Pannipara Mehboobali, Asiri Abdullah M, Alamry Khalid A, Arshad Muhammad N, El-Daly Samy A
Department of Chemistry, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah, 21589, Saudi Arabia.
J Fluoresc. 2014 Nov;24(6):1629-38. doi: 10.1007/s10895-014-1449-1. Epub 2014 Aug 30.
A new chalcone derivative 3-(1-methyl-1H-pyrrol-2-yl)-1-naphthalen-2-yl propenone (MPNP) with electron donor-acceptor group has been synthesized and characterized by IR, (1)HNMR, (13)C NMR and X- ray crystallography. Electronic absorption and emission spectra of MPNP have been studied in solvents of different polarity. A remarkable red shift was observed in the emission spectrum of MPNP compared to the absorption spectrum upon increasing the solvent polarity, indicating a higher dipole moment in the excited state than in the ground state and the transition involved are π-π* with charge transfer character. Lippert-Mataga and Reichardts correlations were used to estimate the change in dipole moments (Δμ); suggest that the emissive state of MPNP is of strong ICT character. Fluorescence quantum yield (ϕf) of MPNP was correlated with empirical solvent polarity parameter ET(30), and it is observed that ϕf increases with increase in solvent polarity of polar aprotic solvents and decrease in alcoholic solvents. The interaction of MPNP with colloidal silver nanoparticles (AgNPs) was also studied in ethanol and ethylene glycol using steady state emission measurements. The fluorescence quenching data reveal that dynamic quenching and energy transfer play a major role in the fluorescence quenching of MPNP by Ag NPs.
一种带有供体-受体基团的新型查尔酮衍生物3-(1-甲基-1H-吡咯-2-基)-1-萘-2-基丙烯酮(MPNP)已被合成，并通过红外光谱、(1)HNMR、(13)C NMR和X射线晶体学进行了表征。在不同极性的溶剂中研究了MPNP的电子吸收光谱和发射光谱。随着溶剂极性的增加，MPNP的发射光谱相对于吸收光谱出现了显著的红移，这表明激发态的偶极矩高于基态，且所涉及的跃迁是具有电荷转移特征的π-π*跃迁。利用Lippert-Mataga和Reichardts相关性来估计偶极矩的变化(Δμ)；结果表明MPNP的发射态具有很强的ICT特征。MPNP的荧光量子产率(ϕf)与经验溶剂极性参数ET(30)相关，并且观察到在极性非质子溶剂中，ϕf随着溶剂极性的增加而增加，在醇类溶剂中则降低。还使用稳态发射测量研究了MPNP在乙醇和乙二醇中与胶体银纳米颗粒(AgNPs)的相互作用。荧光猝灭数据表明，动态猝灭和能量转移在Ag NPs对MPNP的荧光猝灭中起主要作用。
