Metal carbonyls physical properties

We have reviewed experiments on two classes of systems, namely small metal particles and atoms on oxide surfaces, and Ziegler-Natta model catalysts. We have shown that metal carbonyls prepared in situ by reaction of deposited metal atoms with CO from the gas phase are suitable probes for the environment of the adsorbed metal atoms and thus for the properties of the nucleation site. In addition, examples of the distinct chemical and physical properties of low coordinated metal atoms as compared to regular metal adsorption sites were demonstrated. For the Ziegler-Natta model catalysts it was demonstrated how combination of different surface science methods can help to gain insight into a variety of microscopic properties of surface sites involved in the polymerization reaction. 

Nearby elements also display chemistry reflecting alkyne 7rx donation to a vacant metal dir orbital. In Group V, Lippard s coupled carbonyl product Ta(Me3SiOC=COSiMe3)(dmpe)2Cl is a d4 Ta(I) alkyne monomer (116), similar in electron count to CpV(CO)2(RC=CR) complexes (231). The preparative route and physical properties of a series of Ta(CO)2-(RC=CR)(I)L2 d4 monomers are compatible with a four-electron donor description for the alkyne ligands (231a). The d2 configuration has also... 

Properties of compounds containing a CO group directly bound to a transition metal have been extensively reviewed in recent years (7). This work is therefore confined in Part A to a discussion of the nature of the bonds in metal carbonyls, especially metal-carbon and metal-metal bonds, and in Part B to the influence of these bonds on physical and spectroscopic properties. Other bonds will be discussed incidentally, because of their influence on coordinated CO and the correlative possibility of using coordinated CO as a probe into the bonding of the molecxde as a whole. 

Chapter 23 Metal carbonyls synthesis, physical properties and structure 709... 

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