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The long non-coding RNA (lncRNA) urothelial carcinoma associated 1 (UCA1) is an oncogenic lncRNA in bladder cancer, and its upregulation is associated with enhanced cell invasion. However, the underlying mechanism remains to be elucidated. The present study demonstrated that UCA1 was positively associated with cell invasion ability and promoted epithelial-mesenchymal transition (EMT) of bladder cancer cells by inducing high mobility group box 1 (HMGB1). Furthermore, bioinformatics and luciferase reporter assays demonstrated binding sites of the tumor suppressive miR-143 within UCA1 and the 3'untranslated region of HMGB1. UCA1 negatively regulated miR-143 expression in a dose-dependent manner in bladder cancer cells. In addition, UCA1 and HMGB1 were upregulated and miR-143 was downregulated in bladder cancer specimens. Overall, the data suggested that UCA1 may promote the invasion and EMT of bladder cancer cells by regulating the miR-143/HMGB1 pathway, which exhibits an important regulatory role in the pathology of bladder cancer. [ABSTRACT FROM AUTHOR]

By using the activation technique, the cross section for the reaction 165Ho(n,2n) 164Ho was measured at two neutron energies of 13.5 and 14.8 MeV to resolve inconsistencies in the existing database. The 94- and 91.39-keV γ rays from the decay of the 164Hom isomeric state and 164Hog ground state, respectively, were recorded with a high-resolution high-purity germanium detector. The monoenergetic neutron beam was produced via the ³H(d,n) 4He reaction. The cross sections also were estimated with the talys-1.4 nuclear model code that uses different level-density options at neutron energies that vary from the reaction threshold to 20 MeV. Results are also discussed and are compared with some corresponding values found in the literature. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the biological function of HOXB5 in human bladder cancer and explore whether the HOXB5 3'-UTR SNP (1010A/G), which is located within the microRNA-7 binding site, was correlated with clinical features of bladder cancer. Methods: Expression of HOXB5 in 35 human bladder cancer tissues and 8 cell lines were examined using real-time PCR and immunohistochemistry. Next, we explored the biological function of HOXB5 in vitro using cell proliferation, migration and colony formation assays. Using bioinformatics, a SNP (1010A/G) was found located within the microRNA-7 binding site in the 3'-UTR of HOXB5. Real-time PCR was used to test HOXB5 expression affected by different alleles. Finally, multivariate logistic regression analysis was used to determine the relationship between SNP (1010A/G) frequency and clinical features in 391 cases. Results: HOXB5 was frequently over-expressed both in bladder cancer tissues and cell lines. Inhibition of HOXB5 suppressed the oncogenic function of cancer cells. Next, we demonstrated that a SNP (1010A/G), located within the microRNA-7 binding site in the 3'-UTR of HOXB5, could affect HOXB5 expression in bladder cancer mainly by differential binding activity of microRNA-7 and SNP-related mRNA stability. Finally, we also showed the frequency of 1010G genotype was higher in cancer group compared to normal controls and correlated with the risk of high grade and high stage. Conclusion: HOXB5 is overexpressed in bladder cancer. A miRNA-binding SNP (1010A/G) located within 3'-UTR of HOXB5 is associated with gene expression and may be a promising prognostic factor for bladder cancer. [ABSTRACT FROM AUTHOR]

Cross-sections for (n,p), (n,α), (n,n′α), (n,t) and (n,2p) reactions have been measured on 139La isotope at the neutron energy 14.8 MeV using the activation technique in combination with high-resolution gamma-ray spectroscopy. Neutrons were produced via the 3H(d,n)4He reaction using a solid tritium–titanium target. The neutron fluences were determined using the monitor reaction 27Al(n,α)24Na. The neutron energy in this measurement was determined by cross section ratios for the 90Zr(n,2n)89m+gZr and 93Nb(n,2n)92mNb reactions. Data are reported for the following reactions: 139La(n,p)139Ba, 139La(n,α)136Cs, 139La(n,n′α)135mCs, 139La (n,t)137mBa, and 139La(n,2p)138Cs. The cross sections were discussed and compared with experimental data found in the literature, and with the comprehensive evaluation data in ENDF/B-VII.0, JENDL-3.3, JEFF-3.1/A, and TENDL-2008 libraries. [ABSTRACT FROM AUTHOR]

Reduced layered M(C4H4N2)V4O10 ((I, M = Co; II, M = Ni; III, M = Zn); C4H4N2 = pyrazine, pyz) hybrid solids were synthesized via hydrothermal reactions at 200–230 °C, and their structures determined by single-crystal X-ray diffraction (Cmcm, No. 63, Z= 4; a = 14.311(2), 14.2372(4), 14.425(1) A; b = 6.997(1), 6.9008(2), 6.9702-(6) Å; and c = 11.4990(8), 11.5102(3), 11.479(1) Å; for I, II, and III, respectively). All three solids are isostructural and contain V4O102- layers condensed from edge- and corner-shared VO5 square pyramids. A single symmetry-unique V atom is reduced by ½ electron (on average) and bonds via its apical oxygen atom to interlayer M(pyz)2+ chains. Magnetic susceptibility measurements show a strong temperature dependence and a Curie constant that is consistent with two randomly localized spins per V4O102- formula for III. Further, the unusual discovery of a remarkably well-defined transition to a singlet ground state, as well as formation of a spin gap, is found for III at 22(1) K. The temperature-dependent electrical conductivities show apparent activation energies of 0.36 (I), 0.46 (II), and 0.59 eV (III). During heating cycles in flowing N2, the samples exhibit weight losses corresponding to the removal of predominantly pyrazine, pyrazine fragments, and CO2 via reaction of pyrazine with the vanadate layer. The complete removal of pyrazine without loss of crystallinity is found for well-ground samples of I and III. The SEM images of I and II after heating at 400–500 °C show relatively intact crystals, but at 600 °C further structural collapse results in the formation of macropores at the surfaces. [ABSTRACT FROM AUTHOR]

A microporous and an open framework structure, [Cu2(pzc)2(H2O)2ReO4] (I) and [Cu(pzc)(H2O)ReO4]·2H20 (II) (pzc = 2-pyrazinecarboxylate), respectively, have been prepared using hydrothermal methods and characterized using IR, TGA, and X-ray diffraction (I Pnma, No. 62, Z= 4, a = 7.4949(9) Å, b = 24.975(3) Å, c = 9.141(1) Å; II P21/c, No. 14, Z = 4, a = 8.5878(9) Å, b = 12.920(1) Å, c = 9.741(1) Åβ = 92.830(2)°). I and II crystallize as red and blue solids, respectively, and each contains chains constructed from alternating Cu(pzc)2/ReO4 oxide-bridged metal sites. The bidentate pzc ligand further bridges each -Cu-O-Re-O- chain to adjacent chains, via the Cu sites, to form a 3D net in I, with ellipsoidal channels that are ∼3.3–4.7 Å, × 12.5 Å, and in II, stacked layers of square nets with H2O-filled cavities that are ∼4.4 × 5.1 Å. Local ReO4- groups, a component of common oxidation catalysts, are directed at the channels and cavities of each structure, respectively. Thermogravimetric analysis indicates that I loses up to 64% of its H2O content before decomposition at 225°C, while II loses ∼100% of its H2O content by 265°C. [ABSTRACT FROM AUTHOR]

A novel cobalt(II)-organic framework, [Co2(OH)(3,4-PBC)3]n (I), has been acquired by the reaction of CoO with an unsymmetrical pyridylbenzoate ligand, 3-pyrid-4-ylbenzoic acid (3,4-PBC). Single-cristal X-ray diffraction studies reveal that it is comprised of [CoII4(μ3-OH)2] clusters linked by the unsymmetrical ligand 3,4- PBC, forming a novel helical double-layered metal-organic architecture. A significant overall antiferromagnetic behavior has been observed for this compound. [ABSTRACT FROM AUTHOR]

A unique noninterpenetrated 2D bilayer cobalt(II)-organic framework, [{Co(dpe)(NO[sub 2]-BDC)}·0.5(dpe)],·nH[sub 2]O (1), possessing nanoscale rectangular channels that clathrate large organic molecules, has been hydrothermally synthesized by reaction of cobalt(II) salt with 5-nitro-1,3-benzenedicarboxylic acid (NO[sub 2]-H[sub 2]BDC) and 1,2-bis(4-pyridyl)ethylene (dpe). [ABSTRACT FROM AUTHOR]

Circularly polarized light (CPL) detection has sparked the booming interest for versatile chiral-optoelectronic and spintronic devices. For practical device applications, a large asymmetry factor is required to distinguish the handedness of incent light. However, for most chiral CPL active candidates, the difference in optical density or absorption anisotropy is quite subtle under CPL illumination, resulting in a relatively low asymmetry factor (usually ≤ 0.2). Up to date, it remains extremely challenging to achieve CPL response in the achiral crystals. Inch-size achiral perovskite-type crystals of (IBA)2(EA)2Pb3I10 (IBA = 4-isopropylbenzylammonium, EA = ethylammonium), which holds a promise to distinguish CPL with a large asymmetry factor up to ≈0.56 at 405 nm is presented here. This figure-of-merit is comparable or even superior than most of those chiral counterparts. Further First-principles calculations disclose such CPL-active behaviors of (IBA)2(EA)2Pb3I10 are associated with the splitting of its band spin-degeneracy, induced by the breaking of inversion symmetry and spin-orbital coupling (SOC) effects. As far as it is known, the structural origin of CPL-activities of (IBA)2(EA)2Pb3I10 is completely distinctive from the conventional chiral family, which paves a promising pathway to explore new candidates toward high-performance CPL detection. [ABSTRACT FROM AUTHOR]

High-performance bi-functional materials are in urgent demand for the next-generation integrated optical devices. In this work, we successfully synthesized the first tricyanomelaminate with bi-functional optical responses, namely Cs3C6N9·H2O (I), from its analogue Na3C6N9·3H2O by a facile ion exchange method. In contrast to Na3C6N9·3H2O, I realizes an optimal arrangement of π-conjugated (C6N9)3− anion groups in its crystal structure. As a result, the second-order nonlinear optical (NLO) response is greatly enhanced from nearly zero of Na3C6N9·3H2O to ∼9.8 × KH2PO4 of I. Furthermore, I exhibits a giant linear optical anisotropic response (i.e. birefringence) of 0.52 at the wavelength of 550 nm. Both responses are almost the largest among the inorganic compounds of π-conjugated rings, which indicates that I has great potential as a bi-functional optical crystal. Structural and theoretical analyses reveal the microscopic origin of excellent optical properties. This work would attract a lot of interest to the persistently neglected potential of tricyanomelaminates as linear optical and NLO crystals. [ABSTRACT FROM AUTHOR]

The (n,2n) cross sections and their isomeric ratios (σm/σg) in the 13-15 MeV neutron energy range have been measured for 196,198Hg by an activation and offline γ-ray spectrometric technique using the Pd-300 Neutron Generator at the Chinese Academy of Engineering Physics (CAEP). Natural Hg samples and Nb monitor foils were activated jointly to determine the reaction cross section and the incident neutron flux. The neutrons were produced via the ³H(d,n)4He reaction. The pure cross section of the ground state was derived from the absolute cross section of the metastable state and the residual nuclear decay analysis. The 196Hg(n,2n)195Hgm,g and 198Hg(n,2n)197Hgm,g reaction excitation functions and their isomeric cross-section ratios were also calculated theoretically using the talys-1.8 code with different level density models. Results are discussed and compared with corresponding literature data. [ABSTRACT FROM AUTHOR]

The 153Eu(n,2n)152Eum1,m2,g cross section was measured by means of the activation technique at three neutron energies in the range 13-15 MeV. The quasimonoenergetic neutron beam was formed via the ³H(d,n)4He reaction, in the Pd-300 Neutron Generator at the Chinese Academy of Engineering Physics (CAEP). The activities induced in the reaction products were measured using high-resolution γ-ray spectroscopy. The cross section of the population of the second high-spin (8-) isomeric state was measured along with the reaction cross section populating both the ground (3-) and the first isomeric state (0-). Cross sections were also evaluated theoretically using the numerical code TALYS-1.8, with different level density options at neutron energies varying from the reaction threshold to 20 MeV. Results are discussed and compared with the corresponding literature. [ABSTRACT FROM AUTHOR]

Gelation transitions in a colloidal system, where there is a strong reversible attraction between small, soft microgels and large, hard spheres, are systematically investigated. Different from widely studied depletion attraction systems that are also two-component systems, the strong attraction between small solvent and large solute particles introduces bridging attractions between large solute particles. We conclusively demonstrate that the formation of physical gels at the intermediate volume fraction of our bridging attraction system follows more closely with the percolation line that is in stark contrast to what is observed in depletion attraction systems, where the gelation transition is related with the frustrated spinodal separation, not a purely kinetic phenomenon. Our results introduce a different way to control gelation transitions in spherical colloidal systems, and imply that people need to be prudent when generalizing the physical picture of the gelation transitions obtained from systems with different origins of effective attraction as the solvent molecule may play important roles. [ABSTRACT FROM AUTHOR]

The article studies the gas sorption properties of a porous rare earth metal organic framework synthesized by solvothermal reaction. The authors constructed and investigated a highly stable porous lanthanide metal organic framework for hydrogen storage. The framework, the authors add, demonstrated highly selective sorption behaviors of hydrogen over nitrogen gas molecules.

Nonlinear optical (NLO) crystals are the vital components of laser science and technology, as they can convert lasers in common wavelengths into new wavelength bands for ultraviolet (UV), IR, and even terahertz laser output. Known UV NLO crystals mainly focus on crystals containing cations, but covalent crystals have rarely been reported. Here we report two covalent NLO crystals, B2O3 I and B2O3 II. According to the first-principles calculations, B2O3 I and II have extremely short absorption edges of about 134 nm and 141 nm, large NLO coefficients of d22=1.38 pm/V and d24= 0.702 pm/V, as well as sufficient birefringences of 0.037 and 0.031, respectively. Notably, the absorption edges are almost the shortest among NLO crystals. Meanwhile, the NLO coefficients are evidently larger than that of another wellknown covalent NLO crystal α-SiO2 and are comparable to those of the commercial UV NLO crystal LiBO3 with Li+ cation. Furthermore, the birefringences are significantly larger than that of α-SiO2, which are favorable to the phase matching for both crystals. These results reveal that B2O3 I and B2O3 II are excellent candidates for UV NLO applications. In-depth calculations are carried out to reveal the origin of excellent NLO properties. These covalent crystals provide a new direction for the research of UV NLO crystals. [ABSTRACT FROM AUTHOR]

A beryllium-free nonlinear optical (NLO) crystal K3Ba3Li2Al4B6O20F (KBLABF) with sizes up to 18 × 13 × 8 mm3 was successfully grown by the top-seeded solution growth method using LiOH-H3BO3–BaF2 flux. The key limiting factors on the crystal morphologies and sizes were carefully analyzed. Meanwhile, by using the minimum deviation technique, the refractive index dispersion was measured and fitted well by the Sellmeier equations. The results suggest that KBLABF is a negative uniaxial crystal with moderate birefringence of 0.06050–0.06834 at a wavelength range from 363 to 852.1 nm. Furthermore, the type-I phase matching range for fundamental (second harmonic) light is down to 486 (243 nm) in theory, which indicates that KBLABF crystal could achieve 532 and 266 nm light generation by direct second-harmonic generation. As compared with the famous NLO crystals β-BaB2O4 and CsLiB6O10, KBLABF crystal exhibits a smaller walk-off angle and larger acceptance angle at the wavelength of 532 nm while having a comparable short absorption edge, sufficient birefringence, and moderate NLO response. Furthermore, in contrast to highly hygroscopic CsLiB6O10, it is nonhygroscopic. These attributes make KBLABF a promising candidate for practical applications in UV light generation. [ABSTRACT FROM AUTHOR]

A new Sn-based halide compound, Rb4Sn3Cl2Br8, is synthesized by hydrothermal method. This compound crystallizes in orthorhombic noncentrosymmetric space group of Cmc21, and the structure is composed of one-dimensional [Sn4Cl2Br8]¹∞ chains elongated in parallel to the a-axis. Interestingly, in the [Sn4Cl2Br8]¹∞ chains the [SnBr5] and [SnClBr4] groups hold pyramidal configurations which are found for the first time in Sn-based metal halides. Rb4Sn3Cl2Br8 exhibits a high thermal stability (up to 270 °C) and a relatively large bandgap of 2.82 eV. This compound shows a phase-matchable powder second harmonic generation response of 0.5 times of KH2PO4 (KDP), and is the first phase-matchable Sn-based halide nonlinear optical material. The discovery of Rb4Sn3Cl2Br8 will be beneficial to further phase-matchable nonlinear optical materials exploration in Sn-based halides. [ABSTRACT FROM AUTHOR]

The incommensurate (IC) behaviors of ferroelectrics have been widely investigated in inorganic oxides as an exciting branch for aperiodic materials, whereas it still remains a great challenge to achieve such intriguing effects in organic systems. Here, we present that successive ordering of dynamic dipoles in an organic molecular ferroelectric, N-isopropylbenzylaminium trichloroacetate (1), enables unusual incommensurately modulated structures between its paraelectric phase and ferroelectric phase. In particular, 1 exhibits three distinct IC states coupling with a long-range ordering modulation. That is, the incommensurately modulated lattice is ~7 times as large as its periodic prototype, and the IC structure is well solved using a (3 + 1)D superspace group with the modulated wavevector q = (0, 0, 0.1589). To the best of our knowledge, 1 is the first organic ferroelectric showing such a long-range ordering IC structural modulation. In addition, structural analyses reveal that slowing down dynamic motions of anionic moieties accounts for its modulation behaviors, which also results in dramatic reorientation of dipolar moments and concrete ferroelectric polarization of 1 (~0.65 µC/cm²). The combination of unique IC structural modulations and ferroelectricity makes 1 a potential candidate for the assembly of an artificially modulated lattice, which will allow for a deep understanding of the underlying chemistry and physics of aperiodic materials. [ABSTRACT FROM AUTHOR]

A new beryllium-free borate Rb3Ba3Li2Al4B6O20F features a layered structure analogous to that of the solely available deep-ultraviolet nonlinear optical (NLO) material KBe2BO3F2 (KBBF), and thus preserves its outstanding linear and nonlinear optical properties to a great extent. Furthermore, the interlayer bonding in Rb3Ba3Li2Al4B6O20F is significantly reinforced, with a magnitude of more than 15.6 times that of KBBF. As a result, a bulk Rb3Ba3Li2Al4B6O20F crystal is successfully grown in the preliminary experiments. The result demonstrates that the Rb3Ba3Li2Al4B6O20F crystal may have no (or only a tiny) layering growth habit, which severely hinders the practical applications of KBBF. Notably, Rb3Ba3Li2Al4B6O20F overcomes the structural instability problem present in the notable KBBF-family member Sr2Be2B2O7. These results make Rb3Ba3Li2Al4B6O20F a promising candidate for the next generation of deep-ultraviolet NLO materials. First-principles calculations are performed to elucidate the optical properties and structural stability. [ABSTRACT FROM AUTHOR]

Physical properties of phase transition materials are directly linked to the transformation of structural moieties. Here, we report a new hydrogen-bonded binary crystal of cyclohexylaminium chlorodifluoroacetate (1), consisting of two distinct types of the anion-cationic structural moieties, which shows an order-disorder phase transition around 153 K (phase transition point, Tc). Thermal analyses, dielectric, and second-order nonlinear optical (NLO) measurements solidly confirm the symmetry transformation from the point group mmm to mm2. It is noteworthy that 1 exhibits a coexistence of switchable dielectric behaviors and bistable NLO effects. In detail, it is NLO-active below Tc, while its quadratic NLO effects completely disappear above Tc. Such a change reveals the bistable feature of its quadratic NLO properties. Further, variable-temperature structure analyses reveal that the emergence of NLO effects below Tc is ascribed to partial ordering of anions and small-angle reorientation of cations. This mechanism is different from that of the precedent NLO-switching materials, which affords a potential avenue to design new electric-ordered molecular compounds as multifunctional materials. [ABSTRACT FROM AUTHOR]

Significant progress on a new brilliant scheme for the solid phase transition has opened up new possibilities of highly efficiently switching the quadratic nonlinear optical (NLO) properties. However, the NLO switching capacities of previously reported solid-state materials were restrictively modulated between the conventional bistable states. Exploring NLO tristability is strongly required for multistep operations in multilevel memory elements and optoelectronic devices. Here, we first report a tristable molecule-based dielectric, dipropylammonium trichloroacetate (DPA-TCA), which shows an exceptional three-level switching of quadratic NLO effects (i.e., NLO-off, low-NLO, and high-NLO states). This unprecedented three-level switching of the NLO effect originates from the stepwise ordering of the dynamic molecular components in DPA-TCA, associated with the tristability of dielectric phase transitions at 142 and 228 K. It is believed that this finding will shed light on the further design of new multilevel NLO switching materials and promote their prospective device applications. [ABSTRACT FROM AUTHOR]

Reversible phase transition materials (PTMs), of which their photoelectric responses can be modulated upon external heat, pressure, or light, have attracted great interest because of the potential applications for electronic, optical, and energy-based devices. The design strategy of chemical flexible structural components has great feasibility to construct new PTMs with outstanding photoelectric activities. Here, this paper presents our efforts on the design and syntheses of phase transition crystalline materials, as well as the related photoelectric effects. These unique physical properties make them potential candidates as switchable dielectrics, nonlinear optical switches, pyroelectric sensors, etc. [ABSTRACT FROM AUTHOR]

Developing superior deep-ultraviolet (deep-UV) nonlinear optical (NLO) materials is a great challenge because of the contradiction between deep-UV transparency and enhanced second harmonic generation (SHG), especially for deep-UV NLO phosphates in which the constituent P-O groups have relatively small microscopic SHG coefficients. Here we report a new noncentrosymmetric phosphate Cs2LiPO4 (I), whose crystal structure consists of [LiPO4]∞ layered structural units with a novel honeycomb-like topology. As compared with the benchmark deep-UV NLO material KBe2BO3F2, I is beryllium-free, and it is relatively easy to grow its large single crystals because of its congruent melting. Furthermore, it not only is deep-UV transparent but also exhibits an unexpectedly enhanced SHG response of 1.8 × KH2PO4 that hits a new high in deep-UV NLO phosphates. These results demonstrate that I satisfies the key requirements of being a promising deep-UV NLO candidate. Theory calculations and structural analysis reveal that the enhanced SHG response can be attributed to the honeycomb-like topological structure, which endows the constituent [PO4]3- monomers of I with an aligned arrangement and as a result a favorable superposition of their microscopic SHG coefficients. These findings may provide useful insights into the development of both deep-UV NLO materials and honeycomb-like topological structures. [ABSTRACT FROM AUTHOR]

A beryllium-free deep-ultraviolet (deep- UV) nonlinear optical (NLO) material K3Ba3Li2Al4B60 2oF is developed mainly by the element substitution of Be for Al and Li from Sr2Be2B2O7 that was considered as one of the most promising deep-UV NLO materials. K3Ba3Li2Al4B60 2 oF preserves the structural merits of Sr2Be2B2O7 and thus exhibits no layering growth tendency and possesses the optical properties required for deep-UV NLO applications, including deep-UV transparency, phasematchability, and sufficiently large second-harmonic generation (1.5 X KH2PO4). Furthermore, it overcomes the structural instability problem of Sr2Be2B2O7, which is confirmed by the obtainment of large single crystals and phonon dispersion calculations. These attributes make it very attractive for next-generation deep-UV NLO materials. The substitution of Be for Al and Li in beryllium borates provides a new opportunity to design berylliumfree deep-UV NLO materials with good performance. [ABSTRACT FROM AUTHOR]

A new reversible molecular phase transition material [HN(C4H9)3](fumrate)0.5·(fumaric acid)0.5 (1) has been successfully synthesized. Differential scanning calorimetry measurement shows a pair of reversible peaks at 181.9 and 178 K on heating and cooling modes, respectively. The large thermal hysteresis of ~3.9 K discloses its reversible first-order structural phase transition. Specific heat capacity and dielectric constant measurements around Tc further confirm its phase transition behaviors. The detailed structural analyses of 1 at variable temperatures reveal that its structural phase transition is mainly accomplished by the order-disorder transformations of carboxyl oxygen atoms and distinct reorientations among cations and anion-acid infinite sheets together with proton-dynamic motion. All these results open a new way to construct potential phase transition materials through the selection of flexible aliphatic cations with simple carboxyl-based anions. [ABSTRACT FROM AUTHOR]

A new reversible molecular phase transition material [HN(C4H9)3](fumrate)0.5·(fumaric acid)0.5 (1) has been successfully synthesized. Differential scanning calorimetry measurement shows a pair of reversible peaks at 181.9 and 178 K on heating and cooling modes, respectively. The large thermal hysteresis of ~3.9 K discloses its reversible first-order structural phase transition. Specific heat capacity and dielectric constant measurements around Tc further confirm its phase transition behaviors. The detailed structural analyses of 1 at variable temperatures reveal that its structural phase transition is mainly accomplished by the order-disorder transformations of carboxyl oxygen atoms and distinct reorientations among cations and anion-acid infinite sheets together with proton-dynamic motion. All these results open a new way to construct potential phase transition materials through the selection of flexible aliphatic cations with simple carboxyl-based anions. [ABSTRACT FROM AUTHOR]

To switch bulk nonlinear optical (NLO) effects represents an exciting new branch of NLO material science, whereas it remains a great challenge to achieve high contrast for "on/off" of quadratic NLO effects in crystalline materials. Here, we report the supereminent NLO-switching behaviors of a single-component plastic crystal, 2-(hydroxymethyl)-2-nitro-l,3-propanediol (l), which shows a record high contrast of at least 庤150, exceeding all the known crystalline switches. Such a breakthrough is clearly elucidated from the slowing down of highly isotropic molecular motions during plastic-torigid transition. The deep understanding of its intrinsic plasticity and superior NLO property allows the construction of a feasible switching mechanism. As a unique class of substances with short-range disorder embedded in long-range ordered crystalline lattice, plastic crystals enable response to external stimuli and fulfill specific photoelectric functions, which open a newly conceptual avenue for the designing of new functional materials. [ABSTRACT FROM AUTHOR]

An above-room-temperature new phasetransition molecular material,dibutylammonium hydrogen oxalate (1), has been synthesized,which undergoes a reversible phase transition at 321.6 K. Differentialscanning calorimetry (DSC) measurements confirm its reversible phasetransition with a large heat hysteresis of ∼10 K. The dielectricconstants of 1exhibit an obvious step-like anomaly,showing the high and low dielectric constant states at high and room-temperaturephases, respectively, which reveal that 1might be considereda potential switchable dielectric material. Variable-temperature singlecrystal X-ray diffraction analyses disclose that the origin of thisphase transition is greatly attributed to the coupling of the order–disorderchange and reorientation of the dibutylammonium cation; that is, thefrozen ordering of ethyl group in butyl moiety triggered by the decreasingtemperature forces the reorientation of cation, thus resulting inthe structural phase transition. [ABSTRACT FROM AUTHOR]

Poor stability has long been a major obstacle to the practical applications of metal-organic framework (MOF) photocatalysts. This problem can be overcome by the use of structural interpenetration. In this work, by modifying Ru metalloligands, we have rationally designed two Ru-polypyridine based MOFs (with non-interpenetrated and interpenetrated structures, respectively), both of which exhibit similar photocatalytic activities for CO2 photoreduction. Remarkably, the interpenetrated Ru-MOF possesses good photocatalytic durability and recyclability, and shows much higher thermal and photic stability in comparison with its non-interpenetrated counterpart. To the best of our knowledge, this is the first time that the stability of MOF photocatalysts was improved by using structural interpenetration. [ABSTRACT FROM AUTHOR]

A new beryllium-free borate Rb3Al3B3O10F has been synthesized and characterized by single-crystal X-ray diffraction. It features a framework structure consisting of alveolate [Al3(BO3)3OF]∞ layers tightly bound via Al-O and Al-F bridged bonds, with the in-layer [BO3]3- groups in nearly coplanar and aligned arrangement. This compound is transparent down to 200 nm and is phase-matchable with a powder second-harmonic generation efficiency of 1.2 times that of KH3PO4. Remarkably, it exhibits a strong interlayer bonding which is about one order larger than that of the benchmark KBe2BO3F2, thus no layering tendency was observed during the crystal growth. In addition, it is nonhygroscopic and thermally stable up to ∼1462 K. These attributes make Rb3Al3B3O10F a promising nonlinear optical crystal in the deep-ultraviolet region. First-principles calculations, combined with the anionic group theory, were adopted to rationalize the optical properties. [ABSTRACT FROM AUTHOR]

It is challenging to explore deep-ultraviolet (deep-UV) nonlinear optical (NLO) materials that can achieve a subtle balance between deep-UV transparency and high NLO activity. Known deep-UV NLO materials are almost exclusively limited to borates, except few newly discovered phosphates despite their small NLO activities. Here we report two asymmetric phosphates, RbBa2(PO3)5 (I) and Rb2Ba3(P2O7)2 (II), which feature [PO3]∞ chains and [P2O7]4- dimers formed by condensation of [PO4]3- units, respectively. Remarkably, I achieves the desired balance, with the shortest deep-UV absorption edge at 163 nm and the largest NLO activity of 1.4 × KDP (KH2PO4) in deep-UV NLO phosphates. According to first-principles calculations, the enhanced macroscopic SHG response of I can be attributed to the [PO3]∞ chains which exhibit significantly larger microscopic SHG coefficients as compared with the [P2O7]4- dimers. [ABSTRACT FROM AUTHOR]

A new noncentrosymmetric borate CsZn2B3O7 was synthesized by the solid-state reaction techniques. The crystals were obtained by flux method and are of block shape without layering tendency. Single-crystal X-ray diffraction analysis reveals that the crystal structure is composed of [Zn2BO5]8 two-dimensional layers that are bridged by [B3O6]3- groups to form a three-dimensional framework with one-dimensional channels occupied by Cs+ cations along the a and c axes. Thermal analysis indicates that CsZn2B3O7 melts incongruently. UV-visible-near-IR diffuse reflectance spectrum gives a short absorption edge at 218 nm. CsZn2B3O7 is phase-matchable, with a powder second-harmonic generation (SHG) efficiency of 1.5 × KDP (KDP, potassium dihydrogen phosphate) at 1064 nm, based on the Kurtz-Perry method. These results show that CsZn2B3O7 may have prospects as a UV nonlinear optical material. Interestingly, the SHG efficiency of CsZn2B3O7 is about twice that of ?-KBe2B3O7, a structurally analogous alkaline and alkaline earth borate. First-principles calculations combined with atom-cutting analysis reveal that the ZnO4 tetrhedral groups in CsZn2B3O7 account for the SHG enhancement. [ABSTRACT FROM AUTHOR]

A chiral coordination nanotube, [Cd3(BPT)2(H2O)9]∙2H2O (Cd-1; BPT = biphenyl-3,4',5-tricarboxylate), has been synthesized from achiral components and structurally characterized. It consists of homochiral channels based on right-handed helical chains and shows an interdigitated interaction to give a chiral 3D network. The chiral nanotubular framework exhibts dynamic structural transformation upon removal of the guest molecules, and the polarity of this compound induces it to display both ferroelectric and nonlinear-optical properties. [ABSTRACT FROM AUTHOR]

A novel third-order nonlinear optical (NLO) crystal based on the organic borate carboxylate ester, with formula [Na4(H2O)5][B{O2CCH(O)Ph}2]4(abbreviated as LMBNa), has been prepared in aqueous solution. Single-crystal X-ray diffraction analysis reveals that the boron atom is coordinated with two l-mandelic ligands by alkoxide and carboxylate groups, forming the [B{OOCCH(O)C6H5}]−anion. The sodium cation supports its structural framework of borate anions in the formation of a cross-linked structure. Bulk single crystals of LMBNa were grown from acetonitrile/water by the temperature lowering method. Studies of its third-order NLO properties using a Z-scan technique demonstrate that the LMBNa crystal possesses a strong saturable absorption and the self-focusing effect. Its second molecular hyperpolarizability (γ) at 532 nm is calculated to be (3.9 ± 0.2) × 10−31esu. Furthermore, dielectric experiments reveal that LMBNa has a quite low-dielectric constant (∼3.43) and shows an anisotropy of frequency dependence along the different crystallographic directions. Such dielectric behaviors will favor the application of the LMBNa crystal under the electric field. All the results indicate that LMBNa might be a potential candidate material for the third-order NLO applications. [ABSTRACT FROM AUTHOR]

A new entangled metal-organic framework shows reversible structural dynamics and luminescence changing in response to the loss of guest H2O molecules. Furthermore, an intense and sensitive luminescence turn-on sensing was observed by the naked eye for 1 upon detection of the volatile organic solvent molecule CH3CN, accompanied by reversible structural transformation. [ABSTRACT FROM AUTHOR]

An intense visible yellow-orange emission with long lifetime and enhanced quantum yield has been achieved for a metal--organic framework based on a highly light-harvesting dyclo-metalated iridium(III) unit, which shows effective detection of nitroaromatic explosives on the ppm scale. [ABSTRACT FROM AUTHOR]

A three-dimensional complex, [Mn[sub 3](4-aba)[sub 6]][sub n] (1) (4-Haba = 4-aminobenzoic acid), consisting of manganese(Il) chains and 4-aba bridging ligands, has been synthesized and characterized. Magnetic studies show that the compound behaves as a threedimensional metamagnet built of homometallic ferrimagnetic chains. The required noncompensation in spin moments is achieved by alternating interactions in an AF-AF-F sequence (AF = antiferromagnetic; F = ferromagnetic) by considering intrachain magnetic interactions. [ABSTRACT FROM AUTHOR]