Structure resembling effect of clay surface on photochemical properties of meso-phenyl or pyridyl-substituted monocationic antimony(v) porphyrin derivatives

Abstract

Four types of meso-phenyl or pyridyl-substituted monocationic antimony(V) porphyrin derivatives (Sb V Pors)-5, 10,15,20-tetraphenyl; 5,10,15-triphenyl-20-mono(4-pyridyl); 5,15-diphenyl-10,20-di(4pyridyl); and 5,10,15,20-tetra(4-pyridyl)porphyrinato dihydroxo antimony(V) chloride-with different hydrophobicities were synthesised, and their photochemical properties on anionic clay were investigated. The absorption and fluorescence behaviour of the Sb V Pors were strongly affected by complex formation with clay. Interestingly, the absorption transition probabilities and fluorescence quantum yields of the Sb V Pors prominently increased on the clay surface. The more hydrophobic Sb V Por showed greater absorption transition probability increase and fluorescence quantum yield enhancement.These unique effects of the highly flat clay surface on the photochemical behaviour of Sb V Por were discussed mainly from the viewpoint of transition probability, by using the potential energy curves of Sb V Por with and without clay. For the more hydrophobic Sb V Por, the molecular structure of the ground and excited states on the clay surface tended to become similar because of the strong hydrophobic interaction between porphyrin and the clay surface, i.e. the 'structure resembling effect'. This effect induces a change in the transition probabilities. † Electronic supplementary information (ESI) available: The structure of synthetic saponite (Fig. S1), the plot of (3 a /3 b ) C /(3 a /3 b ) W versus f C /f W for Sb V Pors (Fig. S2), and the section entitled "The synthesis of Sb V Pors" are available. See

EUV photofragmentation study of hybrid nonchemically amplified resists containing antimony as an absorption enhancer

“…properties of antimony compounds in inorganic and organic compounds have been studied in the past. [51][52][53] As long as Sb is present and keeps absorbing photons, it will probably emit photons too. Fluorescence measurements were not carried out in the present study.…”

Photophysical Properties and Adsorption Behaviors of Novel Tri-Cationic Boron(III) Subporphyrin on Anionic Clay Surface

“…For many dye molecules, an increase in the transition probability on the saponite surface has been observed. This effect would be induced by an increase in the Franck–Condon factor due to resembling of the molecular structures of the ground and excited states. , In this study, the ∫εdv̅ values of m -B III TMPySp and p -B III TMPySp with the saponite increased about 1.05 and 1.14 times compared to those in the bulk solution, respectively (Table ).…”

“…Recently, we have reported that particular multicationic and planar dye molecules, such as +4-charged porphyrins, could be strongly adsorbed on the clay surface by a strong electrostatic interaction. For such molecules, photophysical properties, such as fluorescence quantum yields or lifetimes have been enhanced because of fixation of the molecular structures onto the clay surface and/or suppression of aggregation and self-fluorescence quenching. − Especially, in the case that the distance between positive charges in the guest molecules and an average negative charge distance on the clay surface coincide well, the guest molecules can be adsorbed up to high density without aggregation because Coulomb’s force is strengthened especially in such conditions (size-matching rule). − …”

Effects of the Surface Charge Density of Clay Minerals on Surface-Fixation Induced Emission of Acridinium Derivatives

“… 29 , 42 Several studies have reported that the major factor for the fluorescence enhancement is a fixation of rotational substituents. 21 , 22 Thus, a strong fixation of Acr on the hydrophobic clay surface, suppressing the rotation of the substituent, could be a reason why the hydrophobic clay induced the large fluorescence enhancement, as in the case with the discussion for the Stokes shift.…”