Coordination Group

Negatively coordinated groups are given before neutral coordinated groups in the examples of Werner scheme names above. Ewens and Bassett presented good reasons why that order should be reversed. The lUPAC rules (20) recommend that ligands be cited in alphabetical order regardless of their... 

Figure 13.2 The cubic structure of skutterudite (C0AS3). (a) Relation to the ReOs structure (b) unit cell (only sufficient Co-As bonds are drawn to show that there is a square group of As atoms in only 6 of the 8 octants of the cubic unit cell, the complete 6-coordination group of Co is shown only for the atom at the body-centre of the cell) and (c) section of the unit cell showing CoAsg octahedra comer-linked to form AS4 squares.

It is only recently that a coordinated group of data became available for wetted areas in Raschig ring and Berl saddle packing [65]. 

In its complex compounds, of which there are many thousands, Co almost invariably has a +3 oxidation number. Apparently, Co+s ion accompanied by six coordinating groups is particularly stable. Cobalt complexes are important in biochemistry. Some enzyme reactions go through a cobalt-complexing mechanism. Although only small traces are needed, cobalt is essential to the diet. 

Charges are omitted for simplicity M denotes [f CTjSn(IV)] (m = 1-3) and L the ligand molecule deprotonated on its coordinating groups and H the protonation. 

Occurrence, Coordination Geometry, Coordinating Groups, and Function of Zinc(II) in Some Metalloenzymes... 

Atwood DA, Hutchison AR, Zhang Y (2003) Compounds Containing Five-Coordinate Group 13 Elements 105 167-201... 

Imidazole is of particular relevance to biological mimic ligands due to the presence of histidine as a coordinating group for zinc in biological systems and has been a particular target for zinc complex formation. 

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