Mossbauer spectroscopy in inorganic chemistry

A number of hydrated cations in aqueous solution undergo exchange with the solvent at rates slow enough to be observed on the NMR spectroscopic timescale by using isotopic labelling has / = f, while both and are NMR inactive. Different chemical shifts are observed for the nuclei in bulk and coordinated water, and from the signal intensity ratios, hydration numbers can be obtained. For example, Al + has been shown to be present as [A1(H20)6] +. 

A redistribution reaction is one in which substituents exchange between species but the types and numbers of each type of bond remain the same. 

The position of equilibrium can be followed by using NMR spectroscopy, since each of the four species has a 

Values of A//° for these types of reactions are almost zero, the redistribution of the groups being driven by an increase in the entropy of the system. 

Mossbauer spectroscopy is by no means as widely used as NMR spectroscopy, and its brief coverage here reflects this. 

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Platinum ammine complexes have been a fertile area for studying transinfluence. Table 3.21 lists data for a range of ammines showing how /(195Pt-15N) depends upon the trans-atom [153]. (A further selection of data can be found in R.V. Parish, NMR, NQR, EPR and Mossbauer Spectroscopy in Inorganic Chemistry, Ellis-Horwood, Chichester, 1991, pp. 76, 87.) Possibly the most detailed study (of complexes of tribenzylphosphine) examined over a hundred neutral and cationic complexes [154] (Table 3.22). 

Parish, R.V. (1990) NMR, NQR, EPR and Mossbauer Spectroscopy in Inorganic Chemistry, Ellis Horwood, Hemel Hempstead. An ageing but still valid coverage of some important resonance methods used in coordination chemistry the title says it all. 

A number of excellent books have been pubHshed and these should be consulted when more extensive treatments of the theory of Mossbauer spectroscopy are required. (1) Mossbauer Spectroscopy, by N.N. Greenwood and T.C. Gibb, Chapman and Hall, 1971 (2) Chemical Apphcations of Mossbauer Spectroscopy , V.l. Goldanskii and R.H. Herber (eds). Academic Press, 1968 and (3) NMR, NQR, EPR and Mossbauer Spectroscopy in Inorganic Chemistry by R. V. Parrish, Ellis Norwood, 1990. 

Two books which cover the majority of the methods described in this Chapter are Structural Methods in Inorganic Chemistry by E. A. V. Ebsworth, D. W. H. Rankin and S. Cradock, Blackwell, Oxford, 1987 and NMR, NQR, EPR and Mossbauer Spectroscopy in Inorganic Chemistry, R. V. Parish. Ellis Hor-wood, Hemel Hempstead, 1990. An older book, but one that covers a wider subject area, with some good chapters is Physical Methods in Advanced Inorganic Chemistry H. A. O. Hill and P. Day, eds.. Interscience, London, 1968. Readable insights into a limited number of particular areas can be found in Spectroscopy of Inorganic-Based Materials (Advances in Spectroscopy Vol 14). R. J. H. Clark and R. E. Hester, eds. John Wiley, Chichester, 1987. 

Return to Technische Hochschule Darmstadt, research work towards Habilitation ( Applications of Mossbauer Spectroscopy in Inorganic Chemistry )... 

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