Colorless Block Research Articles

The crystal structure of the ammonium salt of 2-aminomalonic acid.

The salt ammonium 2-aminomalonate (systematic name: ammonium 2-azaniumylpropanedioate), NH4+·C3H4NO4-, was synthesized in diethyl ether from the starting materials malonic acid, ammonia and bromine. The salt was recrystallized from water as colourless blocks. In the solid state, intramolecular medium-strong N-H...O, weak C-H...O and weak C-H...N hydrogen bonds build a three-dimensional network.

Synthesis and characterization of thiosemicarbazone metal complexes: Crystal structure, and antiproliferation activity against breast (MCF7) and lung (A549) cancers

Thiosemicarbazone compound has pronounced anticancer activity, which increases by metal ions presence. New Ni(II), Cu(II), Pd(II), and Pt(II) complexes synthesized from 2-(2,3-dihydroxy benzylidene)-N-ethylhydrazine-1-carbothioamide ligand H3L and had been characterized via NMR, GC–MS, FTIR, CHNS, UV–vis, TGA, magnetic susceptibility measurements, and molar electric conductivity. X‐ray crystallographic data and the refinement structure of thiosemicarbazide ligand indicated a clear light colorless block with the formula C10H13N3O2S, which belongs to a monoclinic system with P1 21/ c1 space group and adopts orthorhombic crystal with a = 5.1509(3) Å; b = 10.2856(6) Å; c = 11.3261(6) Å. The ligand and the metal complexes were also tested for antiproliferation activity against the MCF7 breast and A549 lung cancer cell lines. The data showed that Ni(II), Cu(II), Pd(II), and Pt(II) complexes had potent antiproliferation activity at the micromolar level. Pt(II) complex with square planar geometry exhibits the highest antiproliferation activity, while Ni(II) complex with distorted octahedral geometry showed the lowest antiproliferation activity in both cell lines.

Methoxybenzamide derivative of nimesulide from anti-fever to anti-cancer: Chemical characterization and cytotoxicity

The repurposing strategy of converting nimesulide from an anti-fever drug to an anti-cancer agent by modifying its main structure targeting HSP27 is gaining great attention these days. The goal of this study focuses on synthesizing a new nimesulide derivative with new ligands that have biological anti-cancer activities in different cancer models using the in-vitro assay. Nimesulide derivative L1 was synthesized, characterized by 1H NMR, 13C NMR, FTIR, melting point, mass spectra, and TGA analysis. A single crystal was diffracted and showed colorless block group P-1. The results revealed that L1 demonstrates potent anti-cancer activity with lung (H292), ovarian (SKOV3), and breast (SKBR3) cancer cell lines in-vitro models with IC50 values below 8.8 µM.

Crystal structure and Hirshfeld surface analysis of (S)-N-methyl-1-phenyl-ethan-1-aminium chloride.

The title compound C9H14N+·Cl-, (1), can be synthesized starting from (S)-N-methyl-1-phenyl-ethan-1-amine (2). Compound 2 upon addition of HCl·Et2O leads to crystallization of compound 1 as colorless blocks. The configuration of compound 1 is stable as well as preserved in space group P212121. Ammonium chlorides, like the title compound, are often observed as undesirable by-products in amino-silylation of chloro-silanes. Additionally, these by-products are usually soluble in selected organic solvents, which require difficult separation steps. Therefore, detailed studies on structural features and inter-molecular inter-actions performed by Hirshfeld atom refinement (HAR) using NoSpherA2 [Kleemiss et al. (2021 ▸). Chem. Sci. 12, 1675-1692] and Hirshfeld surface analysis were used to address structural issues on that separation problem.

Synthesis, crystal structure, DFT calculations, Hirshfeld surface analysis, energy frameworks, molecular dynamics and docking studies of novel isoxazolequinoxaline derivative (IZQ) as anti-cancer drug

Quinoxaline derivatives with the molecular formula [C8H6N2] also named benzopyrazines, which are a valuable class of heterocyclic compounds useful for their numerous industrial and pharmaceutical applications. The new isoxazolquinoxalin (IZQ) 3-phenyl-1-((3-(p-tolyl)-4,5-dihydroisoxazol-5yl)methyl)quinoxalin-2(1H)-one (5) has been synthesized with good yield by stirring the compounds of 1-allyl-3-phenylquinoxalin-2(1H)-one (3, 3.8mmol), and (E)-4 methylbenzaldehydeoxime (4, 1.3mmol) in 20 ml of chloroform. The aqueous solution of sodium hypochlorite (10 ml of water bleach 12°) was added drop wise using bromine funnel. The mixture was stirring at 0°C temperature for 6 hours. Then it dried to obtain a crude product which on recrystallization with ethanol afforded the title compound (5) as colourless rectangular block shape crystals, and then confirmed by H NMR, LC-MS spectra. The structure of the compound has been confirmed by single crystal X-ray diffraction technique. The compound crystallizes in the monoclinic crystal system with the space group P21/c. The unit cell constants; a =15.9437(6) Å, b =16.3936(6) Å, c =7.4913(3) Å, and β =94.178(2)o. DFT calculations were carried out and HOMO-LUMO energy levels have been determined. In the structure, both Intermolecular and intramolecular hydrogen bonds of the type C-H...O were observed along with C-H...cg interactions. Hirshfeld surface studies were performed to understand the different interaction contacts of the molecule and the molecular packing strength of the crystal. Energy frameworks were constructed through different intermolecular interaction energies to investigate the stability of the compound and to know type of the dominate energy. Docking studies predicted anti-cancer activity of the title molecule against homo sapiens protein (pdb code:6HVH) and exhibited prominent interactions at active site region.

Development of colorless wood via two-step delignification involving alcoholysis and bleaching with maintaining natural hierarchical structure

Lignin-free wood has been successfully developed via a two-step chemical treatment while maintaining its inherent hierarchical structure. The first step was alcoholysis which was conducted using ethylene glycol, and whose condition was optimized by monitoring the removal of lignin using infrared spectroscopy. The second step was bleaching wherein the delignification proceeded from the surface to the core of the wood block, and finally resulted in complete decolorization. Although the wood block was free from lignin and hemicellulose as approximately confirmed by the chemical composition analysis, the 3-dimensional colorless wood block was almost unaltered, even after freeze–drying. Then, multidirectional observation was performed to investigate whether the natural hierarchical structure from anatomical- to nano-level was maintained. Optical microscopy, X-ray microcomputed tomography, X-ray diffractometry, and transmission electron microscopy demonstrated that all the stages of hierarchical structure were maintained. The lignin-free wood block has great potential for novel materials that are supported by a 3-dimensional wooden architecture. The derived lignin-free wood is also a suitable specimen that can be used to understand the formation and functionality of the anatomical structure and lignified cell wall.

Development of “Colorless Wood Block” and Its Natural Hierarchical Structure

Development of “Colorless Wood Block” and Its Natural Hierarchical Structure

Molecular Capture Using the Precipitate of Creaming-Down by (-)-Epigallocatechin-3-O-gallate.

An aqueous solution of equimolecular amounts of 2-chloropyrimidine and (-)-epigallocatechin-3-O-gallate (EGCg) afforded a colorless block crystal, which was determined to be a 2 : 2 complex of 2-chloropyrimidine and EGCg by X-ray crystallographic analysis. The 2 : 2 complex was formed by the cooperative effect of three intermolecular interactions, π-π and CH-π interactions, and intermolecular hydrogen bonds. Upon formation of the 2 : 2 complex, a 2-chloropyrimidine molecule was captured by a hydrophobic space formed by the three aromatic rings of A, B, and B' rings of two EGCg molecules. The molecular capture abilities of various heterocyclic compounds using EGCg were evaluated by ratio of the heterocyclic compounds included in the precipitates of complex of EGCg to the heterocyclic compounds used. The amount of the heterocyclic compounds was measured by an integrated value of corresponding proton signals in the quantitative 1H-NMR spectrum.

Crystal structure of 1,3-di-tert-butyl-2-chloro-1,3,2-di-aza-phospho-rinane - a saturated six-membered phospho-rus nitro-gen heterocycle with a partially flattened chair conformation and a long PIII-Cl bond.

Colourless blocks of 1,3-di-tert-butyl-2-chloro-1,3,2-di-aza-phospho-rinane, C11H24ClN2P (1), were obtained by sublimation in vacuo slightly above room temperature. The asymmetric unit of the monoclinic crystal structure of the six-membered N-heterocyclic compound is defined by one mol-ecule in a general position. The six-membered ring of the mol-ecule adopts a cyclo-hexane-like chair conformation; the chair at one side is to some extent flattened as a result of the approximately trigonal-planar coordination of both nitro-gen atoms. In detail, this modified chair conformation is characterized by an angle of 53.07 (15)° between the plane defined by the three carbon atoms and the best plane of the two nitro-gen atoms and the two carbon atoms bound to them, and an angle of 27.96 (7)° between the latter plane and the plane defined by the nitro-gen and phospho-rus atoms. The tert-butyl groups are oriented equatorially and the chloro substituent is oriented axially. The P-Cl bond length of 2.2869 (6) Å is substanti-ally longer than the P-Cl single-bond length in PCl3 [2.034 Å; Galy & Enjalbert (1982 ▸). J. Solid State Chem. 44, 1-23]. Inspection of the inter-molecular distances gives no evidence for inter-actions stronger than van der Waals forces. The closest contact is between the Cl atom and a methyl-ene group of a neighbouring mol-ecule with a Cl⋯C distance of 3.7134 (18) Å, excluding a significant influence on the P-Cl bonding.

Single-crystal growth, structure refinement and the properties of Bis(glycine) Strontium Chloride

Single crystals of Bis (glycine) Strontium Chloride (BGSC) were grown by means of slow evaporation process by using analar grade Glycine and Strontium Chloride Hexahydrate as a parent compound from its aqueous solution at room temperature. The final chemical composition, formed were metallic light colorless block, about the size of 28 mm × 9 mm × 8 mm. A single-crystal x-ray diffraction study revealed an ordered superstructure with orthorhombic symmetry that could be assigned to the space group Pbcn. The structure in BGSC, revealed in the electron density distribution was analyzed by the direct methods (SHELXS-2014) and refined by least squares full matrix method (SHELXL-2014). The crystal structure, including anisotropic atomic displacement parameters for each atom and isotropic atomic displacement parameters for hydrogen atom, was refined to R1 = 0.0395, wR2 = 0.0776 using 1097 independent reflections. The FTIR spectrum of BGSC confirms the protonation of amino groups and the different molecular groups present in BGSC vibrate in different modes. Reverse Indentation Size Effect (RISE) was revealed in BGSC in the micro-hardness analysis using Vicker’s micro-hardness analysis. DTA and DSC results ruled out the possibility of structural change independent of mass change. The AFM studies shows fine nano size fiber like structure of the grown crystals.

Green approach for synthesis of bioactive Hantzsch 1,4-dihydropyridine derivatives based on thiophene moiety via multicomponent reaction.

A novel green and efficient one-pot multicomponent reaction of dihydropyridine derivatives was reported as having good to excellent yield. In the presence of the catalyst ceric ammonium nitrate (CAN), different 1,3-diones and same starting materials as 5-bromothiophene-2-carboxaldehyde and ammonium acetate were used at room temperature under solvent-free condition for the Hantzsch pyridine synthesis within a short period of time. All compounds were evaluated for their in vitro antibacterial and antifungal activity and, interestingly, we found that 5(b–f) show excellent activity compared with Ampicillin, whereas only the 5e compound shows excellent antifungal activity against Candida albicans compared with griseofulvin. The cytotoxicity of all compounds has been assessed against breast tumour cell lines (BT-549), but no activity was found. The X-ray structure of one such compound, 5a, viewed as a colourless block crystal, corresponded accurately to a primitive monoclinic cell.

Reversible ferroelectric phase transition of 1,4-diazabicyclo [2,2,2]octane N,N′-dioxide di(perchlorate)

1,4-Diazabicyclo [2,2,2]octane N,N′-dioxide di(perchlorate), C6H14N2O22+·2ClO4−, was synthesized and separated as colorless block crystals. Differential scanning calorimetry detected that this compound underwent a reversible phase transition at ca. 216K with a hysteresis of 5.5K width, which was also confirmed by dielectric measurements. Single crystal X-ray diffraction data suggested that there was a transition from a room temperature phase with the space group of P21/c (a=6.815(7) Å, b=12.644(13) Å, c=8.676(9) Å, β=101.466(15)°, V=732.7(13) Å3, Z=4) to a low temperature one with a space group of P21 (a=9.892(8) Å, b=12.559(10) Å, c=17.401(13) Å, β=92.065(8)°, V=2160(3) Å3, Z=2). Crystallographic analysis showed that it belonged to chiral space group P21 with ferroelectric behaviors, and a typical ferroelectric feature of electric hysteresis loop was obtained in the low temperature phase. The disorder-order transformation of H2-Dabcodo2+ cation and ClO4− anion as well as the change of hydrogen bonds may drive the phase transition.

Copper(I) thiocyanate networks with aliphatic sulfide ligands

A total of five new CuSCN-L compounds with alkyl sulfide ligands, L=methyl sulfide (Me2S), ethyl sulfide (Et2S), isopropyl sulfide (Pri2S) or tetrahydrothiophene (THT) have been prepared and characterized. X-ray crystal structures for four of the compounds were obtained. Two compounds were collected from solutions of CuSCN in Me2S: {[Cu(SCN)(Me2S)2]}n (1a) in the form of colorless blocks and (CuSCN)(Me2S) (1b) as a white powder. Neat mixtures of CuSCN in the other alkyl sulfide ligands yielded only one product each: {[Cu(SCN)(Et2S)]}n (2); {[Cu(SCN)(Pri2S)]}n (3); and {[Cu(SCN)(THT)2]}n (4). Crystals of 2 and 4 underwent destructive phase changes at lower temperatures. Two networks types were observed: 1:2 decorated 1-D chains (1a and 4) and 1:2 decorated 1-D ladders (2 and 3). Further network formation through bridging of the organic sulfide ligands was not observed.

The effect of counteranions on the molecular structures of phosphanegold(i) cluster cations formed by polyoxometalate (POM)-mediated clusterization.

The effect of counteranions on the molecular structures of phosphanegold(i) cluster cations formed by polyoxometalate (POM)-mediated clusterization was investigated. A novel intercluster compound, [{(AuLCl)2(μ-OH)}2]3[α-PMo12O40]2·3EtOH (1-PMo12), was obtained as orange-yellow plate crystals in 12.0% yield from a 6 : 1 molar ratio reaction of the monomeric phosphanegold(i) carboxylato complex [Au(RS-pyrrld)(LCl)] (RS-Hpyrrld = RS-2-pyrrolidone-5-carboxylic acid; LCl = tris(4-chlorophenyl)phosphane) in CH2Cl2 with the free acid-form of Keggin polyoxometalate (POM), H3[α-PMo12O40]·14H2O. An EtOH/H2O (5 : 1, v/v) solvent mixture was used. The dimeric cation [{(AuLCl)2(μ-OH)}2](2+) in 1-PMo12 was in a parallel-edge arrangement that was formed by self-assembly through the inter-cationic aurophilic interactions of the μ-OH-bridged dinuclear phosphanegold(i) cation. The POM anion in 1-PMo12 was successfully exchanged with a smaller PF6(-) anion by the use of an anion-exchange resin. POM-free, colorless block crystals of [{(AuLCl)3(μ3-O)}2](PF6)2·4CH2Cl2 (2-PF6) were obtained by vapor diffusion in 14.1% yield. During the synthesis of 2-PF6, a compound with mixed counteranions (one POM and one PF6(-) anion), i.e. [{(AuLCl)4(μ4-O)}]2[α-PMo12O40]PF6 (3-PMo12PF6), was obtained in 66.4% yield. Both products were characterized by elemental analysis, TG/DTA, FT-IR, (31)P{(1)H} NMR, (1)H NMR, and X-ray crystallography. X-ray crystallography revealed that the countercation in 2-PF6 was the dimeric cation of the μ3-O-bridged tris{phosphanegold(i)} species, whereas that in 3-PMo12PF6 consisted of an unusual μ4-O-bridged tetragonal-pyramidal tetrakis{phosphanegold(i)} cation. Therefore, we concluded that the POM anion significantly contributed to the stabilization of these countercations (parallel-edged arrangement in 1-PMo12 and μ4-O-bridged tetragonal-pyramid in 3-PMo12PF6). Moreover, the previously reported yellow crystals of [{(AuLF)2(μ-OH)}2]3[PMo12O40]2·3EtOH (4-PMo12: LF = tris(4-fluoro phenyl)phosphane) were successfully converted to the POM-free crystalline OTf(-) salt [{(AuLF)2(μ-OH)}2](OTf)2·0.5Et2O (4-OTf) by the use of an anion-exchange resin. X-ray crystallography also revealed that the parallel-edge arrangement of the dimeric cation in 4-PMo12 was converted to the crossed-edge arrangement of that in 4-OTf. These results illustrate that the AuOPOM and hydrogen-bonding (C-HOPOM and O-HOPOM) interactions between the phosphanegold(i) cluster cation and the Keggin POM anion in the solid state significantly contribute to the structure, composition, and stability of the phosphane gold(i) cluster cations in 4-PMo12.

The structure and dielectric properties of ionic compounds with flexible ammonium moiety

The 3-morpholin-4-yl-propyl-ammine tetrafluoroborate (MPA+) (BF4−) (1) and the 3-morpholin-4-yl-propyl-ammine perchlorate (MPA+) (ClO4−) (2) were synthesized and separated as colorless block crystal. The (MPA+) (BF4−) undergoes a reversible phase transition at ca. 347.3 K with a hysteresis of 16.1 K. Dielectric measurement also can confirm the transition. The crystal structure determined at 300 K (monoclinic, P21/c, a = 9.978(2) Å, b = 7.5206(15) Ǻ, c = 15.058(3) Å, β = 96.99(3)°, v = 1121.6(4) Å3, z = 4) and 373 K (triclinic, P-1, a = 10.021(7) Å, b = 7.662(3) Å, c = 7.920(4) Å, α = 95.012(14)°, β = 101.67(4)°, γ = 91.48(3)°, v = 592.7(6) Å3, z = 2) reveal that this compound has two phase. The most distinct is the BF4− anion is disorder at 373 K, which is probably the driving force of the phase transition. DSC measurement, dielectric measurement and the crystal structure of the compound 2 did not change at 300 K and 100 K.

Crystal structure of 1-(4-nitrobenzylsulfinyl)-4-nitrobenzene, C13H10N2O5S

Abstract C13H10N2O5S, triclinic, P1¯ (no. 2), a = 6.9200(4) Å, b = 8.8062(5) Å, c = 11.0559(6) Å, α = 91.376(4)°, β = 95.563(4)°, γ = 94.905(3)°, V = 667.8 Å3, Z = 2, Rgt(F) = 0.0524, wRref(F2) = 0.1138, T = 296 K.

Temperature-induced isosymmetric reversible structural phase transition in [Cl2Cd(dabco-CH2Cl)]2·(μ-Cl)2

[Cl2Cd(dabco-CH2Cl)]2·(μ-Cl)2 was synthesized and separated as colorless block crystals. DSC and dielectric measurements verified that this compound underwent a reversible phase transition at ca. 157K with a hysteresis of 8.5K. The crystal structures determined at 100K (a=14.3591(10) Å, b=13.5732(9) Å, c=14.1919(10) Å, β=112.6540(10)°, V=2552.6(3) Å3, Z=4) and 293K (a=7.8952(6) Å, b=13.6562(11) Å, c=14.4039(9) Å, β=122.660(3)°, V=1307.46(17) Å3, Z=2) were all monoclinic in P21/c, showing that the phase transition was isosymmetric. The two structures in low-temperature phase (LTP) and room-temperature phase (RTP) differed distinctively in the molar ratios of configurations for the cations. Conformations of the dabco rings showed significant differences between RTP (293K) and LTP (100K) temperature phases. N–C–C–N torsion angle of one dabco ring in ligand moiety was largely twisted as a consequence of the phase transition.

Properties of precipitate of creaming down by (-)-epigallocatechin-3-O-gallate and caffeine.

An aqueous solution of equimolecular amounts of gallated catechin (-)-epigallocatechin-3-O-gallate (EGCg) and caffeine afforded a crude precipitate by creaming, which crystallized slowly for about three months at 10°C to give a colorless block crystal. The crystal was determined to be a 2 : 2 complex of EGCg and caffeine by X-ray crystallographic analysis. The 2 : 2 complex was formed with the cooperative effect of three intermolecular interactions, π-π and CH-π interactions, and intermolecular hydrogen bonds. Upon formation of the 2 : 2 complex, a caffeine molecule was captured by a hydrophobic space formed by the aromatic rings A, B, and B' rings of two EGCg molecules. Judging from the entropy value, the shift value in the chemical shift of proton signals in (1)H-NMR spectra, the NT1 value, and nuclear Overhauser effects (NOEs), it was thought that the structure of complexes of EGCg and caffeine in aqueous solution were the same as their crystal structure.

Temperature-induced reversible structural phase transition of 1-(chloromethyl)-1,4-diazoniabicyclo[2.2.2]octane bis(perchlorate)

1-(Chloromethyl)-1,4-diazoniabicyclo[2.2.2]octane bis(perchlorate), C7H15ClN22+·2ClO4−, was synthesized and separated as colorless block crystals. Differential scanning calorimetry (DSC) measurements detected that this compound underwent a reversible phase transition at ca. 143.9 K with a hysteresis width of 12.7 K, which was also confirmed by dielectric measurements. Single crystal X-ray diffraction data suggested that the compound may undergo phase transition (170 K) from a room temperature phase with a space group of Pbca (a = 13.585(4) Å, b = 12.926(4) Å, c = 16.012(5) Å, V = 2811.8(16) Å3 and Z = 8) to a low temperature one with a space group of P21/c (a = 12.659(4) Å, b = 16.121(5) Å, c = 13.197(4) Å, β = 91.231(4)°, V = 2692.5(14) Å3 and Z = 8.), and symmetry breaking occurred with an Aizu notation of mmmF2/m. The order–disorder transition of ClO4− anions and the ordering of twisting motions of the dabco ring may drive the phase transition.

Crystal structure of 4-(4-methylphenyl)-2,2'-bipyridine-6-carboxylic acid- N,N-dimethylformamide (1:0.5), C18H14N2O2·0.5C3H7NO, C39H35N5O5

Abstract C39H35N5O5, monoclinic, P21/n (no. 14), a = 11.576(1) Å, b = 13.220(2) Å, c = 11.931(1) Å, β = 115.075(2)°, V = 1653.9 Å3, Z = 2, Rgt(F) = 0.0502, wRref(F2) = 0.1567, T = 298 K.