Triclinic Space Group Research Articles

Binuclear azide-bridged hydrazone Cu(II) complex: Synthesis, characterization and evaluation of biological activity

The condensation product of 7-acetyl-6-azaindole and Girard?s T reagent ((E)-2-(2-(1-(1H-pyrrolo[2,3-c]pyridin-7-yl)ethylidene)hydrazineyl)- -N,N,N-trimethyl-2-oxoethan-1-aminium, HL ligand) was used as a ligand in the reaction with Cu(BF4)2?6H2O and NaN3. The reaction led to the formation of a binuclear Cu(II) complex containing two end-to-end (di-?-1,3-N3) azide bridges, as well as two NNO-donor hydrazone ligands, forming an axially elongated square pyramidal geometry around each Cu(II) center. This end-to-end (di- ?-1,3-N3) azide bridge binding mode has not yet been reported, in Cu(II) complexes containing the NNO-donor hydrazone ligands, which makes the structure of the complex even more interesting for further studies. The complex was characterized by elemental analysis, IR spectroscopy and X-ray crystallography, and it was found that it crystallizes in the triclinic space group P?1 with the asymmetric unit comprising one Cu(II) centre, zwitterionic ligand L, one azide (N3 -) ligand and BF4 - counter anion. Examination of antimicrobial activity of the complex shows higher antifungal and antibacterial activity towards tested Gram-positive bacteria in comparison to the hydrazone ligand, with the antifungal activity of the complex even being comparable to the activity of amphotericin B.

Bimetallic dioxidovanadium(V) complex containing a malonohydrazide derivative ligand: Synthesis, characterization, and crystal structure

In this paper, we report the synthesis and characterization of the dioxidovanadium(V) complex derived from a malonohydrazide ligand (N'1,N'3-bis(2-hydroxybenzylidene) malonohydrazide). The newly synthesized complex was characterized by infrared spectroscopy (IR), nuclear magnetic resonance (NMR), and the structure of the complex was also established by a single crystal X-ray diffraction study. The bimetallic complex crystallizes in the triclinic space group P-1 with the following parameters a = 10.8273(5) Å, b = 11.4677(6) Å, c = 15.0366(8) Å, α = 81.591(4)°, β = 83.018(4)°, γ = 76.326(4)°, V = 1787.23(16) Å3, Z = 2, T = 292.5(2) K, μ(MoKα) = 0.600 mm-1, Dcalc = 1.463 g/cm3, 11730 reflections measured (6.236° ≤ 2Θ ≤ 58.062°), 7981 unique (Rint = 0.0231, Rsigma = 0.0506) which were used in all calculations. The final R1 was 0.0496 (I > 2σ(I)) and wR2 was 0.1255 (all data). The ligand was coordinated to the metal ions in a tridentate fashion through the donor O/N/O atoms. The metal ions adopted a square pyramidal geometry with slight distortion. Reaction of the complex with hydrogen peroxide was also carried out, and it was found that the complex reacts with hydrogen peroxide to form a peroxo complex.

Change in the Electronic Structure of the Cobalt(II) Ion in a One-Dimensional Polymer with Flexible Linkers Induced by a Structural Phase Transition

A new 1D-coordination polymer [Co(Piv)2(NH2(CH2)6NH2)]n (1, Piv is Me3CCO2- anion) was obtained, the mononuclear fragments {Co(O2CR)2} within which are linked by μ-bridged molecules of hexamethylenediamine (NH2(CH2)6NH2). For this compound, two different monoclinic C2/c (α-1) and P2/n (β-1) phases were found at room temperature by single-crystal X-ray diffraction analysis, with a similar structure of chains and their packages in unit cells. The low-temperature phase (γ-1) of crystal 1 at 150 K corresponds to the triclinic space group P-1. As the temperature decreases, the structural phase transition (SPT) in the α-1 and β-1 crystals is accompanied by an increase in the crystal packing density caused by the rearrangements of both H-bonds and the nearest ligand environment of the cobalt atom ("octahedral CoN2O4 around the metal center at room temperature" → "pseudo-tetrahedral CoN2O2 at 150 K"). The SPT was confirmed by DSC in the temperature range 210-150 K; when heated above 220 K, anomalies in the behavior of the heat flow are observed, which may be associated with the reversibility of SPT; endo effects are observed up to 300 K. The SPT starts below 200 K. At 100 K, a mixture of phases was found in sample 1: 27% α-1 phase, 61% γ-1 phase. In addition, at 100 K, 12% of the new δ-1 phase was detected, which was identified from the diffraction pattern at 260 K upon subsequent heating: the a,b,c-parameters and unit cell volume are close to the structure parameters of γ-1, and the values of the α,β,γ-angles are significantly different. Further heating leads to a phase transition from δ-1 to α-1, which both coexist at room temperature. According to the DC magnetometry data, during cooling and heating, the χMT(T) curves for 1 form a hysteresis loop with ~110 K, in which the difference in the χMT values reaches 9%. Ab initio calculations of the electronic structure of cobalt(II) in α-1 and γ-1 have been performed. Based on the EPR data at 10 K and the ab initio calculations, the behavior of the χMT(T) curve for 1 was simulated in the temperature range of 2-150 K. It was found that 1 exhibits slow magnetic relaxation in a field of 1000 Oe.

Synthesis, crystal structure, and superconductivity of Ba(Bi0.25Pb0.75)1−xMgxO3−δ

Magnesium has been doped into the B-site of BaBi0.25Pb0.75O3−δ to form a solid solution Ba(Bi0.25Pb0.75)1−xMgxO3−δ (0 ≤ x ≤ 0.10) by solid-state reaction. The X-ray, neutron, and selected area electron diffraction are used to confirm that this solid solution crystallizes in triclinic space group P1. The unit cell volume of Ba(Bi0.25Pb0.75)1−xMgxO3−δ increases with Mg, which is surprising because the radius of Mg2+ is smaller than any radius of Bi3+, Bi5+, Pb2+, and Pb4+. XPS and iodometric titration data of samples show that the oxygen vacancies increase with Mg in Ba(Bi0.25Pb0.75)1−xMgxO3−δ. The increased oxygen vacancies result in increase of Bi3+:Bi5+ and Pb2+:Pb4+ ratios, which is the utmost possible reason for unit cell volume increase. They are all superconductors with TCzero (the highest temperature at which the electrical resistivity becomes “zero”) between 11.2 and 9.2 K.

Crystal structures, Hirshfeld surfaces, Infrared, and XRF/XAFS studies of Long-chain 2D Lead-free Hybrid Perovskite NH3(CH2)9NH3MCl4 (M = Mn, Co, Cu)

Three 2D hybrid perovskite materials based on long chain diammonium NH3(CH2)9NH3MCl4 (M: Mn, Co, Cu) were prepared and characterized. The single crystal X-ray diffraction analysis showed that the novel compound NH3(CH2)9NH3MnCl4 (denoted C9Mn) crystallized in the monoclinic P21/c (Z=4) with the unit cell parameters a=7.405(3) Å, b=7.102(3) Å, c=29.463(11) Å, V=1538.07Å3. The NH3(CH2)9NH3CoCl4 (C9Co) was found to crystallize in the Triclinic space group P¯1 [Z=2; a = 7.3113(4) Å, b = 10.2373(5) Å, c = 12.4701(9) Å; α = 112.323(2)°, β = 92.441(2)°, γ = 93.452(3)°, V=859.68(9) Å3]. The C9Mn and C9Co layered structures contain alternating organic cations +NH3(CH2)9NH3+ and inorganic anions MCl42- (M: Mn, Co), where M is coordinated by six Cl atoms in the octahedral topology MnCl62−, and by four Cl atoms in the tetrahedral CoCl42− unassociated unit. The NH3(CH2)9NH3CuCl4 (C9Cu) crystal quality is not good to do the single crystal X-ray diffraction analysis on this salt. The Hirshfeld surface analyses are performed to compare the importance of attractive H…Cl/Cl…H and detractive H…H intercontacts in the two hybrid compounds. The vibrational modes of alkylenediammonium group of C9Cu, clearly observed in the infrared spectrum, are compared to that observed in the C9Mn and C9Co spectra, discussed based on theoretical group predictions. Analysis was performed at the X-ray absorption fine structure XAFS/XRF beamline to enhance the structure analysis for the salts C9Mn, C9Co and C9Cu.

Synthesis, crystal structure and biological properties of a fluorophore-labelled mixed-ligand copper(II) complex incorporating N-hydroxynaphthalene-1,8-dicarboximide.

The mixed-ligand fluorophore-labelled copper(II) complex aqua[2,4-dioxo-3-azatricyclo[7.3.1.05,13]trideca-1(12),5,7,9(13),10-pentaen-3-olato-κ2O2,O3](1,10-phenanthroline-κ2N,N')copper(II) nitrate, [Cu(C12H6NO3)(C12H8N2)(H2O)]NO3·CH3OH or [Cu(L)(phen)(H2O)]NO3·CH3OH (where phen is 1,10-phenanthroline and HL is N-hydroxynaphthalene-1,8-dicarboximide), (1), was synthesized and structurally characterized. The structure of (1) was confirmed by single-crystal X-ray structure determination. The complex crystallized in the triclinic space group P-1. The geometry around the copper centre is distorted square pyramidal, with the apical position occupied by a water molecule. The complex is highly fluorescent in organic and aqueous solutions. It has good anticancer activity, with an IC50 value of 17 µM, which is almost five times greater than cisplatin (IC50= 82 µM) under identical experimental conditions.

Crystal structure, vibration spectra, antibacterial and non-linear optical properties of a picrate based on triphenylphosphinium dication

An organic crystal, 1,4-phenylenebis(methylene)-bis(triphenylphosphinium) picrate (abbreviated as [TPPBzTPP][PIC]2) was grown by a slow evaporation solution growth technique and characterized by elemental analysis, spectroscopy, thermal analysis, powder and single crystal XRD. The new picrate crystallize in triclinic space group P−1 and consists of [TPPBzTPP]2+ cation and two picrate anions. Experimental vibrational bands (IR and Raman) have been discussed and assigned. The HOMO-LUMO energy gap explains the charge transfer interaction in the molecule. TG-TDA technique reveals that the material was stable up to 280.7 °C. In addition, [TPPBzTPP][PIC]2 showed good antibacterial activities against Escherichia coli and Staphylococcus aureus. The results of DFT calculation indicated that the first hyperpolarizability value (βtot) of the crystal is 20.85 times that of KDP, which exhibited good nonlinear optical properties.

Melt Crystallization of Celecoxib-Carbamazepine Cocrystals with the Synchronized Release of Drugs.

The fixed-dose combination drug products have been increasingly used to treat some complex diseases. A cocrystal containing two therapeutic components, named as a drug-drug cocrystal, is an ideal solid form to formulate as a fixed-dose combination product. The aim of the study is to prepare celecoxib-carbamazepine (CEL-CBZ) cocrystals by melt crystallization to achieve the synchronized release of drugs. The crystal structure of the CEL-CBZ cocrystal was determined from the cocrystals harvested from melt by single crystal X-ray diffraction. The binary phase diagram and crystal growth kinetics of the CEL-CBZ cocrystal from melt were studied to optimize the process parameters of hot-melt extrusion for manufacturing large-scale cocrystals. The intrinsic dissolution rate studies were conducted to compare the dissolution profiles of drugs in the cocrystal and their individual forms. The CEL-CBZ cocrystal crystallized in the triclinic space group with one CEL and one CBZ molecule in the asymmetric unit. The crystallization of CEL-CBZ cocrystals were observed both in the supercooled liquid and glassy state. The formation of drug-drug cocrystals significantly alter the intrinsic dissolution rates of the parent drugs to favor the synchronized release. Melt crystallization is an alternative, efficient and eco-friendly approach for preparing drug-drug cocrystals on a large scale. The synchronized drug release by drug-drug cocrystals can be used to modulate the release profiles of parent drugs in the fixed-dose combination products.

Triazole-Bridged Zinc Dinuclear Complexes: Mechanochemical Synthesis, Crystal Structure, and Biological Activity.

Two zinc (Zn) complexes, [Zn2(DAT)2Cl4] (I) and [Zn2(DAT)2(NO3)4] (II), were prepared by grinding 3,5-diamino-1,2,4-triazole (C2H5N5, DAT) with Zn precursors such as ZnCl2 and Zn(NO3)2, respectively. This solid-state reaction gives the corresponding Zn complex as the sole product in over 99% yield. This mechanochemical method promotes the selective formation of Zn complexes different from those obtained using the conventional solution-based route. The crystal structures of the two complexes were analyzed by single-crystal X-ray diffraction. Complex (I) crystallizes in the monoclinic space group P21/c, whereas complex (II) crystallizes in the triclinic space group P 1̅. Each complex is characterized by the presence of a characteristic DAT-bridged dimer with one DAT ligand per Zn atom, and the DAT ligand provides a bridge between the two Zn metals. All Zn centers of (I) and (II) adopted a slightly distorted tetrahedral geometry. Both complexes contain a hexanuclear Zn2N4 ring, but their ring structures are different. Complex (I) possesses a boat geometry, while complex (II) has a nearly planar structure. The Zn-bound chlorides of complex (I) form intermolecular N-H···Cl hydrogen bonds that link neighboring molecules. In complex (II), the O atoms in the nitrate groups are hydrogen-bonded to the DAT ligand via O···H-N linkages. Both complexes exhibit blue emissions in the solid state at ambient temperature. They were evaluated as anticancer agents in HeLa, NCCIT, and MCF-7 cancer cell lines, exhibiting promising anticancer activities.

2,5,8,11-Tetramethyl-2,5,8,11-tetraazadodecane-2,11-diium bis[hydroxytris(pentafluorophenyl)borate] benzene 2.5-solvate

The title compound of overall stoichiometry, C12H32N4 2+·2C18HBF15O−·2.5C6H6, crystallizes in the triclinic space group P\overline{1} and the stoichiometry of the asymmetric unit consists of two [C12H32N4]2+ dications, two [C18HBF15O]− anions, and 2.5 molecules of benzene as solvate. The dications are both at half occupancy and located on a center of inversion, as is one of the benzene solvate molecules. In the two anions the O—H groups participate in different hydrogen-bonding schemes. In anion A, the OH group participates in a bifurcated 2R 2 2(6) scheme with F atoms on different rings of an adjacent hydroxy[tris(pentafluorophenyl)]borate moiety with an additional N—H...O hydrogen bond with a dication. For anion B, the OH group participates in a single O—H...F R 2 2(6) scheme. In addition, there are both O—H...N and N—H...O hydrogen bonds involving dication D and anion B in an R 2 2(7) motif. There are numerous C—H...π interactions between the dications and all the three benzene solvate molecules. For solvate 3, the C—H...π interactions are on both sides of the benzene ring and link both dications and solvate into a linear chain in the c-axis direction.

A new copper hybrid compound based on 3,3'-diaminodiphenylsulfone as ligand: Growth, crystal structure, spectroscopic analysis, and thermal behavior

A new copper compound with general formula [H2L]2(CuCl4(H2O)2).2Cl·2H2O [L = 3,3′-diaminodiphenylsulfone] was synthesized, at room temperature, by slow evaporation method. The morphology was observed by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscope (EDS). The single crystal X-ray analysis indicates that the studied compound crystallizes in the P-1 triclinic space group. The packing pattern is characterized by organic and inorganic layers alternation stabilized by means of hydrogen interactions. Hirshfeld Surface analysis in combination with 2D fingerprint plots reveal the quantitatively relative contributions of these intermolecular interactions. Infrared and Raman spectroscopic analysis were performed to distinguish the different chemical functional groups and their environments in this compound. Additionally, the optical study was inspected by UV–visible and photoluminescence measurements. The compound exhibits three optical absorption bands at 245, 308 and 554 nm, with 1.54 and 1.64 eV indirect and direct gap energies values, respectively. Thermal analysis (TGA and DSC) was also investigated.

Spectroscopic, crystal structure, antimicrobial and antioxidant evaluations of new Schiff base compounds: An experimental and theoretical study

The increase in multidrug-resistant pathogens has necessitated continuous research for lead antimicrobial compounds. Herein, the design and synthesis of three Schiff base compounds (SB1–SB3) from aroom temperature reaction of an equimolar amount of 2,4-di-substituted anilines and salicylaldehyde as potential antimicrobial agents is reported. The compounds were validated using elemental analysis (CHN), nuclear magnetic resonance [1H, 13C, DEPT,COSY, NOESY, HSQC and HMBC], Fourier transform infrared, UV–Visible spectroscopies, scanning electron microscope-energy dispersive X-ray (SEM-EDX) analysis and mass spectrometry. Single-crystal X-ray diffraction measurements were used to properly establish the structures of compounds. SB1 and SB2 crystallized in a monoclinic P21/c space group, while SB3 crystallizedin a triclinic space group Pī. The compounds' antibacterial activity was tested in vitro against two gram-positive bacteria (Staphylococcus aureus ATCC-25923 and Streptococcus pyogenes ATCC-19615) and two gram-negative bacteria (Escherichia coli ATCC-25922 and Pseudomonas aeruginosa ATCC-27853). All compounds inhibited the bacteria quite well, with SB3 having the lowest MIC of 0.25 g.mL−1 on some of the species. A similar trend was observed for the DPPH radical scavenging activities of the compounds. To estimate chosen quantum chemical parameters of SB1-SB3, ab initio simulations of the compounds' electronic and structural properties were performed. Molecular docking studies were also used to investigate the compounds' mechanism of action against the bacteria. The theoretical findings are consistent with the experimental findings.

Synthesis, crystal structure and Hirshfeld surface analysis of aqua-(3-meth-oxy-cinnamato-κO)bis-(1,10-phenanthroline-κ2 N,N')cobalt(II) nitrate.

The title compound, [Co(C10H9O3)(C12H8N2)2(H2O)]NO3 (I), crystallizes in the triclinic space group P with a monomeric [Co(3-meo-cin)(phen)2(H2O)]+ cation and a nitrate anion (3-meo-cin = 3-meth-oxy cinnamic acid) in the asymmetric unit. The CoII ion is coordinated by four N atoms from two 1,10-phenanthroline ligands and two O atoms, the first from a meth-oxy cinnamate ligand and the second from a coordinated water mol-ecule, forming a distorted octa-hedral geometry. Discrete entities of the cation and nitrate anion are formed by water-nitrate O-H⋯O and phen-nitrate C-H⋯O hydrogen bonds. The components are further assembled into chains along the c-axis direction. Layers are than formed by slipped π-π stacking inter-actions parallel to the bc plane. The inter-molecular inter-actions in the crystal structure were qu-anti-fied and analysed using Hirshfeld surface analysis.

Insight into weakly antiferromagnetic coupling behavior in a non-integer oxidation state bis(2-thioxo-1,3-dithiole-4,5-dithiolate)nickelate molecular semiconductor

In (ImH)[Ni(dmit) 2 ] 2 , the [Ni(dmit) 2 ] 0.5− anions form dimeric stack, and the weakly AFM couplings between anion dimers are achieved through magnetic dipole–dipole interactions. • A non-integer oxidation state [Ni(dmit) 2 ] 0.5− salt was prepared by chemical oxidation together with solvent evaporation. • The columnar [Ni(dmit) 2 ] 2 − stacks are connected by intermolecular S…S interactions into a monolayer. • There exist quietly weak AFM couplings between [Ni(dmit) 2 ] 2 − dimers owing to magnetic exchange through dipole–dipole interactions. In this study, we prepared a salt, (ImH)[Ni(dmit) 2 ] 2 ( 1 ; ImH + = imidazolium; dmit 2− = 2-thioxo-1, 3-dithiole-4, 5-dithiolate), by a facile approach of chemical oxidation together with solvent evaporation at ambient condition. (1) was characterized by microanalysis for C, H and N elements, IR spectroscopy, TG and DSC techniques. 1 crystallizes in triclinic space group P − 1, with two different [Ni(dmit) 2 ] species (Ni1 and Ni2) and one ImH + cation in an asymmetric unit. The characteristic C C, C S and Ni S bond lengths in [Ni(dmit) 2 ] species demonstrated that the valences of two different [Ni(dmit) 2 ] species are −0.5. The anions form dimeric stacks in 1 , which are further connected into monolayers by inter-stack S…S interactions. 1 shows semiconducting feature with σ DC = 1.45 × 10 −3 S cm −1 at 293 K and E a = 0.17 eV; and smaller Weiss constant (−0.67 K) owing to the magnetic couplings being achieved through weak dipole–dipole interactions.

Synthesis, spectroscopic, topological, hirshfeld surface analysis, and anti-covid-19 molecular docking investigation of isopropyl 1-benzoyl-4-(benzoyloxy)-2,6-diphenyl-1,2,5,6-tetrahydropyridine-3-carboxylate

Isopropyl 1-benzoyl-4-(benzoyloxy)-2,6-diphenyl-1,2,5,6-tetrahydropyridine-3-carboxylate (IDPC) was synthesized and characterized via spectroscopic (FT-IR and NMR) techniques. Hirshfeld surface and topological analyses were conducted to study structural and molecular properties. The energy gap (Eg), frontier orbital energies (EHOMO, ELUMO) and reactivity parameters (like chemical hardness and global hardness) were calculated using density functional theory with B3LYP/6–311++G (d,p) level of theory. Molecular docking of IDPC at the active sites of SARS-COVID receptors was investigated. IDPC molecule crystallized in the centrosymmetric triclinic (P1¯) space group. The topological and Hirshfeld surface analysis revealed that covalent, non-covalent and intermolecular H-bonding interactions, and electron delocalization exist in the molecular framework. Higher binding score (-6.966 kcal/mol) of IDPC at the active site of SARS-COVID main protease compared to other proteases suggests that IDPC has the potential of blocking polyprotein maturation. H-bonding and π-cationic and interactions of the phenyl ring and carbonyl oxygen of the ligand indicate the effective inhibiting potential of the compound against the virus.

Titania Nanorods Embedded with 2-Bromo-3-(methylamino)naphthalene-1,4-dione for Dye-Sensitized Solar Cells.

In a recent study, TiO2 nanorod electrodes were prepared by the hydrothermal approach followed by calcination at various temperatures from 300 to 600 °C. The effects of calcination temperature on the morphological and structural properties were investigated. The novel analogue of aminonaphthoquinone(2R-(n-alkylamino)-1,4-naphthoquinone) photosensitizer, viz. BrA1, 2-bromo-3-(methylamino)naphthalene-1,4-dione was synthesized from 2,3-dibromonaphthalene-1,4-dione. X-ray crystallographic data collection and refinement confirm that BrA1 crystallizes in the triclinic space group P1̅. After loading BrA1, the photosensitizer on the annealed TiO2 nanorod (TiO2NR) electrodes, the optical properties of the photoanodes showed broadbands in each of the UV and visible regions, which are attributed to the π →π* and n → π* charge-transfer transitions, respectively. The dye-sensitized solar cell (DSSC) system was formed by loading the BrA1 photosensitizer on TiO2NR. The electrochemical impedance spectroscopy (EIS) analyses confirm that calcination temperature improves the charge transportation by lowering the resistance path during the photovoltaic process in TiO2NR (400 °C) photoanode-based DSSCs due to the sufficient photosensitizer adsorption and fast electron injection. Due to the effective light harvesting by the BrA1 photosensitizer and charge transport through the TiO2 nanorod, the power conversion efficiencies (PCE) of the TiO2NR (400 °C/BrA1-based) DSSCs were improved for 2-bromo-3-(methylamino)naphthalene-1,4-dione.

Structure and cytotoxic properties of 1-hydroxy-5-methyl-7-phenylpyrido[3,4-d]pyridazin-4(3H)-one and its mono- and disubstituted ethyl acetates.

Derivatives of pyrido[3,4-d]pyridazine, namely, 1-hydroxy-5-methyl-7-phenylpyrido[3,4-d]pyridazin-4(3H)-one dimethylformamide monosolvate, C14H11N3O2·C3H7NO (2), ethyl [1-(2-ethoxy-2-oxoethoxy)-5-methyl-4-oxo-7-phenyl-3,4-dihydropyrido[3,4-d]pyridazin-3-yl]acetate, C18H17N3O4 (3), and ethyl [(5-methyl-4-oxo-7-phenyl-3,4-dihydropyrido[3,4-d]pyridazin-1-yl)oxy]acetate, C22H23N3O6 (4), were synthesized with the aim of discovering new potential biologically active agents. The properties of all three derivatives were characterized by 1H NMR, 13C NMR and FT-IR spectroscopic analysis. All the crystals were obtained by a solvent diffusion method from dimethylformamide (DMF) or dimethyl sulfoxide (DMSO) and characterized by single-crystal X-ray diffraction. The collected X-ray data revealed that the crystals of 2 and 4 belong to the triclinic space group P-1, whereas the crystal of 3 belongs to the monoclinic space group P21/c. The presented derivatives crystallized with one molecule in the asymmetric unit, but only compound 2 crystallized as a solvate with DMF. Structure analysis showed that the molecule of 2 exists as its amide-imidic acid tautomer and that O-alkylation occurred before N-alkylation during the synthesis of the mono- and disubstituted derivatives, i.e. 3 and 4, respectively. The molecular geometries of the 5-methyl-7-phenylpyrido[3,4-d]pyridazine core within the studied derivatives differ in the mutual orientation of the rings. The interplanar angles between the heterocyclic ring and the bound aromatic ring are 1.71 (7), 18.16 (3) and 3.1 (1)° for 2, 3 and 4, respectively. The potential cytotoxicity of these compounds was evaluated against one normal (HaCat) and four human cancer cell lines (A549, DU145, MDA-MB-231 and SKOV-3).

Trivalent Cobalt Complexes with NNS Tridentate Thiosemicarbazones: Preparation, Structural Study and Investigation of Antibacterial Activity and Cytotoxicity against Human Breast Cancer Cells

New complexes of trivalent cobalt with substituted thiosemicarbazone ligands having an NNS donor system {HL1 = 4-(4-nitrophenyl)-1-((pyridin-2-yl)methylene)thiosemicarbazide and HL2 = 4-(2,5-dimethoxyphenyl)-1-((pyridin-2-yl)methylene)thiosemicarbazide} were synthesized via the in situ oxidation of divalent cobalt chloride accompanying its addition to the ligands. The complexes C1 and C2 were characterized via elemental (CHNS) analysis and 1H NMR, FT-IR and UV-Vis. spectroscopic data. Further, conductometric studies on the DMF solutions of the complexes indicated their 1:1 nature, and their diamagnetism revealed the low-spin trivalent oxidation state of the cobalt in the complexes. The X-ray diffraction analysis of complex C1 indicated that it crystallizes in the triclinic space group P-1. The metal exhibits an octahedral environment built by two anionic ligands bound via pyridine nitrogen, imine nitrogen and thiol sulfur atoms. The complex is counterbalanced by a chloride ion. In addition, two lattice water molecules were detected in the asymmetric unit of the unit cell. The ligand HL2 (20 mg/mL in DMSO) displayed inhibition zones of 10 mm against both S. aureus and E. coli, and the same concentration of the respective complex raised this activity to 15 and 12 mm against these bacterial strains, respectively. As a comparison, ampicillin inhibited these bacterial strains by 21 and 25 mm, respectively. Screening assay by HL1 on four human cancer cells revealed the most enhanced activity against the breast MCF-7 cells. The induced growth inhibitions in the MCF-7 cells by all compounds (0–100 μg/mL) have been detected. The ligands {HL1 and HL2} and complex C2 gave inhibitions with IC50 values of 52.4, 145.4 and 49.9 μM, respectively. These results are more meaningful in comparison with similar cobalt complexes, but less efficient compared with the inhibition with IC50 of 9.66 μM afforded by doxorubicin. In addition, doxorubicin, HL1 and HL2 induced cytotoxicity towards healthy BHK cells with IC50 values of 36.42, 54.8 and 110.6 μM, but surviving fractions of 66.1% and 62.7% of these cells were detected corresponding to a concentration of 100 μg/mL of the complexes (136.8 μM of C1 and 131.4 μM of C2).

Synthesis, crystal structure, vibrational studies, optical properties and DFT calculation of a new Bi(III) halide complex: (C9H14N3)4[Bi2Cl11][BiCl6].4H2O

This paper reports the synthesis, structural characterization, Infrared spectroscopy and optical properties of the new chlorobismuthate(III) hybrid compound involving discrete binuclear Bi2Cl11 and mononuclear BiCl6 anions coexisting together in the same structure with 1-(2-pyridyl)piperazine -based ligand. The compound structure was determined by single-crystal X-ray diffraction and crystallized in the triclinic space group Pī with cell parameters: a ​= ​14.7757(2) Å, b ​= ​14.7799(2) Å, c ​= ​23.1633(4) Å, α ​= ​89.016(2) °, β ​= ​84.0080(10) °, γ ​= ​74.0400(10) ° and v ​= ​4836.57(13) Å3, Z ​= ​4 ​at 296 ​K. The vibrational spectrum measured at room temperature by FT-IR spectroscopy (4000-400 ​cm−1) on polycrystalline samples shows the presence of organic cation.The optical study revealed the absorption and photoluminescence properties of the compound. Theoretical studies were investigated by means of DFT and TDDFT calculations. A good agreement was found between theoretical data and experimental results. Furthermore, the intermolecular interactions were examined using Hirshfeld surfaces analysis. The thermal analysis shows that this compound is stable below 380 ​K.

Crystal structures of two new divalent transition-metal salts of carb-oxy-benzene-sulfonate anions.

Hexa-aqua-nickel(II) bis-(3-carb-oxy-4-hy-droxy-benzene-sulfonate) dihydrate, [Ni(H2O)6][C6H3(CO2H)(OH)SO3]2·2H2O, (I), crystallizes in the triclinic space group P with the nickel(II) aqua complexes on centers of inversion. The carboxyl-ate group is protonated and neither it nor the sulfonate group is involved in direct coordination to the metal ions. The structure consists of alternating layers of inorganic cations and organic anions linked by O-H⋯O hydrogen bonds that also include non-coordinated water mol-ecules of crystallization. The first-row divalent transition-metal salts of this anion are reported as both dihydrates and tetra-hydrates, with two distinct structures for the dihydrates that are both layered but differ in the hydrogen-bonding pattern. Compound (I) represents the second known example of one of these structures. Hexa-aqua-cobalt(II) bis-(3-carb-oxy-benzene-sulfonate) dihydrate, [Co(H2O)6][C6H4(CO2H)SO3]2·2H2O, (II), also crystallizes in triclinic P with the cobalt(II) aqua complexes on centers of inversion. The structure is also built of alternating layers of complex cations and organic anions without direct coordination to the metal by the protonated carboxyl-ate or unprotonated sulfonate groups. A robust O-H⋯O hydrogen-bonding network involving primarily the coordin-ated and non-coordinated water mol-ecules and sulfonate groups directs the packing. This is the first reported example of a divalent transition-metal salt of the 3-carb-oxy-benzene-sulfonate anion.