Mn carbonyls

Bamford and coworkers [19] have shown that a prolonged aftereffect can be obtained with Mn-carbonyl in the presence of certain additives, notably cyclohexane and acetylacetone (S), It was suggested that the photochemical reaction between Mn2(CO)io and (S) produces the active species (Z), which generates free radicals by interaction with halide and Z probably formed from Mn (CO)6 species ... 

The reaction of 2- and 3-borolenes C4H6BR (R = Ph, Me, C H, OMe) with Co, Fe and Mn carbonyls leads, under dehydrogenation of the borolenes, to i7 -borole complexes. 2-Borolene and 3-borolene also react with Mn2(CO), at 160°C to a red-brown triple-decked complex ... 

Low valent transition metal centers preferentially coordinate to the phosphorus in diazaphospholes. Accordingly, P-coordinated complexes of [l,2,3]diazapho-spholes with Cr, W, Fe, and Mn carbonyls were obtained as early as 1980 [1, 2,4], Later, Kraaijkamp et al. observed [108] both P- or -coordination modes in complexes of [l,2,3]diazaphospholes with MX2(PEt3) (M = Pt, Pd X = C1, Br). Methanolysis of these complexes led to the diazaphosphole ring opening and formation of five membered metallacyclic P,/V-chelates (103), incorporating P-bonded phosphonite and /V-coordinated hydrazone functionalities (Scheme 32) [109],... 

Lever has successfully predicted Mn"/ potentials of 24 Mn-carbonyl complexes containing halide, pseudohalide, isonitrile, and phosphine co-ligands, with additivity parameters derived from the potentials of Ru "/" couples [39]. An important consideration for heteroleptic complexes is the influence of isomerism on redox thermodynamics. For Mn(CO) (CNR)6- complexes, with n = 2 or 3, the Mn"/ potentials for cis/trans and fac/mer pairs differ by as much as 0.2 V [40]. The effect arises from the different a-donor and 7r-acceptor abilities of carbonyl (CO) and isocyanide and their influence on the energy of the highest energy occupied molecular orbital (HOMO). 

Manganese-gallium bonds, formation, 5, 764-765 Manganese isonitriles, synthesis and characteristics, 5, 773 Manganese-nitrogen bonds, in Mn carbonyls, 5, 766 Manganese nitrosyl complexes, synthesis and characteristics, 5, 773... 

A similar attempt has been made for a series of Mn carbonyls containing isocyanide groups. " ... 

In the absence of solvent, the carbonyls thermolysis can be accompanied by some peculiarities. In some systems the Fe, Cr, Co, Ni, and Mn carbonyls can have a catalytic action on the polymer carbonization and graphitization processes—for example, in petroleum, mesogenic pecks (the specific matrices with polycondensed aromatic structures) are able to act as n-ligands stabilizing... 

Pd-catalyzed metallation of carbon electrophiles is also applicable to carbon-transition metal bond formation. Beletskaya and colleagues have reported that, in the presence of a Pd(II) catalyst, zinc salts of metal (Fe, Re, W, and Mn) carbonylates smoothly react with aryl and vinyl halides to afford the corresponding rj -aryl and Tj -vinyl complexes (Table 7 and Scheme 16). " The metallation of vinyl halides proceeds with stereochemical retention as in the case with other metal nucleophiles. The use of alkali salts of the metal carbonylates considerably reduces the yields of coupling products. 

The synthesis of a tetrahydrofurylcyclopentadienyl, Mn carbonyl complex and its photolysis have been reported. The unusual Cp complex (Rc(NBu 2)(Tl -C5H5)(p-C5H4)(li-0) prepared from the reaction of sodium cyclopentadienide with Re(NBu 2)sC THF/Et hM been structurdlv characterised. Finally the bidentate complex (ti -C5H4CH2CH(CH3)N(CH3)-(C3H3)Mn(CO)2 has been prepared in two steps following CO substitution on irradiation of a tricarbonyl precursor. ... 

Relatively simple Mn carbonyl complexes are still open for investigation as can be seen with Huang" and co-workers study of the reactivity of Mn(CO)5Br on the surface of zeolites by FTIR and IR spectroscopy. In the same vein Marynick and Derecskei-Kovacs" have taken a new look at an old reaction. They have investigated the potential energy surface for the thermal carbonyla-tion of Mn(CO)5CH3 and the role of competitive intermediates on the reaction surface. They also comment on the photodecarbonylation of Mn(CO)5(COCH3). 

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