Organometallic sandwich compounds

Ernst Fischer Germany organometallic sandwich compounds... 

CAS 102-54-5. The first organometallic sandwich compound (synthesized in 1951), which served as a prototype for metallocenes. Such compounds are based on cyclic unsaturates combined with a transition metal or its halide. 

Fischer, Ernst Otto. (1918- ). A German inorganic chemist who won the Nobel Prize for chemistry in 1973 with Wilkinson for their independent work on the chemistry of organometallic sandwich compounds. He was the contributor to many publications on organometallic chemistry. His education and work were primarily in Munich. 

An interesting example of the interplay between solid-state clathrands and solution-phase cavitands is provided by cyclotriveratrylene (CTV, 8). In the solid state, the saucer-shaped CTV molecules stack one on top of another in the two most common phases (x and and hence, while the molecules possess shallow molecular cavities, they do not include guests such as solvent molecules, which instead are located in voids between host stacks. However, larger guests such as buckminsterfuller-ene C6o, organometallic sandwich compounds,or carboranes form intracavity inclusion compounds, and the association persists in the solid state, with potential applications, for example, in the selective purification of fullerenes. Thus, CTV is both a cavitand and a clathrand. The cavitand behavior of CTV is highlighted by the chemistry of the double-CTV cryptophanes that form very stable solution complexes with a variety of halocarbon guests. 

T.J. Colacot and N.S. Hosmane (2005) Zeitschrift fur anorganische tmd allgemeine Chemie, vol. 631, p. 2659 - Organometallic sandwich compounds in homogeneous catalysis an overview . 

An interesting spin-off from the deshielding associated with a small homo-lumo gap is that it may correlate with catalytic or other reactivity, as observed for organometallic (sandwich) compounds in 59( 0 or resonance. 

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