Coordination compounds, cobalt

At the time of the first volume of CCC(1987), the biological chemistry of cobalt was almost exclusively concerned with the cobalamins. The field has expanded and developed markedly since then. New cobalt-containing proteins have been characterized and applications of traditional cobalt coordination compounds in biology developed. These developments are illustrated below in some detail, as the field was not reviewed in the first edition. 

The experiments by Werner and his associates on cobalt coordination compounds accomplished two things they increased the chemical knowledge in this extensive area (more than 700 compounds) and helped Werner develop his ideas on coordination theory and stereochemistry. It was only after he had received the Nobel Prize (191S) and after his death (1919) that his ideas of primary and secondary valence were confirmed. Unfortunately, Werner s span of active life was short (1893-1915). A listing is given of his co-workers who researched cobalt compounds. These resulted in 52 papers by Werner, 75 with co-authors, and at least 10 unpublished theses. Research to 1960 on cobalt coordination compounds has been summarized in Gmelins Handbuch der anorganischen Chemie (1963). 

A Ifred Werner (December 12, 1866-November 15, 1919) during his professionally active life (1893-1915) contributed extraordinarily to the knowledge of cobalt coordination compounds. These compounds, no doubt, helped him develop his ideas that resulted in the two theories that made him a leader in two phases of twentieth century chemistry coordination theory and stereochemistry. 

EXPERIMENT 2.3 ANALYSIS OF COBALT COORDINATION COMPOUNDS I SPECTROPHOTOMETRIC DETERMINATION OF COBALT1-5... 

Each student must dry his/her sample of cobalt coordination compound in a weighing bottle (top ajar) for about 1 h at 120 °C and cool to room temperature in a desiccator. It is recommended that this be carried out during a pre-lab lecture or at the start of Procedure 2.2.a. 

Procedure 2.3.b Preparation of the Cobalt Coordination Compound Sample Solution—Decomposition and Reduction of Cobalt(lll) to Cobalt(ll). 

Remove your dried and cooled sample of cobalt coordination compound from the desiccator, and immediately weigh (by difference, using an analytical balance)... 

EXPERIMENT 2.4 ANALYSIS OF COBALT COORDINATION COMPOUNDS II—ACID-BASE TITRIMETRIC DETERMINATION OF AMMONIA16 Level 2... 

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