Synthesis and characterisation of mixed ligand Pt(II) and Pt(IV) oxadiazoline complexes

摘要: The nitrile ligands in trans-[PtX2(PhCN)2] (X = Cl, Br, I) undergo sequential 1,3 dipolar cycloadditions with nitrones R1R2CN+(Me)–O− (R1 H, R2 Ph; R1 CO2Et, CH2CO2Et) to selectively form the Δ4-1,2,4-oxadiazoline complexes trans-[PtX2(PhCN) {NC(Ph)–O–N(Me)–CR1R2}] or trans-[PtX2{NC(Ph)–O–N(Me)–CR1R2}2] high yields. reactivity of mixed ligand trans-[PtX2(PhCN){NC(Ph)–O–N(Me)–CR1R2}] towards oxidation and substitution was studied more detail. Oxidation Cl2 Br2 provides Pt(IV) species trans-[PtX2Y2(PhCN){NC(Ph)–O–N(Me)–CH(Ph)}] (X, Y Br). halide complex Br) undergoes scrambling solution trans-[PtX(4−n)Yn(PhCN){NC(Ph)–O–N(Me)–CH(Ph)}] as a statistical mixture. Ligand trans-[PtCl2(PhCN){NC(Ph)–O–N(Me)–CR1R2}] allows for selective replacement coordinated by nitrogen heterocycles such pyridine, DMAP 1-benzyl-2-methylimidazole produce Pt(II) type trans- [PtX2(heterocycle){NC(Ph)–O–N(Me)–CR1R2}]. All compounds were characterised elemental analysis, mass spectrometry, IR 1H, 13C 195Pt NMR spectroscopy. Single-crystal X-ray structural analysis (R,S)-trans-[PtBr2{NC(Ph)–O–N(Me)–CH(Ph)}2] trans-[PtCl2(C5H5N){NC(Ph)–O–N(Me)–CH(Ph)}] confirms molecular structure trans configuration relative each other.