Activation of the CH bond in [(η5-C5H5)Fe(η5-C5H4CH2N(CH3)CH2C6H4R-4)] induced by platinum (II): Crystal structure of σ-Pt[(η5-C5H5)Fe(η5-C5H3CH2N(CH3)CH2C6H4OCH3-4)]Cl(DMSO)