Tuning the reactivity of dioxoruthenium(VI) porphyrins toward an arylimine by altering porphyrin substituents

Reaction of dioxoruthenium(VI) porphyrins [Ru-VI(Por)O-2] with arylimine HN=CPh2 in dichloromethane afforded bis(methyleneamido)ruthenium(IV) porphyrins [Ru-IV(Por)(N=CPh2)(2)] for Por = 4-Cl-TPP and TMP; (methyleneamido)hydroxoruthenium(IV) porphyrins [Ru-IV(Por)(N=CPh2)(OH)] for Por = TPIP and TTP; and bis(arylimine)ruthenium(II) porphyrins [Ru-II(Por)(HN=CPh2)(2)] for Por = 35-Cl2TPP and 3,5-(CF3)(2)TPP. In dichloromethane solution exposed to air, complex [Ru-II(3,5-Cl2TPP)(HN=CPh2)(2)] underwent oxidative deprotonation to form [Ru-IV(3,5-Cl2TPP)(N= CPh2)(2)]. The new ruthenium porphyrins were identified by H-1 NMR, UV-vis, IR, and mass spectroscopy, along with elemental analysis. X-ray crystal structure determinations of [Ru-IV(4-Cl-TPP)(N=CPh2)(2)b [Ru-IV(TPP)(N=CPh2)(OH)], and [Ru-II(3,5-(CF3)(2)TPP)(HN=CPh2)(2)] revealed the Ru-N(methyleneamido) or Ru-N(arylimine) distances of 1.897(5) angstrom (average), 1.808(4) angstrom, and 2.044(2) angstrom (average), respectively.