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Abstract: In the reactions of doubly bridged biscyclopentadienes (C5H3R(CMe2))(C5H3R(SnMe2)) (R = H (1c), t Bu (2)) with M(CO) n (M = Fe, n = 5; M = Mo, n = 6) in refluxing xylene, the bridging SnMe2 group migrates from the ligand to the corresponding transition metal atoms to give compounds (3, meso- and rac-5, meso- and rac-7) containing the M–Sn–M units; together with the corresponding destannylated products (4, meso- and rac-6, meso- and rac-8); the bridging group CMe2 does not migrate. A plausible pathway for migration of SnMe2 group is proposed. The photochemistry of complexes containing the M–Sn–M unit was also studied. The molecular structures of cis-2, rac-5, and meso-7 were determined by X-ray diffraction. [Copyright &y& Elsevier]

Abstract: Doubly bridged biscyclopentadienyl diruthenium complexes (CR2)(EMe2)[(η 5-C5H3)Ru(CO)2]2 (R = Me, E = Si (2), Ge (5); R = H, E = Si (7), Ge (10)) were synthesized, and fully characterized by 1H NMR, IR, EA and single crystal X-ray diffraction. Due to the rigid double-bridged biscyclopentadienyl ligands and the long Ru–Ru bonds in their structures, a series of reactions about (CMe2)(SiMe2)[(η 5-C5H3)Ru(CO)2]2 (2), as a representative for this type of complexes, were carried out: 2 reacted with halogens to give unexpected halogen-bridged products (CMe2)(SiMe2)[(η 5-C5H3)2Ru2(CO)3(X)](μ-X) (X = I (12), or Br (14)), in addition to the normal Ru–Ru-cleaved compounds (CMe2)(SiMe2)[(η 5-C5H3)Ru(CO)2X]2 (X = I (11), or Br (13)); UV photolysis of 2 with PPh3 resulted in loss of two carbon monoxide ligands and P–C insertion by ruthenium to yield the complex (CMe2)(SiMe2)[(η 5-C5H3)2Ru2(CO)2(σ-Ph)][μ-PPh2] (15); with C2Ph2 yielded [(CMe2)(SiMe2)(η 5-C5H3)2]Ru2(CO)[η 2:η 4-μ 2-C(Ph)C(Ph)C(Ph)C(Ph)] (16). Reactivity of doubly bridged ruthenium complex 2 with the respective non-bridged and singly bridged analogues was compared. The molecular structures of 12, 15 and 16 were also determined by X-ray diffraction. [Copyright &y& Elsevier]