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

Ru(TPP)(CO)(1-MeIm) and Ru(alpha-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(alpha-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(alpha-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 Angstrom out of the 24-atom porphyrin plane toward the CO ligand. The Ru-C-O bond angle is 179.3(2)degrees and the Ru-C(CO) and C-O bond distances are 1.828(2) Angstrom and 1.147(3) Angstrom, respectively. The Ru-N-ax(1-MeIm) distance is 2.187(2) Angstrom, compared with an average Ru-N-eq(porphine) distance of 2.058(3) Angstrom. The molecular structure of Ru(alpha-PocPivP)(CO)(1-MeIm), a sterically protected 'pocket' porphyrin, is more distorted than that of Ru(TPP)(CO)(1-MeIm). In molecule A the Ru atom lies 0.03 Angstrom out of the 24-atom porphyrin plane toward the 1-MeIm ligand whereas in molecule B the Ru atom lies 0.01 Angstrom 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) Angstrom and 1.18(3) Angstrom, respectively, and the Ru-C-O bond angle is 168(3)degrees. Respective values for molecule B are 1.82(2) Angstrom, 1.16(3) Angstrom, and 159(3)degrees. The M-N-ax distances are 2.20(2) Angstrom and 2.16(2) Angstrom, respectively, for molecules A and B. The average M-N-eq distances are 2.03(3) Angstrom and 2.03(5) Angstrom. The CO stretching frequencies are 1939 cm(-1) for Ru(TPP)(CO)(1-MeIm) and 1933 cm(-1) for Ru(alpha-PocPivP)(CO)(1-MeIm). Crystallographic data for Ru(TPP)(CO)(1-MeIm): triclinic, C-i(1)-P (1) over bar, Z = 2, a = 9.796(2) Angstrom, b = 13.320(1) Angstrom, c = 17.618(2) Angstrom, alpha = 74.88(1)degrees, beta = 87.97(1)degrees, gamma = 83.23(1)degrees, T = 153 K, 9049 unique reflections, 579 variables, R(F) (F-o(2) > 2 sigma(F-o(2))) = 0.034, R(w)(F-2) = 0.094. Crystallographic data for Ru(alpha-PocPivP)(CO)(1-MeIm): orthorhombic, C-2v(9)-Pn2(1)a, Z = 8, a = 26.672(5) Angstrom, b = 32.243(6) Angstrom, c = 14.124(3) Angstrom, T = 150 K, 8006 unique reflections, 699 variables, R(F) (F-o(2) > 2 sigma(F-o(2))) = 0.113, R(w)(F-2) = 0.246.