Paramagnetic metal complex chemistry

Furthermore, EPR spectroscopy was used to investigate the chemistry of paramagnetic metal complexes. EPR can potentially yield information on the local structure, coordination structure, symmetry, concentration, and... 

There are a few examples of spin equilibria with other metal ions which have not been mentioned above. In cobalt(III) chemistry there exist some paramagnetic planar complexes in equilibrium with the usual diamagnetic octahedral species (22). The equilibria are the converse of the diamagnetic-planar to paramagnetic-octahedral equilibria which occur with nickel(II). Their interconversions are also presumably adiabatic. Preliminary observations indicate relaxation times of tens of microseconds, consistent with slower ligand substitution on a metal ion in the higher (III) oxidation state (120). 

Kokorin, Alexander I, was bom in 1947. Was graduated as a biophysicist in 1970 Ph.D. (Candidate of Sciences) in 1974 D.Sc. degree (Doctor of Sciences) in physical chemistry - in 1992. At present Principal Researcher and Deputy Head of the Division of Kinetics and Catalysis, N. Semenov Institute of Chemical Physics of Russian Academy of Sciences, Moscow, Russia. Area of research interests chemical methods of solar energy conversion chemical physics of organized molecular systems, including nanosized oxide semiconductors doped with transition metal ions, and polymer-metal complexes the study of their structure, absorptive, catalytic, photocatalytic and photoelectrochemical properties. EPR spectroscopy and spin-spin interaction between paramagnetics. He is the author and co-author of more than 170 publications, including two books and several reviews and book chapters. 

Modem transition metal organometallic chemistry can be said to have been invigorated by the discovery and subsequent bonding description of ferrocene (see Ferrocene) by Wilkinson and Fischer in 1951. As predicted by MO theory, all of the neutral first-row metallocenes (see Metallocene Complexes) (V Ni) are paramagnetic, with the exception of ferrocene. Metallocenes probably represent the most studied of all paramagnetic organometallic complexes. 

In this chapter and in an upcoming review (Part II), the chemistry of mononuclear paramagnetic organometallic complexes of the second- and third-row groups 9(VIIIB) and lO(VlII) platinum metals (Rh, Ir, Pd, Pt) are summarized. In this chapter, the higher valent species (Rh(II), Ir(II), Rh(IV), Ir(IV), Pd(ni), Pt(III) and complexes with oxidized redox noninnocent ligands) are described. In the next chapter, the lower valent species (Rh(0), lr(0), Pd(I), Pt(I), and complexes with reduced redox noninnocent ligands will be discussed. 

---