Bioinorganic complexes

Bioinorganic complexes Bioinorganic complexes include ligands that form in nature. These include side chains of amino acids, and other ligands that bond to proteins. Turn to Chapter 17 for more details on... 

Transition metal thiometalates properties and significance in complex and bioinorganic chemistry. A. Muller, E. Diemann, R. Jostes and H. Bogge, Angew. Chem., Int. Ed. Engl., 1981, 20, 934-955 (227). 

Complexes of molybdenum and tungsten with bidentate sulfur ligands have been investigated extensively. In recent years, the work in this field has been escalated by the impetus of designing models of such bioinorganic enzymes as nitrogenase and xanthine oxidase (125). The early work reviewed by Coucouvanis (1) dealt exclusively with the isolation of oxomolybdenum(V) and -(VI) species. 

Skibsted, L.H. (1986) Ligand substitution and redox reactions of gold(III) complexes. Advances in Inorganic and Bioinorganic Mechanisms, 4, 137-183. 

The first Ni Mossbauer spectrum of nickel in a bioinorganic compound with determinable EFG and isomer shift was reported for a nickel complex compound with planar [NiSJ core and considered as a model compound for hydrogenase. This Mossbauer spectrum from the formal Ni compound is presented in Fig. 7.16. The observed quadrupolar interaction can be understood in terms of ligand field theory. In this approach, the b g and levels (d y2 and d ) are not occupied which is expected to cause a large negative EFG contribution [32]. 

Macrocyclic Schiff base compartmental ligands (750) (Robson-type ligands) derived from the [2 + 2] condensation of a 2,6-diformyl- or 2,6-diketo-substituted phenol and a diamine are very prominent in dinuclear Ni coordination chemistry.1901-1903 Particular interest lies in magnetic exchange interactions between the adjacent metal ions as well as in bioinorganic chemistry, where such dinuclear complexes have been proposed as synthetic analogues for bimetallosites. 

With such reactions, the discussion has progressed rather far from "inorganic" chemistry, as it is easy do when considering complex biochemical species that contain a metal. In this section, a small amount of the chemistry of the vast area known as bioinorganic chemistry has been shown. It should serve as an indication of the types of structures and reactions that constitute the field. 

Since 1960, a very large number of other synthetic macrocycles has been prepared and this has resulted in a great increase in interest in all aspects of the chemistry of macrocyclic systems. From about this time there has also been enhanced interest in the role of metal ions in biological systems and many such bioinorganic studies have involved complexes of both natural and synthetic macrocycles. Thus there has been an element of cross-fertilization between these two developing areas, viz ... 

Owing to their involvement in bioinorganic processes and catalysis, much interest has been attracted by the chemistry of Mo and W 1,2-dithiolene complexes.39,40 Molybdenum oxo-1,2-dithiolene complexes can be typically... 

As the preceding discussion of nitrogenase metal-sulfur clusters indicate, analysis of complex bioinorganic systems requires the use of multiple analytical techniques and the cooperative exchange of data and ideas of many researchers. The descriptions in this chapter have attempted to give students some idea of the scope and complexity of instrumental techniques available to the bioinorganic chemist. It has not been intended to be either comprehensive or theoretical in presentation. Students are encouraged to acquaint themselves further with the theory and practice of instrumental techniques, especially those that are important to their particular research interests. 

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