An experimental and quantum-chemical study of the Raman spectra and rotational isomerism of thiophosphites (RS) n PCl3 - N (R = Me, Et; N = 1, 2)

The Raman spectra of different conformations of CH3SPCl 2, C2H5SPCl2, and (C 2H5S)2PCl are studied within the framework of the density functional theory (B3LYP/6-31G*and B3LYP/6-31+G*) using the method of scaling of force fields. Comparison of the calculated and experimental spectra makes it possible to interpret the latter and to establish the existence of trans and gauche conformers of these molecules, which are formed due to internal rotation about the P-S and S-C bonds. This comparison also shows that, for the prediction of the degrees of depolarization of Raman lines to be correct, it is necessary to introduce diffuse functions into the basis set. © Nauka/Interperiodica 2006

Germylene complexes of tungsten pentacarbonyls W(CO)5{double bond, long}GeCl2 and W(CO)5{double bond, long}Ge{double bond, long}W(CO)5: Electrochemical synthesis and quantum-chemical computations

Convenient synthetic route to prepare the germylene complexes of tungsten pentacarbonyls, W(CO)5{double bond, long}GeCl2 and W(CO)5{double bond, long}Ge{double bond, long}W(CO)5, electrochemically is developed. Combined quantum-chemical/IR spectroscopic approach is used for identification of the synthesized compounds. Good agreement between theoretical and experimental spectra can be regarded as one of the proofs of their supposed structures. © 2007 Elsevier B.V. All rights reserved

First neutral dinuclear cobalt complex formed by bridging [μ-O2P(H)R]- ligands: Synthesis, X-ray crystal structure and quantum-chemical study

© 2015 Mendeleev Communications. Published by Elsevier B.V. The reaction of cobalt dibromide hexahydrate with 2,2′-bipyridine (bpy) and 9-anthrylphosphinic acid AntP(O)(OH)H (Ant = 9-anthryl) leads to the first example of a neutral dinuclear cobalt(ii) complex {Co2Br2[μ-O2P(H)Ant]2(bpy)2} formed by two bridging [μ-O2P(H)Ant]- ligands. The complex has been characterized by X-ray diffraction analysis and quantum-chemical calculations

Synthesis, X-ray crystal structure and quantum-chemical study of new dinuclear cobalt complex {Co2[mmm-O2P(H)Mes] 2(bpy)4}Br2

The reaction of cobalt dibromide hexahydrate with 2,2'-bipyridine (bpy) and mesitylphosphinic acid MesP(O)(OH)H (Mes = = 2,4,6-trimethylphenyl) under solvothermal synthesis conditions leads to a new dinuclear cobalt(ii) complex {Co2[μ-O2P(H)Mes]2- (bpy) 4}Br2 formed by two bridging {μ-O2P(H)Mes}- ligands. X-ray crystal structure analysis of the complex displayed that cobalt ions have distorted octahedral coordination and are doubly bridged by two mesitylphosphinato ligands. © 2013 Mendeleev Communications. All rights reserved

Spectroscopic studies of compounds containing a P —H bond: 4. Vibrational spectra and conformational multiformity of di- tert-butylphosphorous acid molecules

IR and Raman spectra of liquid di- tert-butylphosphorous acid and its two low-temperature crystalline modifications are studied. It is found that at least three stable conformations of acid molecules can exist in the liquid state. © 1995, Plenum Publishing Corporation. All rights reserved

Conformational analysis of mono-and bis(dimethoxyphosphoryl)benzenes

Conformational analysis of mono-and bis(dimethoxyphosphoryl)benzenes with substituents in the benzene ring was performed by the method of dipole moments, IR spectroscopy, and quantum-chemical calculations (DFT B3LYP/6-31G*). Comparison of all calculated and experimental data shows that the compounds studied exist as equilibrium mixtures of conformers with preferred gg orientation of the phosphoryl and methoxy groups. © Pleiades Publishing, Inc., 2006

IR and NMR spectra, intramolecular hydrogen bonding and conformations of para-tert-butyl-aminothiacalix[4]arene in solid state and chloroform solution

It is demonstrated that dissolution of aminothiacalix[4]arene in chloroform results in transformation of 1,3-alternate conformation, adopted in single-crystal and bulk polycrystalline solids, to the pinched-cone form. This conformer is stabilised by the intramolecular hydrogen bonds of two distal amino-groups acting as H-donors with another two amino moieties that appear as H-acceptors. The H-bonds cause quite small (ca. 10-20 cm-1) red shift of the IR bands of the NH2 stretching vibrations, which suggests rather weak NH⋯N hydrogen bonding. This latter is sufficient to stabilize the pinched-cone conformation in the chloroform solution, but the energy gap between the pinched-cone and other conformations is small, and solid-state intermolecular forces easily overcome it, leading to realisation of the 1,3-alternate conformer. The comparison of the DFT computed and experimental vibrational and NMR spectra demonstrates good quality of present quantum-chemical computations, allows complete interpretation of the spectra and reveals simple IR and NMR spectroscopic markers of the conformers of aminothiacalix[4]arenes. © 2009 Elsevier B.V. All rights reserved

Thermal stability of primary and secondary phosphine oxides formed as a reaction of phosphine oxide with ketones

© 2016 Taylor & Francis Group, LLC.We present the study of reactivity of electrochemically generated in situ from white phosphorus P4 phosphine oxide H3PO toward various ketones (acetone, methylethylketone, methyl-n-propylketone). This interaction was found to give a selective formation of mono- and bis-(α-oxyalkyl)phosphine oxides RRʹC(OH)P(O)H2 (1) and (RRʹC(OH))2P(O)H (2) where R = Me; Rʹ = Me, Et, n-Pr. Thermal properties of the formed primary and secondary phosphine oxides have been studied and quantum chemical calculations of thermodynamic stability of these compounds were performed

Complex formation of d-metal ions at the interface of Tb III-doped silica nanoparticles as a basis of substrate-responsive TbIII-centered luminescence

The complex formation of d-metal ions at the interface of Tb III-doped silica nanoparticles modified by amino groups is introduced as a route to sensing d-metal ions and some organic molecules. Diverse modes of surface modification (covalent and noncovalent) are used to fix amino groups onto the silica surface. The interfacial binding of d-metal ions and complexes is the reason for the TbIII-centered luminescence quenching. The regularities and mechanisms of quenching are estimated for the series of d-metal ions and their complexes with chelating ligands. The obtained results reveal the interfacial binding of CuII ions as the basis of their quantitative determination in the concentration range 0.1-2.5 μM by means of steady-state and time-resolved fluorescence measurements. The variation of chelating ligands results in a significant effect on the quenching regularities due to diverse binding modes (inner or outer sphere) between amino groups at the interface of nanoparticles and FeIII ions. The applicability of the steady-state and time-resolved fluorescence measurements to sense both Fe III ions and catechols in aqueous solution by means of Tb III-doped silica nanoparticles is also introduced. © 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim