Preparation and characterization of free-standing pure porphyrin nanoparticles

Abstract

Preparation and characterization of absolutely pure and stable nanoparticles of 5,10,15,20-meso-tetrakis phenyl porphyrin (TPP) and catalytically repute 5,10,15,20-meso-tetrakis pentaflurophenyl porphyrin (H 2 F 20 TPP) by improved 'reprecipitation method' is described. The innovation of this modified 'reprecipitation method' lies on the judicial selection of organic solvent and amount of porphyrin solution to be injected in the aqueous media. Exactly similar process produces relatively small nanoparticles for TPP than that of H 2 F 20 TPP while the stability of the H 2 F 20 TPP nanoparticles is bit higher than nanoparticles of TPP. Absorption and emission spectra reveal that the formation of nanoparticles for both the cases is induced by J-and H-type aggregation. DFT calculations predict the optimized geometries and frontier molecular orbital, which favours the strength of face-to-face interaction with neighbour molecules to be more facile for TPP than that of H 2 F 20 TPP helping the latter to form bigger and relatively more stable and free-standing nanoparticles. The use of no other compounds except dichloromethane, a highly volatile organic solvent and respective porphyrins give absolutely pure nanoparticles. This improved method will lead to produce organic nanoparticles of π-conjugated systems easily and efficiently.

Porphyrin‐Based Nanostructures for Sensing Applications

“…A different approach was pursued by Bangal and Perepogu who recently prepared pure nanoparticles of 5,10,15,20-tetraphenylporphyrin or 5,10,15,20-tetra(pentafluorophenyl)porphyrin (Figures 1(b)-1(c)), without the addition of surfactants as nanoparticle stabilizers [16]. In this case the approach is called "reprecipitation method" and it takes advantage of a careful choice of solvent mixtures, where the first one should act as good and the second as poor solvent to induce the nanoparticles formation.…”

Effect of crystallization on the electronic and optical properties of archetypical porphyrins

“…In addition to the P% 1 triclinic crystal structure, we investigate three additional possible scenarios for thick MgTPP films following the strong and weak interaction idea from Perepogu and Bangal: 32 (1) The simple stack where porphyrin molecules are directly on top of each other. (2) Rotated stack, where porphyrin layers are rotated by 901 with respect to each other (3) Herringbone where each porphyrin is coordinated with the phenyl rings of another porphyrin perpendicular to it.…”

Effect of foam roller, kinesiotaping and dynamic stretching on gait parameters with induced ankle muscle fatigue

“…lar fatigue, for instance in the gastrocnemius and soleus, increases difficulty in maintaining balance and results in reduced postural control [7]. Perepogu and Bangal [8] showed an increase in heel-contact speed and a reduction in ankle dorsiflexion after fatigue. Furthermore, decreases in muscle strength and balance required for gait due to fatigue may increase the risk of falls in the elderly, leading to serious problems [9].…”