Single Crystal XRD Techniques Research Articles

Antioxidant and cytotoxic activity of isoindole compounds in breast cancer cells (MCF-7)

It is well known that heterocyclic scaffolds have a wide occurrence in the field of medicinal chemistry. Isoindoles analogs have been demonstrated to exhibit wide pharmacological activities.The aim of the research presented here is to select a new drug candidate form isoindole-derived heterocycle compounds that would possess antioxidant and cytotoxic activity against MCF-7 and MCF-12A cell lines.Antioxidant activities of the isoindole derivative compounds (25–200 mM) were determined via free radical scavenging, metal chelating and reducing methods. Besides, the cytotoxic activity against MCF-7 (human breast adenocarcinoma) and MCF-12A (normal breast epithelium) were examined by comparing MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) assay and RTCA (real-time cell analysis) with varying concentrations (25–100 μM) of the compounds for 24 h.Metal chelating activity showed similar results with DPPH (1,1-diphenyl-2-picryl-hydrazyl) activity. Compounds showed moderate DPPH activity and the IC50 value was in the range from 93 to 175 μg/mL. Reducing activity was found at very low value comparing to standard synthetic antioxidant compounds. This value was correlated with MTT and real-time cell analysis IC50 value. The antitumor effect against MCF-7 cancer cell line was indicated 100 μM.According to the results of the study, and after analysing compounds that have selective and significant antioxidant activities, we found that they also have cytotoxic effects on MCF-7 cells. The molecular geometry of pyrrolo isoindole hybrid compound (II) was examined by a single-crystal XRD technique and some reactivity properties were determined by DFT based approaches.

Synthesis of novel spirobibenzopyrans as potent anticancer leads inducing apoptosis in HeLa cells

Spirobibenzopyrans are an unexplored class of therapeutics. We report the anticancer activity of novel spirobibenzopyrans, synthesized by a one-pot reaction and extensively characterized. Structure of one of the spirobibenzopyran has been determined by the single crystal XRD technique. The in vitro anticancer activity of these derivatives across the NCI 60-cell line panel was evaluated and for the first time their mechanism of action against HeLa cells was probed via cell morphology analysis and cell cycle analysis. They were determined to be apoptosis inducers with cell cycle arrest in G0/G1 and S phase suggesting CDK-4 protein inhibition and the inhibition of DNA replication. The DNA inhibition was studied and confirmed using the alkaline comet assay for the compound CHX-4MO-SAL showing S phase inhibition. Further, conformity with the in silico Lipinski’s score signify the potential of spirobibenzopyrans as anticancer leads.

Synthesis, characterization, crystal structure, Hirshfeld surface analysis and spectroscopic properties of bis(5-aminoisophthalato)bispicolinecopper (II)

The 2D coordination polymer of Cu(II), [Cu(5-aip) (3-pic)2]n (5-aip = 5-aminoisophthalato, 3-pic = 3-picoline) was characterized by elemental analysis, FT-IR and UV–Vis spectroscopy and single crystal XRD techniques. The X-ray single crystal data revealed that the polymeric coordination complex crystallizes in the monoclinic system with P21/n space group and Cu(II) ion has five (square pyramidal) coordination number. X-ray diffraction analysis show that Cu(II) has a distorted square pyramidal geometry with τ = (175.75–160.0)/60) = 0.2625. Hirshfeld surface analysis was carried out, which reveals the nature of intermolecular contacts, the fingerprint plots and molecular surface contours (dnorm, di and de) provide the information about the percentage contributions [H⋯H (40.5%), C⋯H (29.2%), Cu⋯O (4.7%), N⋯H (4.9%), N⋯O (1.5%) and O⋯H (17.4%)] and revealed them major and minor contributions of the bond interactions for [Cu(5-aip) (3-pic)2]n complex. According to UV–Vis spectrum, d-d transition observed at 712 nm (ε = 65 dm3mol−1cm−1) which is assigned to the dz2 (a1)→dx2-y2 (b1) transition. Thermogravimetric analysis was carried out to fallow the thermal stability of the complex.

Synthesis, Characterization and Anticancer Studies of Rh(I), Rh(III), Pd(II) and Pt(II) Complexes Bearing A Dithiooxamide Ligand

AbstractBreast cancer is the most common type of cancer in women. In the current study, six transition‐metal complexes were reacted with a secondary dithiooxamide (H2‐isopropyl2DTO) to obtain the corresponding mononuclear complexes (1‐6) and their cytotoxicity was evaluated in two human breast cancer cell lines, i. e. MCF‐7 and MDA‐MB‐231. The characterization of the complexes, [LnM(H‐isopropyl2 DTO κ‐S,S M)] (LnM=(C5Me5)RhCl, (1); (COD)Rh, (2); (η3‐allyl)Pd, (3); (trinpropyl‐phosphine)PdCl, (4); (bpy)Pt, (5) and (pph3)PtCl, (6)), and the ion pair form of 1–4, IP1‐IP4, were accomplished through NMR spectroscopy and elemental analysis. The structures of 1 and IP1 were also determined by single crystal XRD technique. In vitro cytotoxicity studies in MCF‐7 and MDA‐MB‐231 (IC50 determination) showed that all complexes are cytotoxic for both cell lines, with the exception of 2. Compound 3 was the most cytotoxic in the conditions tested. In addition, the compounds induce cell death by apoptosis and inhibit the formation of colonies, indicating that these compounds could provide promising new lead derivatives for anticancer drug development.

Structural, spectroscopic and thermal characterizations combined with DFT calculations and Hirshfeld analysis of a novel hydrogen-bonded complex: p-phenylenediammonium dinitrate

The compound p-phenylenediammonium dinitrate (PPDN) has been synthesized and its structure characterized by FT-IR, Raman and single crystal XRD techniques. Thermal behavior of this compound has been studied by TGA/DSC analysis. The three-dimensional framework observed in the PPDN structure is mainly maintained thanks to conventional N–HO hydrogen bonds and weak C–H…O contacts. In the p-phenylenediammonium cation, four carbon atoms of the aromatic ring are disordered over two positions with half occupancy. The geometry, modes of vibrations, atomic charges, thermodynamic parameters and frontier molecular orbitals of the PPDN molecule have been calculated by DFT method at B3LYP/6–311++G(d,p) and B3LYP/cc–pVTZ levels. The intermolecular bonding interactions within this molecule have been investigated using the natural bonding orbital (NBO) analysis at B3LYP/cc–pVTZ level. The 3-D Hirshfeld surface and the associated 2-D fingerprint plot, calculated for the PPDN molecule, have showed the clearly dominance of the H…O/O…H and H…H contacts which together represent more than 80% of the total surface.

Novel report on luminescence, linear and laser induced optical traits of potassium aluminium sulphate crystal for photonic device applications

Optical quality inorganic crystals have emerged as a vital aspect for designing photonic devices hence in current investigation bulk size single crystal of potassium aluminium sulphate (KAS) has been grown by slow solvent evaporation technique. The crystalline phase of KAS crystal has been determined by means of powder X-ray diffraction analysis and its structural parameters have been experimentally determined by single crystal XRD technique. The optical transparency of KAS crystal has been examined within the wavelength range of 200–900 nm by employing the UV–vis spectral analysis. The color centered luminescence behavior of KAS crystal has been investigated within visible range of interest. The remarkable capability of KAS crystal to resist laser exposure has been determined using the pulse mode operated 1064 nm Nd:YAG laser. The third order nonlinear optical (TONLO) properties of KAS crystal have been examined at 640 nm and the nature of TONLO refractive index, absorption and susceptibility has been reported.

An Unusual Cu(II) Mediated C–N Single Bond Cleavage of Pentacoordinating N4S Ligands: Control of Copper Coordination Geometry by Modified Ligand Structure

Complexation of copper(II) with penta-coordinated N4S ligands in alcohols proceeded through unusual reaction paths involving C-N bond cleavage process. The products are square planar compound with a modified ligand structure that includes an alkoxy group provided by the solvent. The complexes are characterized by single crystal XRD, elemental analyses, IR, UV-visible and EPR spectroscopic techniques. Cyclic voltammetry shows Cu(II)/Cu(I) reduction becomes more difficult with the increase in donor strength of alkoxy group.

Synthesis, supramolecular architecture, thermal and optical behavior of 4-methoxyanilinium perchlorate: A promising third-order NLO material for optical limiting device applications

A novel hydrogen bonded supramolecular single crystals of 4-methoxyanilinium perchlorate (4MAPC) has been synthesized by solvent slow evaporation method. Structural and crystallographic data of 4MAPC has been studied by single crystal XRD technique. Three dimensional networks formed by the classical hydrogen bond between nitrogen and oxygen and also the nonclassical intermolecular interaction between carbon and oxygen keeping the crystal structure more stable. Protonation is observed at nitrogen site of 4-methoxyaniline from the perchloric acid. The results of thermal gravimetric and differential themal analysis showed that the grown crystal is stable upto 167 °C. The wide transparency from 340 to 1100 nm was observed by optical studies. The high nonlinear optical susceptibility and nonlinear refraction was obtained from Z-Scan studies.

Synthesis, structural characterization, DNA binding and antioxidant studies of 4,4′-Nitrophenoxyaniline derived azo dyes

Evaluation of DNA sensing and antioxidant potential has always been an open field of interest for pharmacists and other researchers. This paper presents a study on the synthesis, DNA sensing, and free radical scavenging potential of a series of new azo dyes derived from 4,4-nitrophenoxyaniline. The dyes were synthesized by classical diazotization-coupling method involving phenol, naphthol, and resorcinol as coupling component. Structural characterization of the synthesized dyes was done by Fourier transform infrared (FT-IR), Nuclear magnetic resonance (NMR), Ultraviolet–visible (UV/VIS) spectroscopy and single crystal XRD techniques. X-ray diffractions results revealed that dye 1a, 2 b, and 3c crystallized in the monoclinic system with P21/c, P21/n, and P21/c space groups respectively. Furthermore, for the dye 2 b, the single crystal X-ray data revealed a shorter NN bond length confirming predomination of hydrazo-keto form as compared to 1a and 3c dyes. The mode of interaction of these dyes with Salmon Sperm (SS) DNA was investigated using UV/VIS spectroscopy, viscosity, and molecular docking techniques. These results showed that synthesized dyes bind to the SS-DNA in a mixed binding mode with the dominant partial intercalative mode. Furthermore, the antioxidant potential of these dyes was also evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and H2O2 antioxidant assays.

Betti base and its modified phthalonitrile derivative for the turn on fluorimetric detection of Hg2+ and Cr3+ ions

The Betti Base Phenyl-(2-pyridinylamino)-methyl-2-naphthalenol (BB) derived by the multicomponent Mannich aminoalkylations reaction from 2-naphthol, 2-aminopyridine and benzaldehyde. The modified phthalonitrile 4-((1-(phenyl(pyridin-2-ylamino)methyl)naphthalen-2-yl)oxy)phthalonitrile BBPN was obtained by aromatic nucleophilic coupling reaction of 4-nitrophthalonitrile with BB. The compounds were successfully characterized by common spectroscopic and single crystal XRD techniques. The compounds BB and BBPN was exhibited a selective and sensitive fluorescence detection tendency towards mercuric Hg2+ and chromium Cr3+ ions respectively by the fluorescence turn on processes. Job’s plot method is employed to obtain idea about the stoichiometric interaction of metal ions with fluorescent probes. Theoretical calculation was done by Density Functional Theory DFT-B3YLP in order to get atomistic insights into the coordination geometry of Hg2+ and Cr3+ with BB and BBPN respectively. The limit of detection (LOD) of Hg2+ with BB and Cr3+ with BBPN was estimated respectively as 9.7 × 10−7 mol/L and 7.03 × 10−6 mol/L. The fluorescence enhancement of both compounds were induced by the inhibition of Photoinduced Electron Transfer (PET) process in which electron transfer happens from amino group to the fluorophore naphthol unit. The PET process was blocked upon binding of the sensors BB and BBPN with Hg2+ and Cr3+ respectively.

Proton reduction by a Ni(II) catalyst and foot-of-the wave analysis for H2 evolution

A nickel based molecular catalyst [Ni(QCl-tpy)2]Cl2·7H2O (where QCl-tpy = 2-choloro-3-(2,6-di (pyridin-2yl)pyridine-4-yl) quinoline) has been synthesized, characterized by single crystal XRD and other spectroscopic techniques. The complex [NiII(QCl-tpy)2]2+ has also been employed for the electrocatalytic proton reduction in DMF/H2O (95:5 v/v) using trifluoro acetic acid (TFA) as the proton source. It exhibits a reasonably efficient catalytic ability towards proton reduction under organic media. Compared to the parent [NiII(tpy)2]2+ during the electro-catalysis, the complex [NiII(QCl-tpy)2]2+ behaves as a better catalyst in terms of higher catalytic current and 180 mV of lower overpotential as well. It is expected due to the presence of 2-chloroqinoline moiety in the terpyridine framework. The rate of H2 evolution was analysed with the use of Foot-of-the Wave Analysis (FOWA) method. The complex shows a TOF of 3.68 s−1 as obtained from Foot-of-the Wave Analysis (FOWA) at the scan rate 100 mVs−1 for 1.0 mM [NiII(QCl-tpy)2]2+ complex. The acid base equilibria reveals the dechelation followed by protonation at one of the coordinated pyridine rings of the QCl-tpy ligand. There could be a pendant base effect towards hydrogen evolution due to dechelated pyridine ring of the coordinated QCl-tpy ligand, which acts as a proton relay. Based on the spectroscopic evidence and electrochemical studies a plausible mechanism for the reduction of proton to H2 has been proposed.

Synthesis of new Pro-PYE ligands as co-catalysts toward Pd-catalyzed Heck-Mizoroki cross coupling reactions.

The present research work describes the synthesis of five new ligands containing pyridinium amine, [H2L1][OTf]2–[H2L5][I]2 from two new precursors, [P3Et][I] and [P2Me][CF3SO3]. The structure elucidations of the compounds were confirmed by multinuclear NMR (1H, 13C), FT-IR and by single crystal XRD techniques. Theoretical DFT studies were carried out to get better insight into the electronic levels and structural features of all the molecules. These synthesized new Pro-PYE ligands [H2L1][OTf]2–[H2L5][I]2 were found to be significantly active as co-catalysts for Pd(CH3CO2)2 toward Heck–Mizoroki coupling reactions with wide substrate scope in the order of [H2L1][OTf]2 ≫ [H2L2][OTf]2 > [H2L3][OTf]2 > [H2L4][OTf]2 > [H2L5][I]2.

Dinuclear Ternary Copper(II) Complex: Synthesis, Characterization, Structure and DNA-Binding Studies

A dinuclear centrosymmetric copper(II) complex has been prepared and characterized via FT-IR, UV-Visible and electron spin resonance spectroscopy, electrochemical method, and powder and single crystal XRD techniques. The two copper(II) ions are connected by two μ-1,1-O atoms belonging to para-fluorophenyl acetate ligands. Each copper(II) ion is coordinated by two other carboxylate ligands in monodentate and a 2,2'-bipyridine molecule in bidentate manner. Thus the geometry around each penta-coordinated copper(II) ion is square pyramidal with distortion factor τ = 0.04. Purity and uniform crystalline nature of the complex was assessed from powder XRD spectrum. ESR signal consisted of partially resolved hyperfine splitting pattern while electrochemical studies revealed diffusion controlled electron transfer processes with diffusion co-efficient of 1.628×10-7 cm2 s-1. The results of all spectroscopic experiments support each other. The complex afforded mixed binding mode with DNA yielding DNA-binding constant values of 3.667×104and 1.438×104 M-1 using cyclic voltammetry and absorption spectroscopy, respectively. The preliminary studies heralded good structural and biological importance of the synthesized complex.

Structural, Optical and Dielectric Characterization of Guanidine Acrylate (GuAcr) NLO Single Crystals

Organic single crystal of Guanidine Acrylate (GuAcr) was grown by simple inexpensive slow evaporation technique. The grown crystal was subjected into various characterizations like single crystal XRD, UV-Vis, FTIR studies, electrical, mechanical properties and SHG technique. The XRD data shows that the crystal belongs to orthorhombic structure. The UV-Vis spectral studies observed that the cutoff wavelength of the grown crystal is 320nm. Optical band gap of the grown crystal was also calculated, and it was found to be 3.99 eV. Vibrational frequencies of GuAcr crystal were confirmed by FTIR spectra. Electrical properties of the GuAcr single crystals were studied using impedance spectroscopy. Decreasing impedance with increasing temperature is indicated that the negative temperature co-efficient of resistance behavior like an insulator. Dielectric response of the crystal with varying frequencies was also studied. Second harmonic generation of the title compound was studied using Kurtz Perry- powder SHG technique. It reveals that as grown crystal is suitable for Nonlinear Optical (NLO) device fabrications.

Asymmetric Oxygen Bridged Copper(II) Carboxylate: Synthesis, Complete Characterization, and Crystal Structure

Binuclear centrosymmetric copper(II) complex of the formula bipyCu(L)4Cubipy, where bipy = 2,2′- bipyridine and L = 4-methoxy-2-phenyl acetate, is synthesized and characterized by FT-IR, UV-Visible, ESR and mass spectroscopy, electrochemical, thermogravimetric, and single crystal XRD techniques. The complex contains two differently oriented molecules per unit cell stabilized via intermolecular interactions. Geometry around each Cu(II) was found to be square pyramidal affected by asymmetrically bridging oxygen atoms occupying the apical position of one square pyramid and the axial position of another in the same binuclear molecule. The square base is formed by two oxygen atoms from two carboxylate ligands and two nitrogen atoms from the bipyridine moiety. TGA shows that the complex is stable up to 170 °C followed by stepwise loss of coordinated ligands, which was supported by GC-MS data as well. A broad absorption spectrum indicated 2B1g as the ground state and single electron occupancy of the dx2–y2 orbital, which was confirmed by the ESR spectrum. The electrochemical study gives two oxidation curves corresponding to Cu(II)/Cu(III) and Cu(I)/Cu(II) and a reduction signal corresponding to the Cu(II)/Cu(I) process. The robust complex represents an interesting contribution to the understanding of coordination chemistry.

Crystal engineering with palladium(II)-based self-assembled binuclear complexes as tectons

A series of binuclear palladium(II)-based self-assembled metallomacrocycles of Pd2L′2L2 type compositions were synthesized by complexation of an imidazole appended non-chelating bidentate ligand L with different cis-protected palladium(II) components (i.e. PdL′). The complexes [Pd2(en)2(L)2](NO3)4, 1, [Pd2(tmeda)2(L)2](NO3)4, 2, [Pd2(bpy)2(L)2](NO3)4, 3, and [Pd2(phen)2(L)2](NO3)4, 4 were characterized by NMR spectroscopy and their nuclearities were established with the help of ESI-MS. Solid state structures of the complexes 2, 3 and [Pd2(phen)2(L)2](OTf)4, 4′, were established by the single-crystal XRD technique. These metallomacrocycles could act as tectons for crystal engineering by using the available π-surface on their architectures. The crystal packing of these molecules revealed the importance of the π-surface on the ligand moiety as well as on the cis-protecting moiety. Utilization of the π-surfaces afforded 1D to 3D supramolecular networks in solid state.

1-D copper(I) coordination polymer based on bidentate 1,3-dithioether ligand: Novel catalyst for azide-alkyne-cycloaddition (AAC) reaction

A novel 1,3-bis(4-fluorophenylthio)-propane ligand based CuI 1-D polymeric coordination complex having formula ([(CuI)2{ArS(CH2)3SAr}2]n, Ar = 4-F-C6H4) has been synthesized and characterized by 1H NMR, 13C NMR and single crystal XRD techniques. This complex has been employed for the first time as suitable catalyst for base-free one-pot three-component regioselective azide-alkyne cycloaddition (AAC) reaction. A novel 1,2,3-triazole compound with sulfur functionalized pendant arms has also been prepared using our catalytic system in a multicomponent manner via one-pot two-step reaction.

Synthesis, characterization, nucleic acid interactions and photoluminescent properties of methaniminium hydrazone Schiff base and its Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) complexes

An environmental benign and efficient reaction was carried out via amine exchange and condensation reaction in water and methanol mixture (3:1) and absence of catalyst between 1-[3-(2-hydroxy benzylidene)amine)phenyl]ethanone and benzhydrazide yields methaniminium hydrazone Schiff base in high yield. The prepared ligand was structurally characterized by using single crystal XRD, elemental analysis and spectroscopy (UV–Vis, FT-IR, LC-MS and NMR) techniques. The crystal data indicates the ligand crystallizes in orthorhombic system with Pna21 space group. Further, the ligand was used in synthesis of mononuclear Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) complexes and were characterized by elemental analysis, magnetic moment and spectroscopy (UV–Vis, FT-IR and ESR) studies. The spectral data showed that ligand is coordinated to the metal ion through azomethine nitrogen and methaniminium nitrogen. The DNA binding absorption titrations reveals that, ligand, L and its metal complexes, 1–6 are avid binders to CT- DNA. The apparent binding constant values of compounds are in the order of 106 M−1. The nuclease activity of ligand, L and its metal complexes, 1–6 were investigated by gel electrophoresis method using pUC18 DNA. The photoluminescent properties of the methaniminium hydrazone ligand, L and its various metal complexes, 1–6 were investigated. The emission spectra of both ligand (L) and metal complexes (1-6) exhibits emission in the range of blue to red.

Polymeric Copper(II) Paddlewheel Carboxylate: Structural Description, Electrochemistry, and DNA‐binding Studies

A polymeric complex of copper(II) was isolated and purified from the self‐assembly of CuSO4 and 2‐phenyl acetate in aqueous medium. It was characterized through FT‐IR, UV/Vis, electron spin resonance, electrochemical solution studies, and powder and single crystal XRD techniques. The structure was revealed to consist of directly interconnected dimeric paddlewheel building units without any intervening ligand. This type of polymeric paddlewheel structures are found very rarely. Each copper is lying in a CuO5 square pyramid coordinated by four oxygen atoms in the square base while the axial oxygen belongs to the neighboring paddlewheel. Purity and uniform crystalline nature of the complex was assessed from matching theoretical and experimental powder XRD spectra. ESR spectrum consisted of a broad signal with g value = 2.2427, whereas electrochemical studies revealed diffusion controlled electron transfer processes with diffusion co‐efficient = 1.628 × 10–7 cm2·s–1. The results of spectroscopic techniques support each other. The complex afforded mixed binding mode with DNA yielding DNA‐binding constant values of 1.384 × 104 m–1 and 8.845 × 104 m–1 using absorption spectroscopy and cyclic voltammetry, respectively. The complex also exhibited significant activity against anti‐fungal strain Helminthosporium solani by inhibiting its 75 % ± 2.5 growth. The preliminary studies heralded excellent biological potential of the synthesized complex.

Cationic and Anionic Disorder in CZTSSe Kesterite Compounds: A Chemical Crystallography Study

The cationic and anionic disorder in the Cu2ZnSnSe4-Cu2ZnSnS4 (CZTSe-CZTS) system has been investigated through a chemical crystallography approach including X-ray diffraction (in conventional and resonant setup), 119Sn and 77Se NMR spectroscopy, and high-resolution transmission electron microscopy (HRTEM) techniques. Single-crystal XRD analysis demonstrates that the studied compounds behave as a solid solution with the kesterite crystal structure in the whole S/(S + Se) composition range. As previously reported for pure sulfide and pure selenide compounds, the 119Sn NMR spectroscopy study gives clear evidence that the level of Cu/Zn disorder in mixed S/Se compounds depends on the thermal history of the samples (slow cooled or quenched). This conclusion is also supported by the investigation of the 77Se NMR spectra. The resonant single-crystal XRD technique shows that regardless of the duration of annealing step below the order-disorder critical temperature the ordering is not a long-range phenomenon. Finally, for the very first time, HREM images of pure selenide and mixed S/Se crystals clearly show that these compounds have different microstructures. Indeed, only the mixed S/Se compound exhibits a mosaic-type contrast which could be the sign of short-range anionic order. Calculated images corroborate that HRTEM contrast is highly dependent on the nature of the anion as well as on the local anionic order.