丁二烯催化环化三聚中多金属的协同效应

Synergic Effect of Multimetallic Catalysts in the Cyclotrimerization of Butadiene

研究了第二过渡金属化合物对TiCl4／AlEt1.46Cl1.54体系催化了二烯环化三聚的多金属协同效应．结果表明，极少量的第二过渡金属化合物，如Cr（acac）3、Mn（acac）3、NiCl2、ZrCl4等加入TiCl4／AlEt1.46Cl1.54体系后不同程度地提高了丁二烯环化三聚的选择性（除Ni（OAc）2外），并改变了体系的最大速率和催化剂效率．第二过渡金属化合物需在亚催化活性物种形成前加入才能显示出多金属的协同效应，但当其与AlEt1.46Cl1.54单独组成催化体系时，会使丁二烯二聚（Cr，Mn，Fe，Zr等盐）或高聚（Co，Ni盐）．

The synergic effect of multimeta1lic catalysts by the addition of the second transi-tion metal compound to the TiCl4/AlEt1.46Cl1.54 system has been investigated in the cy-clotrimerization of butadiene. The experimental results indicate that with the addition of a very small amount of the second metal compound, Cr(acac)3, Mn(acac)3, NiCl2, ZrCl4 etc.to the Ti-Al system, the selectivity of cyclotrimerization of butadiene was improved(except Ni (OAc)2), the maximum turnover frequency (TOFmax.) and turnover (TO ) were changed.The second metal compound should be added to Ti-Al system before Ti active species formed, otherwise no synergic effect will be observed- The second metal compound/AlEt1.46Cl1.54 systems alone can catalyze the dimerization(Cr, Mn, Fe, Zr sa1ts) or polymerization (Ni, Co salts) of butadiene.