Organotin(IV) derivatives of novel β-diketones: Part V. Synthesis and characterization of di- and triorganotin(IV) derivatives of 4-acyl-5-pyrazolones modified in position 3 of the pyrazole. Crystal structure of (1,3-diphenyl-4-benzoyl-pyrazolon-5-ato)tri

The interaction between R3SnCl, (R3Sn)2O, R2SnO or R2SnCl2 acceptors (R=Me, nBu or Ph) and the two novel β-diketone proligands (LH=1,3-diphenyl-4-R4(CO)-pyrazol-5-one: L1H, R4=Ph; L2H, R4=Me) yields complexes [SnR3(L)(H2O)] (R=Me or nBu, L=L1 or L2), [SnPh3(L)] and [SnR2(L)2] (L=L1 or L2). The phenyl substituent on position 3 induces instability of the triorganotin derivatives in solution with the formation of SnR2(L)2 and SnR4 compounds. Moreover, diorganotin derivatives partially dissociate in solution yielding [SnR2(L)(solvent)]2+ species. When compared with the related 3-methyl species, the crystal structure of (1,3-diphenyl-4-benzoyl-pyrazolon-5-ato)triphenyltin(IV) is not modified by the 3-phenyl substitution. The chemical instability generated by the Ph in position 3 is greater than in positions 1 and 4. In addition, the Ph in position 3 of the pyrazole influences the solution behavior of the free neutral 4-acyl-5-pyrazolones stabilizing a novel amino-diketo tautomeric form.