TRANSFORMATION OF ALKENYL-N-ARYLTHIOAMIDO LIGANDS INTO QUINOLINE-2-THIOLATE LIGANDS IN DIRHENIUM CARBONYL-COMPLEXES

Irradiation of the alkenyl-N-arylthioamido complexes Re(CO)4[(E)-HC=C(CO2Me)C=N-(C6H4-P-R)S]Re(CO)4, 1a-c, R = H, Me, Cl, in the presence of iodine yielded a mixture of four products: Re2(CO)7[mu-2-S-3-CO2Me-6-RNC9H4](mu-I), 2a-c, R=H, Me, Cl; Re(CO)4[(E)-HC=C-(CO2Me)C=N(C6H4-P-R)S]Re2(CO)7(mu-I), 3a-c, R = H, Me, Cl; Re(CO)4[(E)-HC=C(CO2Me)C-(NHC6H4-P-R)=S]Re(CO)4(I),4a-c, R = H, Me, Cl; Re(CO)4(2-S-3-CO2Me-6-RNC9H4), 5a-c, R = H, Me, Cl, with compounds 5 being the major products. Compounds 2a-c, 4a-c, and 5a-c are new. Compounds 4a-c were also obtained from the reaction of 1a-c with HI. UV irradiation of 1b in the absence of iodine yielded the compounds Re2(CO)8[mu-2-S-3-CO2Me-6-MeNC9H4](mu-H), 6b, Re2(CO)7[mu-2-S-3-CO2Me-6-MeNC9H4](mu-H), 7b, and 5b, while UV irradiation of 6b yielded 7b and 5b plus Re3(CO)12(mu-H)3. UV irradiation of 2b in the presence of CO yielded 5b plus Re2(CO)8(mu-I)2. UV irradiation of 3b also yielded 2b, 5b, and some 7b. Treatment of 7b with iodine yielded 2b. Finally, from the UV irradiation of 5b the dimer [Re(CO)3(2-S-3-CO2Me-6-MeNC9H4)]2, 8b, was obtained in 57 % yield. Complexes 2b, 4c, 5b, 6b, 7b, and 8b were characterized by single crystal X-ray diffraction analyses. The compounds 2 and 5-8 all contain substituted quinoline-2-thiolate ligands formed by the coupling of one of the carbon atoms of the aryl ring to the hydrogen-substituted carbon atom of the alkenyl group. Crystal data: (for 2b.CH2Cl2) space group = P1BAR, a = 10.204(2) angstrom, b = 13.733(6) angstrom, c = 9.877(2) angstrom, alpha = 91.18(3)-degrees, beta = 96.17(3)-degrees, gamma = 74.78(3)-degrees, Z = 2, 2746 reflections, R = 0.038; (for 4c) space group = P2(1)/c, a = 7.027(2) angstrom, b = 10.894(2) angstrom, c = 34.470(4) angstrom, beta = 92.75(1)-degrees, Z = 4, 1762 reflections, R = 0.028; (for 5b) space group = P1BAR, a = 11.250(2) angstrom, b = 11.905(2) angstrom, c = 7.312(1) angstrom, alpha = 107.23(1)-degrees, beta = 106.59(1)-degrees, gamma = 67.73(1)-degrees, Z = 2, 1716 reflections, R = 0.024; (for 6b) space group = P2(1)/c, a = 18.603(3) angstrom, b = 17.987(3) angstrom, c = 7.223(1) angstrom, beta = 90.05(2)-degrees, Z = 4, 2099 reflections, R = 0.025; (for 7b) space group = P1BAR, a = 11.877(2) angstrom, b = 13.519(2) angstrom, c = 7.876(1) angstrom, alpha = 98.14(1)-degrees, beta = 103.79(1)-degrees, gamma = 109.25(2)-degrees, Z = 2, 1677 reflections, R = 0.030; (for 8b) space group = C2/c, a = 20.727(4) angstrom, b = 10.669(2) angstrom, c = 14.487(2) angstrom, beta = 106.76(1)-degrees, Z = 4, 1827 reflections, R = 0.022.