Vibrational Spectra of Transition Metal Carbonyl Complexes

Vibrational Spectra of Transition Metal Carbonyl Complexes Linda M. Haines and M. H. Stiddard... 

VIBRATIONAL SPECTRA OF TRANSITION METAL CARBONYL COMPLEXES... 

Infrared and Raman spectral studies of 77-complexes formed between metals and C H rings Vibrational spectra of transition metal carbonyl complexes... 

A general discussion of the infrared spectra of transition metal complexes has been published (23). Although correlations of CO bending modes (24) and of band intensities (25,26) have appeared and vibrations of other ligands are often noted, the number of CO stretching modes and their exact frequencies are the data most frequently cited for metal carbonyl com-... 

Molecular symmetry and ways of specifying it with mathematical precision are important for several reasons. The most basic reason is that all molecular wave functions—those governing electron distribution as well as those for vibrations, nmr spectra, etc.—must conform, rigorously, to certain requirements based on the symmetry of the equilibrium nuclear framework of the molecule. When the symmetry is high these restrictions can be very severe. Thus, from a knowledge of symmetry alone it is often possible to reach useful qualitative conclusions about molecular electronic structure and to draw inferences from spectra as to molecular structures. The qualitative application of symmetry restrictions is most impressively illustrated by the crystal-field and ligand-field theories of the electronic structures of transition-metal complexes, as described in Chapter 20, and by numerous examples of the use of infrared and Raman spectra to deduce molecular symmetry. Illustrations of the latter occur throughout the book, but particularly with respect to some metal carbonyl compounds in Chapter 22. 

Model molecular compounds have been synthesized as analogues of polynuclear transition metal carbonyl clusters grafted onto oxide surfaces. An example is Ph3Si(M2"0)0s3(C0)iQ. The dichloro-dirhodixim complex Rh2(C0)4Cl2 has been considered to serve as a molecular model for the assignment of vibrational spectra of Rh (C0)2 surface complexes. The anions... 

---