PREPARATION, CHARACTERIZATION, AND REACTIVITY OF SCANDIUM OCTAETHYLPORPHYRIN COMPLEXES - X-RAY CRYSTAL-STRUCTURES OF (OEP)SCCH3, (OEP)SCCH(SIME3)2, (OEP)SC(ETA(5)-C9H7), AND [(OEP)SC]2(MU-OH)2

The synthesis of (OEP)ScCl from Li2(OEP)(THF)2 and ScCl3(THF)3 provides a useful entry into the chemistry of a wide range of (OEP)Sc derivatives. Organometallic complexes with sigma- and pi-bonded ligands have been isolated and fully characterized. These include (OEP)ScR species with R = Me, CH(SiMe3)2, CH2CMe3, (eta5-C9H7), (eta-C6H5), (eta5-C5H4Me), and (eta5-C5Me5), three of which have been structurally characterized by X-ray crystallography. For [(OEP)ScMe]2.CH2Cl2: space group P1BAR with a = 10.088(2) angstrom, b = 13.882(2) angstrom, c = 14.813(2) angstrom, alpha = 66.469(12)-degrees, beta = 81.342(14)-degrees, gamma = 76.561(12)-degrees, V = 1845.9(5) angstrom3, Z = 1, R = 3.99 %, and R(w) = 5.34%. For (OEP)ScCH(SiMe3)2: space group P2(1/n) with a = 12.372(10) angstrom, b = 24.194(18) angstrom, c = 15.393(18) angstrom, beta = 112.55(7)-degrees, V = 4255(12) angstrom3, Z = 4, R = 12.6%, and R(w) = 12.8%. For (OEP)Sc(eta5-C9H7): space group Pbca with a = 14.899(2) angstrom, b = 20.999(2) angstrom, c = 23.722(3) angstrom, V = 7421.6(26) angstrom3, Z = 8, R = 7.44%, and R(w) = 5.76%. The sigma-alkyls react with ketones and CO2 to produce alkoxides and acetates, respectively. Additional derivatives with R = OCMe3, O(2,4,6-Me3C6H2),N(SiMe3)2, and triflate have also been prepared. Hydrolysis of these complexes yields the dimeric bridging hydroxide [(OEP)Sc(mu-OH)]2 which has also been crystallographically characterized; it crystallizes in the space group P1BAr with a = 10.992(2) angstrom, b = 13.179(2) angstrom, c = 13.650(2) angstrom, alpha = 59.615(16)-degrees, beta = 67.226(16)-degrees, gamma = 76.234(14)-degrees, V = 1570.6(3) angstrom3, Z = 1, R = 3.5%, and R(w) = 4.2 %.