The reaction of and results in arene displacement and formation of where the number of...

The reaction of and results in arene displacement and formation of where the number of methyl substituents on the arene vary from 1 to 6 (B. Štíbr, M. Bakardjiev, J. Holub, A. R°uži?cka, Z. Pad ?elková, P. Št ?epni?cka, Inorg. Chem., 2011, 50, 3097). Explain why product yields were lowest for the pentamethylbenzene and hexamethylbenzene complexes. Provide four unique trends (spectroscopic and electrochemical) that were correlated to increasing methyl substitution at the arene.