Lewis acid stabilized group 13–15 element analogs of ethylene

Abstract

Stabilization of hydrogen‐substituted group 13–15 compounds H2EE′H2 (E = B, Al, Ga; E′ = P, As, Sb) by Lewis acids is considered at B3LYP/def2‐TZVP, B3LYP‐D3/def2‐TZVP and M06‐2X/def2‐TZVP levels of theory. It is shown, that for many Lewis acids additional reactivity beyond the DA complex formation with H2EE′H2 monomer is expected. In case of complexation with E(C6F5)3, F/H exchange reactions with group 13 bound hydrides are predicted to be exothermic and accompanied by the activation energies which are smaller than dissociation of the complex into components. In case of complex formation with transition metal (TM) carbonyls, additional O → Al, TM–C → Al interactions are observed, which in several cases lead to cyclic structures. The most promising candidates for the experimental studies have been identified. Synthetic approaches to the most promising LA‐only stabilized compounds are recommended.

Structures and Stability of Mixed Main Group Hydrides [PBEH6]n (E = C, Si, Ge; n = 1–4) and Donor–Acceptor Stabilization of Monomeric Chain Isomers

“…In complexes with the transition metal carbonyls, there is an additional bonding between acceptor atom of the chain hydride and carbonyl groups or the transition metal with formation of six-membered cycles for M­(CO) 5 (M = Cr, Mo, W) (Figure e) and four-membered cycles for Fe­(CO) 4 (Figure f). Similar additional interactions were reported for the LA-stabilized 13–15 hydrides. , …”

“…Similar additional interactions were reported for the LA-stabilized 13−15 hydrides. 35,36 The halogen atom migration (Figure 4c) is related to an effective interaction of F, Cl, and Br with SiH 2 LUMO with subsequent dissociation of one B−X bond, despite the fact that the Si−X bond energies are lower than those for B−X. 34 The boron environment becomes planar in this case.…”