Publications

Sol–gel synthesis and characterization of conducting polythiophene/tin phosphate nano tetrapod composite cation-exchanger and its application as Hg(II) selective membrane electrode

4-Nitro-<i>N</i>-[(<i>E</i>)-thiophen-2-ylmethylidene]aniline

In the title compound, C(11)H(8)N(2)O(2)S, there is a twist in the mol-ecule, with the dihedral angle between the five- and six-membered rings being 31.77 (9)°. The nitro group is slightly twisted out of the plane of the benzene ring to which it is attached [O-N-C-C torsion angle = 9.0 (3)°]. The S and N atoms are syn. In the crystal, supra-molecular layers parallel to (-204) are formed by C-H⋯O and C-H⋯N inter-actions. These layers are connected into a three-dimensional architecture by π-π inter-actions occurring between centrosymmetrically related benzene rings [centroid-centroid distance = 3.6020 (11) Å].

Utilizing Biomass-Based Graphene Oxide–Polyaniline–Ag Electrodes in Microbial Fuel Cells to Boost Energy Generation and Heavy Metal Removal

Although regarded as environmentally stable, bioelectrochemical fuel cells or, microbial fuel cells (MFCs) continue to face challenges with sustaining electron transport. In response, we examined the performance of two graphene composite-based anode electrodes-graphene oxide (GO) and GO-polymer-metal oxide (GO-PANI-Ag)-prepared from biomass and used in MFCs. Over 7 days of operation, GO energy efficiency peaked at 1.022 mW/m² and GO-PANI-Ag at 2.09 mW/m². We also tested how well the MFCs could remove heavy metal ions from synthetic wastewater, a secondary application of MFCs that offers considerable benefits. Overall, GO-PANI-Ag had a higher removal rate than GO, with 78.10% removal of Pb(II) and 80.25% removal of Cd(II). Material characterizations, electrochemical testing, and microbial testing conducted to validate the anodes performance confirmed that using new materials as electrodes in MFCs can be an attractive approach to improve the electron transportation. When used with a natural organic substrate (e.g., sugar cane juice), they also present fewer challenges. We also optimized different parameters to confirm the efficiency of the MFCs under various operating conditions. Considering those results, we discuss some lingering challenges and potential possibilities for MFCs.

Catalysis in Confined Spaces of Metal Organic Frameworks

Abstract Compared to homogeneous catalysis, heterogeneous catalysis can achieve product selectivity due to spatial constraints and differences in molecular dimensions of substrates and products by performing the reaction in a confined space. Shape selectivity for substrates, products or transition states is a well‐established phenomenon observed in porous inorganic solids like zeolites with considerable impact in petrochemistry. More recently, metal organic frameworks (MOFs) have emerged as heterogeneous solid catalysts for a broad range of organic reactions due to their unique properties of large surface area, tuneable pore volume and high density of sites. The present mini‐review aims to describe the current evidences showing MOFs as shape‐selective catalysts. After a brief introduction on the concept, types and examples of shape‐selectivity, the available data on MOFs as shape‐selective catalysts have been organized according the nature of active sites promoting the reaction, starting from metal nodes as Lewis acid sites and commenting examples of encapsulated metal nanoparticles (NPs) and molecular guests as centers in various reactions such as addition to carbonyl compounds, hydrogenations, oxidations and oxidative dehydrogenations. The final section provides our view on the current achievements and prospective for future developments in the field.

Insights into the binding of photothermal therapeutic agent bismuth sulfide nanorods with human serum albumin

The interaction of microwave synthesized bismuth sulfide nanorods with human serum albumin was investigated using multispectroscopic techniques such as absorption spectroscopy, fluorescence spectroscopy and circular dichroism spectroscopy.

Mechanistic investigation of the oxidation of Cefuroxime by hexacyanoferrate(III) in alkaline conditions

3,6-Dimethyl-1-phenyl-1<i>H</i>,4<i>H</i>-pyrano[2,3-<i>c</i>]pyrazol-4-one

The title compound, C(14)H(12)N(2)O(2), is almost planar with an r.m.s. deviation for all non-H atoms of 0.038 Å. The observed planarity is rationalized in terms of a close intra-molecular C-H⋯O inter-action. Supra-molecular layers, two mol-ecules thick and with a step topology, are formed in the crystal packing via C-H⋯O contacts involving the carbonyl O atom, which accepts two such bonds, and π-π inter-actions between the components of the fused ring system and the phenyl ring of inversion-related mol-ecules [centroid-centroid distances = 3.6819 (13) and 3.6759 (12) Å].

Recent Progress in Electrocatalytic Methanation of CO₂ at Ambient Conditions

Abstract Electrochemical CO 2 reduction under ambient conditions is a promising pathway for conversion of CO 2 into value‐added products. In recent years, great achievements have been obtained in the understanding the mechanism and development of efficient and selective catalysts for electrochemical CO 2 reduction. However, the electrochemical CO 2 reduction is still far from practical applications. Based on the gap between current research and practical applications, the state‐of‐the‐art of the theoretical and experiment investigations on different electrocatalysts for the electrocatalysis of CO 2 to CH 4 is systematically and constructively reviewed. First of all, strategies for enhancing the catalytic activity and selectivity of electrochemical reduction of CO 2 to CH 4 are also examined in this review. The modulated strategies mainly involve the following aspects: i) tuning the applied potentials, ii) morphology engineering, iii) crystallographic facets engineering, iv) defect engineering, v) alloying. Furthermore, the influence of the electrolyte on the activity and selectivity for electrocatalysis of CO 2 to CH 4 is also reviewed. This review will build a systematic understanding in the electrochemical CO 2 reduction to CH 4 and may help to provide new insight for designing and optimizing the catalysts and/or electrolyte.

Selected MRI and organic fluorescence sensors for the recognition of Zn2+ ions in biological matrixes: A review

Phenothiazine-based dyes containing imidazole with π-linkers of benzene, furan and thiophene: Synthesis, photophysical, electrochemical and computational investigation

5-(2-Thienylidene)barbituric Acid

5-(2-Thienylidene)barbituric acid 3 was prepared by Knoevenagel condensation of thiophene- 2-carboxaldehyde 1 and barbituric acid 2 in ethanol using piperidine as a base [1,2].[...]

Risk Factors and Management of Acute Pancreatitis; A Systematic Review

Pancreatitis, characterized by pancreatic inflammation, commonly stems from triggers such as gallstones and excessive alcohol consumption. Gene-environment interactions intricately contribute to disease onset and progression, challenging the traditional classification of acute, recurring, and chronic pancreatitis as distinct entities. Instead, a disease continuum has emerged, where 30% of acute pancreatitis cases progress into a chronic form, often involving episodes of recurrence. This systematic study aims to explore the Risk Factors and Management of Acute Pancreatitis. Data from PubMed/Medline, Scopus databases, and Embase were analyzed following PRISMA guidelines (2010–2023). Among 329 identified studies, 15 met inclusion criteria, primarily employing surveys and national database analyses. Enhanced comprehension of risk factors, diagnosis, and treatment is crucial for refining future evaluation and management strategies. Pancreatitis exhibits multifaceted characteristics, presenting diverse causes, symptoms, and outcomes. Current understanding of its natural history and treatment remains limited. Long-term follow-up and randomized studies are imperative to unravel gene-environment interactions and formulate innovative therapeutic approaches. The increased incidence has facilitated progress in defining pancreatitis, with identified risk factors including biliary issues, anatomical abnormalities, systemic diseases, medications, trauma, genetics, infections, and metabolic factors. Notably, the proportion of idiopathic cases has decreased due to improved recognition of genetic and anatomical variants. Effective acute pancreatitis management necessitates early and aggressive fluid and nutritional therapy, pain control, and addressing precipitating factors.

Novel dyes derived from hydrazones. Part 4. Synthesis and characterizations of 2-{4-[(2E)-2-(1-arylylidene)hydrazino]phenyl}ethylene-1,1,2-tricarbonitrile

Mechanical, Thermal, and Morphological Properties of Nanocomposites Based on Polyvinyl Alcohol and Cellulose Nanofiber from <i>Aloe vera</i> Rind

This work was devoted to reinforcement of polyvinyl alcohol (PVA) using cellulose nanofibers from Aloe vera rind. Nanofibers were isolated from Aloe vera rind in the form of an aqueous suspension using chemimechanical technique. Mechanical characterizations showed that incorporation of even small amounts of nanofibers (as low as 2% by weight) had significant effects on both the modulus and strength of PVA. Tensile modulus and strength of PVA increased, 32 and 63%, respectively, after adding 2% of cellulose nanofiber from Aloe vera rind. Samples with higher concentrations of nanofibers also showed improved mechanical properties due to a high level of interfacial adhesion and also dispersion of fibers. The results showed that inclusion of nanofibers decreased deformability of PVA significantly. Dynamic mechanical analysis revealed that, at elevated temperatures, improvement of mechanical properties due to the presence of nanofibers was even more noticeable. Addition of nanofibers resulted in increased thermal stability of PVA in thermogravimetric analysis due to the reduction in mobility of matrix molecules. Morphological observations showed no signs of agglomeration of fibers even in composites with high cellulose nanofiber contents. Inclusion of nanofibers was shown to increase the density of composites.

ChemInform Abstract: Synthesis and Biological Evaluation of Some New Bipyrazolylbenzenesulfonamides as Possible Antimicrobial and Chemotherapeutic Agents.

Abstract All products show weak anticancer, antimicrobial and antifungal activities.

Synthesis, photochromic, thermochromic, piezochromic and solvatochromic properties of new bis‐imidazole derived from substituted chlorobenzaldehyds

Purpose To evaluate the photo, thermo, piezo and solvatochromism of new bis‐imidazole derived from three isomers of chlorobenzaldehyde. Design/methodology/approach The synthesis of the three new bis‐imidazoles was accomplished using modified procedure of the previously reported method, by dissolving the imidazol derivative and cooling in ice bath, and adding potassium ferricyanide drop wise. The compounds were used evaluate the effects of the position of the substitutions on the aromatic ring, on the photo, thermo and piezochromic properties. Findings New bis‐imidazole derived from 2‐chloro, 3‐chloro and 4‐chloro phenyl have been synthesised and their photochromic properties upon irradiation with ultraviolet light were studies in different solvents. The photochromic properties and performance were affected remarkably upon changing the solvent. Also, the thermochromic properties upon heating in different solvents were studied. The dimers showed piezochromism on grinding. Practical implications The method reported for the synthesis is simple. The new compounds showed photochromic, thermochromic, piezochromic, and solvatochromic making them potential candidates for many applications such as sensors, optical data storage and heat sensitive materials. Originality/value The method for preparation was modified and improved. The materials prepared were new compounds.

Copper Oxide Based Polymer Nanohybrid for Chemical Sensor Applications

PCC based nanohybrid has been synthesized by simple intercalation of CuO nano-sheets into PPC matrix. The morphological and phisochemical structure of nanohybrid was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Energy dispersive spectroscopy (EDS), and Fourier transforms infrared spectroscopy. Interestingly, the morphology of CuO nano-sheets was changed into nanoparticles after intercalation into the polymer matrix. From application point of view, chemical sensing performance of PPC and nanohybrid was investigated by simple I-V technique using nitrophenol as an organic pollutant. By applying to nitrophenol sensing, both PPC and nanohybrid performed as best nitrophenol chemi-sensor in terms of sensitivity. Nanohybrid showed 11.25 times higher sensitivity (4.50 μA.cm−2.mM−1) than pure PCC (0.40 μA.cm−2.mM−1). Therefore, nanohybridization is an efficient route to improve sensing performance of PPC.

Diethyl 3<i>H</i>-naphtho[2,1-<i>b</i>]pyran-2,3-dicarboxylate

The sp(3)-hybridized methine C atom in the title compound, C(19)H(18)O(5), lies out of the mean plane of the remaining 13 atoms of the naphthopyran fused-ring system by 0.571 (1) Å, and its H atom occupies a pseudo-equatorial site.