Dibromodiphenylstannane: isolated centrosymmetric dimers as a new structure motif for the intermolecular association of diorganotin(IV) dihalides

Abstract

In the crystalline state, the low-melting title compound [common name: diphenyltin(IV) dibromide], [SnBr2(C6H5)2], consists of distorted tetrahedral molecules with compressed halide and enlarged carbon opening angles of 102.741 (9) and 123.53 (8)degrees, respectively, and SnC and SnBr bond lengths of 2.109 (2)/2.113 (2) and 2.4710 (3)/2.4947 (3) angstrom, respectively. Intermolecular Sn...Br interactions, typical for diorganotin(IV) dihalides, R2SnHal2 (with Hal = Cl, Br, I), and sterically less demanding organic groups lead to the formation of a hitherto unknown association pattern consisting of centrosymmetric dimers with an antiparallel orientation of the dipole moments and two weak intermolecular Sn...Br distances of 3.8482 (3) angstrom between one of the two Br atoms and its neighbouring Sn atom, and vice versa. The second Br atom is not involved in intermolecular interactions and lies somewhat outside the association plane that, therefore, is not coplanar [interplanar angle = 1.750 (2)degrees] with the tinhalide plane. The new structure motif of intermolecular tinhalide interaction can be classified as 2ai, which indicates the number of molecules (i.e. `2') composing the oligomer, the antiparallel orientation (i.e. `a') of their dipole moments and the centre of symmetry (i.e. `i') giving rise to the association pattern.