DIORGANYLTIN(IV) BIS[POLY(1-PYRAZOLYL)BORATES] AND RELATED SPECIES

Compounds of the type L2SnR2 (L = poly(1-pyrazolyl)borate, R = hydrocarbon substituent) have been obtained from the reaction of R2SnCl2 with ML (M = Na, K). Complexes with L = [B(pz)4]- (Hpz = pyrazole; R = CH3, C2H5, n-C4H9) do not hydrolyze readily but are of relatively low thermal stability; complexes with L = [R2B(pz)2]- (R = H, C2H5, C6H5) are, in general, not only thermally unstable but also extremely sensitive to moisture. Hydrolysis of the latter species leads to dimeric (boryloxy)diorganyltin(IV) pyrazolides, [R2B(mu-O)(mu-pz)SnR'2]2 (1), in addition to, ultimately, pyrazaboles, R2B(mu-pz)2BR2. The same compounds containing the B(mu-O)(mu-pz)Sn ring system can also be obtained by the reaction of R2BOH with R'2Sn(pz)2, and the complexes with R = C2H5 and R' = CH3, R = R' = C2H5, R = C2H5 and R' = n-C4H9, R = C2H5 and R' = C6H5, and R = C6H5 and R' = CH3 have been prepared. The compound [(C2H5)2B(mu-O)(mu-pz)Sn(CH3)2]2 crystallizes in the triclinic system in space group P1BAR (No. 2) with a = 7.764 (1) angstrom, b = 8.317 (1) angstrom, c = 10.578 (3) angstrom, alpha = 107.12 (2)degrees, beta = 97.04 (2)degrees, gamma = 101.23 (1)degrees, and Z = 2. The anhydrous acid HB(pz)4 has been characterized by NMR data.