Subject tetranuclear

The number of 13C NMR studies on metal carbonyls has greately increased over the last few years as shown by the presently available data on tetranuclear carbonyls (Table 11) compared with that available in 1974 when the last review232 on this subject appeared and contained only two references to tetranuclear clusters. 

The tetranuclear complex Co (OH)2Co(en)2 36 + was first prepared by Werner (6) and has subsequently been the subject of several studies (53, 54, 57,156,245 247). Its ammonia analog has already been mentioned in Section IV,A. As mentioned in Section II,B, the en tetranuclear species may exist in eight optically isomeric forms. All eight isomers are formed during the oxidation reaction and have been separated by column chromatography (57). The yields of the isomers decrease in the order A(AAA) > A(AAA) > A(AAA) > A(AAA). The X-ray crystal structures of... 

Tri- and tetranuclear mercuracarbaboranes were recently prepared and were found to bind halide and other anions by forming host-guest complexes such as 4 and 5 [10-19]. The subject has recently been covered by an excellent review [20]. 

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