Reactions of cyclopentadienyl-naphthalene complexes of lutetium with C- and N-unsaturated compounds: molecular and crystal structure of [CpLu(DME)] 2[1,1-μ-4,4-μ-(Ph)C(Ph)C=C(Ph)C(Ph)

Abstract

The naphthalene derivative of cyclopentadienyllutetium CpLuC 10H 8(THF) 2 ( 1b) (THF-tetrahydrofuran) easily reacts with azobenzene in THF solution to give a dimeric diphenylhydrazido complex [CpLu(THF)] 2(Ph 2N 2) 2 (2). Interaction of CpLuC 10H 8(DME) ( 1a) (DME = 1,2-dimethoxyethane) with diphenylacetylene results in CC coupling and formation of a new type of dinuclear complex with tetracharged bridging [C 4Ph 4] 4− ligand: [CpLu(DME)] 2[1,1-μ-4,4-μ-(Ph)CC(Ph)=C(Ph)C(Ph)] ( 3). The structure of benzene solvate of 3 was determined by X-ray diffraction method (orthorhombic; α = 14.266(8), b = 15.625(7) and c = 21.612(10) Å, space group, Pbcn, Z = 4, 2266 reflections with F > 4 σ( F), R = 0.039). In the molecule of 3 there are two CpLu units joined by a C 4Ph 4 ligand. The shortest LuC μ 2 distances 2.280(7) and 2.336(7) Å are observed between Lu atoms and end C atoms of C 4 fragment. The crystal of 3 contains two enantiomeric forms of molecules connected by symmetry elements. The X-ray data together with the diagmagnetism of 3 suggest in dialkylidene type of bridging ligand in this complex.