Novel five- and six-coordinate diorganotin(IV) complexes with bis(triazol-1-yl)alkanes: linkage coordination polymers

A novel poly(triazol-1-yl)alkane ligand, bis(3,5-dimethyl-1,2,4-triazol-1-yl)methane CH2(3,5-Me(2)Tz)(2), has been synthesized under phase transfer catalytic conditions. This ligand as well as bis(1,2,4-triazol-1-yl)methane CH(2)Tz(2) and 1,2-bis(1,2,4-triazol-1-yl)ethane (CH2)(2)Tz(2) reacts with diphenyltin(IV) halides to yield novel five- and six-coordinate diorganotin complexes. The crystal structure of (CH(2)Tz(2))SnPh2Br2 determined by X-ray analysis shows that bis(triazol-1-yl)methane coordinates to the tin atom through exodentate nitrogen atoms on the 4-position of triazole rings to form linkage coordination polymers, which leads to a bridging instead of a general chelating metal coordination. Possibly owing to the hindrance of methyl groups in the triazole ring of CH2(3,5-Me(2)Tz)(2), this ligand is a weaker donor to an organotin acceptor than CH(2)Tz(2). In the hydrolysis product [SnPh2Br2(H2O)].(CH,(3,5-Me(2)Tz)(2)), the tin atom is five-coordinate with a trigonal bipyramid geometry, and the aqua ligand is simultaneously connected to the exonitrogen atoms of two adjacent CH2(3,5-Me(2)Tz) molecules through hydrogen bonding. (C) 2000 Elsevier Science Ltd. All rights reserved.