The Crystal and Molecular Structure of Tricyclopentadienylethynyluranium(iv)

The history of the sigma-bonded organometallic derivatives of the lanthanide and actinide elements is in fact the history of the general organometallic chemistry of the metals. In 1938, Plets reported2 the discovery of scandium and yttrium organometallics from the Grignard reactions: However, subsequent studies3 have discounted this early claim.