The synthesis and reaction chemistry of new amino-functionalised tin(ii) alkoxides

Abstract

Sn(II) derivatives of the aminoalcohols ^tBu(H)NC(Me)(H)CH₂OH (Htbap, Ib), (R¹R²NCH₂)₂C(H)OH (R¹ = R² = Me, IIa, Hbdmap; R¹ = ^tBu, R² = H, IIb, Hbtbap), (R¹R²NCH₂)₃COH (R¹ = R² = Me, IIIa, Htdmap; R¹ = ^tBu, R² = H, IIIb, Httbap) have been synthesised by reaction of the alcohol with Sn[N(SiMe₃)₂]₂. The structures of the ligands IIb, IIb·H₂O, IIIb along with Sn(ttbap)₂ have been determined; the latter is pseudo-trigonal bipyramidal with nitrogen atoms in axial sites and oxygen atoms and a stereochemically-active lone pair in the equatorial positions. Sn(ttbap)₂ reacts with Fe₂(CO)₉ in 2 : 1 ratio (Sn : Fe = 1 : 1) to afford the donor–acceptor complex (ttbap)₂Sn:→Fe(CO)₄, while in 1 : 1 ratio (Sn : Fe = 1 : 2) the Sn(0) complex (Httbap)Sn[Fe(CO)₄]₂ is formed, in which Httbap is a neutral zwitterionic form of the ligand. The structures of both bimetallic species are reported. Thermal decomposition of (Httbap)Sn[Fe(CO)₄]₂ under low-pressure CVD conditions gives a film containing a mixture of cubic-Sn, cubic-Fe and the hexagonal intermetallic phase Fe₃Sn.