Helicity Modulation in NIR-Absorbing Porphyrin-Ryleneimides.

ABSTRACT: Peripheral substitution of a π-extended porphyrin with bulky groups produces a curved chromophore with four helical stereogenic units. The curvature and stereochemistry of such porphyrins can be controlled by varying the substituents, coordinated metal ions, and apical ligands. In particular, when the achiral saddle-shaped free bases are treated with large metal ions, i.e., Cd^II or Hg^II , the resulting complexes convert to chiral propeller-like configurations. X-ray diffraction analyses show that apical coordination of a water molecule is sufficient to induce a notable bowl-like distortion of the cadmium complex, which however retains its chiral structure. For phenyl- and tolyl-substituted derivatives, the conversion is thermodynamically controlled, whereas complexes

SUBMITTER: Balahoju SA 

PROVIDER: S-EPMC9303407 | biostudies-literature | 2022 Apr

REPOSITORIES: biostudies-literature