Metal carbonyls structure

Many carbonyl and carbonyl metallate complexes of the second and third row, in low oxidation states, are basic in nature and, for this reason, adequate intermediates for the formation of metal— metal bonds of a donor-acceptor nature. Furthermore, the structural similarity and isolobal relationship between the proton and group 11 cations has lead to the synthesis of a high number of cluster complexes with silver—metal bonds.1534"1535 Thus, silver(I) binds to ruthenium,15 1556 osmium,1557-1560 rhodium,1561,1562 iron,1563-1572 cobalt,1573 chromium, molybdenum, or tungsten,1574-1576 rhe-nium, niobium or tantalum, or nickel. Some examples are shown in Figure 17. 

In connection with the structure of carbonyl metal complexes, these bands seem to be the result of the symmetric and the antisymmetric stretching vibrations of two CO molecules bonded linearly with the same Pd(II) ion. Imelik et al. (23) have shown that palladium ions are trigonally coordinated in Si, sites (d Om-Pd = 2 A). Because of chemisorbed CO, the palladium ions acquire a trigonal bypyramidal coordination. 

As a result of the unusually strong reductive character of the penta-carbonyl metalates(-II) [M(CO)5]2 (M = Cr, Mo, W), and the consequent ready oxidizability of the dinuclear anions [M2(CO)10]2 and [HM2(CO)10], only relatively lately have we been able to publish an interpreted IR spectrum of Na2[Cr(CO)5] (31). There is no doubt, however, that the [M(CO)5]2 anions have trigonal bipyramidal structures as the observed intensities and frequency differences of the CO bands are inconsistent with a C4v symmetry of a tetragonal pyramid. 

Carbon tetrafluoride, 1 34 3 178 Carbon tetraiodide, 3 37 Carbonyl azide, formation of, by carbohydrazide, 4 35 Carbonyl fluoride, 6 155 Carbonyls, metal, 2 229 metal, nomenclature of, 2 264 structure of, 2 232 Catalysts, beryllium chloride, 5 25 boron fluoride, 1 23 chromium(III) oxide gel, 2 190... 

F. Calderazzo, R. Ercoli, and G. Natta, Metal Carbonyls Preparation, Structure, and Properties, in Organic Synthesis via Metal Carbonyls, (Eds. I. Wender and P. Pino, Interscience Publishers, New York, 1968, Vol. I, p. 216). 

C- and 0-Bonded Metal Carbonyls Formation, Structures, and Reactions, 23, 219... 

F. Calderazzo, R. Ercoli, and G. Natta Metal carbonyls—preparation, structure and properties, pp. 1-272 (1410). 

The formation of 17-electron radicals as the result of thermal electron transfer from a carbonyl metallate to a cationic pyrylium acceptor (P+) is also observed with the charge-transfer salts of [TpM(CO)3 ] (Tp = hydrido-fn s-(3,5-dimethylpyrazolyl)-borate M = Mo, W, Cr) [127]. Owing to the stability of the TpM(CO)3 radical [182], electron-transfer equilibria (Eet) are established by UV-Vis and IR spectroscopy which generally favor the intimate ion-pair state (see Structure D in Figure 5) in accord with the electron-transfer energetics [127] (Eq. 57). 

A more recent search of the CSD for alkali metal/carbonyl crystal structures also confirmed these re-sults. The average Li—O bond length and the Li—O—C bond angle were found to be 1.99 0.07 A... 

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