertyisimportantforthe use of gadolinium complexesascontrastreagentinMRI scans. A solutionof 4%holmiumoxide in10%perchloricacid,permanentlyfusedintoaquartzcuvette as a wavelengthcalibrationstandard Crystal fieldsplittingisrathersmall forthe lanthanideionsandislessimportantthanspin-orbitcoupling inregard to energylevels.[8] Transitionsof electronsbetweenf orbitalsare forbiddenbythe Laporte rule.Furthermore,becauseof the "buried"nature of the f orbitals,couplingwithmolecularvibrationsis weak.Consequently,the spectraof lanthanideionsare ratherweakandthe absorptionbandsare similarlynarrow.Glasscontainingholmiumoxideandholmiumoxidesolutions(usuallyinperchloric acid) have sharp optical absorptionpeaksinthe spectral range 200–900 nm and can be usedas a wavelengthcalibrationstandardforoptical spectrophotometers,[81] andare available commercially.[82] As f-f transitionsare Laporte-forbidden,once anelectronhasbeenexcited,decaytothe groundstate will be slow.Thismakesthemsuitable foruse inlasersasitmakesthe populationinversioneasyto achieve.The Nd:YAGlaserisone that iswidelyused.Europium-dopedyttrium vanadatewasthe firstred phosphortoenable the developmentof colortelevisionscreens.[83] Lanthanide ionshave notable luminescentpropertiesdue totheirunique4f orbitals.Laporte forbiddenf-f transitionscanbe activated by excitationof abound "antenna"ligand.Thisleadstosharpemissionbandsthroughoutthe visible, NIR,and IR and relativelylongluminescence lifetimes.[84] Occurrence Main article:Rare-earthelement§Geological distribution The lanthanide contractionisresponsibleforthe greatgeochemical dividethatsplitsthe lanthanides intolightandheavy-lanthanideenrichedminerals,the latterbeingalmostinevitablyassociatedwithand dominatedbyyttrium.Thisdivideisreflectedinthe firsttwo"rare earths"thatwere discovered:yttria (1794) and ceria(1803). The geochemical divide hasputmore of the lightlanthanidesinthe Earth's crust, butmore of the heavymembersinthe Earth's mantle.The resultisthatalthoughlarge richore- bodiesare foundthatare enrichedinthe lightlanthanides,correspondinglylarge ore-bodiesforthe heavymembersare few.The principal oresare monazite andbastnäsite.Monazite sandsusuallycontain all the lanthanide elements,butthe heavierelementsare lackinginbastnäsite.The lanthanidesobey the Oddo-Harkinsrule –odd-numberedelementsare lessabundantthantheireven-numbered neighbors. Three of the lanthanide elementshave radioactiveisotopeswithlonghalf-lives(138La,147Sm and 176Lu) that can be usedto date mineralsandrocks fromEarth, the Moon and meteorites.[85]
- 24. Promethiumiseffectivelyaman-made element,asall itsisotopesare radioactivewithhalf-livesshorter than 20 years. Applications Industrial Lanthanide elementsandtheircompoundshave manyusesbutthe quantitiesconsumedare relatively small incomparisontootherelements.About15000 ton/yearof the lanthanidesare consumedas catalystsand inthe productionof glasses.This15000 tonscorrespondstoabout 85% of the lanthanide production.Fromthe perspectiveof value,however,applicationsinphosphorsandmagnetsare more important.[86] The deviceslanthanideelementsare usedininclude superconductors,samarium-cobaltand neodymium-iron-boronhigh-fluxrare-earthmagnets,magnesiumalloys,electronicpolishers,refining catalystsand hybridcar components(primarilybatteriesandmagnets).[87] Lanthanide ionsare usedas the active ionsinluminescentmaterialsusedinoptoelectronicsapplications,mostnotablythe Nd:YAG laser.Erbium-dopedfiberamplifiersare significantdevicesinoptical-fibercommunicationsystems. Phosphorswithlanthanide dopantsare alsowidelyusedincathode raytube technologysuchas televisionsets.The earliestcolortelevisionCRTshada poor-qualityred;europiumas aphosphordopant made goodred phosphorspossible.Yttriumirongarnet(YIG) spherescanact as tunable microwave resonators. Lanthanide oxidesare mixedwithtungstentoimprove theirhightemperature propertiesforTIG welding,replacingthorium,whichwasmildlyhazardoustoworkwith.Manydefense-relatedproducts alsouse lanthanide elementssuchasnightvisiongogglesandrangefinders.The SPY-1radar usedin some Aegisequippedwarships,andthe hybridpropulsionsystemof ArleighBurke-classdestroyersall use rare earthmagnetsincritical capacities.[88] The price forlanthanumoxide usedinfluidcatalytic cracking hasrisenfrom$5 per kilograminearly2010 to $140 per kilograminJune 2011.[89] Most lanthanidesare widelyusedinlasers, andas(co-)dopantsindoped-fiberoptical amplifiers;for example,inEr-dopedfiberamplifiers,whichare usedasrepeatersinthe terrestrial andsubmarine fiber- optictransmissionlinksthatcarryinternettraffic.These elementsdeflectultravioletandinfrared radiationandare commonlyusedinthe productionof sunglasslenses.Otherapplicationsare summarizedinthe followingtable:[17] Application Percentage Catalyticconverters 45% Petroleumrefiningcatalysts 25%
- 25. Permanentmagnets 12% Glasspolishingandceramics 7% Metallurgical 7% Phosphors 3% Other 1% The complex Gd(DOTA) isusedinmagneticresonance imaging. Life science Lanthanide complexescanbe usedforoptical imaging.Applicationsare limitedbythe labilityof the complexes.[90] Some applicationsdependonthe unique luminescence propertiesof lanthanide chelatesor cryptates).[91][92] These are well-suitedforthisapplicationdue totheirlarge Stokesshiftsand extremelylongemissionlifetimes(frommicrosecondstomilliseconds) comparedtomore traditional fluorophores(e.g.,fluorescein,allophycocyanin,phycoerythrin,andrhodamine). The biological fluidsorserumcommonlyusedinthese researchapplicationscontainmanycompounds and proteinswhichare naturallyfluorescent. Therefore,the use of conventional,steady-state fluorescencemeasurementpresentsseriouslimitationsinassaysensitivity.Long-livedfluorophores, such as lanthanides,combinedwithtime-resolveddetection(adelaybetweenexcitationandemission detection) minimizespromptfluorescence interference. Time-resolvedfluorometry(TRF) combinedwithfluorescence resonance energytransfer(FRET) offersa powerful tool fordrugdiscoveryresearchers:Time-ResolvedFluorescence Resonance EnergyTransferor TR-FRET. TR-FRET combinesthe lowbackgroundaspectof TRFwiththe homogeneousassayformatof FRET. The resultingassayprovidesanincrease inflexibility,reliabilityandsensitivityinadditiontohigher throughputandfewerfalse positive/falsenegative results. Thismethodinvolvestwofluorophores:adonorand an acceptor.Excitationof the donor fluorophore(in thiscase,the lanthanide ioncomplex) byanenergysource (e.g.flashlamporlaser) producesanenergy transferto the acceptorfluorophore if theyare withinagivenproximitytoeachother(knownasthe Förster'sradius).The acceptorfluorophore inturnemitslightatitscharacteristicwavelength.
- 26. The two mostcommonlyusedlanthanidesinlifescience assaysare shownbelow alongwiththeir correspondingacceptordye aswell astheirexcitationandemissionwavelengthsandresultantStokes shift(separationof excitationandemissionwavelengths). Donor Excitation⇒Emissionλ(nm) Acceptor Excitation⇒Emissionλ(nm) Stoke'sShift (nm) Eu3+ 340⇒615 Allophycocyanin 615⇒660 320 Tb3+ 340⇒545 Phycoerythrin 545⇒575 235 Possible medical uses Currentlythere isresearchshowingthatlanthanide elementscanbe usedasanticanceragents.The mainrole of the lanthanidesinthesestudiesisto inhibitproliferationof the cancercells.Specifically ceriumand lanthanumhave beenstudiedfortheirrole asanti-canceragents. One of the specificelementsfromthe lanthanide groupthathasbeentestedandusediscerium(Ce). There have beenstudiesthatuse aprotein-ceriumcomplex toobserve the effectof ceriumonthe cancer cells.The hope wasto inhibitcell proliferationandpromote cytotoxicity.[93] Transferrin receptorsincancer cells,suchasthose in breastcancer cellsandepithelialcervical cells,promotethe cell proliferationandmalignancyof the cancer.[93] Transferrinisa proteinusedtotransportironinto the cellsandis neededtoaidthe cancer cellsinDNA replication.Transferrinactsasa growthfactor for the cancerouscellsandis dependentoniron.Cancercellshave muchhigherlevelsof transferrin receptorsthannormal cellsandare verydependentonironfortheirproliferation.[93] Ceriumhasshownresultsasan anti-canceragentdue to itssimilaritiesinstructure andbiochemistryto iron.Ceriummaybindinthe place of ironon to the transferrinandthenbe broughtintothe cancercells by transferrin-receptormediatedendocytosis.[93] The ceriumbindingtothe transferrininplace of the ironinhibitsthe transferrinactivityinthe cell.Thiscreatesatoxicenvironmentforthe cancercellsand causesa decrease incell growth.Thisisthe proposedmechanismforcerium'seffectoncancercells, thoughthe real mechanismmaybe more complex inhow ceriuminhibits cancercell proliferation. SpecificallyinHeLacancercellsstudiedinvitro,cell viabilitywasdecreasedafter48to 72 hoursof ceriumtreatments.Cellstreatedwithjustceriumhaddecreasesincell viability,butcellstreatedwith bothceriumand transferrinhadmore significantinhibitionforcellularactivity.[93] Anotherspecific elementthathasbeentestedandusedasan anti-canceragentislanthanum, more specifically lanthanumchloride (LaCl3).The lanthanumionisusedtoaffectthe levels of let-7aandmicroRNAsmiR- 34a in a cell throughoutthe cell cycle.Whenthe lanthanumionwasintroducedtothe cell invivoorin vitro,itinhibitedthe rapidgrowthandinducedapoptosisof the cancercells(specificallycervical cancer cells).Thiseffectwascausedbythe regulationof the let-7aandmicroRNAsbythe lanthanumions.[94] The mechanismforthiseffectisstill unclearbutitispossible thatthe lanthanumisactingina similar wayas the ceriumandbindingtoa ligandnecessaryforcancercell proliferation.
- 27. Biological effects Due to theirsparse distributioninthe earth'scrustandlow aqueoussolubility,the lanthanideshave a lowavailabilityinthe biosphere,andfora longtime were notknownto naturallyformpartof any biological molecules.In2007 a novel methanol dehydrogenase thatstrictlyuseslanthanidesas enzymaticcofactorswasdiscoveredinabacteriumfromthe phylumVerrucomicrobia, Methylacidiphilumfumariolicum.Thisbacteriumwasfoundtosurvive onlyif there are lanthanides presentinthe environment.[95] Comparedtomostothernondietaryelements,non-radioactive lanthanidesare classifiedashavinglowtoxicity.[86] The same nutritional requirementhasalsobeen observedMethylorubrumextorquensandMethylobacteriumradiotolerans. See also Group 3 element–Group of chemical elements Lanthanide probes References The currentIUPAC recommendationisthatthe name lanthanoidbe usedratherthanlanthanide,asthe suffix "-ide"ispreferredfornegativeions,whereasthe suffix "-oid"indicatessimilaritytoone of the membersof the containingfamilyof elements.However,lanthanideisstill favoredinmost(~90%) scientificarticles[citationneeded] andiscurrentlyadoptedonWikipedia.Inthe olderliterature, the name "lanthanon"wasoftenused. Gray, Theodore (2009). The Elements:A Visual Explorationof EveryKnownAtominthe Universe.New York: BlackDog & Leventhal Publishers.p.240. ISBN 978-1-57912-814-2. Lanthanide Archived11September2011 at the Wayback Machine,EncyclopædiaBritannicaon-line Holden,NormanE.;Coplen,Tyler(January–February2004). "The PeriodicTable of the Elements". ChemistryInternational.26(1): 8. doi:10.1515/ci.2004.26.1.8. Jensen,WilliamB.(2015). "The positionsof lanthanum(actinium) andlutetium(lawrencium) inthe periodictable:anupdate".Foundationsof Chemistry.17:23–31. doi:10.1007/s10698-015-9216-1. S2CID 98624395. Retrieved28 January2021. Scerri,Eric (18 January2021). "Provisional ReportonDiscussionsonGroup3 of the PeriodicTable". ChemistryInternational.43(1): 31–34. doi:10.1515/ci-2021-0115. S2CID 231694898. F Block Elements,OxidationStates,LanthanidesandActinides.Chemistry.tutorvista.com.Retrievedon 14 December2017. Greenwood, NormanN.;Earnshaw,Alan(1997). Chemistryof the Elements(2nded.).Butterworth- Heinemann.pp.1230–1242. ISBN 978-0-08-037941-8. SkrifterNorske Vidensk-Akad.(Mat.-nat.Kl.) V:6
- 28. Hakala, ReinoW.(1952). "Letters".Journal of Chemical Education.29(11): 581. Bibcode:1952JChEd..29..581H. doi:10.1021/ed029p581.2. "lanthanide".OED21.14 on CD-Rom.OUP,1994. "lanthanum".OED2 v.1.14 onCD-Rom.OUP, 1994. "The Elements",Theodore Gray,Black−Dog& Leventhal,Chicago2007: "Lanthanum"and"Cerium" entriesCh57 & 58, pp 134–7 Rocks & Minerals,A Guide To FieldIdentification,Sorrell,StMartin'sPress1972, 1995, pp 118 (Halides), 228 (Carbonates) Minearlsof the World,Johnsen,2000 "The Elements",Theodore Gray,BlackDog& Leventhal,Chicago2007: "Neodymium"and "Praseodymium"entriesCh59 & 60, pp 138–43 Aspinall,HelenC.(2001). Chemistryof the f-blockelements.CRCPress.p.8. ISBN 978-90-5699-333-7. Krishnamurthy,NagaiyarandGupta,ChiranjibKumar(2004) Extractive Metallurgyof Rare Earths,CRC Press,ISBN 0-415-33340-7 Cullity,B.D. andGraham, C. D. (2011) IntroductiontoMagneticMaterials,JohnWiley&Sons,ISBN 9781118211496 Cotton,Simon (2006). Lanthanide andActinide Chemistry.JohnWiley&SonsLtd. Sroor, FaridM.A.; Edelmann,FrankT.(2012). "Lanthanides:TetravalentInorganic".Encyclopediaof Inorganicand BioinorganicChemistry.doi:10.1002/9781119951438.eibc2033. ISBN 9781119951438. Holleman,p.1937. dtv-AtlaszurChemie 1981, Vol.1, p. 220. Bochkarev,Mikhail N.;Fedushkin,IgorL.;Fagin,AnatolyA.;Petrovskaya,TatyanaV.;Ziller,JosephW.; Broomhall-Dillard,RandyN.R.;Evans,WilliamJ.(1997). "SynthesisandStructure of the FirstMolecular Thulium(II)Complex:[TmI2(MeOCH2CH2OMe)3]".Angewandte ChemieInternational EditioninEnglish. 36 (12): 133–135. doi:10.1002/anie.199701331. Winter,Mark. "Lanthanumionisationenergies".WebElementsLtd,UK.Retrieved2September2010. Fukai,Y. (2005). The Metal-HydrogenSystem,BasicBulkProperties,2dedition.Springer.ISBN 978-3- 540-00494-3. Pettit,L.and Powell,K.SC-database.Acadsoft.co.uk.Retrievedon15 January2012. Molander,Gary A.; Harris,ChristinaR.(1 January 1996). "SequencingReactionswithSamarium(II) Iodide".Chemical Reviews.96(1): 307–338. doi:10.1021/cr950019y. PMID 11848755. Nair,Vijay;Balagopal,Lakshmi;Rajan,Roshini;Mathew,Jessy(1January2004). "RecentAdvancesin SyntheticTransformationsMediatedbyCerium(IV) AmmoniumNitrate".Accountsof Chemical Research.37 (1):21–30. doi:10.1021/ar030002z. PMID 14730991.
- 29. Dehnicke,Kurt;Greiner,Andreas(2003)."Unusual Complex Chemistryof Rare-EarthElements:Large IonicRadii—SmallCoordinationNumbers".AngewandteChemie International Edition.42(12): 1340– 1354. doi:10.1002/anie.200390346. PMID 12671966. Aspinall,HelenC.(2001). Chemistryof the f-blockelements.Amsterdam[u.a.]:Gordon&Breach.ISBN 978-9056993337. Kobayashi,Shū;Hamada,Tomoaki;Nagayama,Satoshi;Manabe,Kei (1January2001). "Lanthanide Trifluoromethanesulfonate-CatalyzedAsymmetricAldolReactionsinAqueousMedia".OrganicLetters.3 (2): 165–167. doi:10.1021/ol006830z. PMID 11430025. Aspinall,HelenC.;Dwyer,JenniferL.;Greeves,Nicholas;Steiner,Alexander(1April 1999). "Li3[Ln(binol)3]·6THF:NewAnhydrousLithiumLanthanide BinaphtholatesandTheirUse in Enantioselective Alkyl AdditiontoAldehydes".Organometallics.18 (8):1366–1368. doi:10.1021/om981011s. Parac-Vogt,TatjanaN.; Pachini,Sophia;Nockemann,Peter;VanmHecke,Kristof;VanMeervelt,Luc; Binnemans,Koen(1November2004). "Lanthanide(III) NitrobenzenesulfonatesasNew Nitration Catalysts:The Role of the Metal and of the Counterion inthe CatalyticEfficiency".EuropeanJournalof OrganicChemistry(Submittedmanuscript).2004 (22): 4560–4566. doi:10.1002/ejoc.200400475. Lipstman,Sophia;Muniappan,Sankar;George,Sumod;Goldberg,Israel(1January2007). "Framework coordinationpolymersof tetra(4-carboxyphenyl)porphyrinandlanthanideionsincrystalline solids". DaltonTransactions(30): 3273–81. doi:10.1039/B703698A. PMID 17893773. Bretonnière,Yann;Mazzanti,Marinella;Pécaut,Jacques;Dunand,FrankA.;Merbach,André E. (1 December2001). "Solid-State andSolutionPropertiesof the Lanthanide Complexesof aNew Heptadentate Tripodal Ligand:A Route toGadoliniumComplexeswithanImprovedRelaxation Efficiency".InorganicChemistry.40(26): 6737–6745. doi:10.1021/ic010591+. PMID 11735486. Trinadhachari,GanalaNaga; Kamat,AnandGopalkrishna;Prabahar,Koilpillai Joseph;Handa,Vijay Kumar;Srinu,Kukunuri NagaVenkataSatya;Babu,KorupoluRaghu;Sanasi,Paul Douglas(15 March 2013). "Commercial Scale Processof Galanthamine Hydrobromide InvolvingLuche Reduction: Galanthamine ProcessInvolvingRegioselective 1,2-Reductionof α,β-UnsaturatedKetone".Organic ProcessResearch& Development.17 (3):406–412. doi:10.1021/op300337y. Burgess,J.(1978). Metal ionsinsolution. New York:EllisHorwood.ISBN 978-0-85312-027-8. Nief,F.(2010). "Non-classical divalentlanthanide complexes".DaltonTrans.39 (29): 6589–6598. doi:10.1039/c001280g. PMID 20631944. Evans, WilliamJ.(15 September2016). "Tutorial onthe Role of Cyclopentadienyl Ligandsinthe Discoveryof MolecularComplexesof the Rare-EarthandActinide MetalsinNew OxidationStates". Organometallics.35(18): 3088–3100. doi:10.1021/acs.organomet.6b00466.openaccess Palumbo,C.T.;Zivkovic,I.;Scopelliti,R.;Mazzanti,M. (2019). "MolecularComplex of Tbinthe +4 OxidationState<"(PDF).Journal of the AmericanChemicalSociety.141 (25): 9827–9831. doi:10.1021/jacs.9b05337. PMID 31194529. S2CID 189814301.
- 30. Rice,Natalie T.;Popov,IvanA.;Russo,DominicR.;Bacsa, John; Batista,Enrique R.;Yang, Ping;Telser, Joshua;La Pierre,HenryS.(21 August2019). "Design,Isolation,andSpectroscopicAnalysisof a TetravalentTerbiumComplex".Journal of the AmericanChemical Society.141(33): 13222–13233. doi:10.1021/jacs.9b06622. ISSN 0002-7863. OSTI 1558225. PMID 31352780. S2CID 207197096. Willauer,A.R.;Palumbo,C.T.;Scopelliti,R.;Zivkovic,I.;Douair,I.;Maron, L.; Mazzanti,M. (2020). "Stabilizationof the OxidationState +IV in Siloxide-SupportedTerbiumCompounds".Angewandte Chemie InternationalEdition.59 (9):3549–3553. doi:10.1002/anie.201914733. PMID 31840371. S2CID 209385870. Willauer,A.R.;Palumbo,C.T.;Fadaei-Tirani,F.;Zivkovic,I.;Douair,I.;Maron,L.; Mazzanti,M. (2020). "Accessingthe +IV OxidationState inMolecularComplexesof Praseodymium".Journal of the American Chemical Society.142(12): 489–493. doi:10.1021/jacs.0c01204. PMID 32134644. S2CID 212564931. Kohlmann,H.;Yvon,K. (2000). "The crystal structuresof EuH2 and EuLiH3 by neutronpowder diffraction".Journal of AlloysandCompounds.299 (1–2): L16–L20. doi:10.1016/S0925-8388(99)00818- X. Matsuoka, T.; Fujihisa,H.;Hirao,N.;Ohishi,Y.;Mitsui,T.;Masuda, R.; Seto,M.; Yoda, Y.; Shimizu,K.; Machida, A.;Aoki,K.(2011). "Structural andValence Changesof EuropiumHydride Inducedby Applicationof High-Pressure H2".Physical Review Letters.107 (2):025501. Bibcode:2011PhRvL.107b5501M. doi:10.1103/PhysRevLett.107.025501. PMID 21797616. Tellefsen,M.;Kaldis,E.;Jilek,E.(1985). "The phase diagramof the Ce-H2systemandthe CeH2-CeH3 solidsolutions".Journal of the LessCommonMetals.110 (1–2): 107–117. doi:10.1016/0022- 5088(85)90311-X. Kumar,Pushpendra;Philip,Rosen;Mor,G.K.; Malhotra,L. K.(2002). "Influence of PalladiumOverlayer on SwitchingBehaviourof SamariumHydride ThinFilms".Japanese Journal of AppliedPhysics.41 (Part 1, No. 10): 6023–6027. Bibcode:2002JaJAP..41.6023K. doi:10.1143/JJAP.41.6023. Holleman,p.1942 DavidA. Atwood,ed.(19 February2013). The Rare Earth Elements:FundamentalsandApplications (eBook).JohnWiley&Sons.ISBN 9781118632635. Wells, A.F.(1984). Structural InorganicChemistry(5thed.).OxfordScience Publication.ISBN 978-0-19- 855370-0. Perry,Dale L. (2011). Handbookof InorganicCompounds,SecondEdition.BocaRaton,Florida:CRC Press.p.125. ISBN 978-1-43981462-8. Retrieved17February2014. Ryazanov,Mikhail;Kienle,Lorenz;Simon,Arndt;Mattausch,Hansjürgen(2006)."New SynthesisRoute to and Physical Propertiesof LanthanumMonoiodide†".InorganicChemistry.45(5): 2068–2074. doi:10.1021/ic051834r. PMID 16499368. Vent-Schmidt,T.;Fang,Z.; Lee,Z.;Dixon,D.;Riedel,S.(2016). "Extendingthe Row of Lanthanide Tetrafluorides:A CombinedMatrix-IsolationandQuantum-Chemical Study".Chemistry.22(7):2406–16. doi:10.1002/chem.201504182. hdl:2027.42/137267. PMID 26786900.
- 31. Haschke,John.M. (1979). "Chapter32:Halides".InGschneiderJr.,K.A.(ed.).Handbookonthe Physics and Chemistryof Rare Earths vol 4. NorthHollandPublishingCompany.pp.100–110. ISBN 978-0-444- 85216-8. Kovács,Attila(2004). "Structure and Vibrationsof Lanthanide Trihalides:AnAssessmentof ExperimentalandTheoretical Data".Journal of Physical andChemical ReferenceData.33 (1):377. Bibcode:2004JPCRD..33..377K.doi:10.1063/1.1595651. Adachi,G.; Imanaka,NobuhitoandKang,ZhenChuan(eds.) (2006) Binary Rare Earth Oxides.Springer. ISBN 1-4020-2568-8 Nasirpouri,FarzadandNogaret,Alain(eds.) (2011) NanomagnetismandSpintronics:Fabrication, Materials,CharacterizationandApplications.WorldScientific.ISBN 9789814273053 Flahaut, Jean(1979). "Chapter31:Sulfides,SelenidesandTellurides".InGschneiderJr.,K.A.(ed.). Handbookon the PhysicsandChemistryof Rare Earths vol 4. North HollandPublishingCompany.pp. 100–110. ISBN 978-0-444-85216-8. Berte,Jean-Noel(2009)."Ceriumpigments".InSmith,HughM. (ed.).HighPerformance Pigments. Wiley-VCH.ISBN 978-3-527-30204-8. Holleman,p.1944. Liu, Guokui andJacquier,Bernard(eds) (2006) SpectroscopicPropertiesof Rare EarthsinOptical Materials,Springer Sisniga,Alejandro(2012)."Chapter15". InIniewski,Krzysztof (ed.).IntegratedMicrosystems: Electronics,Photonics,andBiotechnology.CRCPress.ISBN 978-3-527-31405-8. Temmerman,W.M. (2009). "Chapter241: The Dual,Localizedor Band‐Like,Characterof the 4f‐States". In GschneiderJr.,K.A.(ed.).Handbookonthe PhysicsandChemistryof Rare Earthsvol 39. Elsevier.pp. 100–110. ISBN 978-0-444-53221-3. Dronskowski,R.(2005) Computational Chemistryof SolidState Materials:A Guide forMaterials Scientists,Chemists,PhysicistsandOthers,Wiley,ISBN 9783527314102 Hulliger,F.(1979). "Chapter33: Rare Earth Pnictides".InGschneiderJr.,K.A.(ed.).Handbookonthe PhysicsandChemistryof Rare Earths vol 4. North HollandPublishingCompany.pp.100–110. ISBN 978- 0-444-85216-8. Greenwood,NormanN.;Earnshaw,Alan(1997). Chemistryof the Elements(2nded.).Butterworth- Heinemann.pp.297–299. ISBN 978-0-08-037941-8. Spedding,F.H.;Gschneidner,K.;Daane,A.H. (1958). "The Crystal Structuresof Some of the Rare Earth Carbides".Journal of the AmericanChemical Society.80(17): 4499–4503. doi:10.1021/ja01550a017. Wang, X.; Loa,I.; Syassen,K.;Kremer,R.;Simon,A.;Hanfland,M.;Ahn,K. (2005). "Structural properties of the sesquicarbide superconductorLa2C3at highpressure".Physical ReviewB.72 (6):064520. arXiv:cond-mat/0503597. Bibcode:2005PhRvB..72f4520W. doi:10.1103/PhysRevB.72.064520. S2CID 119330966.
- 32. Poettgen,Rainer.;Jeitschko,Wolfgang.(1991)."Scandiumcarbide,Sc3C4,a carbide withC3 units derivedfrompropadiene".InorganicChemistry.30(3):427–431. doi:10.1021/ic00003a013. Czekalla,Ralf;Jeitschko,Wolfgang;Hoffmann,Rolf-Dieter;Rabeneck,Helmut(1996)."Preparation, Crystal Structure,andPropertiesof the LanthanoidCarbidesLn4C7withLn: Ho, Er, Tm, andLu" (PDF).Z. Naturforsch.B.51 (5): 646–654. doi:10.1515/znb-1996-0505. S2CID 197308523. Czekalla,Ralf;Hüfken,Thomas;Jeitschko,Wolfgang;Hoffmann,Rolf-Dieter;Pöttgen,Rainer(1997). "The Rare Earth CarbidesR4C5 withR=Y, Gd, Tb,Dy, and Ho". Journal of SolidState Chemistry.132(2): 294–299. Bibcode:1997JSSCh.132..294C. doi:10.1006/jssc.1997.7461. Atoji,Masao (1981). "Neutron-diffractionstudyof Ho2Cat 4–296 K".The Journal of Chemical Physics. 74 (3): 1893. Bibcode:1981JChPh..74.1893A.doi:10.1063/1.441280. Atoji,Masao (1981). "Neutron-diffractionstudiesof Tb2Cand Dy2C inthe temperature range 4–296 K". The Journal of Chemical Physics.75(3):1434. Bibcode:1981JChPh..75.1434A. doi:10.1063/1.442150. Mori, Takao (2008). "Chapter238:Higher Borides".InGschneiderJr.,K.A. (ed.).Handbookonthe PhysicsandChemistryof Rare Earths vol 38. NorthHolland.pp.105–174. ISBN 978-0-444-521439. Greenwood,NormanN.;Earnshaw,Alan(1997). Chemistryof the Elements(2nded.).Butterworth- Heinemann.p.147. ISBN 978-0-08-037941-8. RefractoryMaterials,Volume 6-IV:1976, ed.AllenAlper,Elsevier,ISBN 0-12-053204-2 Zuckerman,J.J. (2009) InorganicReactionsandMethods,The Formationof Bondsto Group-I,-II,and- IIIbElements,Vol.13,JohnWiley&Sons,ISBN 089573-263-7 Reimer,Ludwig(1993).Image FormationinLow-voltage ScanningElectronMicroscopy.SPIEPress.ISBN 978-0-8194-1206-5. Cotton,S. A.(1997). "Aspectsof the lanthanide-carbonσ-bond".Coord.Chem.Rev.160: 93–127. doi:10.1016/S0010-8545(96)01340-9. MacDonald, R. P.(1964). "Usesfor a HolmiumOxide FilterinSpectrophotometry"(PDF).Clinical Chemistry.10 (12): 1117–20. doi:10.1093/clinchem/10.12.1117. PMID 14240747. Archivedfromthe original (PDF) on5 December2011. Retrieved24February2010. "HolmiumGlassFilterforSpectrophotometerCalibration".Archivedfromthe original on14 March 2010. Retrieved6June 2009. Levine,AlbertK.;Palilla,FrankC.(1964). "A new,highly efficientred-emittingcathodoluminescent phosphor(YVO4:Eu) forcolortelevision".AppliedPhysicsLetters.5(6): 118. Bibcode:1964ApPhL...5..118L.doi:10.1063/1.1723611. Werts,M. H. V. (2005). "Making Sense of Lanthanide Luminescence".Science Progress.88(2): 101–131. doi:10.3184/003685005783238435. PMID 16749431. S2CID 2250959. There existothernaturallyoccurredradioactive isotopesof lanthanideswithlonghalf-lives(144Nd, 150Nd, 148Sm, 151Eu, 152Gd) but theyare notusedas chronometers.
- 33. McGill,Ian (2005) "Rare Earth Elements"inUllmann'sEncyclopediaof Industrial Chemistry,Wiley-VCH, Weinheim.doi:10.1002/14356007.a22_607. Haxel G, HedrickJ, OrrisJ (2006). Rare earth elementscritical resourcesforhightechnology(PDF). Reston(VA):UnitedStatesGeological Survey.USGSFact Sheet:087‐02. Retrieved19April 2008. LivergoodR.(2010). "Rare Earth Elements:A Wrenchinthe SupplyChain"(PDF).CenterforStrategic and International Studies.Retrieved22October2010. Chu, Steven(December2011). "Critical MaterialsStrategy"(PDF).UnitedStatesDepartmentof Energy. p. 17. Retrieved23December2011. Sørenson,ThomasJust;Faulkner,Stephen(2021)."Chapter5. Lanthanide ComplexesUsedforOptical Imaging".Metal IonsinBio-ImagingTechniques.Springer.pp.137–156. doi:10.1515/9783110685701- 011. S2CID 233653968. Daumann,Lena J.;Op denCamp,Huub J.M.; "The Biochemistryof Rare Earth Elements"pp299-324 in "Metals,Microbesand Minerals:The Biogeochemical Sideof Life"(2021) pp xiv+ 341. Walterde Gruyter,Berlin.EditorsKroneck,PeterM.H.and Sosa Torres,Martha. Gruyter.com/document/doi/10.1515/9783110589771-010 DOI 10.1515/9783110589771-010 Bunzil,Jean-Claude;Piguet,Claude (September2005)."Takingadvantage of luminescentlanthanide ions"(PDF).Chemical SocietyReviews.34(12): 1048–77. doi:10.1039/b406082m. PMID 16284671. Archivedfromthe original (PDF) on18 January2013. Retrieved22December2012. Palizban,A.A.;Sadeghi-aliabadi,H.;Abdollahpour,F.(1January2010). "Effectof ceriumlanthanide on Helaand MCF-7 cancer cell growthinthe presence of transferring".ResearchinPharmaceutical Sciences.5(2): 119–125. PMC 3093623. PMID 21589800. Yu, Lingfang;Xiong,Jieqi;Guo,Ling;Miao,Lifang;Liu, Sisun;Guo,Fei (2015). "The effectsof lanthanum chloride onproliferationandapoptosisof cervical cancercells:involvementof let-7aandmiR-34a microRNAs".BioMetals.28(5):879–890. doi:10.1007/s10534-015-9872-6. PMID 26209160. S2CID 15715889. Pol,A.,et al (2014). "Rare Earth MetalsAre Essential forMethanotrophicLife inVolcanicMudpots". EnvironMicrobiol.16 (1): 255–264. doi:10.1111/1462-2920.12249. PMID 24034209. Citedsources Holleman,ArnoldF.;Wiberg,Egon;Wiberg,Nils(2007).LehrbuchderAnorganischenChemie (in German) (102 ed.).Walterde Gruyter.ISBN 978-3-11-017770-1. External links lanthanide SparkleModel,usedinthe computational chemistryof lanthanide complexes USGS Rare Earths StatisticsandInformation Ana de Bettencourt-Dias:Chemistryof the lanthanidesandlanthanide-containingmaterials
- 34. Eric Scerri,2007, The periodictable:Itsstoryand itssignificance,OxfordUniversityPress,New York, ISBN 9780195305739 vte Periodictable 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 1 H He 2 Li Be B C N O F Ne 3 Na Mg Al Si P S Cl Ar 4 K
- 38. Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og s-block f-block d-block p-block vte Periodictable Authoritycontrol:National librariesEditthisatWikidata France (data)GermanyIsraelUnited StatesJapan Categories:PeriodictableLanthanides Navigationmenu Notloggedin Talk Contributions Create account Log in ArticleTalk ReadEditViewhistory
- 39. Search SearchWikipedia Main page Contents Currentevents Randomarticle AboutWikipedia Contact us Donate Contribute Help Learn to edit Communityportal Recentchanges Uploadfile Tools What linkshere Relatedchanges Special pages Permanentlink Page information Cite thispage Wikidataitem Print/export DownloadasPDF Printable version In otherprojects WikimediaCommons
- 40. Languages ية عرب ال Español हिन्दी Bahasa Indonesia Bahasa Melayu Русский Tagalog Winaray 中文 88 more Editlinks Thispage waslasteditedon29 March 2022, at 14:00 (UTC). Textisavailable underthe Creative Commons Attribution-ShareAlike License 3.0;additional termsmay apply.Byusingthissite,youagree to the Termsof Use and PrivacyPolicy.Wikipedia® isaregistered trademarkof the WikimediaFoundation,Inc.,anon-profitorganization. PrivacypolicyAboutWikipediaDisclaimersContactWikipediaMobile viewDevelopersStatisticsCookie statementWikimediaFoundationPoweredbyMediaWiki