Abbas Asghar, Hussain Safdar, Hafeez Noureen, Hasan Aurangzeb, Naseer Muhammad Moazzam
Department of Chemistry, Quaid-i-Azam University, Islamabad 45320, Pakistan.
Department of Forensic Medicine & Toxicology, National University of Sciences and Technology, Islamabad 44000, Pakistan.
Spectrochim Acta A Mol Biomol Spectrosc. 2014 Jun 5;127:32-40. doi: 10.1016/j.saa.2014.02.025. Epub 2014 Feb 21.
A series of new 1,3,5-triaryl-2-pyrazolines (1b-12b) having one to twelve carbon alkyloxy side chains were synthesized and characterized on the basis of their spectral (IR, (1)H &(13)C NMR and GC-MS) and microanalytical data. The UV-Vis and emission spectroscopy was used to study the effect of alkyloxy chain length on absorption and fluorescence properties of 1b-12b. All the compounds showed fluorescence in the blue region of the visible spectrum. Interestingly, the alkyloxy chain length strongly affects the emission intensity of 1,3,5-triaryl-2-pyrazoline framework without causing any major blue- or red-shift in the emission wavelength (λmax(em)). The absorption and emission maxima (λmax(abs) &λmax(em)) for compounds (1b-12b) were observed in the range of 337-364nm and 454-464nm, respectively. Furthermore, the effect of fluorine substituent on aryl ring present at 3-position of pyrazoline moiety on fluorescence properties is also discussed.
合成了一系列具有一至十二个碳的烷氧基侧链的新型1,3,5-三芳基-2-吡唑啉（1b - 12b），并根据其光谱（红外光谱、¹H和¹³C核磁共振光谱以及气相色谱 - 质谱）和微量分析数据对其进行了表征。利用紫外 - 可见光谱和发射光谱研究了烷氧基链长度对1b - 12b吸收和荧光性质的影响。所有化合物在可见光谱的蓝色区域均显示出荧光。有趣的是，烷氧基链长度强烈影响1,3,5-三芳基-2-吡唑啉骨架的发射强度，而不会在发射波长（λmax(em)）上引起任何重大的蓝移或红移。化合物（1b - 12b）的吸收和发射最大值（λmax(abs)和λmax(em)）分别在337 - 364nm和454 - 464nm范围内观察到。此外，还讨论了吡唑啉部分3-位芳环上氟取代基对荧光性质的影响。
