Fluorescence spectra of a series of 1, 3, 5triaryl-2-pyrazolines indicated that substituents in the 3-phenyl ring resulted in the shifting of fluorescence emission wavelength. Moreover, pyrazoline compounds with biological and medicinal applications have been recently receiving much interest. The synthesis of a new derivative of pyrazoline, 1-phenyl-3-biphenyl-5-(N-ethylcarbazole-3-yl)-2-pyrazoline (PBEP) that show promising applications in the study of DNA has also been reported.
Fused heterocyclic systems incorporating the naphthalene moiety and pyrazole ring has been previously synthesized for the purpose of obtaining compounds of biological importance. On the other hand, interest in naphthalene based fluorophores has grown over the past few years because of their advantageous photophysical properties. Changes in their structure have offered a high degree of diversity that has proven useful for the development of novel probes. Their attractive properties, including cation or pH-sensitive probes, are known, and the solubility of pyrazoline fluorophores as probes is also explored. All rights reserved.Īs large extinction coefficient and quantum yields. Among various possible fluorescent probes, pyrazoline-based fluorophores stand out due to their simple structure and favorable photophysical properties suchĬorresponding authors.
In addition to its role as a key precursor for the synthesis of novel organic compounds with medicinal properties, pyrazoline ring compounds show stronger fluorescence because of the double bond hindering which occurred due to cyclization. Pyrazoline is a five-membered heterocyclic compound having two adjacent nitrogen atoms within the ring. Reagents are required with sufficient flexibility in their synthetic strategies, increased quantum yields for fluorescence, longer emission wavelengths, larger stokes shifts and with good photostability. Introduction The design and development of chemical probes for biological labeling and imaging have been the subject of fascination to scientists which led to the introduction of a profound number of novel molecules that exhibited interesting interaction properties with various biological, chemical and medical systems. Keywords: Synthesis Pyrazoline Charge-transfer character Fluorescence Solvent effect TD-DFTġ. The calculations indicate that the exited state dipole moments are larger than those of the ground state in line with the experimental findings. Theoretical calculations were performed for both compounds using time dependent density functional theory (TD-DFT) at B3LYP/6-31G(d, p) level. All results reflect the importance of the medium effect on the analytical application of NPCP as a potential fluorescent label for derivatization of analytes having amine (–NH2) group. The interaction of NPCP and NPCP-P with various micelles has been studied by steady state fluorescence. Due to the presence of proton acceptor linked to the fluorophore, NPCP displays pH-sensitive absorption and fluorescence emission. Furthermore, photophysical properties of the new fluorophores were studied and interesting solvatochromic behaviour was observed. The structures of the new compounds were verified using various spectroscopic tools. The highlight of this fluorescent dye is that, it can be prepared from available starting material via two synthetic steps, easily converted to the corresponding amide derivative by in situ nucleophilic acyl substitution of the corresponding acid chloride, and its purification by simple chromatographic techniques. Synthesis and photophysical properties of a novel pyrazoline – containing fluorophore, 3-naphthyl-1phenyl-5-(4-carboxyphenyl)-2-pyrazoline (NPCP) A, and its proline derivative (NPCP-P) B are presented in this work. Al-Kindy n Department of Chemistry, College of Science, Sultan Qaboos University, Box 36, Al-khod 123, Sultanate of OmanĪrticle history: Received 19 July 2014 Received in revised form 9 October 2014 Accepted 20 October 2014 Available online 29 October 2014
Journal of Luminescence journal homepage: Synthesis, spectroscopic characterization and photophysics of a novel environmentally sensitive dye 3-naphthyl-1-phenyl-5(4-carboxyphenyl)-2-pyrazoline Beena Varghese, Saleh N. Contents lists available at ScienceDirect
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