A5019406946- Crystallography and molecular interactions
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Supramolecular Chemistry and Complexes
- Metal complexes synthesis and properties
- X-ray Spectroscopy and Fluorescence Analysis
- Molecular Sensors and Ion Detection
- Advanced Chemical Physics Studies
- Analytical Methods in Pharmaceuticals
- Lanthanide and Transition Metal Complexes
- Electron and X-Ray Spectroscopy Techniques
- Drug Solubulity and Delivery Systems
- Synthesis and Biological Evaluation
- Advanced NMR Techniques and Applications
- Analytical Chemistry and Chromatography
- DNA and Nucleic Acid Chemistry
- Organic Light-Emitting Diodes Research
- Surfactants and Colloidal Systems
- Chemical Synthesis and Analysis
- Nanocluster Synthesis and Applications
- Carbohydrate Chemistry and Synthesis
- Metal-Catalyzed Oxygenation Mechanisms
- Advanced biosensing and bioanalysis techniques
- Ferrocene Chemistry and Applications
- Inorganic Fluorides and Related Compounds
Swami Ramanand Teerth Marathwada University
2010-2024
Institute of Chemical Technology
2023-2024
Sanskriti Samvardhan Mandal
2017-2020
Dr. Babasaheb Ambedkar Marathwada University
2018-2020
Uppsala University
2014-2016
Savitribai Phule Pune University
2006-2013
The metal L-edge (2p → 3d) X-ray absorption spectra are affected by a number of different interactions: electron-electron repulsion, spin-orbit coupling, and charge transfer between ligands, which makes the simulation challenging. core restricted active space (RAS) method is an accurate flexible approach that can be used to calculate wide range medium-sized systems without any symmetry constraints. Here, applicability tested in detail simulating three ferric (3d(5)) model with well-known...
The valence-excited states of ferric and ferrous hexacyanide ions in aqueous solution were mapped by resonant inelastic X-ray scattering (RIXS) at the Fe L2,3 N K edges. Probing both central ligand atoms enabled identification metal- ligand-centered excited states, as well ligand-to-metal metal-to-ligand charge-transfer states. Ab initio calculations utilizing RASPT2 method used to simulate L2,3-edge RIXS spectra quantification covalencies occupied empty orbitals π σ symmetry. We found that...
The intensities and relative energies of metal K pre-edge features are sensitive to both geometric electronic structures.
The restricted active-space (RAS) approach can accurately simulate metal L-edge X-ray absorption spectra of first-row transition complexes without the use any fitting parameters. These characteristics provide a unique capability to identify unknown chemical species and analyze their electronic structure. To find best balance between cost accuracy, sensitivity simulated with respect method variables has been tested for two models, [FeCl6 ](3-) [Fe(CN)6 . For these systems, reference...
New bicyclic conidine iminosugars 1d and 1e were synthesized from D-glucose. Thus, D-glucose was converted to sugar β-amino acids 3a 3b in good yields. Individual treatment of 3a/3b with the Mukaiyama reagent afforded β-lactams 4a/4b that on reduction LiAlH4/AlCl3 gave azetidines 5a/5b a appendage. Reductive aminocyclization corresponding 1d/1e. Based 1H NMR DFT calculation studies conformation assigned as half chair A2 boat B2. The glycosidase inhibitory activities such α-mannosidase,...
Electronic structure and molecular electrostatic potential (MESP) in ferrocene (FC), cucurbit[n]urils (CB[n]) with n = 5-8, their host-guest complexes are obtained within the framework of density functional theory. MESP topography that is employed to gauge dimensions CB[n] cavity estimates height increases from 7.25 7.70 A along homologue series, whereas diameter CB[8] (8.57 A) larger than twice CB[5] (3.91 A). investigations reveal deeper minima near ureido oxygens large electron-rich...
For first-row transition metals, high-resolution 3d electronic structure information can be obtained using resonant inelastic X-ray scattering (RIXS). In the hard region, a K pre-edge (1s→3d) excitation followed by monitoring dipole-allowed Kα (2p→1s) or Kβ (3p→1s) emission, processes labeled 1s2p 1s3p RIXS. Here restricted active space (RAS) approach, which is molecular orbital method, used for first time to study RIXS processes. This achieved including two sets of core orbitals in...
Cyclodextrins (CDs) are cyclic oligomers of glucose having the toroid sugars elaborating a central cavity varying size depending on number glucoses. The hydrophobic CD shows binding affinity toward different guest molecules, which include small substituted benzenes to long chain surfactant molecules leading variety inclusion complexes when and shape complimentarity host compatible. Further, interaction with outer surface α-CD has also been observed. Primarily it is electrostatic interactions...
Electronic structure, charge distribution, and vibrational frequencies of cucurbit[n]uril, CB[n] (n = 5-12), hosts have been derived using the density functional methods. conformers with different orientations methylene group connecting glycouril units investigated. The that possess uniform cavity turn out to be lowest energy, molecular electrostatic potential (MESP) herein engender shallow minima near ureido oxygens along series. MESP topography has utilized estimate height diameter; ratio...
Hydrogen-bonded interactions in α-, β-, and γ-CD conformers are investigated from the molecular electron density topography chemical shift nuclear magnetic resonance (NMR) spectra calculated by using Gauge Invariant Atomic Orbital (GIAO) method within framework of functional theory. For lowest-energy CD gas phase, O3−H···O2' hydrogen-bonding present. Calculated 1H NMR shifts (δH) correlate well with hydrogen-bond distance as at bond critical point (MED) topography. The β- comprised...
The capability of the multiconfigurational restricted active space approach to identify electronic structure from spectral fingerprints is explored by applying it iron L-edge X-ray absorption spectroscopy (XAS) three heme systems that represent limiting descriptions in Fe–O2 bond, ferrous and ferric [Fe(P)(ImH)2]0/1+ (P = porphine, ImH imidazole), FeII(P). level agreement between experimental simulated shapes calculated using cosine similarity, which gives a quantitative unbiased assignment....
Inverted cucurbit[n]uril (i(x)CB[n], x = 1, 2; n 6-8), the enantiomers of (CB[n]) comprising one or more inverted glycouril units, show distinct selectivity in recognition toward guest by virtue shape and dimensions its cavity. The iCB[n] (x 1 6, 7) are isolated as intermediates during synthesis CB[n]. In this work, density functional theory using hybrid B3LYP has been employed to derive electronic structure NMR chemical shifts i(x)CB[n] hosts. present calculations have shown that inversion...
Host-guest interactions between β-cyclodextrin (β-CD) and flavan-3-Ol enantiomers (guest) namely, (+)-catechin (CA) or (−)-epicatechin (EC), have been analyzed within the framework of density functional theory. Both CA EC consist two phenol rings, I II, a pyran ring, III, which facilitate variety binding patterns with host, β-CD. The minimum energy β-CD−CA complex reveals that ring II interacts primary hydroxyls upper rim engenders hydrogen-bonded secondary hydroxyl from lower CD. On other...
Interactions of sulfur hexafluoride (SF(6)) with cucurbit[6]uril (CB[6]) have been investigated using the density functional calculations. An encapsulation guest within CB[6] cavity as well its binding to either exterior host protons or portal uredio oxygens analyzed. The present calculations predict that complexes complete inclusion SF(6) are favored over those possessing lateral external interactions. interactions between fluorine and ureido carbons (F---C) contribute lowering energy...
Electronic structure, molecular electrostatic potential, and vibrational frequencies of para-substituted calix[n]arene CX[n]-R (n = 4, 5; R H, NH(2), t-Bu, CH(2)Cl, SO(3)H, NO(2)) their thia analogs (S-CX[n]-R; with H t-Bu) in which sulfur bridges two aromatic rings CX[n] have been derived from the density functional theory. A rotation around CH(2) groups connecting phenol engenders four, namely, cone, partial 1,2-alternate, 1,3-alternate conformers. Of these, cone conformer comprising large...
Two new luminescent ruthenium(II) polypyridyl complexes, [Ru(bpy)2 (tpt-phen)]Cl2 (1; bpy=2,2'-bipyridine, tpt-phen=triptycenyl-1,10-phenanthroline) and [Ru(phen)2 (2; phen=1,10-phenanthroline), have been developed as potential nonviral vectors for DNA delivery. Photophysical electrochemical properties of the complexes investigated corroborated with electronic structure calculations. condensation by these has UV/Vis emission spectroscopy, circular dichroism atomic force microscopy, dynamic...
Synthesis of the first selenium containing quinoline probe, selective for superoxide detection via “turn-on” fluorescence response. The probe exhibited better anticancer activity than cisplatin.
Binding patterns and (1)H NMR chemical shifts in the complexes of protonated N-(4-hydroxylphenyl)imidazole (g1), N-(4-aminophenyl)imidazole (g2), 2-phenylimidazole (g3) guests with cucurbit[6]uril (CB[6]), sym-substituted tetramethyl (TMeCB[6]) gas phase as well water have been investigated using density functional theory. It has shown that inclusion g1 g2 CB[6] or TMeCB[6] exhibit selective encapsulation phenyl moiety its substituents binding to portal oxygens on lower rim host imidazole...