Ligand exchange photochemistry of M2(CO)4(μ-η5,η5-C5H4CH2C5H4) (M = Fe or Ru) and thermal acetylene exchange of Ru2(CO)(μ-CO)[μ-η1:η1-(C6H5)2C2](μ-η5,η5-C5H4CH2C5H4) -: The molecular structures of Ru2(CO)(σ-C6H5)(μ-CO)[μ-P(C6H5)2](μ-η5,η5-C5H4CH2C5H4) and Ru2(CO)(μ-CO)[μ-η1,η3-C6H5C=C(C6H5)O]-(μ-η5,η5-C5H4CH2C5H4)

Photolysis of Fe-2(CO)(4)(mu-eta(5),eta(5)-C5H4CH2C5H4) in the presence of phosphines or phosphites results in the formation of simple carbonyl substitution products Fe-2(CO)(mu-CO)(2)L(mu-eta(5),eta(5)-C5H4CH2C5H4) or Fe-2(mu-CO)(2)L-2(mu-eta(5),eta(5)-C5H4CH2C5H4). Acetylenes react photochemically with the diiron compound to give vinylketone-bridged derivatives of the form Fe-2(CO)(mu-CO)[mu-eta(1):eta(3)- RC=C(R)CO](mu-eta(5),eta(5)-C5H4CH2C5H4), where R = CH3O2C and C6H5. Reaction of Ru-2(CO)(4)(mu-eta(5),eta(5)-C5H4CH2C5H4) With triphenylphosphine under photochemical conditions resulted in loss of two carbon monoxide ligands and P-C insertion by ruthenium to yield Ru-2(CO)(sigma-C6H5)(mu-CO)[mu-P(C6H5)(2)](mu-eta(5),eta(5)-C5H4CH2C5H4). Photolysis of Ru-2(CO)(4)(mu-eta(5),eta(5)-C5H4CH2C5H4) With diphenylacetylene gave the previously reported Ru-2(CO)(2)(mu-CO)[mu-eta(1):eta(1)-(C6H5)(2)C-2](mu-eta(5),eta(5)-C5H4CH2C5H4) and an air oxidation product, Ru-2(CO)(mu-CO)[mu-eta(1):eta(3)-C6H5C=C(C6H5)O](mu-eta(5),eta(5)-C5H4CH2C5H4). The diphenylacetylene derivative underwent acetylene exchange, but did not undergo exchange with triphenylphosphine. All compounds have been characterized by spectroscopic methods, elemental analysis and/or mass spectroscopy. The molecular structures of two ruthenium compounds were determined by X-ray crystallography. Ru-2(CO)(sigma-C6H5)(mu-CO)[mu-P(C6H5)(2)](mu-eta(5),eta(5)-C5H4CH2C5H4): monoclinic, P2(1)/c, a = 13.902(3) Angstrom, b = 13.283(3) Angstrom, c = 14.426(4) Angstrom, beta = 101.62(2)degrees, V = 2609(1) Angstrom(3), z = 4, R(F)= 3.98%. RU2(CO)(mu-CO)[mu-eta(1):eta(3)- C6H5C=C(C6H5)O](mu-eta(5),eta(5)-C5H4CH2C5H4): orthorhombic, Pccn, a = 15.000(4) Angstrom, b = 15.662(4) Angstrom, c = 19.053(4) Angstrom, V = 4476(2) Angstrom(3), z = 8, R(F)= 3.05%. (C) 1997 Elsevier Science S.A.