The water-soluble complex, [Cu(Val)(2)(NO(3))(2)]; in which Val = valacyclovir, an antiviral drug, has been synthesized and characterized by elemental analysis, furier transfer-infrared, hydrogen nuclear magnetic resonance (H NMR), and UV-Vis techniques. The binding of this Cu (II) complex to calf thymus DNA was investigated using fluorimetry, spectrophotometry, circular dichroism, and viscosimetry. In fluorimetric studies, the enthalpy and entropy of the reaction between the complex and calf-thymus DNA (CT-DNA) showed that the reaction is endothermic (ΔH = 208.22 kJ mol(-1); ΔS = 851.35 J mol(-1)K(-1)). The complex showed the absorption hyperchromism in its ultra violet-visible (UV-Vis) spectrum with DNA. The calculated binding constant, K(b), obtained from UV-Vis absorption studies was 2 × 10(5) M(-1). Moreover, the complex induced detectable changes in the circular dichroism spectrum of CT-DNA, as well as changes in its viscosity. The results suggest that this copper (II) complex interacts with CT-DNA via a groove-binding mode.

Investigation of new catalysts to improve artificial photosynthesis efficiencies is an absolute need concerning energy demands and environmental issues. In the present study, nanosheets of NiPd, NiZn, and NiPdZn metal alloys, synthesized at the toluene−water interface, have been employed as co-catalysts for hydrogen evolution from water in the presence of CdS nanorods (NRs) as a photosensitizer. Anchoring of alloy nanosheets with CdS NRs resulted in exceptional enhancement in hydrogen evolution activity. Interestingly earth abundant cost-effective CdS/NiZn photocatalyst showed higher hydrogen evolution reaction (HER) activity than comparatively precious photocatalyst CdS/NiPd. Trimetallic alloy nanosheets of NiPdZn further exhibited superior HER activity concerning bimetallic alloys, NiZn and NiPd. An enhancement of 21 times in the hydrogen evolution activity of CdS has been achieved by optimum loading of NiPdZn. Hydrogen yields of 21347.3 μmol h −1 g −1 (AQY = 11.35%) and 53361.3 μmol h −1 g −1 (AQY = 28%) have been obtained from CdS/NiPdZn catalyst under alkaline and acidic conditions, respectively. Noteworthy to mention is that photocatalysts based on these alloy nanosheets not only exhibit remarkable hydrogen evolution activities but also show exceptional stability in alkaline as well as in acidic medium. Spectroscopic and photoelectrochemical measurements are carried out to understand the hydrogen evolution activities.

Covalent functionalization of the semiconducting chalcogenide nanoparticles ZnS, ZnSea nd CdS by reaction with organic halides, specifically iodobenzenes, has been demonstrated. DFT calculations have thrown light on the electronic structure of the functionalized chalcogenides. Chalcogenides with bonded phenyl groups exhibit al ong wavelength charge-transfer band as predicted by theory.F unctionalization has been carried out with fluorophores as well. Functionalization of semiconductingc halcogenide particles offers many possibilities for study of their properties and application.Chemical modificationo fn anomaterials by appropriate functional groups has become an active area of research in recent years. Functionalization enables us to tune physical andc hemical properties of the materials,t hereby making them more suitable for various applications.[1-5] Stability and solventd ispersibility of materials can also be enhanced by surface functionalization.I th as been shown recently that organic halides can be used to functionalize MoS 2 sheets.[3] Thus, the reaction of iodobenzenes with the metallic 1T form of MoS 2 functionalizes the surface forming CÀSb onds. The nucleophilic reaction occurs because of electron transfer betweent he metallic1 T phase and the halide,r esulting in forming the covalentC ÀS bond. Interestingly,s emiconducting sheets of the stable 2H form have been functionalized by reactionw ith iodobenzenes in the presence of aP d 0 catalyst. [6,7] It has also been shown that other organic bromides and iodides including certain fluorophores react with the MoS 2 sheets forming CÀSb onds. Encouraged by these results, we have explored whether covalent functionalization of nanoparticles of semiconducting metal chalcogenides such as ZnS and CdS can be carriedo ut by the reactionw ith organic halides such as iodobenzenes. We find that it is indeed possible to do so by the use of the Pd 0 catalyst. Such covalent functionalization resultsi nc harge-transfer between the sulfide and the benzene, giving rise to al ongwavelength absorption band. DFT calculations, carried out to understand the electronic structure and properties of the functionalized chalcogenides, predict the occurrence of ac hargetransfer band. We shall first examine functionalization of ZnS nanoparticles by iodobenzenes. ZnS nanoparticles of % 5-10 nm diameter ( Figure S1;S upporting Information), prepared by ap rocedure reported in the literature, [8] were reactedw ith iodobenzene, 4-iodoanisole or 4-iodonitrobenzene (Scheme 1) by heating in toluene under an itrogen atmosphere.T he solid products obtained show evidencef or covalentl inking of the phenyl group with ZnS.

Nanosheet of PdNiZn and nanosphere of PdNiZn/reduced‐graphene oxide (RGO) with sub‐3 nm spheres have been successfully synthesized through a facile oil‐water interfacial strategy. The morphology and composition of the films were determined by X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive analysis of X‐ray (EDAX) and elemental mapping. In the present study, we have developed a method to minimize the usage of precious Pd element. Due to the special structure and intermetallic synergies, the PdNiZn and PdNiZn/RGO nanoalloys exhibited enhanced catalytic activity and durability relative to Pd nanoparticles in Suzuki‐Miyaura C‐C cross‐coupling reaction. Compared to classical cross‐coupling reactions, this method has the advantages of a green solvent, short reaction times, low catalyst loading, high yields and reusability of the catalysts.