Nanorings with copper(ii) and zinc(ii) centers: forcing copper porphyrins to bind axial ligands in heterometallated oligomers.

ABSTRACT: The affinity of copper(ii) porphyrins for pyridine ligands is extremely weak, but oligo-pyridine templates can be used to direct the synthesis of Cu-containing cyclic porphyrin oligomers when they also have Zn centers. We report the synthesis of two heterometallated nanorings: a six-porphyrin ring prepared from a Zn/Cu/Zn linear trimer and a ten-porphyrin ring prepared from a Zn/Zn/Cu/Zn/Zn pentamer. Both these macrocycles have copper porphyrins at two specific positions across the diameter of the ring and zinc at other sites. The presence of a paramagnetic metal results in broadening of the ¹H NMR spectra and reduces the relaxation time constants (T₁ and T₂). The changes in T₁ provide quantitative information on the distance

SUBMITTER: Cremers J 

PROVIDER: S-EPMC5355962 | biostudies-literature | 2016 Dec

REPOSITORIES: biostudies-literature