Multinuclear magnetic resonance spectroscopy and crystal structures of iodo-bridged dinuclear Pt(II) complexes with amines |
| |
Authors: | Fernande D Rochon Viorel Buculei |
| |
Institution: | Department of Chemistry, Université du Québec à Montréal, C.P. 8888, Succ. Centre-ville, Montréal, QC, Canada H3C 3P8 |
| |
Abstract: | Complexes of the types cis-Pt(amine)2I2 were transformed into the iodo-bridged dimers, which were characterized mainly by multinuclear (195Pt, 1H and 13C) magnetic resonance spectroscopy. For bulby amines, the dinuclear species were synthesized directly from K2PtI4]. Compounds with several primary aliphatic and cyclic amines and two secondary amines were studied. In 195Pt NMR, two signals were observed between −3899 and −4080 ppm in acetone. These species were assigned to the cis and trans dinuclear compounds I(amine)Pt(μ-I)2PtI(amine). We suggest that the most shielded compound is the trans isomer. The difference between the two isomers is 12-13 ppm for the primary amine system and 26-27 ppm for the two secondary amines. There seems to be a slight dependence of the proton affinity in the gas phase of the amine (linear amines) with the δ(Pt) chemical shifts of the dinuclear Pt(II) compounds. The 2J(195Pt-1HN) coupling constants are slightly larger for the trans isomers (average 67 Hz, vs. 56 Hz). The 3J(195Pt-1H) coupling constants were detected only for the dimethylamine compounds, 46 Hz (trans) and 44 Hz (cis). In 13C NMR, the values of 2J(195Pt-13C) and 3J(195Pt-13C) were also found to be very slightly larger for the trans complexes (average 19 and 25 Hz vs. 15 and 18 Hz). The structures were confirmed by X-ray diffraction studies of the n-butylamine and diethylamine compounds. The two crystals were those of the trans dinuclear complexes. |
| |
Keywords: | Crystal structure Platinum Amine NMR Iodo ligands |
本文献已被 ScienceDirect 等数据库收录! |
|