Vanadium (β-(Dimethylamino)ethyl)cyclopentadienyl Complexes with Diphenylacetylene Ligands

Reduction of the V(III) (β-(dimethylamino)ethyl)cyclopentadienyl dichloride complex [η5:η1-C5H4(CH2)2NMe2]VCl2(PMe3) (1) with 1 equiv of Na/Hg yielded the V(II) dimer {[η5:η1-C5H4(CH2)2NMe2]V(μ-Cl)}2 (2). This compound reacted with diphenylacetylene in THF to give the V(II) alkyne adduct [η5:η1-C5H4(CH2)2NMe2]VCl(η2-PhCCPh) (3). Further reduction of 2 with Mg in the presence of diphenylacetylene resulted in oxidative coupling of two diphenylacetylene groups to yield the diamagnetic, formally V(V), bent metallacyclopentatriene complex [η5:η1-C5H4(CH2)2NMe2]V(C4Ph4) (4).

通过将 V(III) (β-(二甲基氨基)乙基)环戊二烯基二氯化物复合物 [η5:η1-C5H4(CH2)2NMe2]VCl2(PMe3) (1) 与 1 等效的 Na/Hg 反应，得到 V(II) 二聚体 {[η5:η1-C5H4(CH2)2NMe2]V(μ-Cl)}2 (2)。该化合物与二苯乙炔在四氢呋喃中反应，生成 V(II) 烯烃加成物 [η5:η1-C5H4(CH2)2NMe2]VCl(η2-PhC≡CPh) (3)。在二苯乙炔的存在下，将 2 与 Mg 一起进一步还原，导致两个二苯乙炔基团发生氧化偶联，生成抗磁性、形式上为 V(V) 的弯曲金属环戊三烯复合物 [η5:η1-C5H4(CH2)2NMe2]V(C4Ph4) (4)。