Syntheses and characterization of the ruthenium carbonyl porphyrin complexes Ru(TPP)(CO)(1-MeIm) and Ru(α-PocPivP)(CO)(1-MeIm)

Abstract

Ru(TPP)(CO)(1-MeIm) and Ru(α-PocPivP)(CO)(1-MeIm) (TPP = tetraphenylporphyrinato; PocPivP = ‘pocket’ porphyrin dianion) were prepared by metalation of the free-base porphyrins with Ru 3(CO) 12, followed by reaction with 1-MeIm. The structures of Ru(TPP)(CO)(1-MeIm) and Ru(α-PocPivP)(CO)(1-MeIm) have been determined by single-crystal X-ray diffraction methods. The compound Ru(TPP)(CO)(1-MeIm) packs as one crystallographically independent porphyrin molecule with toluene solvate, whereas Ru(α-PocPivP)(CO)(1-MeIm) crystallizes as two crystallographically independent porphyrin molecules, molecule A and molecule B, with disordered solvate, modeled as water. In Ru(TPP)(CO)(1-MeIm) the Ru atom lies 0.032 Å out of the 24-atom porphyrin plane toward the CO ligand. The RuCO bond angle is 179.3(2)° and the RuC(CO) and CO bond distances are 1.828(2) Å and 1.147(3) Å, respectively. The RuN ax(1-MeIm) distance is 2.187(2) Å, compared with an average RuN eq(porphine) distance of 2.058(3) Å. The molecular structure of Ru(α-PocPivP)(CO)(1-MeIm), a sterically protected ‘pocket’ porphyrin, is more distorted than that of (Ru(α-PocPivP)(CO)(1-MeIm). In molecule A the Ru atom lies 0.03 Å out of the 24-atom porphyrin plane toward the 1-MeIm ligand whereas in molecule B the Ru atom lies 0.01 Å out of the porphyrin plane toward the CO ligand. For molecule A the RuC(CO) and CO bond distances are 1.82(3) Å and 1.18(3) Å, respectively, and the RuCO bond angle is 168(3)°. Respective values for molecule B are 1.82(2) Å, 1.16(3) Å, and 159(3)°. The MN ax distances are 2.20(2) Å and 2.16(2) Å, respectively, for molecules A and B. The average MN eq distances are 2.03(3) Å and 2.03(5) Å. The CO stretching frequencies are 1939 cm −1 for Ru(TPP)(CO)(1-MeIm) and 1933 cm −1 for Ru(α-PocPivP)(CO)(1-MeIm). Crystallographic data for Ru(TPP)(CO)(1-MeIm): triclinic, C i 1−P 1, Z = 2, a = 9.796(2) A ̊ , b = 13.320(1) A ̊ , c = 17.618(2) A ̊ , α = 74.88(1)°, β = 87.97(1)°, γ = 83.23(1)°, T = 153 K , 9049 unique unique reflections, 579 variables, R( F) ( F 0 2 > 2 σ( F 0 2)) = 0.034, R w( F 2) = 0.094. Crystallographic data for Ru(α-PocPivP)(CO)(1-MeIm): orthorhombic, C 2v 9−Pn2 1a, Z = 8, a = 26.672(5) A ̊ , b = 32.243(6) A ̊ , c = 14.124(3) A ̊ , T = 150 K , 8006 unique reflections, 699 variables, R( F)( F 0 2 > 2 σ( F 0 2)) = 0.113, R w( F 2) = 0.246.