Synthesis of the First Hydroxomonoaryltin( IV) Complexes. Crystal and Molecular Structure of [{Sn[C,H,( N=NC6H,-M e-4') - 2, Me - 51 C I ( p-0 H )}2]

Abstract

Tin(ti) chloride reacts in refluxing xylene with [HgLCI] [L = C6H,(N=NC6H,R-4')-2,R-5; R = Me (mpap) or Me0 (mopap)] to give metallic mercury and [SnLCIJ (L = mpap 1 or mopap 2). Complex 1 reacts with CI-, dimethyl sulfoxide or [Hg(dmap),] (dmap = C,H,CH,NMe,-2) to give, respectively, [Sn(mpap)CI,] - 3, [Sn(mpap)CI,(OSMe,)] 4 or [Sn(mpap)(dmap)CI,] 5. Several types of hydrolytic process occur when 1,2 or [Sn(mpap)Ph,CI] react with various ligands. Thus, [Hg(dmap)CI] reacts with 1 or 2 as a base to give [{SnLCI,(p-OH)},] (L = mpap 6 or mopap 7) and Hg(Hdmap)CI,. Similarly, PhCH,NMe, (bdma) reacts with 1 (1 :1) to give the hydrolysis product [Hbdma][Sn(mpap)CI,(OH)] 8. By treating 6 with excess of NaBr, [{Sn(mpap)Br,(p-OH)),] 9 can be obtained. Acetic anhydride reacts with complex 6 to give [Sn(mpap)CI,(O,CMe)] 10, but not with 8. The complex [Sn(mpap)Ph,CI] reacts with Tl(acac) (acac = acetylacetonate), NaH or Ag,O to give the hydrolysis product [Sn(mpap)Ph,(OH)] 11. The crystal structure of 6 was determined at -95 "C; the dimeric doubly bridged nature of the compound was confirmed. The Sn-0 bridges are asymmetric, the bond lengths depending on the nature of the trans ligand. Two molecules of diethyl ether form hydrogen bonds to the bridging OH groups; another diethyl ether molecule is disordered over a symmetry centre. The structure of compound 7 was also determined; it too is dimeric with two hydroxo bridges, but the refinement was unsatisfactory, probably because of twinning effects.