the dppv and the central NH or CH2 of the larger dithiolates. The Fe(CO)3 subunit in 1(CO)4 undergoes substitution with PMe3 and cyanide to afford 1(CO)3(PMe3) and (Et4N)[1(CN)(CO)3], respectively. Kinetic studies show that 1(CO)4 reacts faster with donor ligands than does its parent Fe2(S2C2H4)(CO)6. The rate of reaction of 1(CO)4 with PMe3 was first order in each reactant, k = 3.1 x 10(-4) M(-1) s(-1)
Fe2(S2
C2H4)(CO)6与顺式Ph2PCH = CHPPh2(dppv)的反应产生Fe2(S2 )(CO)4(dppv),1(CO)4,其中dppv
配体螯合到单个
铁中心。NMR分析表明,在1(CO)4中,dppv
配体跨越轴向和基础配位点。除轴向基础异构体外,1,3-丙二
硫醇盐和氮杂二
硫醇盐衍
生物还作为二基础异构体存在。密度泛函理论(DFT)计算表明,dppv与较大的二
硫醇盐的中心NH或
CH2之间的非键相互作用会破坏轴向-基础异构体的稳定性。1(CO)4中的Fe(CO)3亚基经过PMe3和
氰化物取代,分别得到1(CO)3(PMe3)和(Et4N)[1(CN)(CO)3]。动力学研究表明1(CO)4与供体
配体的反应比其母体Fe2(S2 )(CO)6更快。1(CO)4与PMe3的反应速率在每种反应物中均为一阶,k = 3.1 x 10(-4)M(-1)s(-1)。该取代反应的激活参数DeltaH