Syntheses and structures of zinc and tin(II) compounds with hemilabile N-silyl-tert-butylamido and N-silyl-p-tolylamido ligands that contain pendent tert-butoxy groups

Syntheses and solid-state structures of zinc and tin(II) compounds, containing the N-silyl-amide ligands ((OBu)-Bu-t)(NR)SiMe2, R = Bu-t (L-tBu), or R = p-tolyl (L-pTol), are reported. The N-silyl amines were synthesized by modified published procedures from commercially available Me2SiCl2, (BuOH)-Bu-t, and (BuNH2)-Bu-t, or p-Me-C6H4NH2, respectively. Treatment of SnCl2 with LiLpTol furnished Sn(L-pTol)(2), which was X-ray structurally characterized and shown to contain two covalent Sn-N bonds and two asymmetrical O -> Sn donor bonds. The single-crystal X-ray structure of Sn(L-tBu)(2) revealed a much more symmetrically-coordinated, pseudo-trigonal-bipyramidal tin atom. Aminolysis of diethylzinc with HLpTol produced [EtZn(L-pTol)](2) which crystallized as a centrosymmetric dimer, containing four-coordinate zinc atoms connected by bridging amides. Zinc dichloride, by contrast, reacted with two equivalents of LiLtBu to produce the homoleptic, pseudo-spirocyclic Zn(L-tBu)(2). (C) 2011 Elsevier Ltd. All rights reserved.