Single Crystal XRD Techniques Research Articles

Hirshfeld surface analysis, experimental and theoretical evaluation of a new monohydrated organic salt of 2-amino-4‑hydroxy-6-methylpyrimidine (AHMP) and 4-acetamidobenzoic acid (AMBA) for nonlinear optical applications

The organic crystal (AHMP+.AMBA−) of the AHMP and AMBA organic compounds was successfully synthesized and grown by the slow evaporation solution process. The present work focuses on the crystal structure, Hirshfeld surface, spectroscopic and DFT analyses of the title salt. The crystal geometry of AHMP+.AMBA− monohydrated salt was characterized by the single-crystal XRD technique. The synthesized salt crystallizes in the triclinic crystal system and P-1 space group. The identification of the functional groups of the compound has been done by FTIR spectroscopy and DFT/B3LYP-D3/6–311++G(d,p) level of theory. Further, Hirshfeld surface mapping and its associated two-dimensional fingerprint plots predict that the O⋅⋅⋅H and H⋅⋅⋅H interactions are dominant for stabilizing the crystal structure. TG-DTA reveals the crystal is thermally stable up to 168 ºC. The optical studies have been performed by the time-dependent DFT (TD-DFT) and UV–Vis spectroscopic methods. Moreover, the Z-scan experiment has been done to obtain third-order NLO properties. Additionally, the HOMO-LUMO energy gap, MEP maps and theoretical NLO parameters have also been calculated.

Unveiling the dual functionality of dimeric Cu(I)/(II) crystal as luminescence and electrochemical probe for Zn2+ and glucose detection—Structural, sensing and molecular docking studies

A new crystalline dinuclear Cu(I)/(II) complex (E.F: C32H28Cu2N6O14) (1) of terephthalic acid (TERE) and 1, 10‐Phenathroline (PHEN) was synthesized under one‐pot approach. Structure identification of the complex was carried out using the single crystal XRD technique, which revealed the penta coordination nature of Cu(I)/(II) in a square pyramidal environment. Further, the structural data was supported by employing other spectroscopic studies (UV, ESR, FT‐IR). In addition, the thermal stability and morphology of the complex were elucidated using TGA and SEM‐EDAX analysis. Photoluminescence experiments revealed the capability of 1 to act as a “turn‐off” sensor towards Zn2+ sensing. This luminescence quenching of 1 exhibited a threefold quenching in intensity by achieving a static quenching process corresponding to a limit of detection (LOD) of 3.7 μM. Further, considering the electroactive nature of Cu(I)/(II) complex, the cyclic voltammetric experiments were performed to study its competence to act as a modifier of GCE for the detection of glucose and its excellent potency to act as an effective electroactive material in the detection of glucose solutions. Also, molecular docking of 1 with human bovine serum (HSA) and bovine serum albumin (BSA) was investigated to prove their ability to act as pharmacological agents.

Electrocatalytic Water Oxidation by Mononuclear Copper Complexes of Bis-amide Ligands with N4 Donor: Experimental and Theoretical Investigation.

The present work describes electrocatalytic water oxidation of three monomeric copper complexes [CuII(L1)] (1), [CuII(L2)(H2O)] (2), and [CuII(L3)] (3) with bis-amide tetradentate ligands: L1 = N,N'-(1,2-phenylene)dipicolinamide, L2 = N,N'-(4,5-dimethyl-1,2-phenylene)bis(pyrazine-2-carboxamide), L3 = N,N'-(1,2-phenylene)bis(pyrazine-2-carboxamide), for the production of molecular oxygen by the oxidation of water at pH 13.0. Ligands and all complexes have been synthesized and characterized by single crystal XRD, analytical, and spectroscopic techniques. X-ray crystallographic data show that the ligand coordinates to copper in a dianionic fashion through deprotonation of two -NH protons. Cyclic voltammetry study shows a reversible copper-centered redox couple with one ligand-based oxidation event. The electrocatalytic water oxidation occurs at an onset potential of 1.16 (overpotential, η ≈ 697 mV), 1.2 (η ≈ 737 mV), and 1.23 V (η ≈ 767 mV) for 1, 2, and 3 respectively. A systematic variation of the ligand scaffold has been found to display a profound effect on the rate of electrocatalytic oxygen evolution. The results of the theoretical (density functional theory) studies show the stepwise ligand-centered oxidation process and the formation of the O-O bond during water oxidation passes through the water nucleophilic attack for all the copper complexes. At pH = 13, the turnover frequencies have been experimentally obtained as 88, 1462, and 10 s-1 (peak current measurements) for complexes 1, 2, and 3, respectively. Production of oxygen gas during controlled potential electrolysis was detected by gas chromatography.

An innovative Schiff-base colorimetric chemosensor for the selective detection of Cu2+ ions and its applications.

A novel Schiff base moiety, (E)-4-(1-hydrazonoethyl)benzene-1,3-diol (2), and 2,4-dihydroxybenzaldehyde were condensed in a 1 : 1 molar ratio to generate 4-((E)-1-(((Z)-2,4dihydroxybenzylidene)hydrazono)ethyl)benzene-1,3-diol (L), which was then characterized using high-resolution mass spectrometry (HRMS), 1H-NMR, 13C NMR, and single-crystal XRD techniques. UV-vis absorbance measurements were used to determine whether the Schiff base could detect the cupric ions more effectively than the other transition metal ions. When Cu2+ ions were involved, a new band was observed at 462 nm. From the Job plot, the binding stoichiometry for the anticipated L : Cu2+ partnership is determined to be 1 : 1. For the purpose of validating structural correlations and absorption data, DFT simulations were performed. Further, docking studies for L indicated high binding affinity for human hemoglobin, providing vital information about the ligand's favorable binding locations inside hemoglobin binding sites and the consequent interactions with HHb. The binding coefficient and limit of detection were found to be 3.02 × 104 M-1 and 42.09 nM, respectively. Reversibility of the complex was seen upon the addition of EDTA to the L-Cu2+ solution, and a colorimetric variation simulating the "INHIBIT" molecular logic gate was seen upon the addition of Cu2+ and EDTA to L. Furthermore, the chemosensor's potential application in the detection of Cu2+ in the solid state by chemosensor L also confirms its usefulness in real-world applications emphasizing its versatility and practical utility.

Synthesis, Physiochemical Characterization and Biological Investigation with Quantum Chemical Computations of Benzotriazole Salicylate

In the present work a new organic single crystal Benzotriazole (BTSA) was synthesized and fully characterized by means of single crystal XRD, FT-IR, FT-Raman and UV-visible spectroscopic techniques. Single-crystal X-ray diffraction was applied to the growing crystal to determine the cell dimensions. It has been found that the HOMO and LUMO computed energies accurately depict the characteristics of electron excitation. The TD-DFT approach was used to analyze the UV-visible spectra and study spectroscopic wavenumbers. Analysis using the quantum theory of atoms in molecules has been done to find all potential non-covalent interactions. Multiwfn has been used to visualize Electron Localization Function (ELF) and Localized Orbital Locator (LOL) to examine the molecule’s electrical characteristics. Antimicrobial activity studies indicate the compound good antibacterial and antifungal activity. The docking parameters were studied with Candida tropicalis proteins and the lowest binding energy −5.95 kcal/mol has been achieved for 6ZD2 protein.

Chan−Evans−Lam coupling for the synthesis of N–aryl derivatives catalyzed by copper(I) chloride and sterically varied imidazolium salts at mild reaction conditions

First-row transition–metal–catalyzed organic transformations have received colossal interest in the modern synthetic organic chemistry due to their step– and atom–economic approaches. As a consequence, direct arylation of azoles through C–H or N–H activations acquired a broad spectrum of applications for accessing valuable small organic molecules that are of pharmaceutical interest. In this connection, sterically varied coumarin–functionalized imidazolium salts bearing bromide (5–7) and hexafluorophosphate anions (8–10) have been prepared and used as NHC precursors. The salts have been characterized by both, spectroscopic and analytical techniques. A hexafluorophosphate salt 9 was also studied for its structure using the single-crystal XRD technique. The salts that indeed, generate carbene that trap Cu(I) to form Cu(I)–NHC complexes in situ for the Chan−Evans−Lam C–N coupling of 1H–azoles/anilines and phenyl/thiopheneboronic acids, resulting in the formation of N–aryl derivatives in moderate to excellent yields. The structure-activity relationship studies revealed that the steric bulk around the metal center would help increase the catalytic Chan−Evans−Lam C–N coupling potential of the catalysts.

A highly selective probe for fluorometric sensing of cyanide in an aqueous solution and its application in quantitative determination and living cell imaging.

A simple fluorescent probe (KS4) containing multiple reaction sites (phenolic -OH, imine and C=C bonds) is successfully synthesized and characterized using 1H NMR, 13C NMR, mass and single crystal XRD techniques. KS4 exhibits high selectivity towards CN- over a wide range of common anions in H2O:DMSO (1:1 v/v) leading to an amazing turn-on fluorescence at 505nm via deprotonation of the phenolic -OH group. The limit of detection (1.3µM) for CN- was much below the standard (1.9µM) set by the World Health Organization (WHO). Stoichiometry of the interaction between KS4 and CN- was ascertained as 1:1 by the Job's plot method and the binding constant was determined to be 1.5x104 M-1. Density Functional Theory (DFT) and Time-Dependent Density Functional Theory (TD-DFT) based theoretical insight has been appealed to understand the optical properties of KS4 before and after the addition of CN- ion. The probe shows respectable real-time applicability for qualitative detection of CN- in almond and cassava powder as well as quantification in real water samples with excellent recoveries (98.8 - 99.8%). In addition, KS4 is found to safe towards living HeLa cells and successfully applied to the detection of endogenous cyanide ions in HeLa cells.

Zinc(II) derivatives of N, O containing Schiff bases: synthesis, characterization, computational and biological studies

Bidentate Schiff bases (I1–I9 ) are synthesized by condensation between substituted anilines, benzothiazoles, and 2-hydroxy aromatic aldehydes. The Zn(II) derivatives (1–9) are prepared by reacting the respective ligand and zinc acetate dihydrate in a 2:1 mole ratio in dry methanol using triethylamine as a base. They are characterized by FTIR, NMR, and single-crystal XRD techniques. The XRD data confirmed distorted tetrahedral molecular geometry for 6; the intermolecular interactions are investigated comprehensively by 3-D Hirschfeld surface analysis and 2-D fingerprint plots. The DFT studies for the compounds are conducted for geometrical and energy optimization by applying 3-21 G* and 6-311++G (d, p)/B3LYP basis sets. Molecular docking data show that ligands possess GOLD scores in the range 51.5–46.7, whereas 2 and 3 have shown good fitness score of 57.7 and 53.3, respectively, with a maximum score of 60.2 for 7. The antibacterial data for 7 shows zone of inhibition as 17.3 mm against Staphylococcus aureus and 16.3 mm against Staphylococcus epidermidis, whereas 2 exhibits maximum value of 15.6 mm against gram negative bacteria Escherichia coli. The maximum and comparable alpha amylase inhibition potential of 12.6 and 12.3% are found for 8 and 3, respectively.

Synthesis, crystal structure, DNA binding, molecular docking, DFT, Hirshfeld surface analysis, and cytotoxicity of copper (II) complex with malonamide and 2,9-dimethyl-1,10-phenanthroline

A new copper (II) complex, [Cu(dmp)(malon)(H2O)](NO3)2 where malon = malonamide and dmp = 2,9-dimethyl-1,10-phenanthroline, has been synthesized and characterized by elemental analysis, FT-IR, UV–Visible and single crystal XRD techniques. The complex was crystallized in a monoclinic system with space group P21/n. Single-crystal XRD studies have established that the copper (II) complex cation has a distorted square-pyramidal geometry, with Jahn-teller distortion occurring in the CuN2O3 core. The DFT/UB3LYP/LANL2DZ level of theory was used to optimize the structure of the present complex. The essential interactions within the crystal structure that lead to molecular packing were identified using Hirshfeld surface analysis. UV–Visible absorption titration, fluorescence, cyclic voltammetry, and viscometric titration studies were used to study the interactions of the present complex with calf thymus DNA (CT-DNA) and propose a partial intercalation binding mechanism. The complex demonstrated strong cytotoxic effects against the human hepatocellular carcinoma cell line (HepG2), and it was discovered to have effective antibacterial and antifungal properties. The efficient binding of the copper (II) complex was observed from molecular docking analysis.

Novel thiourea derivative compounds: Thermal behavior, biological evaluation, Hirshfeld surfaces and frontier orbitals analyses, in silico ADMET profiling and molecular docking studies

This work reports synthesis and structural characterization of N-(allylcarbamothioyl)-2-chlorobenzamide (HL1, C11H11ClN2OS) and N-(allylcarbamothioyl)-2-methylbenzamide (HL2, C12H14N2OS). Structural characterization studies were made via elemental analysis, FT-IR, 1H NMR and single crystal XRD techniques. Thermal behavior of the synthesized compounds were investigated via TG/DTA. The cell similarity calculation was made. The Is value for HL1 and HL2 was found to be 86.9%. The HL1 and HL2 compounds were found to be thermally stable upto 136 and 132 °C, respectively. Anticancer activity of the compounds against MCF-7 breast cancer cells was studied via cell viability test and MTT. The role and the effect of different functional groups present in the compounds on anticancer activity were investigated. The IC50 values were found to be in the range 2.59 – 7.09 µmol.L−1. The HL1 compound showed good antitumor activity at 2.59 µmol.L−1 at 48 h. The Hirshfeld surfaces analyses of the compounds were made. The HOMO-LUMO energy levels of HL1 and HL2 were calculated. The compounds were thoroughly investigated in silico for their ADMET characteristics. The physicochemical, pharmacological, and ADMET characteristics of HL1 and HL2 were investigated together with drug similarity metrics. The compounds were observed to have good drug-like property. Furthermore, molecular docking experiments were carried out to evaluate the interactions between the compoundssynthesized in this study and BRAF (V600E -protein kinase). The acquired results revealed that the synthesized compounds had high binding affinity and inhibitory effect on the BRAF (V600E) protein kinase. The synthesized compounds can be considered potent anticancer agents, according to the data obtained using both in vitro and in silico techniques.

Growth of pyridinecarbothioamides and single crystal XRD studies

A series of pyridinecarbothioamides (PCT) are synthesized to produce parrot green crystals. The crystal structure of the compounds was resolved using single crystal XRD technique. It confirmed the formation of monoclinic system with different space groups depending on the position of side chains in the carbothioamide. The 3D structural arrangements show that molecules in the crystal structure are interlinked by NH … N or SH … S hydrogen bonding. The conversion of pyridinecarbonitrles to their corresponding pyridinecarbothioamides by the treatment of ammonia and H2S was confirmed by their mass spectra. Major peak was observed at m/z of 138. Thermogram of PCTs, shows a single step decomposition thereby confirming the melting points of corresponding PCT’s as 137 °C, 190 °C, 209 °C respectively. Nuclear Magnetic Resonance (NMR) spectroscopic techniques showed the signals corresponding to pyridine ring protons and amino group.

In vitro cytotoxicity activity of copper complexes of imine and amine ligands: A combined experimental and computational study

Two new Cu(II) complexes [CuL1 (µ1,3-NCS)]2, 2ClO4 (A) and [CuL2 (NCS)2] (B) with Schiff base ligand L1 and reduced Schiff base ligand L2 have been synthesized and characterized by various spectroscopic and electrochemical methods along with single crystal XRD techniques. X-ray diffraction analysis confirms the formation of binuclear (A) and mononuclear (B) complexes. Hirshfeld surfaces analysis of the two complexes and their associated two-dimensional fingerprint plots are plotted. The metal complexes were optimized by using the density functional theory (DFT) comprising Becke’s three parameters exchange potential and Lee-Yang-Parr correlation functional (B3LYP) method, with 6-31G(d,p) basis set for the ligand atoms and LANL2DZ for the central metal ions. The synthesized binuclear Complex A and mononuclear Complex B were screened for their in vitro anticancer activity against human colon adenocarcinoma cells (HT-29) and human hepatoma cell line (Hep-G2) and HeLa cell line. Activity results proved that Complex A has excellent antiproliferative activity against colon carcinoma whereas Complex B is active against hepatocellular carcinoma and cervical cancer.

Experimental and theoretical investigation of novel organic L-Glutaminium Benzenesulfonate single crystal – DFT and experimental approach

An organic nonlinear optical crystal of l-Glutaminium Benzenesulfonate (LGBS) crystal was grown by slow evaporation method. Crystallization parameters and structural analysis of LGBS crystal were notified by Single crystal XRD technique and the theoretical structural parameters were also identified and compared using DFT. The grown LGBS crystal crystallizes in monoclinic crystal system with the non-centrosymmetric space group P21. The presence of chemical bonding and functional groups were examined using FTIR and FT Raman spectra and their theoretical assignments were calculated. The lower cutoff wavelength was determined for grown LGBS crystal by UV–visible spectroscopy and it confirms that grown LGBS crystal has wide transmittance in the visible region. The emission region for the grown LGBS crystal was analysed by fluorescence spectrum. The global reactive descriptors and the intermolecular charge transfer interactions were also interpreted. The liberation of organic molecule and melting temperature of LGBS crystal were elucidated by thermo gravimetric analysis (TG) and DSC. The Kurtz and Perry powder technique confirms the formed LGBS crystal exhibits the second harmonic generation (SHG) and its outputs were compared with standard KDP.

Synthesis of new thiourea derivatives and metal complexes: Thermal behavior, biological evaluation, in silico ADMET profiling and molecular docking studies

In this work, N-((5-bromopyridin-2-yl)carbamothioyl)-2-chlorobenzamide (HL1) and N-((5-bromopyridin -2-yl)carbamothioyl)furan-2-carboxamide (HL2) and its Cu, Ni and Co metal complexes were prepared. Elemental analysis, FT-IR, UV–vis.,1H NMR, single crystal XRD techniques, magnetic susceptibility and DTA/TG analysis were used for structural characterization. The thermal behaviors of the HL1, HL2 and its complexes were investigated. HL1 and HL2 ligands were thermally stable up to 119 and 134 °C, respectively. After the structures of the compounds were characterized, anticancer activity studies were performed, and the effects of different groups on the activity were investigated. Cell viability test MTT was made to determine anticancer activities against MCF-7 breast cancer cells. IC50 values for MCF-7 cells were in the range of 2.07 µM – 21.25 µM. The NiL12 complex showed better antitumor activity when at 2.07 µM concentration in 24 h. For their ADMET properties, ligands and metal complexes have been comprehensively studied in silico. Notably, when the physicochemical, pharmacological and ADMET properties of ligands HL1 and HL2 were evaluated together with drug similarity parameters, good drug-like behavior of the compounds was revealed. In addition, molecular docking studies were performed to assess the binding interactions between ligands and complex compounds and BRAF (V600E -protein kinase). According to the obtained results, it was confirmed that all synthesized compounds exhibited high binding affinity and had an inhibitory effect against BRAF (V600E) protein kinase. The results obtained with both in vitro and in silico approaches have shown that the synthesized compounds can be evaluated as potent anticancer agents.

Effect of Charge Transfer and Non-Covalent Interactions of the Synthesized NLO Compound p-Nitrophenol Sodium-Bisulfate Using DFT Method

In the present work a new semiorganic single crystal p-nitrophenol sodium-bisulfate (PNSB) was synthesized and fully characterized by means of single crystal XRD, powder XRD, FT-IR, FT-Raman and UV-visible spectroscopic techniques. The optimized geometrical parameters were obtained at the DFT/B3LYP level of theory and correlate them with similar structures. Normal coordinate analysis, force constants, and potential energy distributions have been used to support the complete vibrational assignments for all vibrational modes. The computed IR and Raman frequencies correlate well with the experiments, as indicated by the correlation factor. The optimized molecular structure reveals the presence of C-H…O hydrogen bonding interaction. The stability of the molecule arising from hyper conjugative interaction and charge delocalization has been analyzed using natural bonding orbital analysis. NBO analysis proved the presence of intermolecular O-H…Na22 hydrogen bonds caused by the interaction of the lone pair of oxygen with the anti-bonding orbital. HOMO, LUMO and ESP analyses were done using DFT, whereas, the absorption band in the UV–vis spectrum was predicted and compared with the experimental data. ESP is used to identify the nucleophilic region, which is located around the sodium atom, and the electrophilic region, which is primarily located at the oxygen atoms of the PNSB molecule. The frontier orbital gap denotes the charge transfer interaction within the compound required for optical activity. Electron Localization Function, Localized Orbital Locator and Reduced Density Gradient analysis were discussed. In order to study the nonlinear optical activity of PNSB, the dipole moment, polarizability and fihyperpolarizabilities were computed. It is found that the calculated first order hyperpolarizability of PNSB is 51.75 times greater than that of urea.

Sterically hindered mononuclear and binuclear Cu(I) complexes: Synthesis, characterization, docking analysis and antimicrobial evaluation

Mononuclear (1:3) and dinuclear (1:1.5 and 1:1), of the Copper(I) halide complexes containing triphenylphosphine, tri-metatolylphosphine, tri-(o-tolylphosphine) and tri-(p-tolylphosphine) were synthesized by the direct reactions of copper halide salts and phosphine ligands. Twelve complexes were synthesized, in which some complexes have been already reported and resynthesized by modifying the previous reported procedure. The structures and composition of the synthesized complexes were characterized by various techniques like Fourier Transform Infra-Red (FTIR), 1H, 13C, 31P NMR spectroscopy, single crystal XRD and EDX techniques. Most of the complexes exhibit mononuclear tetrahedral geometry while those with substituted phosphines exhibit bridged binuclear mode in which one copper atom exhibits distorted tetrahedral while the other copper exhibits trigonal geometry. The synthesized compounds are also evaluated for antibacterial and antifungal activity and theoretically studied for their affinity against different antibacterial targets as well as antifungal target. It was concluded that compound I showed enhanced binding affinity for both antibacterial and antifungal targets.

A multifunctional basic pH indicator probe for distinguishable detection of Co2+, Cu2+ and Zn2+ with its utility in mitotracking and monitoring cytoplasmic viscosity in apoptotic cells.

Metal ions such as Co2+, Cu2+ and Zn2+ have extensive applications in biological and industrial realms, but the toxicity caused by these ions poses a serious threat to mankind. However, there is no report in the literature on the development of a chemosensor for distinguishable detection of these toxic ions. Addressing this challenge, a multifunctional probe as a basic pH indicator with both colorimetric and fluorescence turn-on responses has been reported. The probe selectively discriminates Co2+, Cu2+ and Zn2+ ions with brown, dark yellow and greenish yellow colors, respectively, in DMF : water (9 : 1 v/v, HEPES 10 mM). Additionally, a fluorescence turn-on response specific to Zn2+ has also been observed. The sensing mechanism has been explored using UV-Vis, fluorescence spectroscopy and 1H NMR titration and confirmed with computational results. The inhibition of CN isomerization and excited state intramolecular proton transfer (ESIPT) along with chelation enhanced fluorescence emission (CHEF) result in fluorescence enhancement with Zn2+. Job's plot and HRMS spectra confirm a 1 : 1 (L : M) stoichiometry between the probe and metal ions. The probe is able to exhibit excellent viscochromism in DMF : glycerol medium. Live cell imaging on SiHa cells has been successfully performed for intra-cellular detection of Zn2+ at basic pH. Furthermore, the probe displays its utility in mitotracking and monitoring cytoplasmic viscosity changes in SiHa cells. It is efficiently used to recognize the apoptosis process by displaying an enhancement in fluorescence intensity from cancerous SiHa cells to apoptotic cells.

Synthesis, crystal structure, Hirshfeld surface, DFT and docking studies of 4-[(5‑hydroxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)(phenyl)methyl]-5-methyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one

In the present work, 4-[(5‑hydroxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)(phenyl)methyl]-5-methyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one (BPZ) was synthesized by one pot multicomponent reaction of ethylacetoacetate, phenylhydrazine and benzaldehyde in the presence of Ce-MCM-48 catalyst. The title compound was characterized by FT-IR, 1H NMR, and 13C NMR spectral studies and single crystal XRD technique. The intermolecular contacts of the title compound were studied by Hirshfeld surface (dnorm surfaces and 2D fingerprint plots) analysis whereas an intra-molecular hydrogen bonding interaction was examined through NCI-RDG plot. The geometry of the molecular structure was optimized by using the density functional theory (DFT) at B3LYP/6–311 g(d,p) level. Molecular electrostatic potential (MEP), natural bond orbital (NBO) analysis, nonlinear optical properties (NLO) and global chemical reactivity parameters (GCRP) were described through computational method. Further, the molecular docking study was done for title compound with COVID-19 caused protein structure (6LU7, nCoV-SARS-2 Mpro). The study revealed that the significant conventional hydrogen bonding and other interactions were observed between the active amino acid residue of SARS-nCoV-2 Mpro and BPZ ligand.

Structural manifestations and biological screening for newly synthesized heteroleptic bismuth(V) bis-carboxylates

Six new heteroleptic tri-organobismuth(V) complexes (1-6), of general formula, R3Bi(OOCR')2 where R = C6H5 (1-3), p-CH3C6H4 (4-6) and R' represents deprotonated 2-(methylthio)nicotinic acid (1, 4); 3-thiophenecarboxylic acid (2, 5) and 4-chlorosalicylic acid (3, 6) have been synthesized and characterized by FT-IR, NMR (1H, 13C) and single crystal XRD techniques in addition to elemental analyses. The solid-state structure for 3 has also been elucidated by crystallographic data, manifesting its distorted trigonal bipyramidal molecular geometry with a five-coordinate bismuth center. The carboxylate ligand(s) assume a monodentate coordination mode as predicted by IR and then confirmed by XRD data. The antibacterial, antifungal and antileishmanial potential for 1-6 have been evaluated and the preliminary screening data suggest significant to average biological activities. The antileishmanial activity data manifest comparatively lower IC50 value for 5 than the standard drug. A comprehensive study for 1-6 was also undertaken to testify their stability both in solid and solution phases as well as in leishmanial culture M199, which demonstrate high degree of stability that may ensure their significant antileishmanial effect. The % viability values of the organobismuth(V) bis-carboxylates highlight their role as significantly effective compounds, having potential candidature for future drug discovery and development processes.

Co(II), Ni(II), and Cu(II) metal complexes based on thiourea ligand: synthesis, characterization, thermal behaviors, anticancer, and antioxidant activities

In this study, N-(1,1′-biphenyl)-2-chlorobenzoylthiourea (HL) and its metal complexes were prepared and their structural characterization was made using elemental analysis, FT-IR, 1HNMR, HR-MS, single crystal XRD techniques, and TG/DTA analysis. The crystal structure of HL was investigated using single crystal X-ray diffraction and was observed to crystallize in the monoclinic crystal system with P 1 21/c 1 space group, Z = 4, a = 7.3291(4) Å, b = 20.7880(10) Å, c = 12.0074(6) Å. The structures of the complexes and the molecular orbitals of HL were optimized at B97D/TZVP level. Investigation of the thermal and electrochemical behaviors of the Co(II), Ni(II), and Cu(II) complexes were found to be thermally stable up to 165, 185, and 122 °C, respectively. Cell viability test MTT was made to determine anticancer activities against MCF-7 breast cancer cells and 2,2-diphenyl-1-picrilhydrazyl and 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid analysis for the antioxidant activity. The IC50 values against MCF-7 cells and was found to be in the range 24.3–49.2 µM.