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Riboflavin (RF) sensitized photooxidation of pyridoxine HCl (PD) in the pH range of 2.0-12.0 has been carried out under UV and visible irradiation in aerobic and anaerobic conditions. PD follows first-order kinetics in the absence and presence of RF for its photodegradation. The first-order rate constants ( k obs ) for the photodegradation of PD in the presence of RF (0.05-0.50 × 10 -4 M) in aerobic and anaerobic conditions range from 0.046-0.755 and 0.0089-0.755 × 10 -2 min -1 , respectively. RF acts as a promoter for the photodegradation of PD and the second-order rate constants ( k 2 ) are in the range of 0.026-1.285 and 0.004-0.128 × 10 -2 M -1 min -1 in aerobic and anaerobic conditions, respectively. The k 2 -pH profile for the photodegradation shows a slanted curve, indicating that with an increase in pH, the rate of photodegradation of PD also increases. Green UV-visible spectrometric and high-performance liquid chromatographic (HPLC) methods have been developed for the simultaneous determination of PD and RF in pure and degraded solutions. These two developed methods are statistically compared and it is found that there is no significant difference between them. We have conducted in silico studies to assess the formation of ground state complexes, molecular interactions, and the binding affinities of RF and PD., Competing Interests: Authors declare that there is no conflict of interest., (This journal is © The Royal Society of Chemistry.)

Alloying can effectively modify electronic and optical properties of two-dimensional (2D) transition metal dichalcogenides (TMDs). However, efficient and simple methods to synthesize atomically thin TMD alloys need to be further developed. In this study, we synthesized 25 monolayer Mo x W (1- x ) S 2 y Se 2(1- y ) alloys by using a new liquid phase edge epitaxy (LPEE) growth method with high controllability. This straightforward approach can be used to obtain monolayer materials and operates on a self-limiting growth mechanism. The process allows the liquid solution to come into contact with the two-dimensional grains only at their edges, resulting in epitaxy confined only along the in-plane direction, which produces exclusively monolayer epitaxy. By controlling the weight ratio of MoS 2 /WSe 2 (MoSe 2 /WS 2 ), 25 monolayer Mo x W (1- x ) S 2 y Se 2(1- y ) alloys with different atomic ratios can be obtained on sapphire substrates, with band gap ranging from WS 2 (1.55 eV) to MoSe 2 (1.99 eV) and a continuously broad spectrum ranging from 623 nm to 800 nm. By adjusting the alloy composition, the carrier type and carrier mobility of alloy-based field-effect transistors can be modulated. In particular, the adjustable conductivity of Mo x W (1- x ) S 2 y Se 2(1- y ) alloys from n-type to bipolar type is achieved for the first time. This general synthetic strategy provides a foundation for the development of monolayer TMD alloys with multiple components and various 2D materials., Competing Interests: The authors declare no conflict of interest., (This journal is © The Royal Society of Chemistry.)

A new pyrazole ligand, N , N -bis(2(1',5,5'-trimethyl-1 H ,1' H -[3,3'-bipyrazol]-1-yl)ethyl)propan-1-amine (L) was synthesized and characterized by 1 H-NMR, 13 C-NMR, FT-IR and HRMS. The coordination ability of the ligand has been employed for the construction of a new family of coordination complexes, namely: [Cu 2 LCl 4 ] (1), [ML(CH 3 OH)(H 2 O)](ClO 4 ) 2 (M II = Ni (2), Co (3)) and [FeL(NCS) 2 ] (4). The series of complexes were characterized using single-crystal X-ray diffraction, HRMS, FT-IR and UV-visible spectroscopy. Moreover, the iron(ii) analogue was investigated by 57 Fe Mössbauer spectroscopy and SQUID magnetometry. Single-crystal X-ray structures of the prepared complexes are debated within the framework of the cooperative effect of the hydrogen bonding network and counter anions on the supramolecular formations observed. Furthermore, within the context of biological activity surveys, these compounds were reviewed against different types of bacteria to validate their efficiency, including both Gram-positive as well as Gram-negative bacteria. Enhanced behaviour towards Fusarium oxysporum f. sp. albedinis fungi, were detected for 1 and 4., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

A bio-nanocomposite matrix of polypyrrole grafted ZnO/chitosan (Ppy/C/Z) was synthesized via the in situ polymerization of pyrrole with different weight fractions of ZnO. Incorporation of ZnO nanoparticles with polypyrrole enhances the photocatalytic, antibacterial as well as cytotoxic properties of the resultant composite. Characterizations of the synthesized product were performed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and thermal analysis (TGA and DTA). Surface morphology and particle size were determined by SEM and TEM. The elemental composition of the material was studied by EDX coupled with SEM. Electrochemical surface area was calculated from electrochemical double layer capacitance (EDLC) measurements using cyclic voltammetry. The photocatalytic activity of the composite material was tested by monitoring the degradation of reactive orange-16 (RO-16), Coomassie Brilliant Blue R-250 (CBB-R-250) and Methylene Blue (MB) dyes and the composite was found to be an effective catalyst in the presence of a UV light source. Various scavengers were used to detect the reactive species involved in the photocatalytic process. Furthermore, the stability of the photocatalyst was assessed by recycling experiments. Moreover, the Ppy/C/Z bio-nanocomposite shows potential application with anti-bacterial and anti-cancer activity against Gram-positive and Gram-negative bacterial pathogens and human cancer cell lines (HeLa and MCF-7). The experimental data confirm that the bio-nanocomposite of Ppy/C/Z showed excellent anti-bacterial and anti-cancer activity as compared to a pristine polypyrrole and chitosan formulation (Ppy/C). The apoptosis data with varying concentrations of Ppy/C/Z reveal the remarkable activity against these cancer cell lines., Competing Interests: There are no conflicts of interest to declare., (This journal is © The Royal Society of Chemistry.)