Cyanide complexes, high oxidation state

Use of selenosulfite in combination with EDTA complexed Cd, eliminated the elemental Se contamination, and improved the photoresponse of the as-formed deposits [132]. A second method for avoiding conproportionation, also suggested by Skyllas-Kazacos, was to use a cyanide solution to dissolve elemental Se (or Te) and high concentrations of CdCU [127]. Again, the Se was felt to be in the zero oxidation state. 

Transition metal complexes (1) of 1,2-dicyanoethylene-1,2-dithiol (maleonitrile), mnt, have received special study since this ligand can stabilize transition metals in a variety of oxidation states and the high electron affinity of the terminal cyanide groups aids the delocalization of charge within the complex, thus reducing potential coulombic repulsions. 

Isocyanide appears to be a stronger a-donor than CO, and also a stronger Ti-acceptor than CN and is capable of forming complexes in high and low oxidation states. From Tables 21 and 22 one can see that the number of terminal isocyanides is nearly double that of terminal cyanides. As for cyanides, the terminal bonding mode MC3 of isocyanides is far more common than the two bridging modes of MC4 and MC5. 

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