Synthesis and structures of halides and pseudohalides of bis[2,6-bis(dimethylamino)phenyl]tin(iv)

Abstract

Oxidative addition reactions of Sn{C₆H₃(NMe₂)₂-2,6}₂ [≡ Sn(Ar^N2)₂] (1) with XeF₂, HgCl₂ or TeCl₄, dabco·2Br₂, I₂, or SiMe₃N₃ afforded [Sn(Ar^N2)₂F₂] (3), [Sn(Ar^N2)₂Cl₂] (4), [Sn(Ar^N2)₂Br₂] (5), [Sn(Ar^N2)₂I₂] (6), or [Sn(Ar^N2)₂{N(SiMe₃)₂}N₃] (7), respectively. Compound 3 was also obtained from 6 and aqueous KF. Treatment of 4, under phase transfer conditions using [NBnEt₃]Cl in H₂O, with NaN₃, KOCN, or KSCN yielded [Sn(Ar^N2)₂(N₃)₂] (8), [Sn(Ar^N2)₂(NCO)₂] (9), or [Sn(Ar^N2)₂(NCS)₂] (10), respectively. Alternative pathways to 7 are suggested. Excellent (3–7, 9 and 10) and satisfactory (8) yields were recorded; each compound was characterised by C, H, N microanalysis, mass spectra and multinuclear NMR solution spectra at ambient temperature, which invariably showed equivalent NMe₂¹H and ¹³C signals for the two NMe₂ groups. The X-ray structures of crystalline [Sn(Ar^N2)Cl] (2), 4, 6, 7, 8 and 10 showed that only one of the 2- and 6-Me₂N substituents of an (Ar^N2) group was in a close Sn⋯N contact. Reaction of 2 with Li[AlMe₄] or LiMe gave [Sn(Ar^N2)(μ-Me)₂AlMe₂] (11) or c-(SnMe₂)₆, respectively.