Barium cyclopentadienyl compounds

The barium phosphonium dibenzylide 18, first organobarium compound not belonging to the cyclopentadienyl series, was isolated at the same time (Scheme 12) [58]. In the latter, the Ba + ion is encapsulated by two C2-symmet-ric phosphonium ligands of opposite chirality. 

Calcium, Strontium, and Barium,57 The organic compounds of these metals are of little synthetic use compared to the magnesium compounds. The most interesting and best studied are the cyclopentadienyls and related compounds.58 These can be... 

Recently some papers have appeared which deal with the related structures of the heavier alkali earth metal organometallic compounds. Cyclopentadienyl derivatives of calcium, strontium, and barium proved to possess sufficient stability to permit their synthesis and subsequent crystallization. These results are briefly included in this review (see Table 111). 

T.P. Hanusa (2000) Coordination Chemistry Reviews, vol. 210, p. 329 - Non-cyclopentadienyl organometallic compounds of calcium, strontium and barium . 

Calcium, strontium, and barium. Very little is known about the organic compounds of these metals. The only properly characterized derivatives are the evidently ionic cyclopentadienyls (C5Hs)2M, the complex ethyls M(AlEt4)2 (M = Ca, Sr, Ba) and the red complex Ph3CCaQ(THF)2 (from calcium amalgam and PhsCQ in THF). Some alkylcalcium halides have also been obtained in solution in ether and in THF. 

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