Heteroaryltin compounds. Preparation and characterisation of some 3-furyltin halides. Tin-119 nuclear magnetic resonance and Mössbauer studies of a series of heteroaryltin compounds

Abstract

A series of 3-furyltin halides of the types SnR_nX_4–n(R = 3-furyl; n= 2 or 3; X = Cl or Br) have been prepared and characterised by chemical and spectroscopic techniques. Mössbauer data for triphenyl-phosphine oxide adducts of the tris(3-furyl)tin halides are consistent with five-co-ordinate trigonal-bipyramidal structures bearing equatorial heteroaryl groups. The bis(3-furyl)tin dihalides have been characterised by complex formation with 2,2′-bipyridyl and Mössbauer studies suggest a six-co-ordinate cis-octahedral environment for tin. The 3-furyltin halides have been found to be considerably more stable than their 2-furyl and 2-thienyl analogues. Continued attempts to characterise these less stable compounds by complex formation have met with some success. ¹¹⁹Sn N.m.r. data are presented for the above series of heteroaryltin compounds and also for a range of tetrakis-(heteroaryl)tin systems. The ¹¹⁹Sn n.m.r. and Mössbauer data are discussed in terms of the possible electronic effects of the heteroaryl groups.