Complex sentence: Uranocene U (C 8 H 8) 2 is the most notable cyclooctatetraenide of the f-block elements and one of the first organouranium compounds to be synthesized.
Split into simpler sentences: Uranocene U (C 8 H 8) 2 is the organouranium compound with the formula cyclooctatetraenide. It was one of the first organouranium compounds to be synthesized.