Novel heteroleptic stannylenes with intramolecular O,C,O-donor stabilization

The heteroleptic organotin(II) halides {2,6-[P(O)(OEt)(2)](2)-4-tert-Bu-C6H 2}SnX (1, X = Cl; 2, X = Br) have been prepared starting from {2,6-[P(O)(OE t)(2)](2)-4-tert-Bu-C6H2}Li and SnX2 and have been used as precursors for t he preparation of the heteroleptic stannylenes {2,6[P(O)(OEt)(2)](2)-4-tert -Bu-C6H2}SnX (4, X = SPh; 5, X = CH(SiMe3)(2); 6, X = SiPh3; 7, X = SnPh3; 7a, X = SnMe3), the tetravalent monorganotin derivatives {{2,6-[P(O)(OEt)(2 )](2)-4-tert-Bu-C6H2}SnCl(mu -S)}(2) (8) and {2,6-[P(O)(OEt)(2)](2)-4-tert- Bu-C6H2}SnBr3 (9), the diorganotin cation {2,6-[P(O)(OEt)(2)](2)-4-tert-Bu- C6H2}(Ph3C)(Cl)Sn+PF6- (10), and the metal-stannylene complexes {2,6-[P(O)( OEt)(2)](2)-4-tert-Bu-C6H2}(Cl)Sn[M(CO)(n)] (11, M = W, n = 5; 12, M = Cr, n = 5; 13, M = Fe, n = 4). Multinuclear (H-1, C-13, P-31, Sn-119) NMR of al l compounds, Sn-119 Mossbauer spectra of 1 and 10, and single-crystal X-ray structure analyses of 6, 8, and 12 are reported. The derivatives 6, 7, and 7a are rare examples of compounds containing Sn(II)-Si(IV) and Sn(II)-Sn(I V) bonds, respectively.