Synthesis, characterization and cation-induced dimerization of new aza-crown ether-appended metalloporphyrins?

Dalton Transactions Pub Date: 2012-05-18 DOI: 10.1039/C2DT30123G

Abstract

New metalloporphyrins bearing one or two aryl-aza-crown ether moieties at meso-positions have been synthesized using a palladium catalyzed amination reaction and fully characterized by spectral techniques. X-Ray structural data have been presented for the zinc and copper complexes of mono-substituted aza-crown ether appended metalloporphyrins. UV-Vis and 1H NMR spectroscopic studies showed that addition of K+ cations to a solution of monomeric aza-crowned porphyrins in CHCl3/MeOH led to cation-induced dimerization of these porphyrins, whereas addition of Na+ cations yielded a monomeric complex. Axial coordination of the exobidentate ligand (DABCO) to zinc complexes of aza-crowned porphyrins and following binding metal ions led to formation of sandwich complexes with high stability constants.

Graphical abstract: Synthesis, characterization and cation-induced dimerization of new aza-crown ether-appended metalloporphyrins
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