Manganese carbonyls, decomposition

Diene)Mn(CO)3 anions are stable in solution, and have been characterized by infrared and NMR spectroscopy. However, exposure of the anion solution to oxygen results in decomposition to give the free ligand. Reduction of (crotyl)Mn(CO)4 (62) gives the manganese-carbonyl transfer reagent ( -2-butene)Mn(CO)4. Reaction of 1,3-cycloheptadiene, 1,3-cyclooctadiene, 1,3,5-cycloheptatriene or 1,3,5,7-cyclooctatetraene... 

Manganese pentacarbonyl hydride is a liquid, colorless when pure, but usually yellow from traces of manganese carbonyl due to decomposition. Its extrapolated boiling point is about 100°. Since it is quite air-sensitive and volatile, it is most conveniently handled in a vacuum system. With diazomethane it gives CH3Mn(CO)6 and with tetrafluoroethylene it gives HCF2CF2Mn(CO)8. ... 

Some metal carbonyls, such as nickel, cobalt and manganese compounds have been used to produce metallic deposition. The decomposition occurs in a stepwise manner, producing one CO(g) molecule at each step. 

The electron impact-induced decomposition pathways of several structurally related /u.-methylene complexes of cobalt, rhodium, manganese, and iron have been elucidated by high resolution measurements, analysis of metastable transition (DADI linked scan), and 2H labeling (46). Terminal carbonyl ligands are generally lost prior to further fragmentation of the three-membered frameworks. Subsequent rearrangement reactions of the... 

In a brief survey of other simple binary carbonyls we find that the compounds M(CO)6(M = Cr, Mo, W) and Ru3(CO)12 have only minimal catalytic activity for autooxidizing alcohols or ketones. The compounds Fe(CO)5 and Fe3(CO)12 are decomposed completely when we try to use them as catalysts. When the compound Mn2(CO)i0 is used, there is a considerable enhancement in acid formation. During this reaction there is extensive decomposition to manganese dioxide, and we believe that this compound is the one primarily involved in the catalytic oxidation. 

OSHA PEL TWA 0.2 mg(Mn)/m3 (skin) ACGIH TLV TWA 5 mg(Mn)/m3 SAFETY PROFILE Poison by ingestion, inhalation, skin contact, intravenous, and intraperitoneal routes. A skin irritant. When heated to decomposition it emits toxic fumes of CO. See also MANGANESE COMPOUNDS and CARBONYLS. 

Decomposition of methanesulphonyl azide in aromatic solvents (methyl benzoate or benzotrifluoride), in the presence of transition metal compounds (e.g. copper(ri) acetylacetonate, manganese(ii) acetylacetonate, di-cobalt octacarbonyl, tri-iron dodecacarbonyl, and iron pentacarbonyl) led to a marked decrease in the aromatic substitution product compared with thermolysis, and, with the iron carbonyls, to an increased yield of methanesulphonamide . In addition, the aromatic substitution products shifted from mainly ortAo-substitution with no additives to mainly w ia-substitution in the presence of the additives mentioned above. 

In addition to hydroperoxide decomposition and peroxy-radical reduction, manganese-ion catalysts have a pronounced tendency to promote the rapid oxidation of carbonyl-containing intermediates via enol mechanisms [49, 52-56] ... 

The activation entropy for thermal decomposition of /ra j -[MnX(CO)3(PPh3)2] indicates that manganese-phosphorus bond breaking is rate-determining. The rate law for the decomposition of CoH(CO)4 to Co2(CO)8 plus hydrogen is second-order in cobalt compound. While this decomposition has previously been studied in the gas phase, this is the first report of decomposition kinetics in the liquid phase. The first step in reaction of Co2(CO)s with organomercury halides is solvent-induced disproportionation of the dimeric carbonyl. ... 

---