Manganese compounds decacarbonyl

Manganese forms a decacarbonyl Mn2(CO)10 in which each manganese has the required share in 18 electrons to achieve the noble gas configuration. Reduction of this covalent compound with sodium amalgam gives the salt Na[Mn(CO)5], sodium pentacarbonyl-manganate ( - 1) in the ion Mn(CO)5 the noble gas structure is again attained. 

The decacarbonyls of manganese, technetium, and rhenium, of formula M2(CO)io, have terminal carbonyl groups and a metal-metal bond. The molecular symmetry is D d with the two M(CO)s fragments in a staggered conformation. The heterodinuclear decacarbonyl MnRe(CO)io is also known as obtained by the redox reaction of a rhenium pentacarbonyl halide with the pentacarbonylmanganate(-I) anion at room temperature (at 160 °C or higher, the heterodinuclear carbonyl tends to form the homodinuclear compounds with an equilibrium constant close to the statistical value ). The X-ray diffraction stndy of MnRe(CO)io has shown the Mn-Re distance of 2.909 A to be shorter than the sum of the covalent radii obtained from the homodinuclear compounds (Table 3). 

The reactions of perfluoro-(l-methylpropenyl)silver with chromium-(p. 292), manganese- and rhenium- (p. 298), iron- (p. 303), and cobalt-halogen compounds (p. 318), and its redox reactions with the decacarbonyl-dimetallate ions [Ma(CO)i ] (M = Cr, Mo, or W) (p. 292), have already been described. With di(7r-Qrclopentadienyl)-titanium and -zirconium dichlorides, however, only the corresponding difluorides (w-C5H )aMFa (M = Ti or 7jl) are obtained. ... 

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