Organometallic compounds metal carbonyl complexe

Keto Derivatives of Group IV Organometalloids, 7, 95 Lewis Base-Metal Carbonyl Complexes, 3, 181 Ligand Substitution in Transition Metal ir-Complexes, 10, 347 Literature of Organo-Transition Metal Chemistry 1950-1970, 10, 273 Literature of Organo-Transition Metal Chemistry 1971,11, 447 Literature of Organo-Transition Metal Chemistry 1972, 12, 379 Mass Spectra of Metallocenes and Related Compounds, 8, 211 Mass Spectra of Organometallic Compounds, 6, 273... 

Further examples of coordinate bonds are found in metal carbonyl complexes. Metal carbon (carbon monoxide) bond distances in a selection of (first-row) transition-metal carbonyls and transition-metal organometallics are examined in Table 5-11. As expected, Hartree-Fock models do not perform well. The 6-3IG model is clearly superior to the STO-3G and 3-2IG models (both of which lead to completely unreasonable geometries for several compounds), but still exhibits unacceptable errors. For example, the model shows markedly different lengths for the axial and equatorial bonds in iron pentacarbonyl, in contrast to experiment where they are nearly the same. Hartree-Fock models cannot be recommended. 

Phosphorus trifluoride is a ligand that is used extensively in coordination chemistry. It substitutes readily into various metal carbonyl complexes using either thermal or photochemical techniques. As a ligand, it is unique in its similarity to carbon monoxide in lower-valent organometallic compounds. In its role as a model for CO, a number of studies are possible that cannot be done on the carbonyls themselves.1 The name normally used for PF3 in complexes is trifluorophosphine. 

The photochemical properties of organometallic compounds are investigated, but none to the depth to which metal-carbonyl complexes are subjected. Photosensitivity of the complexes often is cited, but there is little emphasis on synthetic utility. This section examines the synthetic potential of the photochemical transformations. Studies that are concerned solely with mechanistic aspects are excluded, as well as synthetic applications of the mixed compounds, such as h -CjHjCr(CO)3 and h -CjHjMnfCOjj, where the primary photochemical reaction is CO loss these are discussed in 13.2.4. 

Similarly, several other covalent molecules, such as halogens, organometallic compounds, and carbon tetrachloride, take part in such reactions. Susuki and Tsuji reported that addition of carbon tetrachloride to olefins and carbonyla-tion are catalyzed by dinuclear metal carbonyl complexes like [7r-CsHsFe(CO)2]2 and [7r-CsH5Mo(CO)3 ]2 S8-S9>. 

The use of SCFs for organometallic synthesis follows a tradition set by Mason and Ibers, who attempted to synthesize CO2 complexes in liquid CO2 (they were thwarted by residual H2O in the CO2) [20] and by Turner and co-workers who developed the use of liquefied noble gases as solvents [21,22]. Table 4.2-1 lists most of the organometallic compounds that have been synthesized in SCFs. The majority involve one of three ligands (H2, N2 or C2H4) and all share a common synthetic route from the corresponding metal carbonyl complex. 

---