Square planar complexes of the type [2-(1-aminoethyl)phenyl-κ2C1,N]chloro(py-κN)palladium(II)
(py = pyridine derivative) have been prepared by cyclopalladation of 1-phenylethylamine. When opposite enantiomers of the chiral amine and different pyridine ligands were coordinated to the metal, quasiracemic complexes were obtained. The racemisation speed of solutions containing equimolar amounts of such quasiracemic complexes was used to test the compounds for inertness: slow ligand exchange was found for methylated pyridines. Enantiomerically pure complexes of opposite chirality with the electron rich ligands 2,6-collidine and 2,4,6-lutidine were successfully cocrystallised: They form a well-ordered binary solid in which four independent molecules, two of each constituent, are related by pseudo symmetry operations. This quasiracemate as well as its components and the true racemates of the latter were characterised by single crystal X-ray diffraction. The heterochiral crystals, both the cocrystal as well as the racemates, show better space filling than the homochiral solids.
通过环
钯化 1-苯基
乙胺,制备了[2-(1-
氨基乙基)苯基-κ2C1,N]
氯(
吡-κN)
钯(II)(
吡=
吡啶衍生物)类型的方形平面配合物。当手性胺的对映体和不同的
吡啶配体配位到
金属上时,就得到了类
吡啶络合物。我们利用含有等摩尔量此类准手性配合物的溶液的消旋化速度来测试化合物的惰性:发现甲基化
吡啶的
配体交换速度较慢。与富含电子的
配体 2,6-Collidine 和 2,4,6-Lutidine 具有相反手性的对映体纯络合物成功地进行了共晶体化:它们形成了一种秩序井然的二元固体,其中四个独立的分子(每个成分两个)通过假对称操作相互关联。通过单晶 X 射线衍射,对这种准外消旋体及其成分和后者的真正外消旋体进行了表征。异手性晶体(包括共晶体和外消旋体)比同手性固体显示出更好的空间填充性。