The importance of the length of the –(CH2)n– chain on the cycloplatination of the [(η5-C5H5)Fe{(η5-C5H4)–CHN–(CH2)n–NMe2}] (n=2 or 3) ligands and the properties of the platinacycles
作者:Concepción López、Xavier Solans、Mercè Font-Bardía
DOI:10.1016/j.inoche.2005.04.004
日期:2005.7
The study of reaction of [(eta(5)-C5H5)Fe (eta(5)-C5H4)-CH=N-(CH2)(2)-NMe2}] (1b) with cis-[PtCl2(dmso)(2)] under different experimental conditions is reported. When the reaction was carried out in the presence of NaOAc in 5 a OAc-/1b molar ratio = 2 in a mixture of toluene/methanol (20:5) under reflux for 3 days, the cycloplatinated complex: [Pt[(eta(5)-C5H3)-CH=N-(CH2)(2)-NMe2]Fe(eta(5)-C5H5)}Cl(dmso)] (2b) together with small amounts of ferrocenecarboxaldehyde and cis-[Pt(eta(5)-C5H5)Fe[(eta(5)-C5H4)CH=N-(CH2)(2)-NMe2])}Cl-2(dmso)] (3b) was isolated. The X-ray crystal structure of 2b confirmed that the ligand acts as a terdentate [C-(sp2,C-ferrocene),N,N'](-) group. Complex 2b reacted with the stoichiometric amount of PPh3 giving [Pt[(eta(5)-C5H3)CH=N-(CH2)(2)-NMe2]Fe(eta(5)-C5H5)}Cl(PPh3)] (4b). Electrochemical studies of 2b-4b reveal that the proclivity of the ferrocenyl moiety to oxidise is dependent on the mode of binding of the ligand to the platinum(II). (c) 2005 Elsevier B.V. All rights reserved.