1,3-Dimethoxy-1,3-dimethyl-1,3-diphenyl- and 1,3-dimethoxy-1,3-tetraphenyldisiloxanes: synthesis and structure

Russian Chemical Bulletin - 1,3-Dimethoxy- 1,3-dimethyl- 1,3-diphenyl- and 1,3-dimethoxy- 1,3-tetraphenyldisiloxanes were synthesized. Their structures were confirmed by IR and NMR spectroscopy....     

Molecular structure of complexes with bifurcated hydrogen bond: IV. Solvate H-complexes of <Emphasis Type="Italic">N</Emphasis>-methyltrifluoromethanesulfonamide in aprotic protophilic media

Analysis of the IR spectra of N-methyltrifluoromethanesulfonamide, as well as quantum-chemical calculations of solvate complexes of its monomer and open-chain dimer have demonstrated inadequacy of the model assuming the presence in protophilic solvents of a 1:1 monomer H-complex only. A model is suggested, which is based on an equilibrium between the 1:1 monomer H-complexes and open-chain dimer complexes of variable composition. The proposed model is much better consistent with experimental data.     

Synthesis of N-[chloro(diorganyl)silyl]anilines

A series of N-[chloro(diorganyl)silyl]anilines RR′Si(NR″Ph)Cl (R, R′ = Me, Ph, CH₂=CH, ClCH₂, Cl(CH₂)₃; R″ = H, Me) was prepared via the reaction of diorganyldichlorosilanes with aniline or N-ethylaniline in the presence of triethylamine.     

Structure of the molecule of 1,2-Bis(1-ethyl-1<Emphasis Type="Italic">H</Emphasis>-1,2,3-triazol-4-yl)diazene 1-oxide in the crystal and in solutions

Reduction of 4-nitro-1-ethyl-1H-1,2,3-triazole with aluminum in alkaline medium resulted in a syn-isomer of 1,2-bis(1-ethyl-1H-1,2,3-triazol-4-yl)diazene 1-oxide. The latter according to the data of X-ray diffraction analysis existed in the crystal as the most stable s-cis,s-trans-conformer, and in solution, as showed NMR data, as a mixture of s-cis,s-trans- and s-trans,s-trans-conformers. The data of quantum-chemical calculations are in agreement with the results of the structural studies.     

Structure of bis(trifluoromethanesulfonyl)imide in inert and protophilic media

According to the data of IR spectroscopy, dielectrometry, and HF/6-31G**, B3LYP/6-311G** quantum chemical calculations bis(trifluoromethanesulfonyl)imide (CF₃SO₂)₂NH in nonpolar medium (CCl₄) exists as an H-complex formed by its molecules in two tautomeric (NH and OH) forms. In a polar medium (CH₂C1₂) linear chain polyassociates with a bifurcate hydrogen bond are formed similar to those existing in the crystal. In the presence of protophilic solvents ion pairs consisting of the protonated molecule of the base and dimeric anion of bis(trifluoromethanesulfonyl)imide are formed.