Spectroscopy Letters Volume 26 issue 3 1993 [doi 10.1080_00387019308011552] S. S. Kandil; L. H. Madkour -- Synthesis and Characterization of 2,2-Biimidazole Complexes of Oxoca (3)
This article describes the synthesis and characterization of 2,2'-biimidazole complexes of molybdenum and uranium. Two types of complexes were formed - those from slightly acidic solutions had formulas of MO02(H2bim)Cl2.2H20, U02(H2bim)(Ac)2.2H20, and U02(H2bim)Cl2.2H20. Those from alkaline solutions had formulas of Mo204(H2bim)2.2H20 and M02(Hbim)2 where M is molybdenum or uranium. The complexes were characterized using elemental analysis, conductivity measurements, 1H NMR, IR, and electronic spectroscopy
Synthesis and Characterization of New Complexes of 2-(6-Methoxybenzo[d]thiazo...IOSR Journals
Abstract: The synthesis and characterization of manganese (ІІ), cobalt (ІІ), nickel (ІІ), copper (ІІ), zinc (ІІ), cadmium (ІІ) and mercury (ІІ) bidentate 2-(6-methoxybenzo[d]thiazol-2-ylamino)-2-phenyl acetonitrile ligand which was prepared from Benz aldehyde and 6-methoxybenzo[d]thiazol-2-amine in the presence of KCN and acidic medium. The complexes were synthesized by treating an ethanolic solution of the ligand with appropriate amount of metal salts [1:2] [M: L] ratio. The complexes were characterized by using metal and elemental chemical analysis, molar conductance, magnetic susceptibility measurements, FTIR , electronic spectral and mole ratio method. According to the obtained data the probable coordination geometries of manganese (ІІ), cobalt (ІІ), nickel (ІІ), copper (ІІ) zinc (ІІ), cadmium (ІІ) and mercury (ІІ) in these complexes are octahedral. All complexes were found to be non-electrolyte in absolute ethanol, and the complexes were formulated as [ML2Cl2] XH2O. Keywords: 2-(6-methoxybenzo[d]thiazol-2-ylamino)-2-phenyl acetonitrile, N2-donor, transition metals.
Kinetics of Ruthenium(III) Catalyzed and Uncatalyzed Oxidation of Monoethanol...Ratnakaram Venkata Nadh
Kinetics of uncatalyzed and ruthenium(III) catalyzed oxidation of monoethanolamine by N-bromosuccinimide
(NBS) has been studied in an aqueous acetic acid medium in the presence of sodium acetate
and perchloric acid, respectively. In the uncatalyzed oxidation the kinetic orders are: the first order in NBS,
a fractional order in the substrate. The rate of the reaction increased with an increase in the sodium acetate
concentration and decreased with an increase in the perchloric acid concentration. This indicates that free
amine molecules are the reactive species. Addition of halide ions results in a decrease in the kinetic rate,
which is noteworthy. Both in absence and presence of a catalyst, a decrease in the dielectric constant of the
medium decreases the kinetic rate pointing out that these are dipole—dipole reactions. A relatively higher
oxidation state of ruthenium i.e., Ru(V) was found to be the active species in Ru(III) catalyzed reactions. A
suitable mechanism consistent with the observations has been proposed and a rate law has been derived to
explain the kinetic orders.
Synthesis and characterization of some metal complexes of 2- Phenyl-3,4-dihyd...IOSRJAC
2-Phenyl-3,4-dihydro-quinazolin-4-yloxy)-acetic acid (L1) metal complexes with Mn2+ , Co2+, Ni2+ Cu2+ , and Zn2+ ions were studied and the structure of the complexes were elucidated using elemental analyses, infrared (IR), 1H nuclear magnetic resonance (NMR), magnetic moment and thermal analysis measurements. Besides the characterization of complexes by physicochemical technique, Biological activities of the synthesized complexes were examined against some microbial strains for evaluation of antibacterial and antifungal activities.
Synthesis and Characterization of New Complexes of 2-(6-Methoxybenzo[d]thiazo...IOSR Journals
Abstract: The synthesis and characterization of manganese (ІІ), cobalt (ІІ), nickel (ІІ), copper (ІІ), zinc (ІІ), cadmium (ІІ) and mercury (ІІ) bidentate 2-(6-methoxybenzo[d]thiazol-2-ylamino)-2-phenyl acetonitrile ligand which was prepared from Benz aldehyde and 6-methoxybenzo[d]thiazol-2-amine in the presence of KCN and acidic medium. The complexes were synthesized by treating an ethanolic solution of the ligand with appropriate amount of metal salts [1:2] [M: L] ratio. The complexes were characterized by using metal and elemental chemical analysis, molar conductance, magnetic susceptibility measurements, FTIR , electronic spectral and mole ratio method. According to the obtained data the probable coordination geometries of manganese (ІІ), cobalt (ІІ), nickel (ІІ), copper (ІІ) zinc (ІІ), cadmium (ІІ) and mercury (ІІ) in these complexes are octahedral. All complexes were found to be non-electrolyte in absolute ethanol, and the complexes were formulated as [ML2Cl2] XH2O. Keywords: 2-(6-methoxybenzo[d]thiazol-2-ylamino)-2-phenyl acetonitrile, N2-donor, transition metals.
Kinetics of Ruthenium(III) Catalyzed and Uncatalyzed Oxidation of Monoethanol...Ratnakaram Venkata Nadh
Kinetics of uncatalyzed and ruthenium(III) catalyzed oxidation of monoethanolamine by N-bromosuccinimide
(NBS) has been studied in an aqueous acetic acid medium in the presence of sodium acetate
and perchloric acid, respectively. In the uncatalyzed oxidation the kinetic orders are: the first order in NBS,
a fractional order in the substrate. The rate of the reaction increased with an increase in the sodium acetate
concentration and decreased with an increase in the perchloric acid concentration. This indicates that free
amine molecules are the reactive species. Addition of halide ions results in a decrease in the kinetic rate,
which is noteworthy. Both in absence and presence of a catalyst, a decrease in the dielectric constant of the
medium decreases the kinetic rate pointing out that these are dipole—dipole reactions. A relatively higher
oxidation state of ruthenium i.e., Ru(V) was found to be the active species in Ru(III) catalyzed reactions. A
suitable mechanism consistent with the observations has been proposed and a rate law has been derived to
explain the kinetic orders.
Synthesis and characterization of some metal complexes of 2- Phenyl-3,4-dihyd...IOSRJAC
2-Phenyl-3,4-dihydro-quinazolin-4-yloxy)-acetic acid (L1) metal complexes with Mn2+ , Co2+, Ni2+ Cu2+ , and Zn2+ ions were studied and the structure of the complexes were elucidated using elemental analyses, infrared (IR), 1H nuclear magnetic resonance (NMR), magnetic moment and thermal analysis measurements. Besides the characterization of complexes by physicochemical technique, Biological activities of the synthesized complexes were examined against some microbial strains for evaluation of antibacterial and antifungal activities.
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Visible Spectrophotometric Determination of Gemigliptin Using Charge Transfer...Ratnakaram Venkata Nadh
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(y = –0.0302x + 0.928) in the range of 2.0–30.0 μg mL-1. The method was found to be simple and rapid because it does not involve any solvent extraction. The recovery levels of the drug were in the range 99.92 – 100.08.
Spectroscopic, Thermal, Magnetic and conductimetric studies on some 7-hydroxy...IOSR Journals
7-hydroxy-4-methyl-8-(p-methylphenylazo)coumarin (L1) and 7-hydroxy-4-methyl-8-(p-methoxyphenylazo)coumarin (L2) have been prepared and characterized by elemental analysis, infrared (IR), proton nuclear magnetic resonance (1H NMR) and mass spectra. The important infrared (IR) spectral bands corresponding to the active groups in the two ligands and the solid complexes under investigation were studied. Also the important fragments in the ligands and complexes were done using mass spectra and the main peaks were corresponding to the molecular weights of the ligands and complexes. The solid complexes have been synthesized and characterized by elemental and thermal analyses (TG and DTA) as well as by IR, 1H NMR, magnetic measurements, electronic transition, molar conductance, mass and electron spin resonance (ESR) spectra. The proposed steriochemical structures for the investigated metal complexes suggest octahedral geometry with respect to Mn, Co, Ni, Cu and Zn divalent metal ions with the investigated ligands 1:1 and 1:2 complexes and all of the formed complexes contain coordinated and hydrated water molecules. All of the prepared solid complexes behave as non-electrolytes in chloroform.
Chapter 20 carboxylic acids and functional derivativesHashim Ali
HSSC Second year Chemistry course slides for Federal Board Pakistan, lectures by Dr. Raja Hashim Ali (also available on Youtube as a series of videos lectures).
https://www.youtube.com/playlist?list=PLCfCZszhGHBdVLuL1Mxo58BGDad1EtDtx
Bidentate Schiff base ligand 3-(3,4-Dihydroxy-phenyl)-2-[(4-dimethylamino-benzylidene)-amino]-2-methyl-propionic acid was prepared and characterized by spectroscopic techniques studies and elemental analysis. The Cd(II), Ni(II), Cu(II), Co(II), Cr(III),and Fe(III) of mixed-ligand complexes were structural explicate through moler conductance , [FT-IR, UV-Vis & AAS], chloride contents, , and magnetic susceptibility measurements. Octahedral geometries have been suggested for all complexes. The Schiff base and its complexes were tested against various bacterial species, two of {gram(G+) and gram(G-)} were shown weak to good activity against all bacteria.
Visible Spectrophotometric Determination of Gemigliptin Using Charge Transfer...Ratnakaram Venkata Nadh
A visible spectrophotometric method was developed and validated for the determination of gemigliptin present in bulk drug and tablet formulation. It involves an indirect method of charge transfer complex formation in presence of NBS, metol and suphanilic acid. Gemigliptin was subjected to oxidation with excess amount of oxidant (NBS) and the unconsumed NBS oxidizes metol to give p-N-methylbenzoquinone monoamine (PNMM) which in turn forms a charge transfer complex with sulphanilic acid. Then validated the above developed method as per the current ICH guidelines. An excellent correlation coefficient (> 0.999) was found for the obtained regression equation
(y = –0.0302x + 0.928) in the range of 2.0–30.0 μg mL-1. The method was found to be simple and rapid because it does not involve any solvent extraction. The recovery levels of the drug were in the range 99.92 – 100.08.
Spectroscopic, Thermal, Magnetic and conductimetric studies on some 7-hydroxy...IOSR Journals
7-hydroxy-4-methyl-8-(p-methylphenylazo)coumarin (L1) and 7-hydroxy-4-methyl-8-(p-methoxyphenylazo)coumarin (L2) have been prepared and characterized by elemental analysis, infrared (IR), proton nuclear magnetic resonance (1H NMR) and mass spectra. The important infrared (IR) spectral bands corresponding to the active groups in the two ligands and the solid complexes under investigation were studied. Also the important fragments in the ligands and complexes were done using mass spectra and the main peaks were corresponding to the molecular weights of the ligands and complexes. The solid complexes have been synthesized and characterized by elemental and thermal analyses (TG and DTA) as well as by IR, 1H NMR, magnetic measurements, electronic transition, molar conductance, mass and electron spin resonance (ESR) spectra. The proposed steriochemical structures for the investigated metal complexes suggest octahedral geometry with respect to Mn, Co, Ni, Cu and Zn divalent metal ions with the investigated ligands 1:1 and 1:2 complexes and all of the formed complexes contain coordinated and hydrated water molecules. All of the prepared solid complexes behave as non-electrolytes in chloroform.
Chapter 20 carboxylic acids and functional derivativesHashim Ali
HSSC Second year Chemistry course slides for Federal Board Pakistan, lectures by Dr. Raja Hashim Ali (also available on Youtube as a series of videos lectures).
https://www.youtube.com/playlist?list=PLCfCZszhGHBdVLuL1Mxo58BGDad1EtDtx
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Spectroscopy Letters Volume 26 issue 3 1993 [doi 10.1080_00387019308011552] S. S. Kandil; L. H. Madkour -- Synthesis and Characterization of 2,2-Biimidazole Complexes of Oxoca (3)
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Synthesis and Characterization
of 2,2-Biimidazole Complexes
of Oxocations of Molybdenum
(VI, V) and Uranium(VI)
Samir S. Kandil
a
& Loutfy H. Madkour
a
a
Chemistry Department, Faculty of Sciences , Tanta
University , Tanta, EGYPT
Published online: 23 Sep 2006.
To cite this article: Samir S. Kandil & Loutfy H. Madkour (1993) Synthesis and
Characterization of 2,2-Biimidazole Complexes of Oxocations of Molybdenum
(VI, V) and Uranium(VI), Spectroscopy Letters: An International Journal for Rapid
Communication, 26:3, 535-550, DOI: 10.1080/00387019308011552
To link to this article: http://dx.doi.org/10.1080/00387019308011552
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3. SPECTROSCOPY LETERS, 26(3). 535-550 (1993)
Synthesis and Characterization of 2,2'-biimidazole
Complexes of Oxocations of Molybdenum (VI, V) and
Uranium(V1)
BY
Samir S. Kandil* and Loutfy H. Madkour
Chemistry Department, Faculty of Sciences, Tanta University,
Tanta, EGYPT.
ABSTRACT
t22,2.-Biimidazole complexes of Moo2 , Moo2+ and U02f2
have been prepared and characterized by elemental analysis,
conductance; and 'H NMR, IR and electronic spectra. Two
types of complexes have been identified. Those obtained
from slightly acidic solutions have the formulae
MOO2 2(H bim)C12.2H20 'l,U02(H2bim)(Ac)2 2 and U02(H2bim)C12.2H20
whereas those from alkaline solutions have the formulae
M0~0~(Hbim)~.2H~O4, and M02(Hbim)2 ( M = Mo(V1) 5, U(V1) 6).
The infrared spectra of these complexes show characteristic
biimidazole frequencies in the 3200-2500, 1550-1000 and
150 cm-l regions as well as metal oxygen double bonds in
the 900 cm-l region.
complex has been confirmed from 'H NMR signal ratios of
The stoichiometries of the acetate
* Author to whom correspondence should be directed.
3;
535
Copyright 01993 by Marcel Dekker, Inc
Downloadedby[MichiganStateUniversity]at14:1027January2015
4. 536 KANDIL AND MADKOUR
biimidazole to acetate protons at 7.3 and 2.3 ppm, respec-
tively. The electronic spectrum of molybdenum(V) complex
showed d-d transition band at =13,500 cm-' in accord with
that' reported for copper (d ) imidazole complexes; as well
as peaks due to charge transfer bands at 30,000-26,000 c9-l.
Peaks assignable to BIM --+ U(V1) were located at ~ 2 6 , 6 0 0
cm . The most probable structures of these complexes have
been suggested.
9
-1
INTRODUCTION
The chemistry of the transition metals in the high
oxidation states such as Mo(V1) and U(V1) is complicated
in aqueous media due to the formation of 0x0 complex and
polynuclear 0x0 complexes as well as redox reactions .
Molybdenum(V1) acts as a binding site for imidazole moiety
as well as redox site in xanthine oxidase and xanthine
dehydrogenase' ) . Dioxouranium(V1) complexes containing
nitrogenuous chelating ligands such as 2,2*-bipyridine have
been known for many year^(^-^).
derivatives have been involved in the model studies for
some of biologicqlly important systems(9).
ting ligand, 2,2'-biimidazole can complex as the neutral
molecule H2bim, the monoanion Hbim or the dianion bim.
Examples of all of these possibilities have been realized
( 1 )
2,2'-Biimidazole and its
As a coordina-
experimentally with many transition metals in low oxidation
states( 1 0 - 1 5 ) .
The present study describes the synthesis and spectral
properties of some oxocation complexes of Mo(V1, V ) and
U(V1) with 2,2'-biimidazole.
Downloadedby[MichiganStateUniversity]at14:1027January2015
5. 2-2'-BIIMIDAZOLE COMPLEXES
EXPERIMENTAL
537
( A ) Materials and Compound Preparations.
2,2~-Biimidazolewas synthesized according to a pub-
lished procedure(16).
reagent grade.
Na2Mo04.2H20 and U02(Ac)2.2H20 were
Mo02(H2bim)C12.2H20 1: A mixture of Na2Mo04.2H20 (2.42 g,
0.01 mol) and 2,2'-biimidazole (1.34 g, 0.01 mol) in 50 ml
aqueous ethanolic solution containing 0.01 mole HC1 was
stirred in an open flask. To this solution an aqueous
sodium hydroxide was added dropwise to pH 4. After the
solution was stirred for additional 3 hours, the copious
precipitate was filtered off and digested with hot water
several times to remove unchanged ligand. The final pro-
duct was a fine yellow solid and dried over P4Ol0.
M0~0~(Hbim)~.2H~O4: The same procedure as above, except
that the pH of the original solution was adjusted at 8.5.
After stirring for 1 hour, the blue precipitate was col-
lected by filtration; washed with hot water and dried in
vacuum over P40,0.
U0,(H,bim)(A~)~ 2:
mol) was dissolved in 30 m l ethanol. To this solution,
2,2~-biimidazole(1.34 g , 0.01 mol) dissolved in 10 ml
water containing 0.01 mol HC1 was added with stirring; a
Uranyl acetate dihydrate (4.24 g , 0.01
clear yellow solution was obtained. The pH of the solution
was adjusted to 4 by adding few drops of NaOH solution.
Upon partial evaporation of the solvent, a yellow solid
was separated, which was filtered off, washed several times
with hot water, ethanol and diethyl ether and dried over
'4'1 0'
Downloadedby[MichiganStateUniversity]at14:1027January2015
6. 538 KANDIL AND MADKOUR
If an excess of NaCl was added to the original solution
at the same pH the chloro complex U02(H2bim)C12.2H20 3 was
obtained.
!400~(Hbim)~2: A solution of Na2Mo04.2H20 (2.42 g , 0.01
mol) and H2bim (2.68 g, 0.02 mol) in 100 ml of water was
acidified with dropwise addition of 30 m l of 1.5 N HN03 at
Sac. After the solution was stirred for 1 h, the precipi-
tate was filtered, washed with water and dried in vacuum.
The orange solid was suspended in 20 ml water and the pH
was adjusted at 8.5 by adding standard solution of sodium
hydroxide. The insoluble deprotonated complexes was stir-
red for 2 h to ensure complete reaction. The yellow product
was washed with water and dried in vacuum.
U02(Hbim)2 6:
in water (30 m l ) was added to a suspension of H2bim ( 2 . 6 8
g , 0.02 mol) a l s o in water (30 ml) and 0.02 M sodium hydro-
xide solution was added till pH 8.5. An immediate yellow
precipitate was formed, but the mixture was stirred for
2 h to ensure complete reaction. The product was washed
with water and dried in vacuum.
(B) Physical Measurements:
Uranyl acetate dihydrate (4.24 g , 0.01 mol)
v
The metal content of the complexes was determined by
igniting a known weight of a complex to the corresponding
stable oxide (Moo3 and U 3 0 8 ) .
N were carried out using a Perkin-Elmer 2 4 0 0 CHN elemental ana-
lyzer. The H NMR spectra were recorded in d6-dimethyl
sulphoxide on a Brutor EM390, 90 MHZ nmr spectrometer.
The electrical conductances of the complexes were measured
in DMSO at 25'C using a Hanna 8733 conductivity meter.
Microanalysis of C, H and
l
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7. 2-2' -BIIMIDAZOLE COMPLEXES 539
The infrared spectra (KBr discs) were recorded on a Perkin-
Elmer 7430 Ratio Recording spectrophotometer and a Perkin-
Elmer 6 8 3 spectrophotometer. The electronic spectra in
Nujol mull were recorded on a Shimadzu 2 4 0 UV spectrophoto-
meter. All the complexes are insoluble in the common
solvents such as ethanol, nitrobenzene and CHCl
3 '
RESULTS AND DISCUSSION
Treatment of Mo02C12 (prepared in situ by reduction
of Na2Mo04 in 2N HC1) and U02(Ac)2.2H20 with H2bim, results
in the separation of two types of complexes. The analy-
tical data, Table ( l ) , indicates that those obtained from
slightly acidic solutions are formulated as MOO (H bim)C12.2H20
1,U02(H2biml(Ac)2 2 and UO (H bim)C12.2H20 2; whereas those
from slightly alkaline solutions are formulated as
Mo204(Hbim12.2H20 4, and M(Hbirnl2 where M = Mo(V1) 5, U(V1)
-6 . The conductivity measurements on the complexes in the
DMSO solutions at concentration M are too small ( 2 2 -
2 2
2 2
26 S cm') to account for any dissociation. Hence these
complexes can be regarded as nonelectrolytes. The ' Hnmr
spectra of 2, Figure ( 1 1 , obtained in DMSO solutions con-
tains a sharp singlet resonance at 2.3 ppm assigned to
acetato protons and broad multiplet centered at 7 . 2 ppm
assigned to biimidazole hydrogens. Total integration of
peak ratios revealed 3 : 2 acetato to ring biimidazole
protons ratio consistent with U02(H2bim) (Ac)* stoichiometry.
No imino hydrogen resonances could be detected since they
rapidly exchange with the solvent" 6).
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9. 2-2' -BIIMIDAZOLE COMPLEXES 541
t I I I I I I I 1 1
8 7 6 5 4 7 2 I 0 ppm
pigure (1). 'HNMR spectrum of U02(H2bim)(Ac)2 in DMSO.
calibrated in ppm downfield from TMS. ( d l DMSO peaks.
Chemical shifts are
Infrared Spectra
The IR frequencies of the prepared complexes along
with their assignments are given in Tables 2 and 3. The
IR spectra of complexes 1_ - 3 display many characteristic
group frequencies for biimidazole (e.g. v(N-H) = 3200 ern-';
-1
va (C=N-C=C) = 1530-1580 cm-'; v(C=N-C=C) = 1450-1460 cm ,
6 (C-H) = 1100-1130 cm-l and 6 (bim) = 755-735 cm-') as in
the case of [Rh(COD) [H2bim)]C104"3) and C~(H~bim)~Cl~.H~o('~);
whereas the i.r. of complexes 3 - 5 are found to be closely
similar to those of some transition metal complexes reported
to contain Hbim(17).
3200-2500 cm-l in the spectra of 4 I f; is similar to that
of free biimidazole, suggesting the presence of an N-H bond
The broad structure in the region
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11. 2-2' -BIIMIDAZOLE COMPLEXES 543
E.+
e
z
C
0
C
m
C
6
W
rY
M
C
TI
.rl
u
C
U
Lo
W
m7-4a
E
U
C
.r(
u
0
0
L4
0w
mu
mU
U
h
m
ul
CY
.rl
m
h
m
0Fi
v
n
2
u
C
I
00.r(
Lo
U
N
n
E.?I
0
XV
N
8x
ON
"i
T
N
h
E.4
e
Xv
U
R
2
N
h
E.dn
Xv
N
9
I4
a,u
m
W
U.4
uu
m3
w
0
-E
Exv1
V
c
. .
2:
m L o.rl
u e
C I
m z
cu.A
3 **
v -
a 0Q
a II
3 0
* IW W
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12. 544 KANDIL AND MADKOUR
remaining in the monoanion Hbim. This structure is now
being assigned as due to Fermi resonance between N-H stret-
ching Sands and combinations of bands in the 1600-1000 cm-'
regions(18,191
Complete tabulation of the i.r. frequencies of the
prepared complexes and biimidazole reveals drastic changes in
the 1100 and 900 an-' regions (Fig. 2). The in-plane C-H defor-
mation of biimidazole has been replaced by two strong bands
at 1100-1130 cm-l in the complexes as consequences of
lowering symmetry of biimidazole on complexation. In
molybdenyl complex 1,two strong bands appear at 944 and
851 cm-', which do not correspond to any bands in the free
!4 bim, assignable to symmetric and antisymmetric vibrations
of bent Moo2 group(20).
bands due to Mo=O appear to be partially overlapped with
biimidazole ring modes, giving rise to a shoulder at 948
and a stronger band at 896 cm-l in complex 5 and medium
and broad bands at 9 2 0 and 856 cm-l in complex 5.
uranyl complexes, an unusual intense broad bands appear
in the region 890-870 cm-l, ascribed to v 3 anti symmetric
stretch of linear"O=U=O(21
vibrations of biimidazole. The observed low frequency for
2
In molybdenum complexes 4 and 2,
In
overlapped with ring mode
( 2 2 )as compared to that of uranyl acetato complexes"0=U=O'
may be due to the greater perturbation caused by the stronger
chelation of biimidazole group. The occurrence of the asym-
metric and symmetric vibrations of 0-C-0 at 1517 and 1462 cm-'
in complex 2. is consistent with the bidentate nature of
acetato group( 2 3 ) presumbly through chelation to the same
uranium atom. This type of bonding of acetato group has
been well established in closely related systems such as
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13. 2-2‘-BIIMIDAZOLE COMPLEXES
X T
545
-1
cm
Figure ( 2 ) . Infrared spectra of; ( A ) H2bim,
( B ) MoOZ(HZbim)Cl2.2H20 1,( C ) Mo2O4(Hbim).2H20 4,
(D) Mo02(Hbim)2 5, (E) U02(H2bim)CL2.H20 2.
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14. 546 KANDlL AND MADKOUR
x
L.
mL.Y
v1
4
e
200 3 50 550 750 nm
Figure ( 3 ) . Solid state electronic spectra o f ;
(- ) M0~0~(Hbim)~.2H~O
( -- --) U02 (Hbim)
( -..........) U02(H2bim)(Ac)2.
U02(bpy( A C ) ~(’).
due to the water molecules are observed at 3500 and 1600
In the hydrated complexes, absorptions
cm-’ .
In the f a r - I R region, strong to medium bands are ob-
served at 265-240 cm-’ in the complexes, corresponding to
a very weak band at 270 cm-‘ in the free biimidazole, due
to metal-nitrogen stretching vibrations(23).
metal-chlorine are located in 1 at 366 cm-’ and in 2. at
Bands due to
393 cm-’.
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15. 2-2'-9IIMIDAZOLE COMPLEXES 547
Electronic Spectra
The electronic spectra of the molybdenum complexes 1,
-4 and 5 show bands at
assigned as due to ( n ,
BIM -+ Mo overlapped with TI -n* transition of biimida-
zole").
complex at -13,500 cm-' , which is absent in either
Mo02(Hbim)C12.2H20 or M00~(Hbim)~,is assigned as the
expected d-d transition of Mo(V).
26,000 and 3 0 , 0 0 0 cm-l, Figure 3,
- n2) BIM -+ Mo and (nl + n 2 )
The broad absorption exhibited by Mo204(Hbim)2(H20)2
The electronic spectra of the uranyl complexes are
completely different from that of U02(Ac)2.2H20 and show
intense band at 26,600 cm-l due to BIM -+ U02 transition(24).
Additionally, bands at ~24,000cm-' may be assigned to U02
moiety.
Absorption bands below 39,000 cm-l in the spectra of
the prepared complexes have to be assigned as due to the
biimidazole because they are present irrespective of cations.
From the above discussions the most probable structures
of these complexes can be as:
c1 O
II
"M
0
I
H-N
u
M = M o L
M = U 3-
2-
(continued)
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16. 548 KANDIL AND MADKOUR
OH2 F
I, y-M
N
1 AO N
4-
M = M o 5
M = U 6
REFERENCES
1. F.A. Cotton and G. Wilkinson "Advanced Inorganic Che-
mistry" , 3rd ed. , Interscience ( 1972).
2 .
3.
4 .
5.
6 .
7.
a.
9.
E. Ochiai, "Bioinorqanic Chemistry An Introduction", Ch. 1 1 ,
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Y
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17. 2-2’ -BIIMIDAZOLE COMPLEXES 549
10. R. Usan, L.A. O r o , J. Gimeno, M.A. Ciriano and J.A.
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18. 550 KANDIL AND MADKOUR
23. K. Nakarnoto “Infrared and Raman Spectra of Inorganic
and Coordination Compounds”, 4 t h ed., Wiely-Interscience,
New York (1986
24. M. Vidali, P.A
0. Traverso. J
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Date Recei;’ed: September 10, 1992
Date Accepted: November 2, 1992
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