Reactions of Transition-metal Complexes

With an atomic number of 28 nickel has the electron conflguration [Ar]4s 3c (ten valence electrons) The 18 electron rule is satisfied by adding to these ten the eight elec Irons from four carbon monoxide ligands A useful point to remember about the 18 electron rule when we discuss some reactions of transition metal complexes is that if the number is less than 18 the metal is considered coordinatively unsaturated and can accept additional ligands... 

R. G. Wilkins, The Study of Kinetics andMechanisms of Reactions of Transition Metal Complexes JSRyn2iadR2LConH < -yRos. on lsl. 2LSs. 1974. 

R. G. WiUdns, Kinetics andMechanism of Reactions of Transition Metal Complexes, 2nd ed., VCH, Weinheim, Germany, 1991. A critical and selected compilation of kinetics and mechanism data. 

Acid catalysed reactions of transition metal complexes. P. J. Staples, Coord. Chem. Rev., 1973,11, 277-342 (181). 

Oxidative-addition reactions of transition metal complexes. J. Halpern, Acc. Chem. Res., 1970, 3, 386-392 (66). 

As already mentioned, complexes of chromium(iii), cobalt(iii), rhodium(iii) and iridium(iii) are particularly inert, with substitution reactions often taking many hours or days under relatively forcing conditions. The majority of kinetic studies on the reactions of transition-metal complexes have been performed on complexes of these metal ions. This is for two reasons. Firstly, the rates of reactions are comparable to those in organic chemistry, and the techniques which have been developed for the investigation of such reactions are readily available and appropriate. The time scales of minutes to days are compatible with relatively slow spectroscopic techniques. The second reason is associated with the kinetic inertness of the products. If the products are non-labile, valuable stereochemical information about the course of the substitution reaction may be obtained. Much is known about the stereochemistry of ligand substitution reactions of cobalt(iii) complexes, from which certain inferences about the nature of the intermediates or transition states involved may be drawn. This is also the case for substitution reactions of square-planar complexes of platinum(ii), where study has led to the development of rules to predict the stereochemical course of reactions at this centre. 

The strained-ring compound 1,1-dimethyl-l-silacyclobutane (which may be regarded as an olefin of organosilicon chemistry) reacts with diiron nonacarbonyl in benzene at 6°-20°C as shown in Eq. (100) (89). (There is here some analogy with the reactions of transition metal complexes with strained hydrocarbons, which often produce valence tautomerization.) The... 

A60. J. P. Candlin, K. A. Taylor, and D. T. Thompson, "Reactions of Transition-Metal Complexes. Elsevier, Amsterdam, 1968. A review of types of reactions of metal complexes (e.g., substitution, combination, redox) reactions with various reagents (e.g., hydrocarbons, halides, carbon monoxide, and isonitrile) and preparation of new stabilised organic systems (e.g., metallocenes, carbenes). Intended for research workers, consequently written at a fairly high level, with emphasis on organometallics. A61. H. J. Keller, NMR-Untersuchungen an Komplexverbindungen. Springer, Berlin, 1970. Expansion of review article 37.1. 

J. P. Candlin, K. a. Taylor and D. T. Thompson, Reactions of Transition Metal Complexes, Elsevier, Amsterdam, 1968. 

Wilkins, R. G. (1991). Kinetics and Mechanisms of Reactions of Transition Metal Complexes. VCH Publishers, New York. Contains a wealth of information on reactions of coordination compounds. 

As the above discussion indicates, assigning mechanisms to simple anation reactions of transition metal complexes is not simple. The situation becomes even more difficult for a complex enzyme system containing a metal cofactor at an active site. Methods developed to study the kinetics of enzymatic reactions according to the Michaelis-Menten model will be discussed in Section 2.2.4. 

Wilkins, R. G. "The Study of Kinetics and Mechanism of Reactions of Transition Metal Complexes" Allyn and Bacon Boston, 1974 pp 108-110, 205-206. 

In this spirit, an attempt will be made to account for the magnitude of pressure effects on ligand substitution reaction rates. Attention will necessarily be confined to a few simple model systems two recent reviews (1, 2) of pressure effects on reactions of transition metal complexes in solution may be consulted for more comprehensive surveys of the field. 

Kinetics and Mechanism of Reactions of Transition Metal Complexes... 

These regions are particularly useful since few, if any, reactions of transition metal complexes are unaccompanied by spectral absorption changes in these regions. We first show how optical absorbances may be substitued for the concentration changes required in deriving the rate law. 

Kinetics and mechanism of reactions of transition metal complexes / Ralph G. Wilkins. - 2., thoroughly rev. ed. -Weinheim New York Basel Cambridge VCH, 1991 ISBN 3-527-28389-7 (Weinheim. ..) brosch. 

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