Noun
English Wikipedia has an article on:metalloceneWikipedia
metallocene (plural metallocenes)
(organic chemistry) Any of a class of organic compounds containing two cyclopentadienyl anions and a transition metal whose bonding involves overlap of ns and np orbitals of the metal with molecular orbitals of appropriate symmetry of each cyclopentadienyl ring; the rings are parallel to each other, or sometimes canted.
1 H NMR chemical shifts for diamagnetic organotransition-metal compounds is usually observed between 25 and 40 ppm, but this range is much more narrow for diamagnetic metallocene complexes, with chemical shifts usually observed between 3 and 7 ppm. Source: Internet
According to the IUPAC definition, a metallocene contains a transition metal and two cyclopentadienyl ligands coordinated in a sandwich structure, i.e., the two cyclopentadienyl anions are on parallel planes with equal bond lengths and strengths. Source: Internet
Organoberkelium compounds Berkelium forms a trigonal (η 5 –C 5 H 5 ) 3 Bk metallocene complex with three cyclopentadienyl rings, which can be synthesized by reacting berkelium(III) chloride with the molten beryllocene ( Be (C 5 H 5 ) 2 ) at about 70 °C. Source: Internet
Derivatives main After the discovery of ferrocene, the synthesis and characterization of derivatives of metallocene and other sandwich compounds attracted researchers’ interests. Source: Internet
Mechanism of Ziegler–Natta polymerization The structure of active centers in Ziegler–Natta catalysts is firmly established only for metallocene catalysts. Source: Internet
The complexes are activated using MAO, as is done for metallocene catalysts. Source: Internet