Stannylenes: Structures, Electron Affinities, Ionization Energies, and Singlet–Triplet Gaps of SnX₂/SnXY and XSnR/SnR₂/RSnR′ Species (X; Y = H, F, Cl, Br, I, and R; R′ = CH₃, SiH₃, GeH₃, SnH₃)

Abstract

Systematic computational studies of stannylene derivatives SnX(2)/SnXY and XSnR/SnR(2)/RSnR' were carried out using density functional theory. The basis sets used for H, F, Cl, Br, C, Si, and Ge atoms are of double-ζ plus polarization quality with additional s- and p-type diffuse functions, denoted DZP++. For the iodine and tin atoms, the Stuttgart-Dresden basis sets, with relativistic small-core effective core potentials (ECP), are used. All geometries are fully optimized with three functionals (BHLYP, BLYP, and B3LYP). Harmonic vibrational wavenumber analyses are performed to evaluate zero-point energy corrections and to determine the nature of the stationary points located. Predicted are four types of neutral-anion separations, plus adiabatic ionization energies (E(IE)) and singlet-triplet energy gaps (ΔE(S-T)). The dependence of all three energetic properties upon choice of substituent is remarkably strong. The EA(ad(ZPVE)) values (eV) obtained with the B3LYP functional range from 0.70 eV [Sn(CH(3))(2)] to 2.36 eV [SnI(2)]. The computed E(IE) values lie between 7.33 eV [Sn(SnH(3))(2)] and 11.15 eV [SnF(2)], while the singlet-triplet splittings range from 0.60 eV [Sn(SnH(3))(2)] to 3.40 eV [SnF(2)]. The geometries and energetics compare satisfactorily with the few available experiments, while most of these species are investigated for the first time. Some unusual structures are encountered for the SnXI(+) (X = F, Cl, and Br) cations. The structural parameters and energetics are discussed and compared with the carbene, silylene, and germylene analogues.

Diatomic Silylynes, Germylynes, Stannylynes, and Plumbylynes: Structures, Dipole Moments, Dissociation Energies, and Quartet-Doublet Gaps of EH and EX (E = Si, Ge, Sn, Pb; X = F, Cl, Br, I)

“…Stannylynes have proved to be important in understanding new organometallic chemistry . However, isolated low-valence stannylynes R-Sn(I) are rarely observed since usually they are assumed to be unstable species.…”

Lewis Base Stabilized Group 14 Metalylenes

“…The chemistry of heavier group 14 elements has been developed due to the interest in comparative studies with the lighter congener carbon . In recent years, the highly reactive metalylenes (heavier group 14 element analogues of carbene) have attracted considerable attention due to their potential role in the development of advanced semiconductors, and in microelectronic engineering . In 1994, West et al isolated the first divalent dicoordinate N-heterocyclic silylene, which is comparable to the N-heterocyclic carbene reported by Arduengo et al in 1991.…”

Computational Thermochemistry of Mono- and Dinuclear Tin Alkyls Used in Vapor Deposition Processes

“…The 298 K, 1 atm enthalpies of formation, standard entropies of formation, and heat capacities of all tin-containing fragments are compiled in Table . Fragment species were generated based on known and predicted paths from experimental and theoretical studies of the decomposition of alkyltin molecules, ,, as well as from related studies of silicon compounds. , The molecules include saturated tin species in which hydrogen replaces methyl groups, e.g., Me 3 SnH, and unsaturated compounds such as stannylenes (R 2 Sn), , distannenes (R 2 SnSnR 2 ), , stannynes, H 2 Sn 2 , and radical species such R 3 Sn·. The thermochemical quantities for saturated (CH 4 and C 2 H 6 ) and unsaturated (C 2 H 4 and C 2 H 2 ) hydrocarbons, methyl radical (CH 3 ·), hydrogen, and atomic and diatomic tin were also calculated and are listed in the Supporting Information.…”