Structural Organozinc Chemistry

Abstract

Introduction Organozincates Dialkyl‐ and Diarylzinc Compounds Heteroleptic RZn Y Compounds Organozinc Compounds Containing a Zinc–Transition Metal Bond Conclusions

Structural Diversity of Coordination Cores in Homoleptic Tetraaryltin(IV) Dioxolane, Aldehyde and Imines: The First Octacoordinated Double Helicate Tetraorganotin(IV) Compound

“…The magnitude of the 119 -133.2 ppm). [22] For compounds 3-5, the 119 Sn chemical shifts are comparable to that reported for [2-(Me 2 NCH 2 C 6 H 4 )] 4 Sn (δ = -144 ppm), [16] taking into account the differences in the nature of the pendant arm and in the coordination number.…”

“…The molecular structures of homoleptic tetraaryltin(IV) compounds 1-5 feature some common patterns: (1) The C 4 Sn core is distorted tetrahedral, and the distortion results from the combined effects of the intramolecular coordination of the heteroatoms from the pendant arms to tin and the steric impediments imposed by the aryl ligands. (2) At least two heteroatoms (O for 1a and 2; N for 3, 4 and 5a) are coordinated intramolecularly to the metal centre, which results in the hypervalent organotin(IV) species.…”

“…(2) At least two heteroatoms (O for 1a and 2; N for 3, 4 and 5a) are coordinated intramolecularly to the metal centre, which results in the hypervalent organotin(IV) species. (3) All intramolecular EǞSn (E = O, N) interactions are directed on a vector almost trans to a Sn-C bond, which thus brings the donor E atom into a capping position with respect to a trigonal face of the tetrahedral C 4 Sn core. The coordination numbers at the tin atom are thus increased from four to six for 1a and 4, to seven for 3 and 5a and to eight for 2.…”

“…[17] This results in different coordination environments of the metal centre, that is, distorted dicapped tetrahedron (C,O) 2 SnC 2 core in 1a (hypervalent 12-Sn-6 species), [18] in which only two oxygen atoms form OǞSn intramolecular interactions, and distorted tetracapped tetrahedron (C,O) 4 Sn core in 2 (hypervalent 16-Sn-8 species), in which all four oxygen atoms coordinate the tin atom (see also the Supporting Information). The shorter OǞSn interaction distances for 1a compared to those of 2 (see Tables 1 and 2) reflect the slightly stronger Lewis acid character of the hexacoordinate tin in 1a compared to the octacoordinated tin present in 2.…”

“…[1] There are few other reports on organotin species containing other related monoanionic ligands with an sp 3 -nitrogen atom in the pendant arm, that is, 2-(Et 2 NCH 2 )C 6 H 4 [2] or 2-[Me 2 NCH-(R)]C 6 H 4 (R = Me, [3] tBu [4] ). Notably, the 2,6-(Me 2 -NCH 2 ) 2 C 6 H 3 group, which usually acts as a "pincer" N,C,N ligand, [5] can also act as a C,N ligand if the nitrogen atom of one pendant arm is protonated or if crowding around the metal prevents coordination of both nitrogen atoms to the tin atom.…”