Molybdenum complexes octahedral

Finally, highly dehydroxylated alumina were prepared by heating at 800 °C under vacuum and their interaction with [Mo(CO)e] followed by infrared [19]. At room temperature, the hexacarbonyl molybdenum complex is physisorbed and the interaction of one oxygen atom of a CO ligand with defective aluminium sites (tetrahedral and octahedral sites were identified)... 

Similarly, metathetical exchange of the labile acetonitrile ligands in the octahedral molybdenum complex (CO)2(MeCN)2BrMo( 3-C3Ph3) with a variety of bidentate amines led to the corresponding amino complexes (equation 267)311. These form crystalline acetonitrile solvates suitable for X-ray determination, which confirm the octahedral structure of these complexes and the occurrence of the cyclopropenyl and bromide groups in a tram-relationship. 

More contrasting behavior is displayed by the somewhat related molybdenum complex of l-[(dimethylamino)methyl]-2-(diphenylphosphino)ferrocene, (FcCNP)-Mo(CO)4, in which the octahedral geometry around the molybdenum atom is achievd by coordination of one P atom and one N atom of the adjacent substituents attached to a single cyclopentadienyl ring (see the sketch in Fig. 7-10). In CH2CI2, the irreversible oxidation of the molybdenum fragment precedes the reversible oxidation of the ferrocene moiety [40],... 

The neutral complexes of chromium, molybdenum, tungsten, and vanadium are six-coordinate and the CO molecules are arranged about the metal in an octahedral configuration as shown in stmcture (3). Vanadium carbonyl possesses an unpaired electron and would be expected to form a metal—metal bond. Steric hindrance may prevent dimerization. The other hexacarbonyls are diamagnetic. 

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