Bhaskar Biswas

The hybrid photocatalyst, MOF-QD, turns visible light into clean H ₂ . This review connects their interfacial chemistry with performance and provides transferable, mechanism-driven design guidelines for the next generation of MOF-QD based catalysis.

A phenalenyl–pyrene hybrid system is presented here as an effective photocatalyst for the direct C(sp ² )─H arylation of p ‐benzoquinone under visible light. This process yields a range of biologically and optically relevant redox‐active tetra‐arylated‐ p ‐benzoquinones, utilizing aryl diazonium salts as radical sources. Additionally, the catalyst facilitates the conversion of tetra‐arylated‐ p ‐benzoquinones into dibenzofuran‐type molecules through intramolecular O─C coupling when aryl groups contain powerful inductive withdrawing groups. This study also provides mechanistic insights into the catalytic reaction and the structural characteristics of the synthesized tetra‐arylated products.

This work reports a scalable, air-stable NBU-1 MOF-derived amorphous NiP _1.42 O _x /C/C–N OER electrocatalyst termed NBU-1500 obtained via one-step calcination without external dopants.

The direct α-oxygenation of arylmethanamines to amides is a cornerstone transformation in organic synthesis; however, traditional methods suffer from harsh conditions, reactive reagents, and expensive transition metal catalysts. This study introduces a novel approach using a redox-active aryl-substituted bis(imino)acenaphthene (Ar-BIAN)-based organic radical anion as a catalyst that mimics transition metal catalysis in the aerial oxidation of arylmethanamines into their corresponding amides for the first time. This protocol showcases a wide substrate scope along with tolerance of common organic functional groups. Through various experiments and theoretical calculations, a plausible mechanism has been proposed, involving dehydrogenation of amine to nitrile and its subsequent hydrolysis to amide.

Herein, we report four newly synthesized iron complexes 1 , 2 , 3 , and 4 based on functionalized bipyridine, phenanthroline, and pyridine–imidazole ligands, along with their structural characterization and catalytic activity toward selective oxidation of alcohols to aldehydes. Structural analysis revealed that the oxidation state of iron is +2 in all the complexes with stabilization in the crystal lattice facilitated by diverse noncovalent interactions, including π–π stacking, C─H···π interactions, halogen···π interactions, and dipole–dipole interactions. Among the series, the electron‐rich complex 1 demonstrated superior catalytic efficiency within short reaction times. Using NaIO ₄ as a terminal oxidant, complex 1 enabled the conversion of a wide range of alcohols into the corresponding aldehydes in good to excellent yields, while being tolerant of common organic functional groups. The selective conversion of alcohols to aldehydes without overoxidation is highly essential in organic synthesis. The comparative catalytic performances of complexes 1–4 are rationalized by correlating their redox and structural properties. Based on several control experiments and literature reports, we have also proposed a plausible mechanism for present protocol.

Green ammonia (NH ₃ ) is emerging as a cornerstone for building a sustainable energy economy, aligning with global goals for decarbonization and industrial transformation. Its versatility extends across agriculture, sustainable hydrogen production, and carbon‐neutral transportation, making it a critical enabler of a greener future. While the Haber–Bosch process remains the conventional method for ammonia synthesis, it is highly energy‐intensive and carbon‐heavy. To address these challenges, innovative technologies, including electrochemical and plasma‐based processes, are being developed to enable large‐scale ammonia production with reduced greenhouse gas emissions. Recent advances in catalysis have been central to this transition. Novel catalysts such as metal hydrides, nitrides, and single‐atom systems offer enhanced efficiency, enabling ammonia synthesis at lower temperatures and pressures compared to the traditional Haber–Bosch route. In parallel, electrochemical nitrogen reduction reactions (NRRs) and photocatalytic pathways using advanced materials provide new opportunities for sustainable NH ₃ generation. Another important technology is ammonia cracking, which decomposes NH ₃ into H ₂ and N ₂ . Collectively, these developments improve the viability, scalability, and cost‐effectiveness of green ammonia for applications in agriculture, energy, and environmental systems.

Increased mortality and escalating healthcare expenses are two major consequences of the ever-growing peril to global health posed by drug-resistant diseases in recent times. To combat these problems, it is crucial to develop suitable biocompatible materials that possess potential antibacterial properties. In this context, metal-organic frameworks are emerging candidates in overcoming antibacterial resistance, especially those composed of zinc. Herein, we report the synthesis, characterisation, and subsequent antibacterial evaluation of a zinc and 4,4'-bipyridine-based, 1D MOF, NBU-7, employing a facile solvothermal method. X-ray diffraction studies divulge the structural facets of the MOF, while spectroscopic and analytical details further augment the successful formation of the MOF. NBU-7 also displays good solubility and stability in water with low minimum inhibitory concentrations and reduced cell viability against Gram-negative and Gram-positive bacterial strains. Further, NBU-7 shows minimal cytotoxicity towards mammalian fibroblasts (L929), while SEM analysis reveals the ability of the Zn-MOF to rupture the bacterial cell membrane, leading to lysis. Additionally, the hemolysis assay with variable concentrations showed insignificant deviation from normal saline, depicting a hemolytic rate below 5%. These findings render NBU-7 MOF as a potential agent for antibacterial applications.

The design and development of bioinspired coordination compounds are crucial for laying the foundation to deliver low‐cost, energy‐efficient materials that promote energy sustainability. In this work, isostructural copper complexes, Cu‐L _N2S2 and Cu‐L _N3S , in tune with the donor centers in the ligand backbone, (L _N2S2 = 1,2‐bis((pyridin‐2‐ylmethyl)thio)ethane and L _N3S =N‐(pyridin‐2‐ylmethyl)‐2‐((pyridine‐2‐ylmethyl)thio)ethane‐1‐amine) have been prepared, structurally characterized, and evaluated for their electrocatalytic fate towards the sustainable hydrogen production activities in water. Single‐crystal X‐ray crystallography reveals that the copper centers in both complexes adopt a distorted square pyramidal geometry. Cu‐L _N2S2 exhibits superior electrocatalytic performance over Cu‐L _N3S in acidic aqueous media, achieving an outstanding turnover frequency (TOF) of 2.90 × 10 ³ s ⁻¹ with 96% Faradaic efficiency. Detailed mechanistic insights, supported by spectroscopic, analytical, and DFT calculations, reveal divergent HER pathways: Cu‐L _N3S follows an ECEC mechanism, while Cu‐L _N2S2 operates via a CECE sequence. Protonation and reduction site analyses highlight the critical role of mixed hard–soft donor environments in modulating redox behavior and promoting hydride formation for efficient hydrogen production. The greater structural distortion arises from the higher number of sulfur donors in the ligand environment of Cu‐L _N2S2 , which in turn promotes the formation of the observed coordination geometry feasible for sustainable electrocatalytic evolution of hydrogen in water.

Herein, we have successfully implemented two dinuclear copper complexes based on N, O donor ligands as efficient and selective catalysts for the arylation of N‐heterocycles using aryl iodides, aryl bromides, and even less reactive aryl chlorides under relatively mild conditions. This is a dinuclear approach where metal–metal cooperation through a bridging ligand can enhance the catalytic process more efficiently than traditional mononuclear complexes. The structural characterization of a dinuclear copper complex of the form Cu ₂ L ¹ ₄ , 1 based on N, O donor 8‐hydroxyquinoline (HL ¹ ), reveals the formation of interesting isomeric structures. The complex 1 shows better catalytic activity toward N‐arylation compared to the bis‐chelating Schiff base N, O donor 2,2 ^′ ‐[naphthalene‐1,5‐diylbis(nitrilo­methanylyl­idene)]diphenol (H ₂ L ² )‐coordinated dinuclear copper complex ClCu(μ‐L ² )CuCl, 2 . The current protocol is effective for the arylation of imidazole, pyrazole, benzimidazole, 1,2,4‐triazole, pyrrole, and indole, with tolerance of common functional groups. The N‐arylation reaction catalyzed by 1 has been successfully scaled up to Gram scale without significantly reducing the product yield. A mechanistic route for this N‐arylation reaction has been proposed by considering various control experimental and spectroscopic results.