Cobalt complexes, absorption electronic configuration

Recent infrared absorption and x-ray diffraction studies have shown that metals of the first transition series normally form M—N bonds with the thiocyanate group.12-14 X-ray diffraction studies have shown that the isothiocyanato groups are trans to each other in the tetrapyridine complexes of iron, cobalt, and nickel 14-17 this configuration has been confirmed for the iron compound by electronic spectra.4... 

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