Stereochemically non-rigid transition metal complexes of 2,6-bis[(1-phenylimino)ethyl]pyridine (BIP) Part 2. Dynamic NMR studies of fac-[ReX(CO)3(BIP)] (X = Cl, Br, or I). Crystal structure of fac-[ReBr(CO)3(BIP)]
作者:Keith G. Orrell、Anthony G. Osborne、Vladimir Šik、Mateus Webba da Silva、Michael B. Hursthouse、David E. Hibbs、K.M. Abdul Malik、Nikolay G. Vassilev
DOI:10.1016/s0022-328x(96)06933-1
日期:1997.6
The complexes fac-[ReX(CO)3(BIP)] (X = Cl, Br or I; BIP = 2,6-bis[(1-phenylimino)ethyl]pyridine) have been synthesised and characterised as involving BIP as a bidentate chelate ligand. In solution the ligand exists in three conformational forms, namely E,E- and both distal and proximal E,Z-isomers. 2D-EXSY NMR has been used to measure 1,4-metallotropic shifts of the ReX(CO)3 moiety between equivalent
已经合成了配合物fac- [ReX(CO)3(BIP)](X = Cl,Br或I; BIP = 2,6-双[(1-苯基亚氨基)乙基]吡啶),并被表征为涉及BIP作为二齿螯合配体。在溶液中,配体以三种构象形式存在,即E,E-以及远端和近端的E,Z-异构体。2D-EXSY NMR已用于测量当量E,E形式,亚胺官能团的E,Z-异构化和该化合物的悬挂臂的受限CC旋转之间ReX(CO)3部分的1,4-金属向位移BIP配体。活化能ΔG ≠所有这些过程的(298.15 K)值都相当,范围在79–88 kJ mol -1之间,并且基本上与卤素无关。还检测到与重新配位的氮相连的苯环的旋转受限,ΔG ≠ = 67.3±0.2 kJ mol -1。fac- [ReBr(CO)3(BIP)]的晶体结构证实了亚胺侧基官能团的E-构型及其N原子顺式与吡啶基氮。