Reduction of C,O-chelated organotin(IV) dichlorides and dihydrides leading to protected polystannanes

A series of aryloxy organotin compounds Ph3Sn(CH2)(3)OC6H4R (5: R = H; 6: R = Ph; 7: R = OCH3, 8: R = CF3), Ph2ClSn(CH2)(3)OC6H4R (9: R = H; 10: R = Ph) and PhCl2Sn(CH2)(3)OC6H4R (12: R = H; 13: R = Ph) have been synthesized and characterised by NMR (H-1, C-13, Sn-119) spectroscopy. X-ray structure determinations of 9, 10, 12 and 13 reveal a distorted trigonal bipyramidal geometry at Sn with Cl trans to the datively bonded O whereas 8 possesses tetrahedral geometry and a Sn center dot center dot center dot O dative interaction is absent. Triorganotin hydrides Ph2HSn(CH2)(3)OC6H4R (14: R = H; 15: R = Ph) and diorganotin dihydrides PhH2Sn(CH2)(3)OC6H4R (16: R = H; 17: R = Ph) were prepared by reduction of the corresponding dihalides with LiAlH4. Catalytic dehydrocoupling of dihydrides 16 or 17 with a late transition metal catalyst afforded asymmetrical hypercoordinated polystannanes [PhSn(CH2)(3)OC6H4R](n) (18: R = H; 19: R = Ph) with relatively high molecular weights (M-w = 1.3 x 10(4) - 2.5 x 10(5) Da) and narrow polydispersities (PDI's = 1.3-3.3). NMR and UV-Vis spectroscopy studies indicate that the new polymers display dramatically improved light stability, but remain sensitive to moisture. (C) 2014 Elsevier B.V. All rights reserved.