An extremely bulky boryl-amide ligand, [N(SiMe3){B(DAB)}](-) (TBoN; DAB = (DipNCH)2, Dip = C6H3Pr(i)2-2,6), has been utilised in the preparation of the first isolable, two-coordinate acyclic diaminosilylene (ADASi), viz. :Si(TBoN)2. This is shown to have a frontier orbital energy separation, and presumed level of reactivity, intermediate between those of the two classes of previously reported i...

The insertion reactions of CH,, CHF, CF2, SiH2, SiHF, and SiF2 into hydrogen molecule have been investigated by ab initio molecular orbital methods. Reactants, loose clusters, transition structures, and products were optimized at HF/3-21G and HF/6-3 1G*. For each structure, relative energies have been calculated at MP4SDQ/6-3 lG* and vibrational frequencies at HF/3-21G. A dramatic increase in t...

A kinetic isotope effect (kD/kH) of 7.4 has been found for the reaction of chlorosilylene with trimethysilane (Me3SiD vs Me3SiH). Such a value can be accounted for by theoretical modelling, but only if an internal rearrangement of the initially form complex is included in the mechanism. This provides the first concrete evidence for such complexes. The insertion reaction of silylenes into Si-H b...

Structures, vibrational frequencies, and energies for the chlorinated disilenes, their dibridged isomers, and the transition states connecting the chlorinated disilenes to the corresponding silylsilylenes are presented. Geometries and frequencies were obtained at the MP2/6-31G(d,p) level, and energetics were calculated at the G2, G2(MP2), MP4/6-31+G(2df,p), and/or MP2/6-31+G(2df,p) levels of th...

Product contamination by gas-phase nucleation within the processing environment often limits the deposition rate that can be obtained during chemical vapor deposition (CVD) of materials for microelectronics applications. A fundamental understanding of how these particles nucleate and grow may allow us to enlarge the process envelope, providing higher growth rates without particle contamination....

with the aim of recognizing the steric effects on the silylenic r2c6h6si structures, dft calculationsare carried out on 8 structures of r2c6h6si (where r is hydrogen (h), methyl (me), isopropyl (i-pro),and tert-butyl (tert-bu)). these species are at either triplet (t) or singlet (s) states. singlet–tripletenergy separations ( me (20.32) > t-bu (15.92).all singlet states of r2c6h6si, are more st...

We report singlet and triplet state splittings (I:J.EsT) for fluorine-substituted methylenes and silylenes using dissociation-consistent configuration interaction (CI) (based on generalized valence bond wave functions). These relatively simple CI calculations emphasize correlation consistency between the singlet and triplet states. Values of I:J.Esr for CH2, CF2, SiH2, and SiF2 are in excellent...

Recently synthesized acyclic silylenes have the potential to rival transition metal complexes in performing single site small molecule activation, which is significant because of the need to find cheap and green alternatives to transition metal complexes for this important class of reactions. However, the current computational study, a full quantum chemical investigation with density functional...

A variety of transition-metal complexes with terminal silylene ligands have become available in recent years, because of the discovery of several preparative methods. In particular, three general synthetic routes to these complexes have emerged, on the basis of anionic group abstraction, coordination of a free silylene, and alpha-hydrogen migration. The direct transformation of organosilanes to...