Polymorphism of l-Tryptophan.

A new polymorph of l-tryptophan was prepared through crystallization from the gas phase, with structure determination carried out directly from powder XRD data augmented by periodic DFT-D calculations. The new polymorph (denoted ß) and the previously reported polymorph (denoted α) are both based on alternating hydrophilic and hydrophobic layers, but with substantially different hydrogen-bonding arrangements. The ß polymorph exhibits the energetically favourable l2-l2 hydrogen-bonding arrangement, which is unprecedented for amino acids with aromatic side chains. The specific molecular conformations adopted in the ß polymorph facilitate this hydrogen-bonding scheme while avoiding steric conflict of the side chains.

Powder-XRD and (14) N magic angle-spinning solid-state NMR spectroscopy of some metal nitrides.

Some metal nitrides (TiN, ZrN, InN, GaN, Ca3 N2 , Mg3 N2 , and Ge3 N4 ) have been studied by powder X-ray diffraction (XRD) and (14) N magic angle-spinning (MAS) solid-state NMR spectroscopy. For Ca3 N2 , Mg3 N2 , and Ge3 N4 , no (14) N NMR signal was observed. Low speed (νr = 2 kHz for TiN, ZrN, and GaN; νr = 1 kHz for InN) and 'high speed' (νr = 15 kHz for TiN; νr = 5 kHz for ZrN; νr = 10 kHz for InN and GaN) MAS NMR experiments were performed. For TiN, ZrN, InN, and GaN, powder-XRD was used to identify the phases present in each sample. The number of peaks observed for each sample in their (14) N MAS solid-state NMR spectrum matches perfectly well with the number of nitrogen-containing phases identified by powder-XRD. The (14) N MAS solid-state NMR spectra are symmetric and dominated by the quadrupolar interaction. The envelopes of the spinning sidebands manifold are Lorentzian, and it is concluded that there is a distribution of the quadrupolar coupling constants Qcc 's arising from structural defects in the compounds studied.

Synthesis of Cu and Zr-based coordination polymers with N/O donors and investigation of their photocatalytic activity against dye.

The coordination polymers (CPs) of Cu and Zr were synthesized by the hydrothermal method. The orotic acid potassium salt (H3KL) was used as a linker, which coordinates via O-O. Whereas, 4,4'-trimethylenedipyridine (4,4'-TMDP) was used as a bifunctional monomer, which coordinates via N-N. The synthesized CPs were characterized by FTIR, P-XRD, TGA, DSC and SEM. The photocatalytic activity was investigated against methylene blue (MB) under sunlight irradiation. Both Cu-CP and Zr-CP exhibited potential activity for the degradation of MB, which was 72 % for Cu-CP and 93 % for Zr-CP. The band gap of the CPs was also investigated, and the observed value was 2.2 eV. The band gap indicates that these compounds could bring breakthroughs as photocatalysts instead of semiconductors. These kinds of CPs could be used for multiple purposes in industry and in a green environment.

Fabrication and characterization of binary composite MgO/CuO nanostructures for the efficient photocatalytic ability to eliminate organic contaminants: A detailed spectroscopic analysis.

Design and eco-friendly fabrication of affordable and sustainable materials for the treatment of wastewater consisting of dyes, antibiotics, and other harmful substances has always been demanding. Untreated wastewater being released from industries imposes serious threats to our ecosystem, seeking convenient approaches to diminish this alarming issue. Here in this work, we synthesized MgO/CuO nanocomposites from a plant extract of Ammi visnaga L. and then employed these nanocomposites for the treatment of organic dye (methylene blue). We characterized the synthesized nanocomposites by dynamic light scattering (DLS), zeta potential, scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), x-ray diffraction (XRD), and X-ray photoelectron microscopy (XPS). DLS presented information about the explicit size of nanocomposites, while the surface charge was examined by zeta potential. XRD provided detailed information about the crystalline behavior and the information regarding surface morphology and size was extracted by SEM, TEM, and AFM. Moreover, the fabricated nanocomposites were used as a photocatalyst in the treatment of methylene blue. The overall catalytic reaction took an hour to complete, and the value of percentage degradation was 98 %. Substantially, a detailed account of the kinetics, rate of reaction, and mechanism is also fostered in the context. The presented study can assist scientists and researchers around the world to reproduce the results and use them to apply them on a broader scale.

Paracetamol Inclusion in Mechanically Interlocked Nanocages.

The solid-state synthesis and fast crystallization under kinetic control of poly-[n]-catenanes self-assembled of mechanically interlocked metal organic cages (MOCs) is virtually unexplored. This is in part, due to the lack of suitable crystals for single crystal X-ray diffraction (SC-XRD) analysis which limits their progress as advanced functional materials. Here we report the unprecedented inclusion of paracetamol in the cavities of amorphous materials constituted of M12L8, interlocked MOCs synthesized by mechanochemistry under kinetic control. Full structure determination of a low-crystallinity and low-resolution powders of the M12L8 poly-[n]-catenane including paracetamol has been carried out combining XRD data and Density Functional Theory (DFT) calculations using a multi-step approach. Each M12L8 cage contains six paracetamol guests which is confirmed by thermal analysis and NMR spectroscopy. The paracetamol loading has been also carried out by the instant synthesis method using a saturated paracetamol solution in which TPB and ZnI2 self-assemble immediately (i. e., 1-5 seconds) encapsulating ~7 paracetamol molecules in the M12L8 nanocages under kinetic control also giving a good selectivity. Benzaldehyde has been included in the M12L8 cages using amorphous M12L8 polycatenanes showing that the icosahedral cages can serve as potential nanoreactors for instance to study Henry reactions in the solid-state.

Crystal Structure, Raman, FTIR, UV-Vis Absorption, Photoluminescence Spectroscopy, TG-DSC and Dielectric Properties of New Semiorganic Crystals of 2-Methylbenzimidazolium Perchlorate.

Single crystals of 2-methylbenzimidazolium perchlorate were prepared for the first time with a slow evaporation method from an aqueous solution of a mixture of 2-methylbenzimidazole (MBI) crystals and perchloric acid HClO4. The crystal structure was determined by single crystal X-ray diffraction (XRD) and confirmed by XRD of powder. Angle-resolved polarized Raman and Fourier-transform infrared (FTIR) absorption spectra of crystals consist of lines caused by molecular vibrations in MBI molecule and ClO4- tetrahedron in the region ν = 200-3500 cm-1 and lattice vibrations in the region of 0-200 cm-1. Both XRD and Raman spectroscopy show a protonation of MBI molecule in the crystal. An analysis of ultraviolet-visible (UV-Vis) absorption spectra gives an estimation of an optical gap Eg~3.9 eV in the crystals studied. Photoluminescence spectra of MBI-perchlorate crystals consist of a number of overlapping bands with the main maximum at Ephoton ≅ 2.0 eV. Thermogravimetry-differential scanning calorimetry (TG-DSC) revealed the presence of two first-order phase transitions with different temperature hysteresis at temperatures above room temperature. The higher temperature transition corresponds to the melting temperature. Both phase transitions are accompanied by a strong increase in the permittivity and conductivity, especially during melting, which is similar to the effect of an ionic liquid.

Fabrication, depiction, DNA interaction, anti-bacterial, DFT and molecular docking studies of Co(II) and Cu(II) complexes of 3-methyl-1-phenyl-4-[(E)-(pyridin-2-yl)diazenyl]-1H-pyrazol-5-ol ligand.

Cobalt(II) and copper(II) complexes of the (3-methyl-1-phenyl-4-[E-(1iazinyl-2-yl)1iazinyl]-1H-pyrazole-5-ol) ligand were obtained by the diazotization reaction of 5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one with 2-amino pyridine. The synthesized compounds were confirmed by analytical, and spectroscopic analyses (like, UV-Visible, FT-IR, NMR, and mass spectroscopy). Calf thymus DNA interaction with metal complexes is inspected by UV-Visible spectra, viscosity measurements, and thermal denaturation techniques. The intrinsic binding constant (Kb) was found to be 1.17 × 106 M-1, and 0.98 × 106 M-1 for Co(II) and Cu(II) complexes respectively. The Cleavage of pUC-19 DNA was monitored by gel electrophoresis. The computerized in silico molecular dockage studies of the composites with the target receptor Glu-6p and results showed that the compounds are potent drugs for the target enzyme. Further, the optimized structure of the azo dye ligand was obtained by the density functional theory (DFT) by Gaussian09 program by the RB3LYP at 6-311 G (++, g, d, p) basis set. Furthermore, screened for the bacterial action in contradiction of pathogenic organism's gram-negative Klebsiella pneumonia, gram-positive Bacillus subtills by a diffusion method.Supplemental data for this article is available online at https://doi.org/10.1080/15257770.2021.1991373 .

Identification and differentiation of commercial and military explosives via high performance liquid chromatography - high resolution mass spectrometry (HPLC-HRMS), X-ray diffractometry (XRD) and X-ray fluorescence spectroscopy (XRF): Towards a forensic substance database on explosives.

The identification of confiscated commercial and military explosives is a crucial step not only in the uncovering of distribution pathways, but it also aids investigating officers in criminal casework. Even though commercial and military explosives mainly rely on a small number of high-energy compounds, a great variety of additives and synthesis by-products can be found that can differ depending on the brand, manufacturer and application. This makes the identification of commercial and military explosives based on their overall composition a promising approach that can be used to establish a pan-European Forensic Substance Database on Explosives. In this work, three analytical techniques were employed to analyze 36 samples of commercial and military explosives from Germany and Switzerland. An HPLC-HRMS method was developed, using 27 analytes of interest that encompass high-energy compounds, synthesis by-products and additives. HPLC-HRMS and XRD were used to gather and confirm molecular information on each sample and XRF analyses were carried out to gain insight on the elemental composition. Combining the results from all three techniques, 41 different additives could be identified as being diagnostic analytes and all samples showed a unique analytical fingerprint, which allows for a differentiation of the samples. Therefore, this work presents a set of methods that can be used as a foundation for the creation and population of a database on explosives that enables the assigning of specific formulations to certain brands, manufacturers and countries of origin.

Structural, vibrational and optical studies on semiorganic crystals of boric acid potassium acetate.

A semiorganic crystal of Boricacid potassium acetate has been grown by low temperature solution growth technique at room temperature using deionized water as a solvent. The crystalline nature of the compound was confirmed by the sharp and well defined peaks observed from the powder X-ray diffraction pattern. By single crystal X-ray diffraction method, the structure of the grown crystal has been studied. The Boric acid Potassium Acetate (BAPA) crystal has good optical transmittance in the entire UV visible region. FT-IR and FT-Raman spectral studies were performed to identify the vibrations of functional groups. The mechanical strength of the grown crystal was determined by Vicker's micro hardness test. Photoluminescence study was carried out on the crystal. The SHG study represents the nonlinear optical efficiency of the crystal.

Indole-derived water-soluble N, O bi-dentate ligand-based mononuclear transition metal complexes: in silico and in vitro biological screening, molecular docking and macromolecule interaction studies.

A novel tryptophan-derived Schiff base ligand (potassium (E)-2-((4-chloro-3-nitrobenzylidene)amino)-3-(1H-indol-3-yl)propanoate) and a series of its transition metal complexes of the types [ML2] and [ML(1,10-phen)2]Cl where M = Cu(II), Co(II), Ni(II) and Zn(II) were prepared. They were analyzed by various spectral and physicochemical studies. The XRD data were also used to determine the average lattice parameters and crystalline size of the compounds. All the synthesized compounds were tested against a series of five bacterial and fungal strains. The obtained results showed that the biological activity of free ligand was increased on complexation. PASS online software predicts the various biological activities of ligand such as enzyme inhibitor, antiviral, analgesic and antituberculosis. The in silico theoretical prediction of synthesized compounds is also deliberated by Swiss ADME predictor which gives the properties of molecular hydrophobicity (log P), topological polar surface area (TPSA) and oral bioavailability score. The binding energy of the docked molecule with macromolecules 1BNA and 3EQM is also determined by using Hex 8.0 software. The ligand has the least binding energy score which signifies that the potential of binding is greater in the receptor. Moreover, the interactions of complexes with DNA have been explored by electronic absorption titration, fluorescence emission titration, viscosity measurements and gel electrophoresis. HighlightsSynthesis and characterization of novel indole-derived compounds.X-ray diffraction studies demonstrate average crystalline size of the compounds.Metal complexes act as good metallointercalators.Metal complexes show higher antimicrobial activity compared to ligand.Prediction of biological activities of the ligand by PASS online software.Drug-like nature and bioavailability of synthesized compounds predicted by Swiss ADME predictorDocking of the synthesized compounds with 1BNA and 3EQM using HEX 8.0 software.Communicated by Ramaswamy H. Sarma.

Effect of yttrium ion on the properties of tri ethyl ammonium picrate single crystals.

Tri Ethyl Ammonium Picrate (TEAP) and Yttrium (Y2+) ions doped single crystals were grown by slow evaporation technique at room temperature. The estimated band gap of the pure TEAP, 0.10 mol % and 0.15 mol % of Y2+ ions doped TEAP are 3.76 eV, 3.82 eV and 3.86 eV. Crystallite size of the grown materials was calculated from powder XRD as 1.456 nm for TEAP, 3.2028 nm for 0.10 mol % of Y2+ ions doped TEAP and 6.934 nm for 0.15 mol % of Y2+ ions doped TEAP single crystals. Y-O stretching mode was assigned by FTIR spectral peak at 549 cm-1. The PL excitation wavelength of the grown materials is 350 nm. The EDAX analysis confirmed by the Carbon, Nitrogen, Oxygen and Yttrium were presented in grown crystals.

Synthesis, Spectral Characterization, Antibacterial and Anticancer Activity of some Titanium Complexes.

BACKGROUND: After the discovery of cisplatin, first non platinum anticancer drugs having excellent efficacy were budotitane and TiCl2(cp)2 but action mechanism is not clear. Therefore, we hereby reporting synthesis and biological activities novel titanium complexes to explore their mode of action. OBJECTIVES: Synthesis, spectral characterization, antibacterial and anticancer activity of some titanium complexes. Antibacterial studies on various bacterial strains and anticancer studies on HeLa, C6, CHO cancerous cell lines have been performed. Further, the cell death mechanistic study was done on CHO cell lines. METHOD: Titanium complexes with and without labile groups have been synthesized by reacting of TiCl4 with nitrogen containing ligands viz. 1,2-diaminocyclohexane, 1,10-Phenanthroline, adamantylamine, 2,2'-bipyridine, 4,4'-dimethyl-2,2'-bipyridine in predetermined molar ratios. Antibacterial and anticancer studies were performed by agar well diffusion method and MTT assay respectively. Cell cycle analysis is done by using flow cytometry. RESULTS: Complex 2 i.e TiCl2(Phen)2 showed better activity than other complexes as an antibacterial as well as anticancer agent. Phase contrast imaging indicates that observed morphological changes of cells was dose dependent. Cell death mechanistic study have shown the increase in sub G0 phase population as well as formation of blebbing and fragmentation of chromatin material which is an indicative measure of apoptosis. CONCLUSION: Complex 2 proved to be more effective bactericide and cytotoxic agent. Cell cycle analysis showed cell arrest in G0 phase. Apoptosis percentage was found to increase in a dose dependent manner. So, prepared titanium complexes can be put to use as an important chemotherapeutic agents.

Self-assembly of sugar based glyco-lipids: Gelation studies of partially protected d-glucose derivatives.

A series of sugar-based glycolipid derivatives were prepared by N-glycosylamines, and their organogelation property has been analyzed. We have observed the efficient gelation for some of the anilines substituted glycolipids derivatives in different aromatic and aliphatic solvents. It was found that the gelation occurred predominantly in aliphatic solvents with CGC of 0.8% (w/v) attributed to the presence of long alkyl chain in the glycolipids. The structural and morphological properties of the xerogels were investigated by NMR, powder XRD, and FE-SEM respectively. Furthermore, the thermal stability was analyzed by DSC.

Synthetic, spectral, thermal and powder X-ray diffraction studies of bis(O-alkyldithiocarbonato-S,S') antimony(III) dialkyldithiocarbamates.

Compounds of antimony(III) with mixed sulfur donor ligands of the type [(ROCS2)2SbS2CNR'2] (where, R=C2H5, and (i)C3H7; R'=CH3, C2H5, and CH2CH2) have been synthesized using anhydrous acetone as a solvent by the one pot reaction of antimony(III) tris(O-alkyldithiocarbonato-S,S'), antimony(III) chloride and sodium/ammonium salt of dialkyldithiocarbamate in 2:1:3molar ratios. These compounds have been characterized by physicochemical [melting points, molecular weight determinations, elemental analyses (C, H, N, S, and Sb)], spectral [UV, IR, Far-IR and NMR ((1)H and (13)C)] studies. In IR spectra strong band was observed at 1028-1051cm(-1) which indicates anisobidentate mode of bonding of both the ligands with antimony metal. NMR spectral data of these compounds show expected proton resonance due to corresponding moieties. The powder XRD, ESI-Mass and thermal (TG and DTA) studies have also been performed to get the information about geometrical parameters, fragmentation pattern and last thermal decomposition product, respectively. The powder XRD studies lead to the structural properties of the synthesized compounds and show the nanorange crystallite size and monoclinic crystal system. Thermal data of these compounds indicate the formation of antimony sulfide (Sb2S3) as a final thermal degradation product which is used in a number of ways like switching devices television cameras and microwave devices.

Growth and characterization of Cadmium Thiosemicarbazide Bromide crystals for antibacterial and nonlinear optical applications.

Semiorganic nonlinear optical crystals of Cadmium Thiosemicarbazide Bromide was grown by slow evaporation solution growth technique. The unit cell parameters were estimated by subjecting the crystals to single crystal X-ray diffraction. The grown crystals were subjected to Powder X-ray diffraction for analyzing the crystalline nature of the sample. FTIR studies reveal the functional groups and the optical characters were analyzed by UV-Vis spectral studies. Mechanical stability of the sample was assessed by Vicker's micro hardness test. The presence of surface dislocations was identified by chemical etching technique. Antibacterial study was carried out against ACDP declared harmful pathogens. SHG efficiency of CTSB crystal was tested using Nd: YAG laser and it was found to be ∼1.8 times that of potassium dihydrogen phosphate.

Copper thiocyanato complexes and cocaine - a case of 'black cocaine'.

The chemical composition of a black powder confiscated by German customs was elucidated. Black powders are occasionally used as a 'transporter' for cocaine and are obviously especially designed to cloak the presence of the drug. The material consisting of cocaine, copper, iron, thiocyanate, and graphite was approached by analytical tools and chemical modelling. Graphite is added to the material probably with the intention of masking the typical infrared (IR) fingerprints of cocaine and can be clearly detected by powder X-ray diffraction (XRD) and Raman spectroscopy. Cu(2+) and NCS(-) ions, when carefully reacted with cocaine hydrochloride, form the novel compound (CocH)2 [Cu(NCS)4 ] (CocH(+) = protonated cocaine), which has been characterised by single crystal XRD, IR, NMR, UV/Vis absorption and EPR spectroscopy. Based on some further experiments the assumed composition of the original black powder is discussed.

Structural, optical, mechanical and dielectric studies of pure and doped L-Prolinium trichloroacetate single crystals.

In the present work, pure and metal substituted L-Prolinium trichloroacetate (LPTCA) single crystals were grown by slow evaporation method. The grown crystals were subjected to single crystal X-ray diffraction (XRD), powder X-ray diffraction, FTIR, UV-Visible-NIR, hardness, photoluminescence and dielectric studies. The dopant concentration in the crystals was measured by inductively coupled plasma (ICP) analysis. Single crystal X-ray diffraction studies of the pure and metal substituted LPTCA revealed that the grown crystals belong to the trigonal system. Ni(2+) and Co(2+) doping slightly altered the lattice parameters of LPTCA without affecting the basic structure of the crystal. FTIR spectral analysis confirms the presence of various functional groups in the grown crystals. The mechanical behavior of pure and doped crystals was analyzed by Vickers's microhardness test. The optical transmittance, dielectric and photoluminescence properties of the pure and doped crystals were analyzed.

A novel one-dimensional metal-organic framework with a µ-cyanido-argentate group: catena-poly[[(5,5'-dimethyl-2,2'-bipyridyl-κ(2)N,N')silver(I)]-µ-cyanido-κ(2)N:C].

The design and synthesis of metal coordination and supramolecular frameworks containing N-donor ligands and dicyanidoargentate units is of interest due to their potential applications in the fields of molecular magnetism, catalysis, nonlinear optics and luminescence. In the design and synthesis of extended frameworks, supramolecular interactions, such as hydrogen bonding, π-π stacking and van der Waals interactions, have been exploited for molecular recognition associated with biological activity and for the engineering of molecular solids.The title compound, [Ag(CN)(C12H12N2)]n, crystallizes with the Ag(I) cation on a twofold axis, half a cyanide ligand disordered about a centre of inversion and half a twofold-symmetric 5,5'-dimethyl-2,2'-bipyridine (5,5'-dmbpy) ligand in the asymmetric unit. Each Ag(I) cation exhibits a distorted tetrahedral geometry; the coordination environment comprises one C(N) atom and one N(C) atom from substitutionally disordered cyanide bridging ligands, and two N atoms from a bidentate chelating 5,5'-dmbpy ligand. The cyanide ligand links adjacent Ag(I) cations to generate a one-dimensional zigzag chain. These chains are linked together via weak nonclassical intermolecular interactions, generating a two-dimensional supramolecular network.

Synthesis, and spectroscopic studies of charge transfer complex of 1,2-dimethylimidazole as an electron donor with π-acceptor 2,4-dinitro-1-naphthol in different polar solvents.

The charge transfer (CT) complex of 1,2-dimethylimidazole (DMI) as an electron donor with π acceptor 2,4-dinitro-1-naphthol (DNN) has been studied spectrophotometrically in different solvents like chloroform, acetonitrile, methanol, methylene chloride, etc. at room temperature. The CT complex which is formed through the transfer of lone pair electrons from DMI to DNN exhibits well resolved CT bands and the regions of these bands were remarkably different from those of the donor and acceptor. The stoichiometry of the CT complex was found to be 1:1 by a straight-line method between donor and acceptor with maximum absorption bands. The novel CT complex has been characterized by FTIR, TGA-DTA, powder XRD, (1)H NMR and (13)C NMR spectroscopic techniques. The Benesi-Hildebrand equation has been used to determine the formation constant (K(CT)), molar extinction coefficient (ε(CT)), standard gibbs free energy (ΔG°) and other physical parameters of the CT complex. The formation constant recorded higher values and molar extinction coefficient recorded lower values in chloroform compared with methylene chloride, methanol and acetonitrile, confirming the strong interaction between the molecular orbital's of donor and acceptor in the ground state in less polar solvent. This CT complex has been studied by absorption spectra of donor 1,2-dimethylimidazole (DMI) and acceptor 2,4-dinitro-1-naphthol (DNN) by using the spectrophotometric technique in various solvents at room temperature.

Vibrational spectra, powder X-ray diffractions and physical properties of cyanide complexes with 1-ethylimidazole.

The heteronuclear tetracyanonickelate(II) complexes of the type [M(etim)Ni(CN)4]n (hereafter, abbreviated as M-Ni-etim, M=Mn(II), Fe(II) or Co(II); etim=1-ethylimidazole, C5H8N2) were prepared in powder form and characterized by FT-IR and Raman spectroscopy, powder X-ray diffraction (PXRD), thermal (TG; DTG and DTA), and elemental analysis techniques. The structures of these complexes were elucidated using vibrational spectra and powder X-ray diffraction patterns with the peak assignment to provide a better understanding of the structures. It is shown that the spectra are consistent with a proposed crystal structure for these compounds derived from powder X-ray diffraction measurements. Vibrational spectra of the complexes were presented and discussed with respect to the internal modes of both the etim and the cyanide ligands. The C, H and N analyses were carried out for all the complexes. Thermal behaviors of these complexes were followed using TG, DTG and DTA curves in the temperature range 30-700 °C in the static air atmosphere. The FT-IR, Raman spectra, thermal and powder X-ray analyses revealed no significant differences between the single crystal and powder forms. Additionally, electrical and magnetic properties of the complexes were investigated. The FT-IR and Raman spectroscopy, PXRD, thermal and elemental analyses results propose that these complexes are similar in structure to the Hofmann-type complexes.