Polymeric metal complexes dibenzoylmethane

The first attempt to imprint a metal complex with a reaction intermediate coordinated to the metal center was reported by Mosbach and coworkers [51], A Co monomer coordinated with dibenzoylmethane, which is as an intermediate for the aldol condensation of acetophenone and benzaldehyde, was tethered to a styrene-DVB copolymer matrix. After, the template, dibenzoylmethane was removed from the polymer, the resulting molecularly imprinted cavity had a shape similar to the template due to the interaction of the template with the polymerized styrene-DVB monomers through n-n stacking and van der Waals interactions. The rate of aldol condensation of adamantyl methyl ketone and 9-acetylanthracene was lower than the rate of condensation with acetophenone, indicating some degree of increased substrate selectivity. This is the first known formation of a C-C bond using a molecularly imprinted catalytic material. 

Metal complexes play many roles in biological systems as catalysts, stimuli responsive centers and structural materials. Introduction of metals into synthetic biomaterials can result in similarly diverse functions, useful for imaging, degradation, and bioactivity. Biomaterials with single well-defined metal centers can result from the combination of coordination chemistry and controlled polymerizations. Efforts in our laboratory to adapt these reactions to bipyridine (bpy) and dibenzoylmethane (dbm) ligand and metal complex reagents, and to explore the ways that metals and polymers mutually affect each other are reviewed below, with poly(lactic acid) (PLA), poly(ethylene glycol) (PEG), poly(ethylenimine) (PEI), and selected acrylate systems, poly(t-butyl acrylate) (PtBA) and poly(acrylic acid) (PAA), as examples. 

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