The Mechanism of 1,2-Addition of Disilene and Silene: Hydrogen Halide Addition Part 2; for Part 1 see: T. Veszprémi, M. Takahashi, B. Hajgató, M. Kira, J. Am. Chem. Soc. 2001, 123, 6629.

Quantum Chemical Characterization of theX̃(1A′),ã(3A′′) andÃ(1A′′) States of CHBr and CHI and Computed Heats of Formation for CHI and CI†

“…The computed geometries and frequencies of CHBr and CHI areconsistentwithwhatisalreadyintheliterature,experimental 6,15-22 and theoretical. 13,14,17,[20][21][22][49][50][51] The computed singlet-triplet splitting of 5.73 kcal mol -1 for CHBr is in excellent agreement with the latest experimental values: 5.80 17 and 5.64 52 kcal mol -1 , as well as the theoretical value of Dixon et al, 13 once the latter is corrected for zero point vibrations. The analogous quantity in CHI was computed to be 3.70 kcal mol -1 , which is in good agreement with the recent experimental lower bounds of 3.76 21 and 4.1 22 kcal mol -1 .…”

Molecular Structure of Carbene Analogues: A Computational Study

“…This assumption was made in some of the earlier studies as well. 11,12 In the first series of calculations (CCSD(T)/EC) the same or similar basis sets and effective core potentials were used as the ones in refs 14-17 (MRSDCI/EC), to see the difference produced by the different theoretical approaches, excluding effects coming from the basis set. Thus, from the fourth period on, the relativistic ECPs of Christiansen et al were used, [20][21][22] both on the central atom and the ligand, retaining the outermost s 2 p 2 and s 2 p 5 shells, respectively.…”

“…We ignored zero point energy (ZPE) correction, because its effect is shown to be smaller than the basis set effects or the effects due to the different approximations of the different theoretical approaches; 12 consequently, the ZPE correction is not expected to alter the observed trends.…”

“…8 The experimental singlet-triplet gap of CCl 2 reported by Lineberger and co-workers 9 has initiated further investigations such as the one of Barden and Schaefer, 10 Lee et al, 11 Hajgató et al, 12 and Hargittai et al 13 The above works vary much in the sophistication of the theory and the dimension of the basis set. Thus, the large number of computational data of various accuracies on the different AX 2 molecules makes it hard to draw conclusions on the variation of structural parameters.…”

“…Especially methylene [2][3][4] and its halogen derivatives [5][6][7][8][9][10][11][12][13] have received much interest recently by computations, whereas relatively fewer studies appeared on the heavier analogues (i.e., substituting carbon by other members of its group). [14][15][16][17][18] Focusing mainly on relativistic effects, Balasubramanian and co-workers performed systematic studies on AX 2 molecules, A ) Ge, Sn, Pb, X ) H, F, Cl, Br, I, during the 1990s.…”