TD-DFT and structural investigation of natural photosensitive phenanthroperylene quinone derivatives

Abstract

Structural modification of the phenanthroperylene quinone core affects the electronic structure of a series of natural product photosensitizers.

Aromaticity and Electron Density of Hypericin

“…Optimization of the 7,14-dihydrophenanthro­[1,10,9,8- opqra ]­perylene derivatives was performed with the Gaussian 09 program . Structure optimization of a series of 7,14-dihydrophenanthro­[1,10,9,8- opqra ]­perylene derivatives performed previously showed that optimized geometries were similar in many functionals . Optimization of the compounds in this paper was performed at the DFT B3LYP/6-311++G**-DG3 level including Grimme dispersion .…”

“…66 Structure optimization of a series of 7,14-dihydrophenanthro[1,10,9,8-opqra]perylene derivatives performed previously showed that optimized geometries were similar in many functionals. 38 Optimization of the compounds in this paper was performed at the DFT B3LYP/6-311++G**-DG3 level including Grimme dispersion. 67 Vibrational frequencies were calculated to verify the structures as a minima on the potential-energy surface.…”

“…The large number of substituents affects the properties of the polycyclic system. The presence of carbonyl oxygens, the peri-hydroxy groups introduces the possibility of intramolecular hydrogen bond formation. , According to the molecular structure, 16 tautomers can be created for hypericin . Previous investigations reported the presence of 1,6- and 7,14-dioxo tautomers of hypericin. , However, the 7,14-dioxo c tautomer (Scheme ) is confirmed to be the most stable structure in many solutions. − …”

“…The presence of carbonyl oxygens, the peri-hydroxy groups introduces the possibility of intramolecular hydrogen bond formation. 37,38 According to the molecular structure, 16 tautomers can be created for hypericin. 39 Previous investigations reported the presence of 1,6-and 7,14-dioxo tautomers of hypericin.…”

Distinguishing Activities in the Photodynamic Arsenals of the Pigmented Ciliates Blepharisma sinuosum Sawaya, 1940 and Blepharisma japonicum Suzuki, 1954 (Ciliophora: Heterotrichea)

“…However, the bioactive potential and the photodynamics behind the ciliate HLPs still need to be elucidated. The hypericinic molecules derived from ciliates include peculiar structural traits along the dianthrone backbone and, since minor alterations in the structure of these quinones are known to confer different physicochemical and biological properties (10,11), new functional features are expected to be associated with each of these pigments.…”