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The density functional theory calculations are used to study the geometric and electronic structure of the new polymorph of tantalum oxynitride, [gamma]-TaON, and its structural stability. The results have shown that the new polymorph [gamma]-TaON is metastable and only 20 kJ/mol less stable when compared to the grDund-state [beta]-polymorph.

Research has been conducted on the Lewis acid-base (P (sub)4 E (sub)3).(BX (sub)3) (E= S, Se; X= Br, I) and (P (sub)4 Se (sub)3).(NbCl (sub)5) adducts. The preparation of these compounds and their characterization via the Raman, IR and solid-state (super)31 P MAS NMR spectroscopy have been carried out and the results are reported.

Research has been conducted on sodium dicyanamide NaC (sub)2 N (sub)3. The use of temperature-dependent X-ray powder diffractometry and thermal analysis is discussed.

Research has been conducted on the transition metal dicyanamides and coordination compounds. The synthesis of ammonium dicyanamide carried out via the aqueous ion exchange is described.

The production of a single-phase melem (2,5,8-triamino-tri-s-triazine) as a crystalline powder by thermal treatment of C-N-H compounds is described. The structural and vibrational properties of the melem are studied using X-ray powder diffractometry, solid-state NMR, and various theoretical studies.

Investigates the solid-state trimerization of sodium dicyanamide using X-ray powder diffractometry. Phases of transitions of the sodium dicyanamide; Crystallization of the sodium dicyanamide in a monoclinic system; Occurrence of the reconstructive phase transition in the solid-state without involvement of intermediates.

An enantio- and diastereoselective Cu-H-catalyzed silylation of acyclic secondary alcohols with a vicinal quaternary stereocenter is reported. The reaction kinetically selects one out of four stereoisomers, affording the fastest-reacting stereoisomer as the silyl ether in enantio- and diastereomerically enriched form. The obtained motif with a quaternary carbon atom in the β-position of the hydroxy group is otherwise not easy to access., Competing Interests: The authors declare no competing financial interest., (© 2021 The Authors. Published by American Chemical Society.)

A copper-catalyzed nucleophilic displacement of α-triflyloxy nitriles and esters with silicon nucleophiles allows for the stereospecific generation of highly enantioenriched α-silylated carboxyl compounds. The enantioselective synthesis of α-silylated nitriles is unprecedented. The catalytic system exhibits good functional group tolerance. The stereochemical course of the substitution is shown to proceed with inversion of the configuration. The new reaction is an addition to the still limited number of methods for catalytic C(sp 3 )-Si cross-coupling.

The first N-donor-stabilized phosphasilene LSi(SiMe(3))═PSiMe(3) (L = PhC(NtBu)(2)) has been synthesized in 87% yield through 1,2-silyl migration of the (Me(3)Si)(2)P-substituted, N-heterocyclic silylene [LSi-P(SiMe(3))(2)]. Remarkably, the latter reacts with dichlorotriphenylphosphorane Ph(3)PCl(2) to give the unprecedented 4π-electron Si(2)P(2)-cycloheterobutadiene [(LSi)(2)P(2)] with two-coordinate phosphorus atoms. The striking molecular structures as well as the (29)Si and (31)P NMR spectroscopic features of both products indicate the presence of zwitterionic Si═P bonds which is also in accordance with results by DFT calculations.