Cleavage of α-nitroketones by platinum(II) and platinum(0) and formation of platinum(II) complexes containing fulminato- and carboxylato-groups

Abstract

Reaction of the complex [(PPh₃)₂PtCl₂] with Tl^Isalts of 2-nitroacetophenone (PhCOCH₂NO₂), nitroacetone (MeCOCH₂NO₂), and 1-nitrobutan-2-one (MeCH₂COCH₂NO₂)(molar ratio 1 : 1 to 1 : 2) in benzene occurs with breaking of the carbon–carbon bond internal to the α-nitroketonic group, the fragments produced then co-ordinating to Pt^II as fulminato- and carboxylato-groups. The complexes isolated have formulae [(PPh₃)₂PtCl(CNO)], [(PPh₃)₂Pt(OCOR)(CNO)], and [(PPh₃)₂PtCl(OCOR)](R = Me, Et, or Ph). Reaction of the complex [Pt(PPh₃)₄] and 2-nitroacetophenone in benzene–ethanol–water (4 : 1 : 1) has also been studied and the complexes [(PPh₃)₂Pt-(OCOPh)(CNO)] and [(PPh₃)₂Pt(CNO)₂] isolated. I.r. spectra indicate that isomerization of the fulminato-groups to isocyanato-groups occurs.