Trinuclear complexes of [CuL] (H₂L = N,N′-bis(salicylidene)-1,4-butanediamine) with HgX₂ (X⁻ = N₃⁻ and NCO⁻): facile crystallization with Z′ = 1 and Z′ = 0.5 for both complexes

Two trinuclear centrosymmetric hetero-metallic copper(II)–mercury(II) complexes of general formula [(CuL)₂HgX₂] (where X = N₃⁻ for 1 and 1′ or OCN⁻ for 2 and 2′) have been synthesized using [CuL] as ‘‘ligand complex” (where H₂L = N,N′-bis(salicylidene)-1,4-butanediamine) and structurally characterized. Rapid crystallization of both the complexes yielded isomorphous crystals with two independent half molecules (Z′ = 1) in 1 and 2 but the crystals that were grown slowly from the same solutions are not isomorphous and contain single half molecule (1′ and 2′) in the asymmetric units (Z′ = 0.5). Crystal structure analyses reveal that the complexes have discrete trinuclear entity in which two square planar [CuL] units are bonded to a mercury ion through double phenoxido bridges. The Hg(II) is in a six-coordinate distorted octahedral environment being bonded additionally to two mutually trans nitrogen atoms of terminal azide (for 1 and 1′) and cyanate (for 2 and 2′). Higher Z′ compounds are stabilized probably due to weak interactions (C–H⋯N/O and C/H⋯π interactions) that help to hold two independent molecules together

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In the field of agriculture, there is need of recognizing as well as classifying diseases from leaf images that are taken from plant. Finding the diseases of paddy leaf by making use of image processing mechanism would reduce the reliance on farmers in order to save the product related to agricultural activity. This research paper is finding and categorizing the disease in paddy leaf with the help of CNN with integration of edge detection mechanism. The proposed work is focusing on the classification of paddy leaf on the basis of the brown spot, bacterial blight, blast disease and sheath rot after spot detection. However, there have been some previous researches to fulfill such objectives but the proposed work used edge detection mechanism to reduce the time consumption as well as space consumption.Leaves of the rice plant have been captured from the field for the normal, brown spot, bacterial blight, blast diseases and sheath rot. During the pre-processing operation RGB images have been converted in HSV images. Image processing is made on the basis of hue and saturation. The portions of binary graphical contents have been captured to split the infected and non-infected portion. A clustering mechanism has been used for segmentation of the infected portion. However, there are several existing researches that have classified diseases with the support of optimized DNN_JOA (Deep Neural Network with Jaya Optimization Algorithm). Time and space consumption are the major issue in those researches. There is need to provide the solution to improve the performance and space consumption thus proposed work is making use of deep neural network with integration of canny edge detection. In this paper, pattern detection using edge based CNN (convolution neural network) algorithm is proposed

Exploring the coordinative adaptation and molecular shapes of trinuclear Cu^II₂M^II (M = Zn/Cd) complexes derived from salen type Schiff bases: structural and theoretical studies

Three new trinuclear hetero-metallic complexes [(CuL) 2Zn(NCS) 2] (1), [(CuLR)2Zn(NCS)(μ1,1-NCS)] (2) and [(CuLR) 2Cd(μ1,3-NCS) 2] (4) have been synthesized using [CuL] and [CuLR] as “metalloligands” (where H2L = N,N′-bis(salicylidene)-1,3-propanediamine and H2LR = N,N′-bis(2-hydroxybenzyl)-1,3-propanediamine). All three complexes are characterized by elemental analysis, spectroscopic methods and single crystal XRD. Complex 1 is an angular trinuclear species, in which two terminal four-coordinate square planar “metalloligands” [CuL] are coordinated to a central Zn(II) through double phenoxido bridges along with two mutually cis nitrogen atoms of terminal isothiocyanate ions as is usually found in such complexes. In contrast, in complex 2, the two terminal “metalloligands” [CuLR] are square pyramidal, as one of the SCN− ions makes an unusual μ1,1-NCS bridge between copper centers while the other one coordinates to Zn(II) through a N atom in a usual fashion making its geometry also square pyramidal. For 4 which possesses an angular trinuclear structure, in addition to double phenoxido bridges from two terminal [CuLR], both the SCN− ions are S-bonded to Cd(II) and form a bridge (cis-μ1,3-SCN) between Cd(II) and each of the terminal Cu(II) ions. This structure is different from its unreduced analogue in which NCS− was N-terminal coordinated to Cd(II) (3/3′). All the structures have been optimized using Density Functional Theory (DFT) calculations. It has been found that for H2L, optimized structures like 1 and 2 differ only by 0.4 kcal mol−1 but the H2LR structure 2 is more stable by 5.5 kcal mol−1 than the structure resembling 1. For Cd(II) complexes also, H2L optimized structures such as 3 and 4 do not differ significantly in energy (1.0 kcal mol−1) but the H2LR structure 4 is more stable than that of 3 by 4.6 kcal mol−1. In fact, structure 4 has been found to be the most stable one among the other possible isomers of H2LR

The influence of H-bonding on the ‘ambidentate’ coordination behaviour of the thiocyanate ion to Cd(II): a combined experimental and theoretical study

Two new trinuclear hetero-metallic copper(II)–cadmium(II) complexes [(CuL) ₂Cd(NCS) ₂] (1) and [(CuL^R) ₂Cd(SCN) ₂] (2) have been synthesized using [CuL] and [CuL^R] as “metalloligands” (where H₂L = N,N′-bis(salicylidene)-1,4-butanediamine and H₂L^R = N,N′-bis(2-hydroxybenzyl)-1,4-butanediamine) respectively. Both the complexes were characterized by elemental analysis, various spectroscopic methods and single crystal XRD. Complex 1 is an angular trinuclear species, in which two terminal four-coordinate square planar “metalloligands” [CuL] are coordinated to a central Cd(II) through double phenoxido bridges along with two mutually cis nitrogen atoms of terminal thiocyanate ions. In complex 2, which is linear, in addition to the double phenoxido bridge, two SCN⁻ coordinate to the trans positions of the central octahedral Cd(II) via S atoms. Theoretical calculations on the energetic difference between the two possible coordination modes of the thiocyanate anion to the Cd atom reveal that N-coordination is preferred over S-coordination in agreement with the much greater abundance of the reported N-bonded structures. In 2, there is a strong N–H⋯NCS–Cd H-bonding interaction, the binding energy of which is computed to be approximately −9.3 kcal mol⁻¹, which is sufficient to compensate the 9.0 kcal mol⁻¹ of energetic cost due to the unusual Cd–SCN coordination mode

Metabolic profiling of Chimonanthus grammatus via UHPLC-HRMS-MS with computer-assisted structure elucidation and its antimicrobial activity

Chimonanthus grammatus is used as Hakka traditional herb to treat cold, flu, etc. So far, the phytochemistry and antimicrobial compounds have not been well investigated. In this study, the orbitrap-ion trap MS was used to characterize its metabolites, combined with a computer-assisted structure elucidation method, and the antimicrobial activities were assessed by a broth dilution method against 21 human pathogens, as well as the bioassay-guided purification work to clarify its main antimicrobial compounds. A total of 83 compounds were identified with their fragmentation patterns, including terpenoids, coumarins, flavonoids, organic acids, alkaloids, and others. The plant extracts can strongly inhibit the growth of three Gram-positive and four Gram-negative bacteria, and nine active compounds were bioassay-guided isolated, including homalomenol C, jasmonic acid, isofraxidin, quercitrin, stigmasta-7,22-diene-3β,5α,6α-triol, quercetin, 4-hydroxy-1,10-secocadin-5-ene-1,10-dione, kaempferol, and E-4-(4,8-dimethylnona-3,7-dienyl)furan-2(5H)-one. Among them, isofraxidin, kaempferol, and quercitrin showed significant activity against planktonic Staphylococcus aureus (IC50 = 13.51, 18.08 and 15.86 µg/ml). Moreover, their antibiofilm activities of S. aureus (BIC50 = 15.43, 17.31, 18.86 µg/ml; BEC50 = 45.86, ≥62.50, and 57.62 µg/ml) are higher than ciprofloxacin. The results demonstrated that the isolated antimicrobial compounds played the key role of this herb in combating microbes and provided benefits for its development and quality control, and the computer-assisted structure elucidation method was a powerful tool for chemical analysis, especially for distinguishing isomers with similar structures, which can be used for other complex samples

The influence of H-bonding on the ¿ambidentate¿ coordination behaviour of thiocyanate ion to Cd(II): A combined experimental and theoretical study

[eng] Two new trinuclear hetero-metallic copper(II)-cadmium(II) complexes [(CuL)2Cd(NCS)2] (1) and [(CuLR)2Cd(SCN)2] (2) have been synthesized using [CuL] and [CuLR] as "metalloligands" (where H2L = N,N'-bis(salicylidene)-1,4-butanediamine and H2LR = N,N'-bis(2-hydroxybenzyl)-1,4-butanediamine) respectively. Both the complexes were characterized by elemental analysis, various spectroscopic methods and single crystal XRD. Complex 1 is an angular trinuclear species, in which two terminal four-coordinate square planar "metalloligands" [CuL] are coordinated to a central Cd(II) through double phenoxido bridges along with two mutually cis nitrogen atoms of terminal thiocyanate ions. In complex 2, which is linear, in addition to the double phenoxido bridge, two SCN− coordinate to the trans positions of the central octahedral Cd(II) via S atoms. Theoretical calculations on the energetic difference between the two possible coordination modes of the thiocyanate anion to the Cd atom reveal that N-coordination is preferred over S-coordination in agreement with the much greater abundance of the reported N-bonded structures. In 2, there is a strong N-H⋯NCS-Cd H-bonding interaction, the binding energy of which is computed to be approximately −9.3 kcal mol−1, which is sufficient to compensate the 9.0 kcal mol−1 of energetic cost due to the unusual Cd-SCN coordination mode

Unprecedented structural variations in trinuclear mixed valence Co(II/III) complexes: theoretical studies, pnicogen bonding interactions and catecholase-like activities

Three new mixed valence trinuclear Co(II/III) compounds cis-[Co₃L₂(MeOH)₂(N₃)₂(μ_1,1-N₃)₂] (1), trans-[ Co₃L₂(H₂O) ₂(N₃) ₂(μ_1,1-N₃) ₂]•(H₂O) ₂ (2) and [Co₃L^R₂(N₃)₃(μ_1,3-N₃)] (3) have been synthesized by reacting a di-Schiff base ligand (H₂L) or its reduced form [H₂L^R] (where H₂L = N,N′-bis(salicylidene)-1,3-propanediamine and H₂L^R = N,N′-bis(2-hydroxybenzyl)-1,3-propanediamine) with cobalt perchlorate hexahydrate and sodium azide. All three products have been characterized by IR, UV-vis and EPR spectroscopies, ESI-MS, elemental, powder and single crystal X-ray diffraction analyses. Complex 1 is an angular trinuclear species in which two terminal octahedral Co(III)N₂O₄ centers coordinate to the central octahedral cobalt(II) ion through μ₂-phenoxido oxygen and μ_1,1-azido nitrogen atoms along with two mutually cis-oxygen atoms of methanol molecules. On the other hand, in linear trinuclear complex 2, in addition to the μ₂-phenoxido and μ_1,1-azido bridges with terminal octahedral Co(III) centres, the central Co(II) is bonded with two mutually trans-oxygen atoms of water molecules. Thus the cis–trans configuration of the central Co(II) is solvent dependent. In complex 3, the two terminal octahedral Co(III)N₂O₄ centers coordinate to the central penta-coordinated Co(II) ion through double phenoxido bridges along with the nitrogen atom of a terminal azido ligand. In addition, the two terminal Co(III) are connected through a μ_1,3-azido bridge that participates in pnicogen bonding interactions (intermolecular N–N interaction) as an acceptor. Both the cis and trans isomeric forms of 1 and 2 have been optimized using Density Functional Theory (DFT) calculations and it is found that the cis configuration is energetically more favorable than the trans one. However, the trans configuration of 2 is stabilized by the hydrogen bonding network involving a water dimer. The pnicogen bonding interactions have been demonstrated using MEP surfaces and CSD search which support the counter intuitive electron acceptor ability of the μ_1,3-azido ligand. Complexes 1–3 exhibit catecholase-like activities in the aerial oxidation of 3,5-di-tert-butylcatechol to the corresponding o-quinone. Kinetic data analyses of this oxidation reaction in acetonitrile reveal that the catecholase-like activity follows the order: 1 (k_cat = 142 h⁻¹) > 3 (k_cat = 99 h⁻¹) > 2 (k_cat = 85 h⁻¹). Mechanistic investigations of the catalytic behaviors by X-band EPR spectroscopy and estimation of hydrogen peroxide formation indicate that the oxidation reaction proceeds through the reduction of Co(III) to Co(II)

Nutritional Properties, Antioxidant and Antihaemolytic Activities of the Dry Fruiting Bodies of Wild Edible Mushrooms Consumed by Ethnic Communities of Northeast India

A variety of cultivated mushrooms in Northeast India are well known for their taste, nutritional and medicinal benefits. Many wild-growing mushrooms are also consumed due to their exotic flavours and tastes; however, the scientific exploration of their nutritional and bioactive properties is still negligible. In the present study, the 32 wild edible mushroom samples of 11 species collected from different parts of Northeast India were evaluated for their proximate composition, mineral and vitamin (ascorbic acid and riboflavin) contents, antioxidant and antihaemolytic activity, and profiles of organic and phenolic acids. Lentinus sajor-caju and Lentinus squarrosulus had the highest carbohydrate content (49.80 g/100 g dry weight (d.w.) and 46.36 g/100 g d.w., respectively), crude protein content (20.72 g/100 g d.w. and 20.54 g/100 g d.w., respectively) and a considerable content of minerals. The highest fat content was determined in Lentinus velutinus (7.17 g/100 g d.w.). Among the minerals, potassium was found as the most abundant in all the samples. The extracts of L. sajor-caju, L. squarrosulus, and Pleurotus pulmonarius were characterized by the highest antioxidant activity, while these of L. sajor-caju, Pleurotus ostreatus, P. pulmonarius and Agaricus bisporus showed the highest antihaemolytic potential. The HPLC analysis allowed determining the high contents of ascorbic acid and a few organic and phenolic acids such as lactic acid, gallic acid, 3,4-dihydroxybenzoic acid and trans-cinnamic acid in the tested mushrooms. Other compounds viz. citric acid, caffeic acid, riboflavin, vanillic acid, pyruvic acid, and p-coumaric acid were detected with variations. This study established the nutritional and health-promoting benefits of wild edible mushrooms of Northeast India region for consumption as functional foods in human diet