“…It appears that the selectivity of TM macrocycles towards a chemical and/or electrochemical reaction is "set" by the TM centre, and the activity is then "tuned" by the peripheral substituents [4,5]. The number and position of these substituents both on the macrocyle and on one or both of the metal centre's axial sites can significantly change both its' electro-catalytic and purely chemical catalytic activity, as well as the associated reaction mechanisms [4,5,13,21,23,26,27,29,[31][32][33]. Conversely, strongly electron donating substituents at the para-position on all four meso (5,10,15,20) phenyls in TM TPP increases catalytic activity [13,31,32].…”