Structure and Photochemistry of Manganese Porphyrin Sulfate Complexes

New sulfate and hydrogen sulfate complexes of metalloporphyrins have been synthesized and crystallographically characterized and their photochemistry examined. Irradiation of [Mn(TPP)],(SO,) and Mn(TPP)(OS03H) (where TPP = 5,10,15,20-tetraphenylporphyrinate(2-)) produces Mn"(TPP) quantitatively, with quantum yields of 7.1 X IO4 and 9.8 X IO-', respectively. In contrast to other manganese oxoanion complexes, metal-oxo species are not formed and oxidation of hydrocarbons does not occur. The X-ray crystal structures of [Mn(TPP)]2(S04)~2C6H6.1/2CSH12~1/2H20 and Mn(TPP)(OS03H).CH2CI, show stereochemistry similar to that of the analogous iron complexes. In the sulfate complex [Mn(TPP)],(S04), the average Mn-pyrrole N distance is 2.008 A in both rings, with the metal displaced above the mean plane of the nitrogen atoms by 0.19 and 0.22 A for Mn(l) and Mn(2), respectively. The sulfate ion is coordinated in an unidentate fashion. In Mn(TPP)(OS03H) the average Mn-pyrrole nitrogen distance is 1.991 A with the metal 0.23 A above the mean plane of the nitrogen atoms. The hydrogen sulfate ion is coordinated through one of the oxy ens, with Mn-O = 2.078 A. Crystal data for Mn(TPP)(OS0,H).CH2C12: space group Pi, 4 = 13.782 ( 8 ) A, b = 13.861 (6) 1. c = 13.504 ( 8 ) A, a = 108.57 (4)O, j3 = 118.77 (4)', y = 60.43 (4)O, V = 1956 (3) A', and 2 = 2. Crystal data for [Mn(TPP)]2(S0,).2C6H6~'/zc~Hlz~1/zH20 at 5 OC: space group Pi, a = 14.585 (16) A, b = 21.949 (10) A, c = 13.142 (6) A, a = 90.11 (4)', B = 104.65 (6)O, y = 96.47 (5)', V = 4042 (9) A', and Z = 2.