Department of Chemistry, The Ohio State University, Columbus, OH 43210, USA.
Dalton Trans. 2009 Nov 14(42):9237-45. doi: 10.1039/b910669c. Epub 2009 Sep 2.
The bulky diimine CH(2){C((t)Bu)N-2,6-Pr(i)(2)C(6)H(3)}(2), BDIH, is shown to exist in two isomers trans-trans, 1a and cis-trans, 1b that interconvert slowly on the NMR time-scale. Treatment of the diimine with (n)BuLi in hexane proceeds slowly to give the lithium beta-diketoiminate LiBDI, 2, which upon hydrolysis yields the eneimine tautomer of BDIH which has been characterized by X-ray studies in three rotamers, 3a, 3b and 3c. Dialkylmetal compounds (M = Mg, R = Bu; M = Zn, R = Et) react with either 1 or 3 in hydrocarbon and ether solvents to give BDIMg((n)Bu)THF, 4, and BDIZnEt, 5, which have been structurally characterized. M(N(SiMe(3))(2))(2) compounds where M = Mg, Zn or Ca failed to react with either 1 or 3 in hydrocarbon solvents. The reactions between ZnCl(2) and 2 yield BDIZnCl, 6, and a further reaction with LiNMe(2) yields BDI*ZnNMe(2), 7. The compounds 5 and 6 are shown to contain trigonal planar, M(2+) ions. Compounds 4, and 7 initiate ring-opening polymerization, ROP, of rac-lactide to give atactic polylactide, PLA. The rate of ROP depends on the metal M = Mg > Zn and is slower than that observed for the related beta-diketoiminate complexes where the bulky-(t)Bu group is replaced by Me.
庞大的二亚胺 CH(2){C((t)Bu)N-2,6-Pr(i)(2)C(6)H(3)}(2), BDIH，被证明存在两种异构体 trans-trans，1a 和 cis-trans，1b，它们在 NMR 时间尺度上缓慢互变。用（n）BuLi 在己烷中处理二亚胺反应缓慢，生成锂β-二酮亚胺 LiBDI，2，它在水解后生成 BDIH 的烯胺互变异构体，已通过 X 射线研究在三种旋转异构体 3a、3b 和 3c 中进行了表征。二烷基金属化合物（M = Mg，R = Bu；M = Zn，R = Et）与 1 或 3 在烃和醚溶剂中反应，生成 BDIMg((n)Bu)THF，4，和 BDIZnEt，5，它们的结构已得到表征。M(N(SiMe(3))(2))(2) 化合物，其中 M = Mg、Zn 或 Ca，在烃溶剂中均不能与 1 或 3 反应。ZnCl(2)和 2 之间的反应生成 BDIZnCl，6，和与 LiNMe(2)的进一步反应生成 BDI*ZnNMe(2)，7。化合物 5 和 6 被证明含有三角平面的 M(2+)离子。化合物 4 和 7 引发 rac-丙交酯的开环聚合，ROP，生成无规立构聚丙交酯，PLA。ROP 的速率取决于金属 M = Mg > Zn，并且比相关的β-二酮亚胺络合物慢，其中庞大的-(t)Bu 基团被 Me 取代。
