周期表中从镧开始的十三个金属,一般称为镧系金属或稀土金属,直到近代还没有引起更多人们的注意。某些元素例如镥,对—般化学家来说还是不熟悉的,然而近年来,很多稀土金属有机衍生物已被合成出来。这些有机镧化合物具有丰富的化学内容,它们有时候不同于邻近的过渡金属。作者等发现,烷基镧化合物作为烯烃聚 Thirteen metals in the periodic table starting from lanthanum, commonly referred to as lanthanides or rare earth metals, have not attracted the attention of more people in modern times. Some elements, such as acenaphthene, are not familiar to chemists, but many rare earth metal derivatives have been synthesized in recent years. These organic lanthanides have a rich chemical content, sometimes different from the adjacent transition metals. The authors found that alkyl lanthanum compounds as polyolefins