348081-91-4Relevant academic research and scientific papers
Effect of regioisomerism on the self-assembly, photophysical and gelation behavior of aroylhydrazone based polycatenars: Synthesis and characterization
Kanth, Priyanka,Singh, Hemant Kumar,Kumar, Vijay,Singh, Sachin Kumar,Rao, D.S. Shankar,Prasad, S. Krishna,Singh, Bachcha
, (2019/07/02)
In this paper we report five series of aroylhydrazone based polycatenars differing from each other in number and position of alkoxy chains on one end of the core; keeping other end the same. A systematic variation in the structures was carried out to understand the effect of position and chain length on the mesophase behavior. In the case of single alkoxy chain at 4-position, there is a transition from Smectic C to Smectic A mesophase during cooling and Smectic A to Smectic C transition in heating cycle in all the homologues except n = 6 & n = 8. In the case of two alkoxy chains at 3-, 5-positions, the compounds are non-mesogenic in nature. On changing the position of alkoxy chains from 3-, 5-positions to 3-, 4-positions, intermolecular forces weaken and these compounds become liquid crystalline and show columnar rectangular mesophase resulting from the effect of regioisomerism. Moving on to the series with three alkoxy chains, it was observed that 2-, 3-, 4-trialkoxy substituted compounds exhibit columnar rectangular mesophase except lower chain length (n = 6 & 8) while 3-, 4-, 5-trialkoxy substituted aroylhydrazones show columnar rectangular mesophase; except n = 10 which shows columnar oblique mesophase. Thus it was established that on increasing density of alkoxy chains around one terminal, mesophase changes from smectic to columnar mesophase. Temperature dependent Raman studies confirm the presence of intermolecular hydrogen bonding. Further, effect of substitution pattern did not show much influence on the photophysical properties of the mesogenic series in solid and solution state. However, the non-mesogenic series showed a different absorption and emission transition from the mesogenic series in solid and solution state. Solid state fluorescence studies show almost similar emission maxima in all the series. However, it was also noticed that non-mesogenic series show maximum red shifted emission maxima in solid state as compared to that of solution. All the series showed good gelation properties with less than 1% CGC (wt%) suggesting the strong ability of molecules to form gel. These H-bonded liquid-crystalline gels have immense potential for applications in emissive displays.
A Porphyrin-Based Conjugated Polymer for Highly Efficient In Vitro and In Vivo Photothermal Therapy
Guo, Bing,Feng, Guangxue,Manghnani, Purnima Naresh,Cai, Xiaolei,Liu, Jie,Wu, Wenbo,Xu, Shidang,Cheng, Xiamin,Teh, Cathleen,Liu, Bin
, p. 6243 - 6254 (2016/12/07)
Conjugated polymers have been increasingly studied for photothermal therapy (PTT) because of their merits including large absorption coefficient, facile tuning of exciton energy dissipation through nonradiative decay, and good therapeutic efficacy. The high photothermal conversion efficiency (PCE) is the key to realize efficient PTT. Herein, a donor–acceptor (D–A) structured porphyrin-containing conjugated polymer (PorCP) is reported for efficient PTT in vitro and in vivo. The D–A structure introduces intramolecular charge transfer along the backbone, resulting in redshifted Q band, broadened absorption, and increased extinction coefficient as compared to the state-of-art porphyrin-based photothermal reagent. Through nanoencapsulation, the dense packing of a large number of PorCP molecules in a single nanoparticle (NP) leads to favorable nonradiative decay, good photostability, and high extinction coefficient of 4.23 × 104m?1 cm?1 at 800 nm based on porphyrin molar concentration and the highest PCE of 63.8% among conjugated polymer NPs. With the aid of coloaded fluorescent conjugated polymer, the cellular uptake and distribution of the PorCP in vitro can be clearly visualized, which also shows effective photothermal tumor ablation in vitro and in vivo. This research indicates a new design route of conjugated polymer-based photothermal therapeutic materials for potential personalized theranostic nanomedicine.
Synthesis, characterization and aggregation induced emission properties of anthracene based conjugated molecules
Balasaravanan, Rajendiran,Siva, Ayyanar
, p. 5099 - 5106 (2016/07/06)
Aggregation induced emission-active branched and linear 9,10-distyrylanthracene derivatives with different length alkoxy chains have been designed, synthesized and the effect of chain length on the solid-state fluorescence properties systematically investigated. All the three anthracene derivatives possess typical aggregation induced emission (AIE) properties, i.e., they exhibit faint emission in their solutions, but intense emission in their aggregate states, as a result of the dominant nonradiative decay of free intramolecular torsion in the solution and also the restricted torsional motion from supramolecular interaction in the solid states. The results show that these materials exhibit not only AIE properties, but also observed were position and chain length dependent fluorescence properties. The shorter alkoxy chains were more red shifted than the longer ones and also different aggregation behaviours for branched and linear molecules were observed. This work demonstrates once again the accessibility of tuning the solid-state optical properties of organic fluorophores by combining the simple alternation of molecular chemical structures and the physical change of aggregate morphology under external stimuli.
Tuning the thermotropic properties of liquid crystalline p-substituted aroylhydrazones
Singh, Hemant Kumar,Singh, Sachin Kumar,Nandi, Rajib,Singh, Madan Kumar,Kumar, Vijay,Singh, Ranjan K.,Rao, D. S. Shankar,Prasad, S. Krishna,Singh, Bachcha
, p. 44274 - 44281 (2015/06/02)
The synthesis and mesomorphic properties of forty substituted aroylhydrazones with peripheral mono-, di- and tri- alkoxy chains derived from a p-amino aroylhydrazone core are described. The compounds with two side chains exhibited a smectic A phase, while the compounds with six soft alkoxy side chains at symmetrical positions formed a rectangular columnar mesophase. The structures of these mesophases were confirmed by differential scanning calorimetry (DSC) analysis, polarized optical microscopy (POM) and powder X-ray diffraction (XRD) studies. Raman studies with the help of density functional theory on some of the mesogenic members have been performed to understand the changes in the intermolecular interactions during phase transitions. A structure-property relationship has been deduced, and mesogenic properties are found to be dependent on the chain length, density and position of the alkoxy chains around the molecular core.
Synthesis of a highly hydrophobic cationic lipid and structural and thermodynamic studies for interaction with DNA
Nishimura, Tomoki,Cho, Takeshi,Kelley, Andrew M.,Powell, Magdalena E.,Fossey, John S.,Bull, Steven D.,James, Tony D.,Masunaga, Hiroyasu,Akiba, Isamu,Sakurai, Kazuo
experimental part, p. 1010 - 1018 (2011/01/09)
Synthetic DNA-transfection reagents can overcome safety issues raised by use of viral DNA vectors. One of these candidates is a cationic lipid that can form a supramolecular complex with DNA. We have been working in a series of aromatic diamine lipids wit
Giant meso-meso-linked porphyrin arrays of micrometer molecular length and their fabrication
Aratani, Naoki,Takagi, Akihiko,Yanagawa, Yoshiki,Matsumoto, Takuya,Kawai, Tomoji,Yoon, Zin Seok,Kim, Dongho,Osuka, Atsuhiro
, p. 3389 - 3404 (2007/10/03)
On the basis of the AgI-promoted coupling reaction of zinc(II)-5,15-bis(3,5-dioctyloxyphenyl)porphyrin Z1, chain elongation has been attempted by using a stepwise doubling approach, which provides Z2, Z4, Z8, Z16, Z32, Z64, Z128, Z256, Z384, and Z512. The porphyrin arrays up to Z128 are sufficiently soluble in CHCl3 and THF despite their very long molecular lengths and rodlike structures, while the arrays over Z128 show a significant drop in solubility and stability. The discrete porphyrin arrays thus isolated were characterized by means of 1H NMR spectroscopy, matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry, UV/Vis spectroscopy, gel-permeation chromatography (GPC), cyclic voltammetry (CV), single-crystal X-ray crystallography, scanning tunneling microscopy (STM), and atomic force microscopy (AFM). Contrary to expected linear conformations of the arrays Z n (where n is the number of porphyrins), the single molecular images of Z128, Z256, and Z512 revealed largely bent structures; this finding indicates the substantial conformational flexibility of Zn. We also exploited an effective synthetic route by means of which Zn can be fabricated with a thiol-protected aryl group to provide ZnS2 through ZnBr2, by bromination with N-bromosuccinimide and subsequent Pd-catalyzed Suzuki-Miyaura arylation. Finally, the reaction of Z256 provided Z512, Z768, and Z1024. Collectively, this work provides an important milestone in the preparation of sub-microscale discrete organic molecules and the fabrication of molecular-based materials, hence significantly contributing to device applications.
