Manganese complexes dicarboxylates

In a comparable study in which unsaturated dicarboxylic acids (H2A) were used as substrates, activation enthalpies were observed for the formation of the intermediates remarkably similar to those above in reactions of both H2A and HA with oxidant. The authors in this paper, however, chose to describe the ester intermediate as a manganese(v) complex, an observation which has been rejected on spectroscopic grounds. In the reaction with crotonic acid, the optical density changes at 525 nm and 420 nm paralleled those described above. The spectra both of Mn and of the intermediates formed by the reactions... 

Champness and coworkers prepared the complexes c-[M(bpydc)(CO)3X] (M = Mn, Re bpydc = 2,2 -bipyridine-5,5 -dicarboxylate) and reacted them with manganese(II) to form MOFs in which Mn(II) cations are the nodes and the diimine complexes are the linkers. On treatment with UV radiation, fac to mer isomerization was observed, as witnessed by IR spectroscopy and X-ray crystallography. ... 

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