| Abstract |
The nitrile ligands in the platinum(IV) complexes trans-[PtCl4(RCN)(2)] (R = Me, Et, CH2Ph) and cis/trans[ PtCl4(MeCN)(Me2SO)] are involved in a metalla-Pinner reaction with N-methylbenzohydroxamic acid (N-alkylated form of hydroxamic acid, hydroxamic form; F1), PhC(=O) N(Me) OH, to achieve the imino species [PtCl4\NH=C(R) ON( Me) C(=O) Ph\(2)] (1 - 3) and [PtCl4\NH=C(Me) ON(Me) C(=O) Ph\(Me2SO)] (7), respectively. Treatment of trans-[PtCl4( RCN)(2)] (R = Me, Et) and cis/ trans-[PtCl4(MeCN)(Me2SO)] with the O-alkylated form of a hydroxamic acid ( hydroximic form), i.e. methyl 2,4,6-trimethylbenzohydroximate, 2,4,6-(Me3C6H2) C(OMe). NOH (F2A), allows the isolation of [PtCl4\NH=C(R) ON=C(OMe)(2,4,6- Me3C6H2)\(2)] (5, 6) and [PtCl4\NH=C(Me) ON=C(OMe)(2,4,6- Me3C6H2)\( Me2SO)] (8), correspondingly. In accord with the latter reaction, the coupling of nitriles in trans-[PtCl4(EtCN)(2)] with methyl benzohydroximate, PhC(OMe) = NOH (F2B), gives [PtCl4\NH=C(Et) ON=C(OMe) Ph\(2)] (4). The addition proceeds faster with the hydroximic F2, rather than with the hydroxamic form F1. The complexes 1 - 8 were characterized by C, H, N elemental analyses, FAB(+) mass-spectrometry, IR, H-1 and C-13\H-1\ NMR spectroscopies. The X-ray structure determinations have been performed for both hydroxamic and hydroximic complexes, i.e. 2 and 6, indicating that the imino ligands are mutually trans and they are in the E-configuration. |
