TIN(IV) AND ORGANOTIN(IV) DERIVATIVES OF NOVEL BETA-DIKETONES .1. DIALKYLTIN(IV) COMPLEXES OF 1-PHENYL-3-METHYL-4-R'(C=O)-PYRAZOL-5-ONE (R'-CCL3, O-CH3, O-C2H5, O-I-C3H7, O-C7H7) - CRYSTAL AND MOLECULAR-STRUCTURE OF METHYL-4-I-PROPOXYCARBONYL-PYRAZOLON-5-ATO]TIN(IV)

Stable six-coordinate tin(IV) and organotin(IV) derivatives R(2)SnQ(2 ) (R=Me, Et, Bu-n, Bu-t) (HQ = 1-phenyl-3-methyl-4-trichloroacetyl-py razol-5-one) have been synthesized in basic (triethylamine) solution o f chloroform. These complexes have been characterized by elemental ana lysis and spectroscopic (IR and far-IR, H-1, C-13 and Sn-119 NMR) data . In basic (KOH) alcoholic R'OH solutions (R'=Me, Et, Pr-i, benzyl), t he tin acceptor induces cleavage of the C-CCl3 bond in the donor (Q)( -) and the new derivatives -phenyl-3-methyl-4-alkoxycarbonyl-pyrazolon -5-ato) R2Sn(IV) (R = Me, Et, Bu-t or Bu-n) and thyl-4-ethoxycarbonyl- pyrazolon-5-ato)-Me2Sn(IV)Cl have been obtained. Structural informatio n has been derived from Sn-119 NMR parameters such as (1)J(Sn-119-C-13 ), (2)J(Sn-119-H-1) and delta(Sn-119). The diffraction study of the co mplex 1-phenyl-3-methyl-4-(CO-OPri)-pyrazolon-5-ato)(2)] shows the met al to be six-coordinate in a skewed trapezoidal bipyramidal (STB) geom etry; Sn-O distances are 2.10(1) and 2.39(1) Angstrom in one ligand, a nd 2.09(1) and 2.39(1) Angstrom in the other ligand, and the Me-Sn-Me bond angle is 157.0(8)degrees. The title compound crystals are monocli nic, space group P2(1)/c; cell parameters: a=11.489(4), b=14.558(7), c =18.973(8) Angstrom, beta=77.14(3)degrees.