Tuning the Reactivity of Dioxoruthenium(VI) Porphyrins toward an Arylimine by Altering Porphyrin Substituents

Reaction of dioxoruthenium(VI) porphyrins [RuVI(Por)O2] with arylimine HNCPh2 in dichloromethane afforded bis(methyleneamido)ruthenium(IV) porphyrins [RuIV(Por)(NCPh2)2] for Por = 4-Cl-TPP and TMP; (methyleneamido)hydroxoruthenium(IV) porphyrins [RuIV(Por)(NCPh2)(OH)] for Por = TPP and TTP; and bis(arylimine)ruthenium(II)
porphyrins [RuII(Por)(HNCPh2)2] for Por = 3,5-Cl2TPP and 3,5-(CF3)2TPP. In dichloromethane solution exposed
to air, complex [RuII(3,5-Cl2TPP)(HNCPh2)2] underwent oxidative deprotonation to form [RuIV(3,5-Cl2TPP)(NCPh2)2]. The new ruthenium porphyrins were identified by 1H NMR, UV−vis, IR, and mass spectroscopy, along
with elemental analysis. X-ray crystal structure determinations of [RuIV(4-Cl-TPP)(NCPh2)2], [RuIV(TPP)(NCPh2)(OH)], and [RuII(3,5-(CF3)2TPP)(HNCPh2)2] revealed the Ru−N(methyleneamido) or Ru−N(arylimine) distances
of 1.897(5) Å (average), 1.808(4) Å, and 2.044(2) Å (average), respectively.