CuNi sulphidation maximizes MOR activity by expanding the accessibility of active sites!

Sulphidation of a CuNi alloy of Cu : Ni ratio 81 : 19 led to an exponential activity enhancement in the alkaline methanol oxidation reaction (MOR) by four fold due to an order of magnitude increase in the number of active Cu and Ni sites and improved charge transfer properties.

A tri-functional self-supported electrocatalyst featuring mostly NiTeO3 perovskite for H2 production via methanol-water co-electrolysis

A self-supported NiTeO3 perovskite is made by deploying an extended hydrothermal tellurization strategy with a restricted Te content, which was found to be exceptionally active towards the oxidation of water and methanol and the reduction of water in 1.0 M KOH where it delivered -10 mA cm-2 at just -1.54 V for a full cell featuring MOR‖HER.

Synthesis, vibrational spectra, DFT calculations, Hirshfeld surface analysis and molecular docking study of 3-chloro-3-methyl-2,6-diphenylpiperidin-4-one

A newly synthesized molecular complex 3-chloro-3-methyl-2,6-diphenylpiperidin-4-one [CMDP] crystallizes in the triclinic space group P1. The piperidin-4-one ring exhibits a distorted chair conformation with the puckering parameters Q = 0.559 (3) Å, θ = 173.3 (3°) and φ = 180 (2°). The methyl substituent on the third position of the piperidine ring takes up a syn-periplanar positioning although the chloro substituent takes up an anti-clinical positioning with dihedral angle: Cl1-C2-C1-O1 = 113.3 (2°) due to the repulsion from an adjacent oxygen atom. The optimized molecular geometry and fundamental vibrational frequencies of the CMDP compounds are interpreted with the help of normal coordinate force field calculations based on DFT method B3LYP/6-31+G (d,p) level basis set. The HOMO-LUMO energy gap of the molecule is 5.4194 eV. The hardness value (η) of the CMDP molecule is 2.7097 eV. Hirshfeld surface analysis and fingerprint plots are supportive for determining the molecular shape and visually analyzing the intermolecular interactions in the crystal structure. The Hirshfeld surfaces like d_i,d_e,d_norm, shape index and curvedness of C₁₈H₁₈NOCl were pictured and discussed. The various levels of electronic transitions have been predicted by Time-Dependent Density Functional Theory (TD-DFT) calculations and compared with the recorded absorption spectrum. Molecular docking study was performed and reported for the synthesized compound against 4ey7 protein.

Synthesis, crystal structure, DFT calculations and Hirshfeld surface analysis of 3-butyl-2,6-bis-(4-fluoro-phen-yl)piperidin-4-one

The title compound, C21H23F2NO, consists of two fluoro-phenyl groups and one butyl group equatorially oriented on a piperidine ring, which adopts a chair conformation. The dihedral angle between the mean planes of the phenyl rings is 72.1 (1)°. In the crystal, N-H⋯O and weak C-H⋯F inter-actions, which form R 2 2[14] motifs, link the mol-ecules into infinite C(6) chains propagating along [001]. A weak C-H⋯π inter-action is also observed. A Hirshfeld surface analysis of the crystal structure indicates that the most significant contributions to the crystal packing are from H⋯H (53.3%), H⋯C/C⋯H (19.1%), H⋯F/F⋯H (15.7%) and H⋯O/O⋯H (7.7%) contacts. Density functional theory geometry-optimized calculations were compared to the experimentally determined structure in the solid state and used to determine the HOMO-LUMO energy gap and compare it to the UV-vis experimental spectrum.

Crystal structures of two new 3-(2-chloro-eth-yl)-r(2),c(6)-diarylpiperidin-4-ones

The syntheses and crystal structures of 3-(2-chloro-eth-yl)-r-2,c-6-di-phenyl-piperidin-4-one, C19H20ClNO, (I), and 3-(2-chloro-eth-yl)-r-2,c-6-bis-(4-fluoro-phen-yl)piperidin-4-one, C19H18ClF2NO, (II), are described. The piperidone ring adopts a chair conformation in (I), whereas a slightly distorted chair conformation is formed in (II). The dihedral angle between the mean plane of the phenyl rings is 59.1 (1)° in (I) and 76.1 (1)° in (II). The crystal packing features weak inter-molecular N-H⋯O hydrogen bonds in each structure.

Crystal structures of three 3-chloro-3-methyl-2,6-di-aryl-piperidin-4-ones

The syntheses and crystal structure of 3-chloro-3-methyl-r-2,c-6-di-phenyl-piperidin-4-one, C18H18ClNO, (I), 3-chloro-3-methyl-r-2,c-6-di-p-tolyl-piperidin-4-one, C20H22ClNO, (II), and 3-chloro-3-methyl-r-2,c-6-bis-(4-chloro-phen-yl)piperidin-4-one, C18H16Cl3NO, (III), are described. In each structure, the piperidine ring adopts a chair conformation and dihedral angles between the mean planes of the phenyl rings are 58.4 (2), 73.5 (5) and 78.6 (2)° in (I), (II) and (III), respectively. In the crystals, mol-ecules are linked into C(6) chains by weak N-H⋯O hydrogen bonds and C-H⋯π inter-actions are also observed.

t-3-Benzyl-r-2,c-6-diphenylpiperidin-4-one oxime

In the title compound, C24H24N2O [systematic name: (E)-3-benzyl-2,6-diphenylpiperidin-4-one oxime], the piperidine ring adopts a slightly distorted chair conformation and the phenyl rings and the benzyl group substituents are attached equatorially. The oxime group makes a dihedral angle of 42.88 (12)° with the piperidine ring. The dihedral angle between the phenyl rings is 71.96 (8)°. The benzyl ring makes dihedral angles of 63.01 (8) and 59.35 (8)° with the two phenyl rings. In the crystal, molecules are linked by O—H...N hydrogen bonds, formingC(7) chains along thecaxis. The chains are linked by C—H...π interactions, forming slabs lying parallel to thebcplane.

3-Chloro-r-2,c-6-bis(4-fluorophenyl)-3-methylpiperidin-4-one

The title compound, C18H16ClF2NO, contains one independent molecule in the asymmetric unit, with the piperidin-4-one ring adopting a slightly distorted chair conformation and an equatorial orientation of all the substituents except chlorine. A single weak intermolecular C—H...O interaction influences the crystal packing, forming infinite one-dimensional zigzag chains along the a axis. The structure was refined as a two-component inversion twin.

t-3-Benzyl-r-2,c-6-diphenylpiperidin-4-one

The asymmetric unit of the title compound, C24H23NO, contains two crystallographically independent molecules (AandB). In both molecules, the piperidine rings adopt a chair conformation and the phenyl rings and the benzyl group substituents are attached equatorially. The dihedral angle between the phenyl rings is 60.80 (10)° in moleculeAand 68.43 (9)° in moleculeB. The phenyl ring of the benzyl group makes dihedral angles of 76.95 (9) and 42.25 (10)° with the phenyl rings in moleculeA, and dihedral angles of 81.38 (11) and 30.19 (11)° in moleculeB. In the crystal, the two molecules are linked by N—H...O hydrogen bonds, forming –A–B–A–B– chains along [100]. In addition, five C—H...π interactions are also present, linking the chains to form a three-dimensional structure.

White spot syndrome virus (WSSV) genome stability maintained over six passages through three different penaeid shrimp species

White spot syndrome virus (WSSV) replicates rapidly, can be extremely pathogenic and is a common cause of mass mortality in cultured shrimp. Variable number tandem repeat (VNTR) sequences present in the open reading frame (ORF)94, ORF125 and ORF75 regions of the WSSV genome have been used widely as genetic markers in epidemiological studies. However, reports that VNTRs might evolve rapidly following even a single transmission through penaeid shrimp or other crustacean hosts have created confusion as to how VNTR data is interpreted. To examine VNTR stability again, 2 WSSV strains (PmTN4RU and LvAP11RU) with differing ORF94 tandem repeat numbers and slight differences in apparent virulence were passaged sequentially 6 times through black tiger shrimp Penaeus monodon, Indian white shrimp Feneropenaeus indicus or Pacific white leg shrimp Litopenaeus vannamei. PCR analyses to genotype the ORF94, ORF125 and ORF75 VNTRs did not identify any differences from either of the 2 parental WSSV strains after multiple passages through any of the shrimp species. These data were confirmed by sequence analysis and indicate that the stability of the genome regions containing these VNTRs is quite high at least for the WSSV strains, hosts and number of passages examined and that the VNTR sequences thus represent useful genetic markers for studying WSSV epidemiology.

Association of dual viral infection with mortality of Pacific white shrimp (Litopenaeus vannamei) in culture ponds in India

Pacific white shrimp, Litopenaeus vannamei has been introduced recently for culture practice in India. Though SPF stocks are imported for larval production and thereafter culture practice, these are prone to infection with the existing viruses in the environment. Here we report mortality of L.vannamei in several farms in India with minimum biosecurity. The shrimp were harvested early within 50-72 days of culture due to the onset of disease and consequent mortality. As per the analysis carried out, the shrimp were infected with two virus, white spot syndrome virus (WSSV) and infectious hypodermal and hematopoietic necrosis virus (IHHNV). About 80 % of the samples collected had either or both of the viruses. A majority of these samples (60 %) had dual infection with WSSV and IHHNV. Infection of shrimp with WSSV and IHHNV could be detected both by PCR and histopathology. Some of the samples had either exclusively WSSV infection or IHHNV infection and were also harvested before the completion of the required culture period. All the samples analyzed were negative for taura syndrome virus, yellow head virus and infectious myonecrosis virus. While it is difficult to point out the exact etiological agent as the cause of mortality, strict biosecurity measures are advisable for the continuity of L. vannamei culture in India.