Diligating Tripodal Amido-Phosphine Ligands: the Effect of a Proximal Antipodal Early Transition Metal on Phosphine Donor Ability in a Building Block for Heterometallic Complexes
作者:Hua Han、Mona Elsmaili、Samuel A. Johnson
DOI:10.1021/ic060692d
日期:2006.9.1
P(CH2NH-3,5-(CF3)2C6H3)3 (1a), P(CH2NHPh)3 (1b), and P(CH2NH-3,5-Me2C6H3)3 (1c), react with the reagents Ti(NMe2)4 and tBuN=Ta(NEt2)3 to generate metal complexes of the type P(CH2NAr(R))3TiNMe2 (2a-c) and P(CH2NAr(R))3Ta=NtBu (3a-c) (where Ar(R) = 3,5-(CF3)2C6H3, Ph, and 3,5-Me2C6H3). Due to ring strain, the phosphine lone pair cannot chelate and is available to bind a second metal, and this feature can
配体前体P(CH2NH-3,5-(CF3)2C6H3)3(1a),P(CH2NHPh)3(1b)和P(CH2NH-3,5-Me2C6H3)3(1c)与试剂反应Ti(NMe2)4和tBuN = Ta(NEt2)3生成P(CH2NAr(R))3TiNMe2(2a-c)和P(CH2NAr(R))3Ta = NtBu(3a-c)类型的金属配合物(其中Ar(R)= 3,5-(CF3)2C6H3,Ph和3,5-Me2C6H3)。由于环应变,膦孤对不能螯合并且可用于结合第二种金属,并且该特征可用于合成杂金属多核络合物。在早期过渡金属与酰胺供体的配位过程中观察到的31P化学位移很大,并且在这些配位化合物中CPC结合角增加的方向相反。这些不寻常的变化是由于P-Ti和P-Ta距离明显短于范德华半径之和。2c与Ni(CO)4的反应首先产生双金属配合物(CO)3Ni [P(CH2N-3,5-Me2C6H3)3Ti