A glycyl-substituted porphyrin as a starting compound for the synthesis of a π–π-stacked porphyrin–fullerene dyad with a frozen geometry

Abstract

A synthetic route for obtaining a porphyrin-fullerene dyad with a constrained geometry forcing the [60]fullerene sphere to lie on the porphyrin plane is reported, revealing a strong interaction in the ground state between the two chromophores.

A π‐Stacked Porphyrin–Fullerene Electron Donor–Acceptor Conjugate That Features a Surprising Frozen Geometry

“…Interestingly, in the near‐infrared part of the spectrum, that is, between 600 and 800 nm, low‐intensity absorption bands were found for 1 and 2 . On the basis of earlier reports,10 we attribute this band to a charge‐transfer state due to ground‐state interactions between the two chromophores. To better visualize the charge‐transfer bands, the spectra of ZnTPP and C 60 ‐ref or H 2 TPP and C 60 ‐ref were subtracted from those of 2 or 1 , respectively.…”

“…Porphyrin–fullerene conjugates with more rigid geometries have also been reported in which the fullerenes are linked to the β‐pyrrole position,8 directly to the meso position of the porphyrin ring,9 or through the benzene ring at the ortho position, as in the electron donor–acceptor conjugate 1 (Figure 1). 10 Compound 1 differs from most other conjugates8, 9 because it contains a direct link between the carbon of the phenyl ring of the porphyrin and the pyrrolidine nitrogen of the fullerene, which gives rise to a completely frozen geometry similar to that found in cocrystallized porphyrin–fullerene systems 6a. 11 In addition, the close proximity between the two chromophores results in considerable ground‐state electronic interactions, as demonstrated by NMR and UV/Vis spectroscopy 10.…”

“…10 Compound 1 differs from most other conjugates8, 9 because it contains a direct link between the carbon of the phenyl ring of the porphyrin and the pyrrolidine nitrogen of the fullerene, which gives rise to a completely frozen geometry similar to that found in cocrystallized porphyrin–fullerene systems 6a. 11 In addition, the close proximity between the two chromophores results in considerable ground‐state electronic interactions, as demonstrated by NMR and UV/Vis spectroscopy 10. A further advantage of 1 is that additional photo‐ and electroactive chromophores that bear an aldehyde functionality suitable for cycloaddition reactions to C 60 can be introduced.…”

Fullerene-Indole-Nitrobenzene Hybrid System Connected Through Pyrazoline Ring: Synthesis, Electrochemical, and Photophysical Studies

“…During the past few years, electron donor-acceptor (DA) dyads based on [60] fullerene, which upon photoexcitation give rise to photoinduced charge-separated states, have been the focus of intensive research as candidates for artificial photosynthetic reaction centers (5)(6)(7)(8)(9)(10). Remarkably, small reorganization energies (11) associated with the reduction of the C 60 cage lead to efficient photoinduced electron transfer occurring, with the generation of relatively long-lived charge-separated (CS) states.…”

Synthesis, Properties, and Potential Applications of Porphyrin-Fullerenes

“…Thus, a glycyl-substituted porphyrin 31 was utilized as a starting compound for the synthesis of a π-π-stacked porphyrin-fullerene dyad with a frozen geometry. [28] An ester 31a was synthesized via the condensation of initial 5-(2-aminophenyl)-10,15,20-triphenylporphyrin 30 with methyl iodoacetate (Scheme 14).…”