Thermochemistry of organometallic

The application of newer methods to studies of gas phase organometallic reactions will lead to the development of routine techniques for determination of the thermochemistry of organometallic species. The examples discussed above demonstrate that an analysis of kinetic energy release distributions for exothermic reactions yields accurate metal ligand bond dissociation energies. This can be extended to include neutrals as well as ions. For example, reaction 15 has been used to determine accurate bond dissociation energies for Co-H and C0-CH3 (57). 

It is not intended to discuss the details of the various methods of thermochemical measurement and the evaluation of results. This has been done in authoritative articles by Skinner1 and by Pilcher2) which have appeared recently, and which deal specifically with the thermochemistry of organometallic compounds. Instead this article will survey the results which may be derived from the information which is available and relate them to features of metal carbonyl chemistry in particular. 

Pilcher, G. Thermochemistry of organometallic compounds containing metal-carbon linkages. MTP Review of Science. Series 2. Physical chemistry, Vol. 10. Chapter 2. 1975, p. 45 Cox, J. D., Pilcher, G. Thermochemistry of organic and organometallic compounds. London Academic Press 1970... 

G. Pilcher, H. A. Skinner. Thermochemistry of Organometallic Compounds. In The Chemistry of the Metal-Metal Bond F. R. Hartley, S. Patai, Eds. Wiley New York, 1982 chapter 2. 

The energies were obtained from J. D. Cox and G. Pilcher, Thermochemistry of Organometallic Compounds, Academic Press, London, 1970. In some cases, the energies were estimated from those of related compounds. 

As mentioned in the introduction, TT-bonded Ag-olefin complexes are paradigms in the thermochemistry of organometallic species. Nonetheless, there are comparatively few relevant quantitative data. 

Gas-Phase Thermochemistry of Organometallic and Coordination Complex Ions... 

Pilcher, G., Thermochemistry of Organometallic Compounds Containing Metal-Carbon Linkages, MTP [Med. Tech. Publ. Co.] Intern. Rev. Sci. Phys. Chem. Sen Two 10 [1975] 45/80. 

Pilcher, G. and Skinner, H. (1982) in The Chemistry of the Metal-Carbon Bond (Thermochemistry of organometallic compounds. Vol. I, Ch. 2), (eds Hartley, F.R. and Patai, S.), Wiley/Interscience, Chichester. 

Heats of formation have since been reported for some 150 or more organometallic compounds, but several of these are of doubtful reliability. However, the development of rotating-bomb calorimetry and the application of novel reaction calorimetric techniques have provided more effective means than hitherto for investigating the thermochemistry of organometallic compounds, making it almost certain that the present lack of reliable data will be short-lived. 

Beauchamp, J.L., van Koppen, P.A.M., 1992. Fundamental gas phase studies of the mechanism and thermochemistry of organometallic reactions. In Martinho Simoes, J.A. (Ed.), Energetics of Organometallic Species, vol. 367. Springer, Netherlands, p. 287. 

Pilcher G, Skinner HA (1982) Thermochemistry of organometallic compounds. In Hartley FR, Patai S (eds) The chemistry of the metal-carbon bond. Wiley, New York. The d state is the one corresponding to the metal configuration principally responsible for bonding, i.e. the parent configuration of the principal bond diagram. 

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