Adduct Formation of Dichloridodioxidomolybdenum(VI) and Methyltrioxidorhenium(VII) with a Series of Bidentate Nitrogen Donor Ligands
作者:Ahmad M. Al‐Ajlouni、Alev Günyar、Ming‐Dong Zhou、Paul N. W. Baxter、Fritz E. Kühn
DOI:10.1002/ejic.200801103
日期:2009.3
do not form adducts with MTO, and only 6,6'-dimethyl- and 6,6'-diphenyl-2,2'-bipyridines form adducts with MoO(2)Cl(2). However, these adducts are much less stable than other methyl derivatives of 2,2'-bipridine adducts. The steric strain between the two methyl groups in 3,3-dimethyl-2,2'-bipyridine influences the bipyridine planarity upon complexation and reduces the adduct stability. The thermodynamic
MoO(2)Cl(2) 和 (CH(3))ReO(3) (MTO) 的各种双齿 N 碱加合物的稳定性在 thf 和 CH(2)Cl(2) 作为溶剂进行了调查。形成常数由基于 1:1 加合物形成的分光光度数据确定。[MoO2Cl(2)L(2)](L(2) = 二齿氮配体)的加合物形成常数比 [(CH(3))ReO(3) 高 10(4)-10(6) 倍)L(2)] 在相同条件下具有相同的配体。两个系统的加合物稳定性对配体的电子性质非常敏感,并随着它们的供体能力而增加。形成常数与西格玛的哈米特相关性给出了相对较大的反应常数负值(rho(Re) = -5.9,rho(Mo) = -6.6)。稳定性还受空间和应变因素的影响。因此,空间位阻的 6,6'-二取代-2,2'-联吡啶不与 MTO 形成加合物,只有 6,6'-二甲基-和 6,6'-二苯基-2,2'-联吡啶与 MoO(2)Cl(2) 形成加合物。然而,这些加合物的稳定性远低于