DIRHENIUM COMPLEXES CONTAINING LINKED DIPHENYLACETYLENE MOLECULES FROM THE PHOTOREACTION OF H3Re3(CO)12 WITH PhCPhC. CRYSTAL AND MOLECULAR STRUCTURES OF Re2(CO)5(C4Ph4)(C2Ph2) AND Re2(CO)4(C6Ph6)(C2Ph2)*0.5 HEXANE

Article abstract of DOI:10.1016/0022-328X(84)80548-3

Photolysis of H3Re3(CO)12 in presence of diphenylacetylene (DPA) yields Re2(CO)10, HRe(CO)5, and the three alkyne complexes Re2(CO)7(DPA)2, Re2(CO)5(C4Ph4)(DPA) (4) and Re2(CO)4(C6Ph6)(DPA) (3), the latter two which were shown by X-ray crystallography to possess linked DPA ligands.The complex Re2(CO)5(C4Ph4)(DPA) crystallizes in the triclinic space group P<*> (No.2) with a 11.277(3), b 12.301(3), c 14.851(3) Angstroem, α 97.37(2), β 104.68(2), γ 104.49(2) deg, V 1889(2) Angstroem³, and Z = 2.The structure was refined using the 4548 reflections with I <*> 2?(I) to give final residuals of R = 0.031 and R_w = 0.041.Complex 4 possesses a rhenacyclopentadiene group bonded to the second rhenium atom and an η²-DPA ligand bound to the rhenium atom of the metallacycle.The complex Re2(CO)4(C6Ph6)(DPA) crystallizes in the monoclinic space group P2₁/c (No.14) with a 17.048(4), b 16.676(2), c 18.569(4) Angstroem, β 106,70(2) deg, V 5056(3) Angstroem³, and Z = 4.For the 3568 reflections with I <*> 2?(I), the structure refined to R = 0.078 and R_w = 0.074.Three of the DPA molecules in Re2(CO)4(C6Ph6)(DPA) are linked together to form a fly-over bridge between the two rhenium atoms.The fourth DPA molecules is η²-bound to one rhenium center.