THE SYNTHESIS AND CHARACTERIZATION OF C,N- HYPERCOORDINATE STANNANES, DISTANNANES AND POLYSTANNANES

Candidate: Nicola Piccolo
Supervisor: Dr. Daniel Foucher

ABSTRACT

Hypercoordinate stannanes and distannanes containing the 2-(Me2NCH2)C6H4- coordinating ligand have been synthesized and characterized. The organotin (IV) compound 2- (Me2NCH2)C6H4SnPh3 (34) was prepared in moderate yield from salt metathesis reaction of organolithium [2-(Me2NCH2)C6H4]Li (33) and Ph3SnCl. The organotin (IV) chloride, 2- (Me2NCH2)C6H4SnPh2Cl (35) was isolated via chlorination of 34 in high yield. The organotin (IV) bromide, 2-(Me2NCH2)C6H4SnPh2Br (36) was also prepared via bromination of 34 in high yield. The synthesis of the corresponding organotin hydride 2-(Me2NCH2)C6H4SnPh2H (38) via LiAlH4 and the organotin dimer {2-(Me2NCH2)C6H4SnPh2}2 (22) via a dehydrocoupling reaction of 38 with Wilkinson’s catalyst were also carried out. Additionally, asymmetric organotin (IV) compounds containing a semi-flexible ethyl-2-pyridyl ligand were synthesized and characterized. The triphenyl derivative, 2-(PyC2H4)SnPh3 (39), was prepared in high yield via the hydrostannylation reaction between Ph3SnH and 2-vinylpyridine. The dibromide derivative, 2- (PyC2H4)SnPhBr2 (40), was recovered in high yield via the bromination of 39 with 1M Br2 solution. The synthesis of the corresponding organotin dihydride 2-(PyC2H4)SnPh2H (41) via NaBH4 was completed in high yield. The synthesis of organotin polymer 42 containing the 2- (PyC2H4)- ligand was also achieved using RhCl(PPh3)3 in moderate yield. Purification and analysis of 42 yielded the distannoxane 43. All stannane intermediates and monomers were fully characterized by NMR (1H, 13C, 119Sn) spectroscopy and where required high-resolution mass spectrometry and compared to literature values.