Photochemical reaction of W(CO)6 with GeCl4 as a source of germyl and germylene compounds acting as initiators for ring-opening metathesis polymerization of norbornene
作者:Marcin Górski、Andrzej Kochel、Teresa Szymańska-Buzar
DOI:10.1016/j.jorganchem.2006.05.031
日期:2006.8
(ROMP) of cyclic olefins, their reactivity towards norbornene has been studied. In chloroform-d1 solution the ROMP reaction is accompanied by the formation of a new olefin, 2,2′-binorbornylidene (bi-(NBE)), as a result of carbene–carbene coupling. In reaction of norbornene carried out in benzene solution the ROMP reaction is accompanied by the formation of 2-phenylnorbornane (hydroarylation product)
W(CO)6在含有GeCl 4的正庚烷溶液中的光解导致形成两个具有直接WGe键的七配位化合物:[(CO)4 W(μ-Cl)3 W(GeCl 3)( CO)3 ](1)和[(μ-GeCl 2)W(CO)5 } 2 ](2)。这两种钨锗化合物的分子结构已通过单晶X射线衍射研究确定。菌种化合物1是先前合成的钨(II)与d 4的双核络合物电子构型,而在新的亚种金属化合物2中,钨原子以d 6电子构型和直接WW键形式处于零氧化态。为了确定化合物1和2是否可以用作环状烯烃的开环复分解聚合(ROMP)的预催化剂,已经研究了它们对降冰片烯的反应性。在氯仿中-d 1解决方案由于卡宾-卡宾偶合,ROMP反应伴随着新烯烃2,2'-双降冰片烯(bi-(NBE))的形成。在苯溶液中进行的降冰片烯反应中,ROMP反应伴随着2-苯基降冰片烷(氢芳基化产物)和少量的bi-(NBE)的形成。一般地,在烯烃的存在下,化合物2