Manganese complexes anions

Analogously, reaction of group 7 metal carbonyl anions M(CO)5 (M = Mn, Re) with MeC(CFFI), gave cyclopropylcarbinyl complexes. Flowever, whereas rhenium produces the normal (/-metal bonded cyclopropylcarbinyl complex, the manganese complex furnished (cyclopropylacetyl)Mn(CO)5, where carbonyl insertion into the manganese-alkyl bond occurred (equation 56)114. 

A more general route to these anionic manganese complexes has recently been described34 35 and involves Red-Al reduction of [Mn(2-methylallyl)(CO)4] to yield [Mn(butene)(CO)4]r which reacts with a variety of both cyclic and acyclic dienes or polyenes to give [Mn(Tj4-diene)(CO)3] or [Mn(tj4-polyene)(CO)3] complexes in moderate to good isolated yields (equation 10). 

In the case of the anionic manganese complexes, subsequent protonation affords the neutral alkylcarbene complexes. Intramolecular addition of deprotonated dppe to the a-carbon occurs on reaction of [Fe(=C=CMe2XdppeX C5H5)J+ with base [NaN(SiMe3)2 or KOH in tet-... 

Another class of Mn( III) complexes involves the polyaminocarboxylic acid ligands. The earliest study appeared in 1962 ( 44) and was followed shortly by studies of the cyclohexane analog of EDTA as well as other derivatives of EDTA (45). A recent paper discusses the reactivity of the manganese (III )-diaminocyclohexanetetraacetate complex with hydrogen peroxide (46). A mechanism is proposed which involves complexation by the peroxide anion followed by subsequent electron transfer to produce the Mn(II) complex and the H02 radical. The results are interesting and indicate the potential for selective catalysis by the higher oxidation state manganese complexes. 

A rather interesting synthetic method for a PF3 manganese complex containing the unusual octahydrotriborate anion (B3H8 ) involves a change in the denticity of the coordinated anion on addition of PF3 (Scheme 15) (method F). 

The cationic iron and manganese complexes 25 and 27 were similarly prepared by the reaction of the chloro- (24) or methoxy-substituted (26) cyclopropenylium ions with anionic carbon-ylferrate and manganate complexes. 

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