Search

In addition to the appealing semiconducting properties displayed by layered SnII or PbII halidometallates, intriguing phase-transition-induced properties, such as dielectric and ferroelectric properties, have recently been found by us in (benzylammonium)2PbCl4 and (cyclohexylammonium)2PbBr4–4xI4x (x = 0–1). The simple molecular structures of the layered compounds allow further chemical design for the modification of the physical properties. Thus, we extended the study to layered compounds templated by structurally similar organic cations to achieve future functions. Here, we report the design of a layered perovskite templated by cyclohexylmethylammonium cations, namely, bis[(cyclohexylmethyl)ammonium] tetrabromidolead(II). We found that this compound exhibits not only photoluminescence with a remarkably high efficiency (quantum yield = 21 %) but also interesting phase-transition-related physical properties, such as striking dielectric responses. These results reveal the great application potential of organic–inorganic hybrid compounds in the field of phase-transition multifunctional materials. More interesting phase-transition crystals are expected to be tailored in the future by taking advantage of the richness of layered perovskites.

Dysregulation of miR-378 has been found in diverse types of tumors as well as in leukemia. The role of miR-378 in chronic myeloid leukemia (CML) remains unclear. The aim of the study was to reveal the potential effects of miR-378 in the pathological process and progress in CML. Our results showed general level of miR-378 was significant higher in CML patients compared to controls. Overexpression of miR-378 dramatically promoted cell proliferation and drug-resistance. Additionally, apoptosis was inhibited in cells transfected with miR-378. More and bigger stem cell sphere formation was observed in miR-378 transfected cells. Furthermore, enhanced expression of miR-378 was associated with upregulation of stem-cell makers OCT4 and c-Myc. Further study validated that miR-378 inhibited the expression of FUS1. Our research demonstrated the oncogenic nature of miR-378 in CML, and might contribute to the progress of CML.

Compounds showing multi-switchable properties represent a type of new multi-stimuli responsive material that would find some promising applications. In this study, an organic–inorganic hybrid crystal (TA)2{(H3O)[Co(CN)6]} (1, TA = thiazolium) with a two-dimensional network constructed by the [Co(CN)6]3− anions and the hydronium cations via hydrogen-bonds was synthesized. 1 undergoes a structural phase transition between two polar phases at about 230 K due to the order–disorder transition of the TA cation. Detailed characterization, including variable-temperature structural analyses, differential scanning calorimetry (DSC), second-harmonic generation (SHG), dielectric and pyroelectric measurements, indicate that the local structural changes trigger multi-switchable properties of the dielectric constant, SHG and polarization. The discovery of multi-switchable responses based on polar compounds might provide a good strategy to search for new promising materials for smart switches.

A bistable optical–electrical duple switch belongs to a class of highly satisfying intelligent materials that can transform optical and electrical responses simultaneously in one device. A perovskite-type high-temperature phase transition compound with one-dimensional chain-like crystal structure, ([(CH3)3PCH2OCH3][PbBr3], 1), displays remarkable bistable photoluminescent-dielectric duple switching behaviors. The noteworthy order–disorder transition of the phosphonium cation and the motions of anions contribute to the phase transition, leading to the space group P21/c at a low temperature phase to C2/c at a high temperature phase. 1 exhibits a prominent step-like dielectric anomaly at 401.0 K and demonstrates novel optical properties with a band gap of 3.54 eV. The photoluminescence intensity suddenly declines from 398 K to 408 K, which may be attributed to the occurrence of phase transition. The electron cloud distributions of the frontier orbital in compound 1 have been calculated using a DFT program.

The present study was aimed to investigate SCIN expression as well as promoter methylation and further explore their clinical relevance in acute myeloid leukemia (AML) patients. Real-time quantitative PCR was carried out to detect the expression level of SCIN in 119 AML patients and 37 healthy controls. Real-time quantitative methylation-specific PCR and bisulfite sequencing PCR were carried out to detect SCIN promoter methylation levels in 103 AML patients and 29 controls. As compared with controls, the level of SCIN transcript was significantly down-regulated in AML patients (P = 0.001), and the level of methylated SCIN promoter was significantly higher in AML patients (P = 0.001). Moreover, the level of promoter methylation was weakly negatively correlated with SCIN expression in AML patients (R = -0.265, P = 0.027). Demethylation of SCIN promoter by 5-aza-2'-deoxycytidine could restore its expression in leukemic cell line THP1. The age of SCINlow patients was significantly higher and C/EBPA mutation was significantly less than SCINhigh patients (P = 0.039 and 0.038, respectively). Moreover, the rate of complete remission (CR) of SCINlow patients was significantly lower than SCINhigh patients (P = 0.009). Kaplan-Meier analysis showed that low SCIN expression was associated with shorter overall survival (P = 0.036). Cox regression analysis demonstrated low SCIN expression was an independent poor prognostic factor (P = 0.047). Furthermore, SCIN expression was restored in those patients who achieved CR after induction therapy (P = 0.003). These findings indicate that decreased SCIN expression associated with its promoter methylation is a valuable biomarker for predicting adverse prognosis in AML patients.

An investigation into the reaction of cyanomethyltriethylammonium (CTA) halide salts with HgCl2 afforded into [(CTA)+(Hg3Cl4Br3)−]n (1) and [(CTA)+]2 (Hg2Cl6)2 − (2). The two compounds have same propeller-like quaternary ammonium cations. The anion in compound 1 was a novel two-dimensional architecture and in compound 2 was an isolated centrosymmetrical dimer. Some C H⋯N and C H⋯X (X = Cl, Br) hydrogen bonds have been found in the two compounds, which assemble the cations and anions into a three-dimensional network. Variable-temperature dielectric properties have been studied for them. There was no dielectric anomaly in 1, whereas an obvious reversible dielectric anomaly was found in 2. The differential scanning calorimetric (DSC) and variable-temperature powder XRD properties have been studied for 2. The combined results showed that compound 2 has a solid–solid phase transition from crystalline to non-crystalline.

The triethylbenzylammonium perchlorate, C13H22N+·ClO4− was synthesized and separated as block colorless crystals. DSC measurement detected that this compound undergoes a reversible phase transition at ca. 196 K with a hysteresis of 18 K width. Dielectric measurements also confirm the transition. The crystal structures determined at 93(2) K (a = 12.114(4)A, b = 14.320(5)A, c = 16.418(6)A, V = 2848.0(17)A3, Z = 8) and 291(2) K (a = 8.3891(17)A, b = 12.300(1)A, c = 14.513(1)A, V = 1497.5(3) A3, Z = 4) show that the phase transition is a type of isosymmetric change with the space group of Pbca (No. 61) in the low-temperature phase (LTP) to the space group of Pbcm (No. 57) in the room-temperature phase (RTP). The distinct difference between the LTP and the RTP structure is the different orientation for the anions and the H-bond interactions between the perchlorate anions and triethylbenzylammonium cations. Hydrogen bond interactions may play a role in the phase transition as shown by the changes in the hydrogen bonding pattern as the temperature decreased. The order–disorder type transition of the anions is probably the driving force of the phase transition.

Bis(triethylbenzylammonium) tetrachlorocobaltate(II), (C13H22N+)2·CoCl42– was synthesized and separated as blue block crystals. DSC measurement detected that this compound undergoes a reversible phase transition at ca. 336 K with a hysteresis of 10 K. Dielectric measurements confirm the transition at ca. 336 K. The crystal structures determined at 291(2) K (a = 16.72 A, b = 9.32 A, c = 20.36 A, β = 106.90°, V = 3035.1 A3, Z = 4) and 353(2) K (a = 20.16 A, b = 9.35 A, c = 34.29 A, β = 108.61°, V = 6126.7 A3, Z = 8) show that the phase transition is a type of isostructural change with the same space group P21/c (No. 14). The most distinct difference between the two structures in high-temperature phase (HTP) and room-temperature phase (RTP) is the different molar ratios of configurations for the cations. The rotation of ethyl groups bonding with the N atom between the propeller-like configuration and butterfly-like configuration is probably the driving force to the phase transition. Non-classic hydrogen bonding effect on the transition was shown to be negligible.

A new 1:1 inclusion complex, 4-ethylanilinium tetrafluoroborate–1,4,7,10,13,16–hexaoxacyclooctadecane(1/1), formed between 18-crown[6] and 4-ethylanilinium tetrafluoroborate undergoes a reversible ferroelastic phase transition at ca. 180 K, as evidenced by DSC measurement with a hysteresis of 1.3 K and the variable-temperature crystal structure determinations. The single crystal X-ray diffraction data obtained at 113 and 298 K suggests that the phase transition undergoes from a room temperature paraelectric phase with a space group of P nma to a low temperature paraelectric one with a space group of P 2 1 /c, the symmetry breaking occurs with an Aizu notation of mmmF2/m . The phase transition seems to be associated with slight swing of the ethyl group of the cation brought about by reduced strength of the hydrogen bonds at elevated temperature.

Treatment of o-carborane, n-butyllithium, selenium, and [(p-cymene)RuCl2]2 under argon leads to the complexes (p-cymene)Ru(Se2C2B10H10) (1), [(p-cymene)RuCl(Se−SeC2B10H11)][(p-cymene)Ru(Se2C2B10H10...

The reaction of the 16e half-sandwich complex CpCo[S2C2B10H10] (1S) with phenylacetylene at ambient temperature led to 2S, 3S, and 4S. In 3S the alkyne is twofold inserted into one of the Co−S bond...

A new organic-inorganic hybrid switchable and tunable dielectric compound, [(CH3)4P]4[Mn(SCN)6] (1), exhibits three distinct dielectric states above room temperature and undergoes two reversible solid-state phase transitions, including a structural phase transition at 330 K and a ferroelastic phase transition with the Aizu notation of mmmF2/m at 352 K. The variable-temperature structural analyses disclose that the origin of the phase transitions and dielectric anomalies can be ascribed to the reorientation or motion of both the [(CH3)4P](+) cations and [Mn(SCN)6](4-) anions in solid-state crystals.

The crystal structure of the title novel one-dimensionalABX3-type organic–inorganic hybrid complex {(C10H16N)[CdCl3]}n, (I), consists of benzyltrimethylammonium (Me3BzN+) cations and one-dimensional anionic {[Cd(μ-Cl)3]−}∞chains. Each CdIIcentre is hexacoordinated by bridging chloride ligands, giving a slightly distorted octahedral Cd(μ-Cl)6arrangement. The octahedra are linked by two opposite shared faces, giving rise to an almost perfectly linear anionic {[Cd(μ-Cl)3]−}∞chain in thea-axis direction. Me3BzN+cations located in the inter-chain spaces balance the charge. Noncovalent static attracting forces (Coulombic and van der Waals forces) and nonclassical C—H...Cl hydrogen-bond interactions stabilize the crystal structure.

[(p-cymene)RuCl2]2 reacts with 1,2-dicarba-closo-dodecaborane-1,2-dithiolate in the presence of excess sulfur to generate the first dinuclear complex, (p-cymene)Ru(μ-S2)Ru(S2C2B10H10)2 (1). Treatment of 1 with alkynes affords the addition complexes (p-cymene)Ru(μ-S2)Ru(S2C2B10H10)2(R1CCR2) (R1 = H (CO2Me), R2 = CO2Me (H), 2a (2b); R1 = C6H5, R2 = H, 3b; R1 = R2 = CO2Me, 4).

A series of ruthenium complexes cis-[Ru(bpy)2(L–L)] derived from cis-Ru(bpy)2 Cl2 and nicotinoyl or isonicotinoyl hydrazones have been synthesized, where bpy=2,2′-bipyridine′, and L–L=nicotinoyl or isonicotinoyl hydrazones, p-dimethylaminobenzaldehyde nicotinoylhydrazone (PDNH), p-dimethylaminobenzaldehyde isonicotinoylhydrazone (PDINH), p-methoxybenzaldehyde nicotinoylhydrazone (PMNH) and, p-methoxybenzaldehyde␣isonicotinoylhydrazone (PMINH). The spectra of the complexes reveal that the ligands PMNH, PMINH and PDINH were coordinated to ruthenium in keto form, while PDNH, PNNH and PNINH were coordinated to the ruthenium in the enol form. Single crystal structure analysis of cis-Ru(bpy)2(PDNH)(ClO4)2 established that the coordination geometry about ruthenium is distorted octahedral with four nitrogen atoms from bipyridine molecules, the enol oxygen atom and azomethine nitrogen atom from PDNH.

The structure of the title compound, {(C5H5ClN)2[Hg3Cl8]}n, consists of 4-chloropyridinium cations and one-dimensional [Hg3Cl8]2−anion chains. There are two coordination environments for HgIIin the inorganic chain. The first is a distorted tetrahedral geometry made up of an HgCl2unit with two Cl−anion bridges, while the second is an octahedral coordination geometry consisting of an HgCl2unit and four chloride-anion bridges. This gives rise to a novel three-layer centrosymmetric polymer. Finally, the three-dimensional network comes about through the many C—H...Cl and N—H...Cl hydrogen bonds that link the organic and inorganic layers.

In the crystal structure of the title molecular salt, C8H12N+·C7H7O3S−, the 4-ethylanilinium cations and 4-methylbenzenesulfonate anions are linked into chains parallel to the b axis by intermolecular N—H...O hydrogen bonds.

The asymmetric unit of the title compound, C15H15N3O2S, contains two independent molecules corresponding to the R and S enantiomers. The dihydropyrimidinone rings adopt a flattened boat conformation. One of the ethyl groups is disordered over two orientations with occupancy factors of 0.700 (7) and 0.300 (7). In the crystal structure, molecules are linked by intermolecular N—H...O hydrogen-bonding interactions into one-dimensional chains along the c-axis direction. The chains are further connected by N—H...S hydrogen bonds, forming a three-dimensional network.

In the title compound, C25H18O2S·C4H8O2, there are intermolecular O—H...O hydrogen bonds between the main molecule and the solvent molecule. The thiophene ring is oriented at dihedral angles of 70.87 (7) and 75.36 (4)° with respect to the mean planes of the two naphthyl ring systems.

Two new ruthenium(II) arene complexes, 2a (C(24)H(34)B(10)FeRuS(2)) and 2b (C(15)H(26)B(10)O(2)RuS(2)), bearing a carborane unit and other different functional groups were synthesized, and their cytostatic effects on cancerous cells were evaluated. Our observations illustrate that a structural change from a ferrocene unit to a carboxyl group could lead to high selectivity toward cancer cells and facilitate the efficient inhibition of the proliferation of target cells, indicating that the tuning of the overall properties of the ruthenium(II) arene complex by appropriate ligand tagging is critical to creating a selective antineoplastic agent.

The molecule of the title compound, C9H8N4S, adopts an E configuration about both the C=N and C—NH bonds. In the crystal structure, adjacent molecules are linked by intermolecular N—H...S hydrogen-bonding interactions, forming chains running parallel to the b axis.

The addition reactions of the 16e half-sandwich complexes (p-cymene)M(S2C2B10H10) (1S, M = Ru; 2S, M = Os) and Cp*Ir(E2C2B10H10) (3S, E = S; 3Se, E = Se) with ethynylferrocene lead selectively to the 18e complexes (p-cymene)Ru(S2C2B10H9)(H2CCFc) (Fc = ferrocenyl) (4S), (p-cymene)Os(S2C2B10H9)(H2CCFc) (5S), Cp*Ir(S2C2B10H9)(H2CCFc) (6S) and Cp*Ir(Se2C2B10H9)(H2CCFc) (6Se), in which the alkyne is regio- and stereoselectively inserted into one of the M–E bonds that may further lead to metal-induced B–H activation, hydrogen atom transfer from the carboranevia the metal center to the inserted alkyne, and the generation of a M–B bond. In all complexes the S-η2-(Fc)C–C and C–B(M) moieties occupy a cisoid position. The four new complexes are characterized by IR, MS, NMR spectroscopy and microanalysis, and the X-ray structural analysis of 4S is performed. 4S was observed to promote the uptake of anticancer drug daunorubicin in drug-resistant leukemia K562 cells.

Treatment of 1a and 1b with phenylacetylene, 1,4-diethynylbenzene, and ethynylferrocene affords addition complexes, (p-cymene)Ru(mu-E2)Ru(S2C2B10H10)2(R1C=CR2), (R1 = Ph (H), R2 = H (Ph), 2a, 2b, 3a, 3b; R1 = -Ph-C[triple bond]CH (H), R2 = H (-Ph-C[triple bond]CH), 4a, 4b, 5a, 5b; R1 = Fc (H), R2 = H (Fc), 6a, 6b, 7a, 7b). Alkyne addition occurs at sulfur atoms of two different chelating 1,2-dicarba-closo-dodecaborane-1,2-dithiolate ligands that leads to a change of 16e Ru(IV) in 1a and 1b to 18e Ru(II) in 2a-7a and 2b-7b, respectively. Moreover, the reaction of 1a with ethynylferrocene produces an unprecedented tetranuclear mixed-valent Ru(IV)Ru(II)3S12 cluster (8a) consisting of two 1a and one ethynylferrocene through the cleavage and generation of Ru-S, S-S, and C-S bonds. The complexes were characterized by IR, MS, and NMR spectroscopy and microanalysis. X-ray structural analyses were performed on 1b, 2a, 3b, 5a, 5b, 7b, and 8a.

In the title molecular salt, (C10H16N)2[CuBr4], the CuII ion adopts a squashed tetrahedral geometry with Br—Cu—Br angles varying between 99.29 (3) and 132.53 (3)°. In the crystal, the components are linked by C—H...Br interactions, thereby generating a three-dimensional network.

The asymmetric unit of the title compound, C(8)H(12)N(+)·ClO(4) (-.)C(12)H(24)O(6), contains one half of the cationic [(C(2)H(5)-C(6)H(4)-NH(3))(18-crown-6)](+) moiety and one half of the ClO(4) (-) anion. Two O atoms of the crown ether, four C atoms and the N atom of the ethylanilinium unit and the Cl and two O atoms of the anion lie on a mirror plane. In the crystal structure, the -NH(3) (+) group lies in the 18-crown-6 ring, forming a supra-molecular rotator-stator-like structure linked by intra-molecular N-H⋯O hydrogen bonds. The six O atoms of the crown ether lie approximately in a plane, the mean deviation being 0.1771 (3) Å; the N atom lies approximately 0.855 (3) Å from the centroid of the crown ether ring.

In the crystal structure of the title compound, C8H12N+·C3H3O4−, the hydrogen malonate anions are linked into infinite chains parallel to the b axis by intermolecular O—H...O hydrogen bonds of the type COO−...HO2C in a head-to-tail fashion. The 4-ethylanilinium cations link adjacent anion chains by intermolecular N—H...O hydrogen bonds into a two-dimensional network parallel to the b and c axes.

In the crystal structure of the title compound, NH(4) (+)·PF(6) (-)·C(12)H(24)O(6), the cation is situated in the 18-crown-6 ring, forming a supra-molecular rotator-stator-like structure held by N-H⋯O hydrogen bonds. The six O atoms of the crown ether lie approximately in a plane [mean deviation 0.2129 (3) Å]; the N atom is displaced by 0.864 (3)Å from the centroid of the 18-crown-6 ring. The slightly distorted tetra-hedral cations further inter-act with the slightly distorted octa-hedral anions via inter-molecular N-H⋯F hydrogen bonds.

The thio­semicarbazone mol­ecule in C10H12N6S2·2C3H7NO has \overline 1 symmetry. The thio­semicarbazone moiety and the benzene ring are essentially coplanar, with mean and maximum deviations of 0.03 and 0.11 A, respectively. The di­methyl­form­amide mol­ecules bridge the thio­semicarbazone moieties, forming two-dimensional sheets through N—H⋯O hydrogen bonds.

The title molecule, C14H19NO6, was synthesized by the reaction of glyoxylic acid, ethyl acetoacetate and NH4HCO3. In the crystal structure, the dihydropyridine ring adopts an asymmetric boat-type conformation with the C atom bearing the carboxyl group showing a signficantly larger deviation [0.325 (2) Å] from the base plane then the N atom [0.137 (2) Å]. One of the ethyl groups is disordered over two positions with occupancies of 0.741 (10) and 0.259 (10). The crystal is stabilized by strong intermolecular hydrogen bonds. N—H...O interactions form infinite chains in the a direction. O—H...O hydrogen bonds form typical carboxylic acid dimers, which link the N—H...O chains into a ladder-type double chain.

The title compound, C17H12N2O, was synthesized by an ether synthesis from quinolin-6-ol and 4-(bromomethyl)benzonitrile. The phenyl ring of the benzonitrile group makes a dihedral angle of 47.52 (6)° with the plane of the quinoline fragment. The crystal structure is stabilized by intermolecular C—H...π interactions between a benzene H atom of the benzonitrile group and the benzene ring of the quinoline fragment. In addition, the crystal structure also exhibits a weak intermolecular C—H...N hydrogen bond.

The aromatic mol-ecule of the title compound, C(20)H(14)N(4)·2C(3)H(7)NO, occupies a special position on an inversion center. The benzimidazole unit (planar to within 0.008 Å) forms a dihedral angle of 9.1 (2)° with the central benzene ring. The benzimidazole H atom participates in a hydrogen bond with the dimethyl-formamide solvent molecule, thus giving rise to the title 1:2 aggregate. These aggregates are further linked in the crystal structure by aromatic π-π stacking inter-actions [centroid-centroid distance = 6.356 (2) Å].

In the title compound, C(13)H(9)N(3)O(2)·C(3)H(7)NO, the benzimidazole ring system and the benzene ring are essentially coplanar, forming a dihedral angle of 0.86 (5)°. The crystal packing is stabilized by an inter-molecular N-H⋯O hydrogen bond and a π-π stacking inter-action with a centroid-centroid separation of 3.685 (4) Å.

The mol-ecule of the title compound, C(17)H(10)N(4)O, has crystallographically imposed C(2) symmetry. The urea group and the benzene ring are nearly coplanar, the dihedral angle between them being 4.15 (7)°. The crystal packing is stabilized by aromatic π-π stacking inter-actions, with a centroid-to-centroid separation of 3.833 (4) Å.

The molecule of the title compound, C8H8N4O2S, adopts an E configuration about both the C—N bonds. In the crystal structure, adjacent molecules are linked by intermolecular N—H...S hydrogen-bonding interactions, forming chains running parallel to the b axis.