This PDF presentation describes briefly my research experiences in synthetic organic and analytical chemistry. The time period of these research projects range from 09/2006 to 06/2015. All the projects were carried out at various academic institutes/university in the Czech republic and Poland. Time period, place of work and position were mentioned at the first slide of individual project. To noted that all the experimental synthesis, separation/purification, characterization and applied analytical experiments were performed independently by me.
A ruthenium trinuclear polyazine complex was synthesized and subsequently immobilized through
complexation to a graphene oxide support containing phenanthroline ligands (GO-phen). The developed
photocatalyst was used for the photocatalytic reduction of CO2 to methanol, using a 20 watt white cold
LED flood light, in a dimethyl formamide–water mixture containing triethylamine as a reductive
quencher. After 48 h illumination, the yield of methanol was found to be 3977.57 5.60 mmol gcat
1.
The developed photocatalyst exhibited a higher photocatalytic activity than graphene oxide, which
provided a yield of 2201.40 8.76 mmol gcat
1. After the reaction, the catalyst was easily recovered and
reused for four subsequent runs without a significant loss of catalytic activity and no leaching of the
metal/ligand was detected during the reaction.
This PDF presentation describes briefly my research experiences in synthetic organic. The time period of these research projects range from 1999 to 10/2005. Projects of later positions were also included but not all. Time period, place of work and position were mentioned at the beginning of each project. To noted that all the experimental synthesis, separation/purification, characterization and spectral interpretation were performed independently by me.
Synthesis and Crystal Structure of Anickel (II) and Zinc (II) Complex From 1,...IOSRJAC
:The title mononuclear nickel and zinc complexes, Ni(C11H9N4S3)2andZn(C11H9N4S3)2 .2(C3H7NO), were prepared by the reaction of Nickel(II) or Zinc(II)acetate with 1,5-bis[(2- thiophenyl)methylidene]thiocarbonohydrazide in a methanol solution. It features mono-deprotonated bisbidentate ligands, which coordinate to metal (II) ions by hydrazylN and thiocarbony lS atoms, yielding a tetracoordinated metal ions complexes. In Ni(II) complex the geometry around the metal ion is described as square planar. In the Zn(II) the metal atom shows severely tetrahedral distortion from anideal square-planar coordination geometry, as reflected by the dihedral angle between ZnN2and ZnS2 planes of 73.03(13)°. Two intramolecular hydrogen bonds are observed between the solvate dmf molecules and the coordinated ligands:N2—H2N…O1i and N6—H6N…O2 ii in this complex
X-Ray Line Profile Analysis of Chemically Deposited Nanostructured PBS FilmsIOSR Journals
Nanocrystalline films of PbS have been deposited on glass sustrates at room temperature by CBD
method. The structural parameters of PbS films have been studied by X-ray line profile analysis using
Williamson Hall and Modified Williamson Hall method. The crystallite sizes are found in between 4.99-53.9 nm,
strain in the films in the range of 7.4x10-4 – 2.82 x 10-3 and dislocation densities are found to be very high ~
1015-1016 m-
Nuclear Magnetic Resonance (NMR) Analysis of D - (+) - Glucose: A Guide to Sp...IOSR Journals
NMR spectroscopy has a wide range of applications including exchange phenomena, the
identification and structural studies of complex biomolecules. 1D 1H-NMR without water suppression, 1D
Carbon, 1D 13C-DEPT135, 2D Cosy, 2D HSQC, 2D TOCSY, 2D HMQC, and 2D HMBC techniques were used
to completely elucidate the structure of glucose with spectral induced at 400MHz.. The spectral were analysed
using spinworks 3. The results obtained from the spectral data were systematically combined to elucidate the
structure of the D-glucose. Full characterisation of D-glucose was achieved by assigning 1H and 13C signals,
starting from the known to unknown signals.
A ruthenium trinuclear polyazine complex was synthesized and subsequently immobilized through
complexation to a graphene oxide support containing phenanthroline ligands (GO-phen). The developed
photocatalyst was used for the photocatalytic reduction of CO2 to methanol, using a 20 watt white cold
LED flood light, in a dimethyl formamide–water mixture containing triethylamine as a reductive
quencher. After 48 h illumination, the yield of methanol was found to be 3977.57 5.60 mmol gcat
1.
The developed photocatalyst exhibited a higher photocatalytic activity than graphene oxide, which
provided a yield of 2201.40 8.76 mmol gcat
1. After the reaction, the catalyst was easily recovered and
reused for four subsequent runs without a significant loss of catalytic activity and no leaching of the
metal/ligand was detected during the reaction.
This PDF presentation describes briefly my research experiences in synthetic organic. The time period of these research projects range from 1999 to 10/2005. Projects of later positions were also included but not all. Time period, place of work and position were mentioned at the beginning of each project. To noted that all the experimental synthesis, separation/purification, characterization and spectral interpretation were performed independently by me.
Synthesis and Crystal Structure of Anickel (II) and Zinc (II) Complex From 1,...IOSRJAC
:The title mononuclear nickel and zinc complexes, Ni(C11H9N4S3)2andZn(C11H9N4S3)2 .2(C3H7NO), were prepared by the reaction of Nickel(II) or Zinc(II)acetate with 1,5-bis[(2- thiophenyl)methylidene]thiocarbonohydrazide in a methanol solution. It features mono-deprotonated bisbidentate ligands, which coordinate to metal (II) ions by hydrazylN and thiocarbony lS atoms, yielding a tetracoordinated metal ions complexes. In Ni(II) complex the geometry around the metal ion is described as square planar. In the Zn(II) the metal atom shows severely tetrahedral distortion from anideal square-planar coordination geometry, as reflected by the dihedral angle between ZnN2and ZnS2 planes of 73.03(13)°. Two intramolecular hydrogen bonds are observed between the solvate dmf molecules and the coordinated ligands:N2—H2N…O1i and N6—H6N…O2 ii in this complex
X-Ray Line Profile Analysis of Chemically Deposited Nanostructured PBS FilmsIOSR Journals
Nanocrystalline films of PbS have been deposited on glass sustrates at room temperature by CBD
method. The structural parameters of PbS films have been studied by X-ray line profile analysis using
Williamson Hall and Modified Williamson Hall method. The crystallite sizes are found in between 4.99-53.9 nm,
strain in the films in the range of 7.4x10-4 – 2.82 x 10-3 and dislocation densities are found to be very high ~
1015-1016 m-
Nuclear Magnetic Resonance (NMR) Analysis of D - (+) - Glucose: A Guide to Sp...IOSR Journals
NMR spectroscopy has a wide range of applications including exchange phenomena, the
identification and structural studies of complex biomolecules. 1D 1H-NMR without water suppression, 1D
Carbon, 1D 13C-DEPT135, 2D Cosy, 2D HSQC, 2D TOCSY, 2D HMQC, and 2D HMBC techniques were used
to completely elucidate the structure of glucose with spectral induced at 400MHz.. The spectral were analysed
using spinworks 3. The results obtained from the spectral data were systematically combined to elucidate the
structure of the D-glucose. Full characterisation of D-glucose was achieved by assigning 1H and 13C signals,
starting from the known to unknown signals.
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...Ana Luísa Pinho
Functional Magnetic Resonance Imaging (fMRI) provides means to characterize brain activations in response to behavior. However, cognitive neuroscience has been limited to group-level effects referring to the performance of specific tasks. To obtain the functional profile of elementary cognitive mechanisms, the combination of brain responses to many tasks is required. Yet, to date, both structural atlases and parcellation-based activations do not fully account for cognitive function and still present several limitations. Further, they do not adapt overall to individual characteristics. In this talk, I will give an account of deep-behavioral phenotyping strategies, namely data-driven methods in large task-fMRI datasets, to optimize functional brain-data collection and improve inference of effects-of-interest related to mental processes. Key to this approach is the employment of fast multi-functional paradigms rich on features that can be well parametrized and, consequently, facilitate the creation of psycho-physiological constructs to be modelled with imaging data. Particular emphasis will be given to music stimuli when studying high-order cognitive mechanisms, due to their ecological nature and quality to enable complex behavior compounded by discrete entities. I will also discuss how deep-behavioral phenotyping and individualized models applied to neuroimaging data can better account for the subject-specific organization of domain-general cognitive systems in the human brain. Finally, the accumulation of functional brain signatures brings the possibility to clarify relationships among tasks and create a univocal link between brain systems and mental functions through: (1) the development of ontologies proposing an organization of cognitive processes; and (2) brain-network taxonomies describing functional specialization. To this end, tools to improve commensurability in cognitive science are necessary, such as public repositories, ontology-based platforms and automated meta-analysis tools. I will thus discuss some brain-atlasing resources currently under development, and their applicability in cognitive as well as clinical neuroscience.
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
Richard's entangled aventures in wonderlandRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
2. 21
5, 20
o- tol
p-Me
7, 8
17, 18
12, 13
2, 3
NH
m- tol
Figure. 1H NMR spectrum of 10,15-Ditolyl-21-carbachlorin 4 in CDCl3.
HR-MS(ESI+): m/z calcd for C35H29N3+ H+: 492.2440; found 492.2460
3. 3
Modified cucurbit[n]urils:
Synthesis and supramolecular interactions
Ph.D. Defense Presentation
Date: 1st October 2012
Place of work: Department of Chemistry,
Masaryk University Brno, Czech Republic
09/2006 - 09/2012
4. 4
Chemical structure of cucurbit[n]uril and the reactive sites of it’s modification?
Sites for functionalization
CB[n]: Cucurbit[n]uril
(n = 5-8, 10)
Glycoluril
(Building block of CB[n])
Cucurbit[6]uril
Peripheral (equatorial) position
Methylene bridge (axial) position
, 100°C,
24 h
1. Kim, J.; et. al. J. Am. Chem. Soc. 2000, 122, 540-541. 2
5. 5
1. Extremely low solubility in common organic/aqueous solvents
(except for aqueous solution of strong acids).
2. Problem of accessing CB[n] derivatives/analogues by tailor-made synthetic procedures
What are the limitations in the CB[n] chemistry ?
1. To prepare functionalized CB[n] compounds.
2. To improve their solubility in both aqueous and organic solvents.
3. To access their wide range of applications.
Why is modification of CB[n] compounds necessary ?
6. 6
Methods of preparing functionalized cucurbit[n]uril: Three possible routes
2. Kim, K.; et. al. Chem. Soc. Rev., 2007, 36, 267-279.
Route 1
Route 2
Direct method of
functionalization
Indirect method of
functionalization
Route 3
Indirect method of
functionalization
Substitution at the peripheral position
Substitution at the CH2 bridge position
(so far found to be unsuccessful)
Substitution at the peripheral position
7. 7
Research aims of this dissertation work
Two major projects
Project 1
Synthesis and separation of new
monosubstituted CB[6]
compounds modified at the CH2
bridge (axial) position.
Project 2
Synthesis, purification and supramolecular interactions of a water soluble CB[6] derivative,
namely, hexamethylcucurbit[6]uril (MeCB[6]).
Here, different pyridinium guests (G1, G3, G4) were used to study their supramolecular
complexations with the MeCB[6] macrocycle both in the solution and solid state.
8. Scheme. Reaction Scheme for Synthesis of Monosubstituted CB[6]
Figure. X-ray crystal structure of Monosubstituted CB[6]
3. L. Gilberg, M. Shamsul Azim Khan, M. Enderesova, V.Sindelar. Organic Letters, 16 (9), 2446-2449, 2014.
Project 1: Synthesis of monosubstituted CB[6]
(0.2%)
10. 10
Project 2: Synthesis of hexamethylcucurbit[6]uril (MeCB[6]) and its
supramolecular interactions with different pyridinium guests
4. Khan, M.S.A.; Heger, D., Necas, M.; Sindelar, V. J. Phys. Chem B. 2009, 113, 11054-11057.
X-ray crystal structure of MeCB[6]•acetone•19H2O complex
The “acetone molecule” was not
possible to remove completely
from MeCB[6] cavity even after
drying at 100 °C for 24 h.
11. 11
Figure. 1H NMR spectrum (500 MHz, D2O) of pure hexamethylcucurbit[6]uril, MeCB[6].
4. Khan, M.S.A.; Heger, D., Necas, M.; Sindelar, V. J. Phys. Chem B. 2009, 113, 11054-11057.
12. 12
Supramolecular interactions of MeCB[6] with pyridinium guests (G1, G3, G4)
Two different modes of interaction between MeCB[6] and the pyridinium guests were
studied
1. Binding mode in the solid state (using X-ray crystallography)
2. Binding mode in the solution using
a) 1H NMR titration method
b) UV-vis spectrophotometric titration method
13. 13
Supramolecular interactions of MeCB[6] with methylviologen (MeV2+ = G1) guest
4. Khan, M.S.A.; Heger, D., Necas, M.; Sindelar, V. J. Phys. Chem B. 2009, 113, 11054-11057.
Binding mode between MeCB[6] and MeV2+in the pure D2O solution: 1H NMR fast exchange kinetics
NN CH3
CH3
+ +
Crystal preparation of
MeCB[6]•MeV2+•8H2O complex
Slow evaporation of aqueous
solution of the host and guest in 1:1
ratio resulted X-ray quality single
crystals.
Binding mode between MeCB[6] and MeV2+in solid state: X-ray crystallography - wireframe model
Methyl protons of MeV2+ (red ●), MeCB[6] (green ▲), and acetone (blue ♦).
α β
β
α
β α
α β
(A)
(B)
(C)
Free MeV2+
0.5 : 1
1 : 1
MeCB[6]: MeV2+
14. 14
Determination of binding constants (K / M-1) for the complexation between MeCB[6] and
methylviologen (MeV2+) guest : UV-vis spectrophotometric titration method
4. Khan, M.S.A.; Heger, D., Necas, M.; Sindelar, V. J. Phys. Chem B. 2009, 113, 11054-11057.
Figure. Electronic absorption spectrum of the
complexation between MeV2+ and MeCB[6] in
pure water.
P S I - P l o t W o r k i n g D e m
w w w . p o l y s o f t w a r e . c o m
P S I - P l o t W o r
w w w . p o l y s o f
P S I - P l o t W o r k i n g D e m
w w w . p o l y s o f t w a r e . c o m
P S I - P l o t W o r
w w w . p o l y s o f
P S I - P l o t W o r k i n g
w w w . p o l y s o f t w a r e
P S I - P l o t
w w w . p o l
P S I - P l o t W o r k i n g
w w w . p o l y s o f t w a r e
P S I - P l o t
w w w . p o l
Legend
0.1mM NaCl
fit1
0.5mM
fit2
1mM
fit3
3mM
fit4
5mM
fit5
10mM
fit6
20mM
fit7
P S I - P l o t W o r k i n g D e m o
w w w . p o l y s o f t w a r e . c o m
P S I - P l o t W o r k i n g D e m o
w w w . p o l y s o f t w a r e . c o m
P S I - P l o t W o r k i n g D e m o
w w w . p o l y s o f t w a r e . c o m
P S I - P l o t W o r k i n g D e m o
w w w . p o l y s o f t w a r e . c o m
P S I - P l o t W o r k i n g D e m o
w w w . p o l y s o f t w a r e . c o m
P S I - P l o t W o r k i n g D e m o
w w w . p o l y s o f t w a r e . c o m
P S I - P l o t W o r k i n g D e m o
w w w . p o l y s o f t w a r e . c o m
P S I - P l o t W o r k i n g D e m o
w w w . p o l y s o f t w a r e . c o m
c(MeCB[6]) in mol / L
0.0000 0.0001 0.0002 0.0003 0.0004
Absorbanceat257nm(a.u.)
0.40
0.45
0.50
0.55
0.60
0.65
0.70
0.75
0.80
Effect of NaCl on the binding constant K
Figure. Fitting of the absorbance data for the 1:1 complex
formation between MeV2+ and MeCB[6].
257 nm
K = (2.05 ± 0.21) × 105 M-1
MeCB[6]
concentration
increases
15. Table: Values of Association Constants of the MeCB[6]-MeV2+ Complex (KMeCB[6]) and the
CB[7]-MeV2+ Complex (KCB[7]): UV-vis Spectrophotometric and 1H-NMR Titration methods
4. Khan, M.S.A.; Heger, D., Necas, M.; Sindelar, V. J. Phys. Chem B. 2009, 113, 11054-11057.
NaCl/mM KMeCB[6] / M-1 KCB[7] / M-1
0 (1.23 ± 0.15) × 105c Ndd
0 (2.05 ± 0.21) × 105 (1.68 ± 0.30) × 106
0.1 (1.97 ± 0.13) × 105 ndd
0.2 (1.03 ± 0.06) × 105 ndd
0.4 (6.85 ± 0.43) × 104 ndd
0.5 (7.17 ± 0.45) × 104 ndd
0.8 (3.15 ± 0.28) × 104 ndd
1 (2.84 ± 0.31) × 104 ndd
2 (2.47 ± 0.21) × 104 ndd
3 (1.17 ± 0.12) × 104 ndd
5 (3.76 ± 0.35) × 103 ndd
10 (2.15 ± 0.20) × 103 (8.3 ± 1.8) × 105
20 (7.6 ± 1.4) × 102 ndd
30 (3.02 ± 0.55) × 102 ndd
40 (1.25 ± 0.63) × 102 ndd
50 (1.00 ± 0.67) × 102 (3.45 ± 0.52) × 105
100 nbb (1.49 ± 0.16) × 105
200 (6.0 ± 2.5) × 101c (9.4 ± 1.0) × 104
a The standard deviation of the fit is given for each measurement. b K not obtained by
UV-vis spectroscopy. c Determined by 1H NMR titration. d Not measured.
CB[7]•MeV2+ complex
NN CH3
CH3
+ +
MeCB[6]•MeV2+ complex
> 2000-fold
decrease
only 5-fold
decrease
17. Collaborative project: Deprotection of propylene bridged glycoluril dimer
6. Stancl, M.; Khan, M.S.A.; Sindelar, V. Tetrahedron, 2011, 67, 8937-8941.
Figure. Chemical structures of mono- (A), di- (B), tri- (C) and tetra- (D) hydroxy- bis(propylene)glycoluril dimers.
N N
NN
O
O
N N
NN
O
O
NH N
NNH
O
O
N NH
NHN
O
O
K2
S2
O8
/ H2
O
(Glycoluril dimer, Yield: 37.4 %)Bis(propylene)glycoluril dimer
N2 atm / 78°C, 6h
Characterization: 1H, 13C NMR (d6-DMSO) spectroscopy and HRMS (ESI+)
18. 0,1
0,15
0,2
0,25
0,3
0,35
0 0,00001 0,00002 0,00003 0,00004 0,00005
Conc. of CB6 / M
Absorbanceat317nm
CB6·2 complex (1:1) at 0.05 M NaCl
K = (2.1 ± 0.2) × 106 M-1
UV-vis titration method
Figure. 1H NMR spectra (300 MHz, 0.05 M NaCl-D2O)
5. Kolman, V.; Khan, M.S. A.; Babinský, M.; Marek, R.; Sindelar, V. Org. Lett. 2011, 13, 6148-6151.
Guest G4
0.5 : 1
1 : 1
CB6●2
Slow exchange process in the 1H NMR time scale
Collaborative project: Supramolecular shuttle based on CB6 and guest 2 (BPE)
Figure. Structures of synthesized host (CB6)
and guest 2 (BPE).
19. Calix[n]phyrin chemistry
Place of work: (current position- Postdoctoral fellow)
University of Chemical Technology Prague, Czech Republic
05/2013 - 06/2015
20. 1. Synthesis of calix[n]phyrin conjugates with Tröger's bases (TB).
2. sensing of cations /anions of the synthesized compounds.
Research goals
Calix[4]phyrin-TB conjugate
V shape
24. 2 x NH
18 x CH: TB
8 x CH: pyrrole
6 x CH2: CB
4 x CH3
3 x NH
27 x CH: TB
12 x CH: pyrrole
9 x CH2: TB
6 x CH3
A) TB-calix[4]phyrin, 8a
B) TB-calix[6]phyrin, 8b
Compound 8a: HRMS-ESI+: for [M+H]+ (C62H53N8) calcd: 909.44; found 909.44 and for
[M+2H]2+ (C62H54N8) calcd: 455.22; found 455.22
Compound 8b: HRMS-ESI+: for [M+H]+ (C93H79N12) calcd: 1364.66; found 1364.66 and for
[M+2H]2+ (C93H80N12) calcd: 682.83; found 682.83
28. Cyclodextrin chemistry - dimerization of cyclodextrins
Place of work: (Position- Research assistant)
Institute of Organic Chemistry and Biochemistry, Prague,
Academy of Sciences of the Czech Republic
08/2011 - 12/2012
29. Concept: Duplex Cyclodextrins Connected with Reversible Linkages
Guest
Duplex CD
Cleavage by external stimuli
Guest
release
31. • Synthesis of cyclodextrin homoduplexes and heteroduplexes linked by disulfide bonds
Cyclodextrin Duplexes Linked by Disulfide Bonds - Outline
• Dynamic exchange of building blocks in the presence of a guest (template effect)
• Thermodynamic stabilities of inclusion complexes with organic molecules
• Cleavage of disulfide bonds by reducing thiols
• Applications in supramolecular / material chemistry
32. 5 steps, 69 %
5 steps, 65 %
J. Org. Chem. 2009, 74, 1082.
α-CD
O
OH
OHO
O
OH
OH
AcS O
O OH
OH
OH
O
O
O
OH
OH
O
OH
OH
SAcO
OOH
OH
OH
O
OH
OH
β-CD
O
OH
OH
O
O
OH
OHAcS
O
O
OH
OH
OH
O
O
OH
OH
OOH
OH
SAc
O
O
OH
OH
OH
O
OH
OH
O
OHOH
OH
O
O
Starting Cyclodextrin Disulfanyl Building Blocks
Figure. Gradient parameters for the elution of the mixture reaction of
β-cyclodextrin heteroduplex formation (volume of each collected fraction was 39 ml).
= =
33.
34.
35. Synthesis of 3-hydroxyadamantane-1-acetamidohexanol in dry DMF
Figure. Chromatograms of βCD-
heteroduplex: A) in equimolar
mixture with the template (guest),
and for the synthesis of βCD-
heteroduplex B) without template,
and C) with template. The solvent
system in HPLC analysis was 22-60%
MeOH-water (30 min).
A
B
C
Host : template; 1:1
Host: no template
Host: with template