Diorganotin(IV) compounds containing 2-(Et2NCH2)C6H4 moieties: Configurational stability in solution and solid state structures

Hypercoordinated diorganotin(IV) dichloride, [2-(Et2NCH2)C6H4]2SnCl2 (1), was prepared by reacting [2-(Et2NCH2)C6H4]Li with SnCl4. Halide-exchange reactions between 1 and the appropriate potassium halides gave [2-(Et2NCH2)C6H4]2SnX2 [X = F (2), Br (3), I (4)]. Reaction of 1 with excess of Na2S gave the cyclo-[{2-(Et2NCH2)C6H4}2SnS]2 (5). The solution behavior of the title compounds in solution was investigated by multinuclear (1H, 13C, 19F and 119Sn) NMR spectroscopy, including variable temperature studies. Single-crystal X-ray diffraction analysis revealed for all compounds intramolecular N → Sn coordination thus resulting in distorted octahedral (C,N)2SnX2 configurations. Planar chirality is observed as result of the non-planarity of the SnC3N rings; all compounds, however, crystallizing as racemates. The isomers are linked by extensive hydrogen bonds to give different supramolecular architectures in the crystals of compounds 1, 3 and 4.