Synthesis and characterization of Sn( <scp>ii</scp> ) complexes supported by amino bis-phenoxide ligands

The coordination behavior of a series of [Sn(OR)₂] systems modified by substituted amine-bis(phenolate)ligands was investigated. The complexes were synthesised from the reaction of Sn[N(SiMe₃)₂]₂ and the appropriate pro-ligand: <i>N</i>,<i>N</i>-bis(3,5-dimethyl-2-hydroxybenzyl)ethylamine (L1H2), <i>N</i>',<i>N</i>'-bis(2-hydroxy-3,5-dimethylbenzyl)-<i>N</i>,<i>N</i>-dimethylethylenediamine (L2H2), <i>N</i>,<i>N</i>'-bis(3,5-dimethyl-2-hydroxyphenylmethyl)-<i>N</i>,<i>N</i>'-dimethylethylenediamine (L3H2), 1,4-bis(2-hydroxy-3,5-dimethylbenzyl)-1,4-diazepane (L4H2), 2,2',4,4'-tetramethyl-6,6'-piperazine-1,4-diylbis(methylene)-bisphenol (L5H2) and <i>N</i>',<i>N</i>',<i>N</i>'',<i>N</i>''-tetrakis(2-hydroxy-3,5-dimethylbenzyl)-1,2-ethanediamine, and the products were identified as follows: [{L¹}Sn]₂ (1), [{L²}Sn] (2), [{L³}Sn] (3), [{L⁴}Sn], (4) and [{L⁶}Sn₂]·(Py)₂ (5). Reaction of complex (1) with O₂ results in the formation of the Sn(IV) species [{L¹}₂Sn] (6), the molecular structure of which was also determined.