基于钒的预催化剂，带有贫化的 1,3-杯[4]芳烃，用于乙烯或 ε-己内酯聚合。

Vanadium-based pro-catalysts bearing depleted 1,3-calix[4]arenes for ethylene or ε-caprolactone polymerization.

机构信息

Energy Materials Laboratory, School of Chemistry, University of East Anglia, Norwich NR4 7TJ, UK.

出版信息

Inorg Chem. 2011 Aug 15;50(16):7838-45. doi: 10.1021/ic2010198. Epub 2011 Jul 12.

DOI:10.1021/ic2010198

Abstract

Reaction of [V(X)(OR)(3)] (X = O, Np-tolyl, R = nPr, tBu) with 5,11,17,23-tBu-25,27-dihydroxycalix[4]arene (LH(2)) led to the formation of V(X)(OR)L X = O, R = nPr (1); X = Np-tolyl, R = nPr (2); X = Np-tolyl, R = tBu (3) as the major product. In the case of X = O, the minor hydrolysis product {VO(OnPr)(μ-O)L}(2) (4) has also been characterized. Complexes (1)-(4), in the presence of the co-catalyst dimethylaluminum chloride and the reactivator ethyltrichloroacetate, are highly active (≤16,400 g/mmol h bar), thermally stable pro-catalysts for the polymerization of ethylene. The use of silica supports with (1) and (2) under slurry conditions yielded polymer with activities ≤30 g/mmol h. Complexes (1)-(3) have also been screened as pro-catalysts for the ring-opening polymerization of ε-caprolactone; the conversion rate order (1) (94%) > (2) (46%) > (3) (20%) was observed at 80 °C over 72 h.

摘要

[V(X)(OR)(3)]（X=O、Np-甲苯基、R=nPr、tBu）与 5,11,17,23-tBu-25,27-二羟基杯[4]芳烃（LH(2)）反应生成了V(X)(OR)L X=O、R=nPr（1）；X=Np-甲苯基、R=nPr（2）；X=Np-甲苯基、R=tBu（3）作为主要产物。在 X=O 的情况下，还鉴定了少量水解产物{VO(OnPr)(μ-O)L}(2)（4）。在助催化剂二甲基铝氯和活化剂三氯乙酸乙酯的存在下，配合物（1）-（4）是高效（≤16,400 g/mmol h bar）、热稳定的乙烯聚合前体。在淤浆条件下使用（1）和（2）的硅胶载体，得到的聚合物的活性≤30 g/mmol h。配合物（1）-（3）也被筛选为ε-己内酯开环聚合的前体催化剂；在 80°C 下反应 72 小时，转化率顺序为（1）（94%）>（2）（46%）>（3）（20%）。