EARLY TRANSITION-METAL PORPHYRINS - SYNTHESIS, CHARACTERIZATION, AND REACTIVITY OF NOVEL OUT-OF-PLANE CIS-LIGATED ZIRCONIUM PORPHYRIN DERIVATIVES

A new class of coordinatively unsaturated zirconium porphyrin compounds, (OEP)ZrR2 [OEP = dianion of octaethylporphyrin; R = chloride, trifluoromethanesulfonate (triflate, OTf), acetate, alkoxide, alkyl, aryl; R2 = cyclooctatetraenyl], has been prepared. (OEP)ZrCl2, prepared by metathesis between Li2OEP(DME)n and ZrCl4(DME), serves as starting material for further functionalization. The organometallic derivatives are very reactive, readily undergoing protonolysis, hydrogenolysis, and insertion of CO2 and acetone into the Zr-C bonds. Cis-ligation in these out-of-plane zirconium porphyrin compounds has been inferred from H-1 NMR measurements and confirmed in three derivatives by X-ray diffraction. Crystallographic data are as follows. (OEP)ZrCl2.0.5Tol: space group P1BAR with a = 9.870(2) angstrom, b = 14.143(3) angstrom, c = 14.498(3) angstrom, alpha = 66.257(17)-degrees, beta = 88.003(17)-degrees, gamma = 79.645(17)-degrees V = 1820.9(8) angstrom3, and Z = 2. (OEP)Zr(O(t)BU)2: space group P1BAR with a = 12.4441(12) angstrom, b = 13.1594(21) angstrom, c = 13.9541(18) angstrom alpha = 89.972(11)-degrees, beta = 99.192(9)-degrees, gamma = 115.487(11)-degrees V = 2045.7(10) angstrom3, and z = 2. (OEP)ZrMe2: space group P1BAR with a = 10.007(3) angstrom, b = 13.062(4) angstrom, c = 14.558(3) angstrom, alpha = 82.83(2)-degrees, beta = 88.24(2)-degrees, gamma = 79.98(2)-degrees, V = 1859.1(12) angstrom3, and Z = 2.