Synthesis and photophysical properties of a novel phthalimide derivative using solvatochromic shift method for the estimation of ground and singlet excited state dipole moments

A systematic review of polycyclic aromatic hydrocarbon pollution: A combined bibliometric and mechanistic analysis of research trend toward an environmentally friendly solution

Pollution caused by polycyclic aromatic hydrocarbons (PAHs) is a significant concern. This concern has become more problematic given the rapid modification of PAHs in the environment during co-contamination to form substituted PAHs. This review aims to integrate bibliometric analysis with a rigorous study of mechanistic insights, resulting in a more comprehensive knowledge of evolving research trends on PAH remediation. The results show that research in this field has progressed over the years and peaked in 2022, potentially due to the redirection of resources toward emerging pollutants, hinting at the dynamic nature of environmental research priorities. During this year, 158,147 documents were published, representing 7 % of the total publications in the field between 2000 and 2023. The different remediation methods used for PAH remediation were identified and compared. Bioremediation, having >90 % removal efficiency, has been revealed to be the best technique because it is cost-effective and easy to operate at large scale in situ and ex-situ. The current challenges in PAH remediation have been detailed and discussed. Implementing innovative and sustainable technologies that target pollutant removal and valuable compound recovery is necessary to build a more robust future for water management.

Synthesis and Solvent Dependent Fluorescence of Some Piperidine-Substituted Naphthalimide Derivatives and Consequences for Water Sensing

Novel fluorescent strigolactone derivatives that contain the piperidine-substituted 1,8-naphthalimide ring system connected through an ether link to a bioactive 3-methyl-furan-2-one unit were synthesized and their spectroscopic properties investigated. The solvatochromic behavior of these piperidine-naphthalimides was monitored in solvents of different polarity using the electronic absorption and fluorescence spectra. These compounds exhibited a strong positive solvatochromism taking into account the change of solvent polarity, and the response mechanism was analyzed by fluorescence lifetime measurements. According to Catalan and [f(n), f(ε), β, α] solvent scales, the dipolarity and polarizability are relevant to describe the solute-solvent interactions. The emission chemosensing activity was discussed in order to determine the water content in organic environments. The emission intensity of these compounds decreased rapidly in dioxane, increasing water level up to 10%. Measuring of quantum yield indicated that the highest values of quantum efficiency were obtained in nonpolar solvents, while in polar solvents these derivatives revealed the lowest quantum yield. The fluorescence decay can be described by a monoexponential model for low water levels, and for higher water contents a biexponential model was valid.

Fluorescein Based Fluorescence Sensors for the Selective Sensing of Various Analytes

Fluorescein molecules are extensively used to develop fluorescent probes for various analytes due to their excellent photophysical properties and the spirocyclic structure. The main structural modification of fluorescein occurs at the carboxyl group where different groups can be easily introduced to produce the spirolactam structure which is non-fluorescent. The spirolactam ring opening accounts for the fluorescence and the dual sensing of analytes using fluorescent sensors is still a topic of high interest. There is an increase in the number of dual sensors developed in the past five years and quite a good number of fluorescein derivatives were also reported based on reversible mechanisms. This review analyses environmentally and biologically important cations such as Cu2+, Hg2+, Fe3+, Pd2+, Zn2+, Cd2+, and Mg2+; anions (F-, OCl-) and small molecules (thiols, CO and H2S). Structural modifications, binding mechanisms, different strategies and a comparative study for selected cations, anions and molecules are outlined in the article.