Abstract
[2 + 3] Cycloaddition reactions of the diazidoplatinum(II) complexes cis-[Pt(N-3)(2)(PPh3)(2)] 1 and cis-[Pt(N-3)(2)(2,2 '-bipy)] 4 with organonitriles NCR 2 give the bis(tetrazolato) complexes trans-[Pt(N4CR)(2)(PPh3)(2)]3 [R = Me (3a), Et (3b), Pr (3c), Ph (3d), 4-ClC6H4 (3e)] and cis-[Pt(N4CR)(2)(2,2 '-bipy)]5[R = Me (5a), Et (5b), Pr (5c), Ph (5d)]. The reaction of cis-[Pt(N-3)(2)(PPh3)(2)] 1 with propionitrile also affords, apart from 3b, the unexpected mixed cyano-tetrazolato complex trans-[Pt(CN)(5-ethyltetrazolato)(PPh3)(2)]3b ' which is derived from the reaction of the bis(tetrazolato) 3b with propionitrile, with concomitant formation of 5-ethyl-1H-tetrazole, via a suggested unusual oxidative addition of the nitrile to PtII. All these reactions are greatly accelerated by microwave irradiation and this method also shows a higher selectivity in the case of the reaction of propionitrile with 1, leading only to the formation of 3b. All the complexes obtained were characterized by IR, H-1, C-13 and P-31{H-1} (for complexes 3) NMR spectroscopies, FAB-MS and elemental analyses. Complexes 3b ', 3d, 3e and 5d were also characterized by X-ray structural analyses.