Synthesis of new porphyrin/fullerene supramolecular assemblies: a spectroscopic and electrochemical investigation of their coordination equilibrium in solution

Abstract

Two new fullerene ligands have been designed to provide relatively simple frameworks to build supramolecular systems containing both fullerene and Zn-porphyrin moieties. The coordination of the fullerene ligands to the Zn-porphyrin was supported by UVevis titration, nuclear magnetic resonance and electrochemical data. The resulting spectrophotometric data were processed both graphically and computationally to yield the stoichiometry, stability constant, and molar absorptivity of the species in equilibrium.

Synthesis of novel zinc porphyrins and their photocatalytic activity

“…The unreacted solid salt was filtered and the solvent removed in vacuo. The crude product was purified by chromatography on a silica gel column with dichloromethane/petroleum ether to offord compound 4a (Santos et al, 2011).…”

Harnessing the Synergistic and Complementary Properties of Fullerene and Transition-Metal Compounds for Nanomaterial Applications

“…Formation constants for these coordination complexes vary in the range from 1.2 × 10 3 to 3 × 10 8 M –1 , indicating strong coordination bonding and the high stability of such systems (Scheme ). Fullerene ligands bearing one pyridine group have been shown to form 1:1 C 60 –transition-metal complexes when coordinated to monoporphyrin or phthalocyanine moieties (Figure , compounds 32 and 33 ). ,,,,,,,, While examples of two pyridyl fullerene molecules coordinating to one metal porphyrin moiety are rare (Figure , compound 36 ), the introduction of a second pyridyl group to the same fullerene ligand allows it to coordinate to two metalated porphyrins or phthalocyanines, forming 1:2 fullerene–metal complexes (Figure , compound 34 ). ,− ,,, Fullerene functionalized with three pyridyl units was successfully combined with Eu­(III) to form a 1:1 complex; however, only one pyridyl group participated in metal coordination (Figure , compound 35 ) …”

Synthesis, Properties, and Potential Applications of Porphyrin-Fullerenes

“…[39] Structure 56 was afforded by azidealkyne click cycloaddition between azide-bearing Zn porphyrin 54 and tripropargylamine 55 in the presence of CuSO 4 •5H 2 O and sodium ascorbate. The porphyrin trimer was shown to be capable of the inclusion complexation with pyridyl-functionalized fulleropyrrolidine 57, yielding complex 58 stabilized by π-π-interactions of two porphyrin macrocycles with the fullerene sphere and by the (pyridyl) nitrogen-zinc coordination (association constant is 1.1•10 5 M −1 ).…”