Search

This paper presents experimental and numerical approaches to systematically investigate the aerodynamic characteristics of streamlined box girder at angles of attack (AoA) of up to 12°. The effects of AoA on the pressure characteristics and total forces are first studied through wind tunnel experiments. Based on three-dimensional large-eddy simulations (3D LES), the flow topology is investigated to study the influence mechanism of AoAs. The results show that the flow topology around the section can be divided into three types: (i) completely attached flow pattern as |α| ≤ 4°; (ii) separated-reattached flow pattern as 6°≤|α|≤8°; (iii) fully separated flow pattern as |α| ≥ 10°. The combination of experimental and numerical results presents a deep understanding of the aerodynamic characteristics of a streamlined box girder and reveals the relationships between the pressure features and flow topology. The pressure characteristics and total forces are very sensitive to the flow separation and reattachment. At small AoAs, the flow attaches to the bridge section, the mean and RMS pressure, total force, as well as streamwise correlations change slightly with AoAs. Besides, the shear layer is a laminar pattern and has less impact on the span-wise correlations. Moreover, the vortices in the wake remain successive in the span-wise direction, and the Strouhal numbers are larger. On the other hand, with the increase of AoAs, large separation bubbles can be observed around the bridge section. Especially for fully separated flow pattern as |α| ≥ 10°, the shear layer no longer attaches to the bridge section and the separation bubble is longer than the section width. Accordingly, the mean and RMS pressure, total force, as well as streamwise correlations increase significantly. Besides, the shear layer is a turbulent pattern, and the turbulent fluctuations in wake become complex and less organized in the span-wise direction, then the St is lower than others. [ABSTRACT FROM AUTHOR]

Two new methyl viologen halocadmium charge-transfer salts with isostructures, [(MV)(CdI)]·3HO ( 1) and (MV)(CdI)·HO ( 2) (MV = methyl viologen, i.e., 1,1′-dimethyl-4,4′-bipyridinium), have been structurally determined. 1 and 2 consist of CdI clusters, MV dications, lattice waters with isostructures, and C-H···I hydrogen bonds are presented in 1 but absent in 2, furthermore, their relative stabilities based on were investigated by DFT calculations. Both compounds display photoluminescences in the visible region under visible-light excitations, and their thermochromism effects are observed. But their photoluminescence and thermochromic behaviors differ greatly with the presence or absence of hydrogen bonds. Moreover, their absorption spectra have also been discussed. [ABSTRACT FROM AUTHOR]

Four uranium(VI)-polycarboxylatesframeworks with honeycomb (6,3) nets have been assembled from solvothermalsystems, which contain different guest molecules (transition metalcomplexes and methyl viologen). These compounds exhibit photocatalyticactivities for the degradation of rhodamine B. Interestingly, themethyl viologen-containing one possesses the highest efficiency, whichcan be attributed to the electron acceptor nature of methyl viologenfor the stabilization of active peroxide anions. [ABSTRACT FROM AUTHOR]

Two new heterometallic uranyl-organic frameworks (UOFs), [Cd(phen)2(H2O)2][(UO2)2(BDC)3]·2H2O (1) and [Ni(phen)3][(UO2)2(BDC)3]·2H2O (2), were obtained under hydrothermal conditions. Both crystal structures were characterized by single-crystal X-ray diffraction analyses and the results indicate that both complexes feature a similar 2D honeycomb framework that is connected by rigid benzenedicarboxylate (BDC) ligands and uranyl units. BDC works as a linker to bridge neighboring UO22+ units, where UO22+ is tris-chelated. Different guest molecules guided the stacking of 2D layers and lead into their 3D supramolecular crystal structures with different space groups. As a result, 1 crystallized in a polar space group Cc, whereas 2 belongs to a chiral space group P6122. Thermogravimetric measurements were performed to study their thermal stability. UV-visible diffuse reflectance spectroscopy measurements indicate an experimental optical bandgap of 3.87 eV and 3.63 eV, respectively, for 1 and 2. Luminescent studies of both samples show strong green light emissions. [ABSTRACT FROM AUTHOR]

As bacterial resistance is becoming increasingly serious, the development of antibacterial nanomaterials is an effective method of solving this problem. Gold nanoparticles have good stability and excellent biocompatibility and are easily modified, and their antibacterial properties can be enhanced by changing their structure and size or adding ingredients. Gold nanoparticles are also excellent drug carriers that can improve the antibacterial effects of loaded antibacterial drugs. After being modified and combined with other antibacterial drugs, gold nanoparticles can also play a better antibacterial role for effective antibacterial strategies against some resistant bacteria. Gold nanoparticles have photothermal effects, and modified gold nanoparticles can be a good medium for photothermal treatments to kill bacteria. By adding functionally modified gold nanoparticles, many materials can obtain much needed antibacterial properties. Gold nanoparticles can also be combined with cations, low-temperature plasma, various surface ligands, and other potential antibacterial agents. In short, the antibacterial characteristics of functionalized gold nanoparticles demonstrate that they have considerable practical application value and provide more ideas to solve antibacterial problems. At the same time, the application of gold nanoparticles in oral biology is also increasing. [ABSTRACT FROM AUTHOR]

Under the template of methyl viologen (MV2+ = methyl viologen) and ethyl viologen (EV2+ = ethyl viologen), two new viologen/iodobismuthate hybrids, (MV)5(Bi2I10)(Bi2I9)2 (1) and (EV)3(Bi4I18) (2) have been structurally determined. The highly interesting feature of 1 lies in its combination of two kinds of dimeric iodobismuthate clusters, i.e. (Bi2I10)4− and (Bi2I9)3− in one lattice induced by MV2+, which are constructed from edge- and face-sharing BiI6 octahedra respectively. But the (Bi4I18)6− tetramer in 2 is based on edge- and vertex-sharing BiI6 octahedra. C–H···I hydrogen bonds contribute to the formation of quasi-3-D networks. The smaller gap of 1 might be led by more versatile C–H···I hydrogen bond interactions due to the presence of mixed type iodobismuthate clusters. Two hybrids display reversible thermochromism behaviors. Theoretical calculation suggests that the terminal iodine is dominated in electron transfer of thermochromisms, rather than bridged iodine. [ABSTRACT FROM AUTHOR]

Donor–acceptor (D–A) hybrid heterostructures are an emerging class of hybrid complexes with potential applications in current optoelectronic technologies. To achieve high photoinduced charge-carrier generation and separation in a heterostructure, a common strategy is the fabrication of continuous or bicontinuous structures by the crystallization of semiconductive donor and acceptor tectons at the molecular level. So far, only a few such heterostructures have been fabricated, most of which involve unstable and narrow band gap metal halides. In this paper, we extended these unique hybrid heterostructures to continuous alkaline-earth metal oxide clusters. The combination of the naphthalene diimide (NDI) tecton bearing four carboxylates at two extremities with Ca2+ (or Sr2+) cations led to two isostructural D–A hybrid heterostructures with infinite 1-D carbon-doped alkaline-earth metal oxide clusters and X-aggregated NDI dimers as electron donors and acceptors, respectively. Due to the different metal cations in inorganic clusters, they exhibited diametrically opposite photochromic sensitivities and photocatalytic activities. To better rationalize them, a plausible photoinduced electron transfer process for the D–A hybrid heterostructures with photoactive acceptors has been developed. [ABSTRACT FROM AUTHOR]

Through the incorporation of Cu(II) ions as additional connecting nodes to form heterometallic uranyl-organic frameworks with rigid ligands, we have successfully synthesized three extended complexes with varying dimensions. Notably, complex 1 features a robust 3D cds net structure and demonstrates exceptional thermal stability above 250 °C. [Display omitted] By introducing Cu(II) ions as additional connecting nodes to construct stable heterometallic uranyl-organic frameworks (UOFs) with thiophene-2,5-dicarboxylic acid (H 2 TDC) and N -donor auxiliary ligands, three new uranyl complexes, namely, [Cu(phen)(UO 2)(TDC) 2 ] (1), [Cu(phen-NO 2) 2 (UO 2)(TDC) 2 ]·3H 2 O (2), and [Cu(phen-NH 2)(H 2 O) 2 (UO 2)(TDC) 2 ]·4H 2 O (3) (phen = 1,10-phenanthroline) have been successfully synthesized by hydrothermal reaction. Complex 1 exhibits a rare three-dimensional (3D) network structure of cds topology connected by UO 2 , Cu(phen), and TDC units. Both complexes 2 and 3 feature similar one-dimensional chain structures based on UO 2 , TDC, Cu(Phen-NO 2) 2 and UO 2 , TDC, Cu(phen-NH 2)(H 2 O) 2 respectively. The N -donor auxiliary ligands play a key role in determining their structural dimensionalities and bandgaps formation. Among the three uranyl complexes, phen with a smaller size than its derivatives, phen-NO 2 and phen-NH 2 , was found to be favorable for constructing 3D UOFs. Moreover, complexes with both phen-NO 2 and phen-NH 2 showed varying degrees of redshift on optical spectra. The UV–Visible diffuse-reflectance spectra, analyzed with Tauc's fitting in considering Urbach tailing, revealed an indirect bandgap of 2.94 eV, an indirect bandgap of 2.67 eV, and a direct bandgap of 2.45 eV for 1 , 2 and 3 , respectively. Moreover, thermogravimetric analyses indicate that 3D anhydrous uranyl complex 1 possessed a robust structure and excellent thermal stability above 250 ℃. [ABSTRACT FROM AUTHOR]

The study about the effect of the stacking mode on the photo/electrical performance of crystalline organic/inorganic hybrids will be beneficial for the design of new photo/electrically active materials. In this work, D–π–A stilbazolium-type chromophores bearing novel ortho-N-alkyl substituents were synthesized and incorporated with iodoargentates to generate three crystalline stilbazolium/iodoargentate hybrids, i.e., [(CMAMP)(Ag2I3)]n (1), [(HMAMP)(Ag2I3)]n (2), and [(HMAHP)2(Ag5I7)]n (3). When the substitutes on the amine group range from –C2H5CN (for CMAMP+) to –C2H5OH (for HMAMP+), the same (Ag2I3)nn− anions will be produced, and the π⋯π stacking interactions among stilbazoliums will be observed from absence to presence (weak head-to-head H-aggregation). Furthermore, when the substituent on the ortho-N of pyridine was also set as –C2H5OH (for HMAHP+), more electron-rich (Ag5I7)n2n− anion can be generated, and strong head-to-tail H-aggregation among HMAHP+ cations will happen. The enhanced aggregation strengthening in 3 can lead to its larger blue-shift photoluminescence, higher photocurrent, and better resistive switching performance (much higher ON/OFF ratio of 4.51 × 102). Their binary resistive switching mechanism can be explained as the SCLC model, and the better photo/electrical performances of 3 stem from its stronger head-to-tail H-aggregations, more negatively charged (Ag5I7)n2n− anion, and stronger (Ag5I7)n2n−–HMAHP+ interaction. The highly delocalized π antibonding orbitals between the empty p-orbitals of ethylene in its LUMO of (HMAHP)22+ dimer of 3 also support this conclusion. The good structure–property correlation based on accurate structural information in these stilbazolium/iodoargentate hybrids will be beneficial for the design of next-generation memory devices. [ABSTRACT FROM AUTHOR]

In the field of biomemorizers, the simultaneous enhancement of resistive switching (RS) performance and environmental robustness, and the understanding the RS mechanism involving interfacial interaction is still challengeable. Herein, the bio-composites by encapsulating graphene (GR), graphene oxide (GO) and reduced graphene oxide (RGO) into chitosan (CS) have been fabricated as memory devices with the structure of FTO/bio-composite/Ag. Among them, FTO/GO@CS(12 %)/Ag biomemorizer exhibits the best RS performance with high ON/OFF ratio (105.92), and it possesses good thermal (170 °C) and irradiation stabilities (UV exposure for 96 h). The RS mechanism is due to the migration of oxygen vacancies accompanied by formation of Ag conducting filaments in the bio-composite films. Therefore, the enhanced resistive switching performance after encapsulating into CS can be explained as the increment of defects, the higher current densities and quenched radicals. Specially, for the first time we find the presence of voltage-induced packing mode changes in GO@CS composite, which can facilitate the migration of oxygen vacancies and render its best RS performance. In all, the more carboxyl groups can strengthen the GO-CS interfacial interactions through the formation of stable hydrogen bonding network and covalent bonds, which can enhance the stabilities and makes the composites be more sensitive to electrical stimulus. The rules drawn in this work will be significant for the construction of new biomemorizers with good environmental robustness. [Display omitted] • Graphene derivants (graphene, graphene oxide and reduced graphene oxide) have been encapsulated in chitosan to construct biomemorizers. • FTO/GO@CS (12 %)/Ag biomemorizer exhibited the good RS performance with high ON/OFF ratio and excellent thermal/irradiation stabilities. • The presence of voltage-induced packing mode changes in bio-composites can facilitate the migration of oxygen vacancies. • The more carboxyl groups can strengthen the GO-CS interfacial interactions, which can enhance the stabilities and makes the composites be more sensitive to electrical stimulus. [ABSTRACT FROM AUTHOR]

Two new copper(I) iodide-based hybrids, i.e. (Py3P–O–PPy3)(Cu2I4) (1) and (Py3P–O–PPy3)(Cu4I6) (2) (Py = pyrrolidine), have been prepared, in which the tripodal diphosphonium (Py3P–O–PPy3)2+ is in situ generated in the one-pot synthesis. The disordered (Cu4I6)2− tetramers are rare with two sets of tetracuprate centers. Interestingly, 1 exhibits sensitive luminescence mechanochromism, which is ascribed to the disturbed cuprophilic Cu⋯Cu interactions and the crystalline packing adjustment by destroying C–H⋯I hydrogen bonds during mechanical force. In particular, the luminescence thermochromism is unique, whose fluorescence intensity is strengthened with the elevated temperature. This could be due to the S2–S1 internal conversion on the linear P–O–P backbone, which will be bent upon heating. Simultaneous luminescence thermo/mechanochromism can also be monitored in 1. However, no luminescence thermo/mechanochromic performances can be detected in 2, so the luminescence thermo/mechanochromism of 1 could be quenched with DMF. The conclusions in this work might provide a new large-scale synthesis strategy for intelligent responsive luminescent materials. [ABSTRACT FROM AUTHOR]

Studies on the recycling of uranium, such as its usage as new materials, can promote the safe treatment of nuclear waste. In this work, with the direction of transition-metal complex cations, three uranyl–organic frameworks (UOFs) with different dimensions have been synthesized via a hydrothermal reaction, i.e. [Cu(phen)2(SO4)(UO2)(TDC)·H2O]n (1), {[Zn(phen)3][(UO2)2(TDC)3(TDC)]·6H2O}n (2), and {[Cd(phen)3][(UO2)2(TDC)2(OX)·2H2O]}n (3), (TDC = thiophene-2,5-dicarboxylic acid, OX = oxalate, and phen = 1,10-phenanthroline). With the presence of SO42−, 1 presents a rare neutral 1-D Cu/U heterometallic chain. Under the similar [Zn(phen)3]2+ and [Cd(phen)3]2+ templates, 2 is a 2-D [(UO2)2(TDC)3]n planar non-interpenetrated honeycomb layer, but 3 presents an interesting twofold interpenetrated (6,3) sheet structure, which is led by the larger cavity of the hexagonal motif with the presence of the second ligand OX. This trend could be helpful for the oriented construction of UOFs. Intra- and inter-layer hydrogen bonds between the honeycomb structure and guest cations and π–π stacking interactions contribute to the stabilization of the overall framework. Complete quenching of uranyl luminescence via nonradiative decay can be observed in 1, and 2 and 3 emit yellow fluorescence with well-resolved vibronic fine structures. The interpenetrated arrangements could give rise to weakened uranyl emission. [ABSTRACT FROM AUTHOR]

Strong electron-poor cation diphenyliodonium was firstly incorporated with transition metal thiocyanates to obtain three new photo-sensitive hybrids, (DPI)3[Mn(SCN)5(H2O)]·0.25H2O (α-1), {(DPI)2[Ni(SCN)4]}n (α-2) and {(DPI)6[Cd3(SCN)12]}n (α-3) (DPI+ = diphenyliodonium), whose photo-induced structural transformations to corresponding β-phases have been disclosed. After irradiating, all the MX6 octahedrons stretch clearly along the M–S directions, and C–H⋯π interactions and the secondary hypervalent I(III)⋯S halogen bonds are weakened. The hydrogen bonds are also weakened, except for those in 1. Time-dependent solid-state UV-vis spectra, PXRD patterns and EPR spectra before and after irradiating were obtained to prove the irreversible structural transformations of the hybrids, during which minor structural adjustments occurred. Consequently, the fluorescence emission changed from blue (α-3) to yellow (β-3) upon irradiation. Interestingly, obvious photomagnetization on 1 with a χMT increase of 14.89% and photodemagnetization on 2 with a χMT decrease of 12.82% can be observed. Finally, these hybrids can be used as long-term inkless and erasable print media. This work demonstrates the potential application of diphenyliodonium-based hybrids in some photo-sensitive functional materials. [ABSTRACT FROM AUTHOR]

The development of new‐type memristors with special performance is of great interest. Herein, an inorganic‐organic hybrid crystalline polyoxometalate (POM) with usual dynamic structures is reported and used as active material for fabricating memristor with unique temperature‐regulated resistive switching behaviors. The hybrid POM not only exhibits tunable thermochromic properties, but also thermal‐induced reversible aggregation and disaggregation reactions, leading to reversible structural transformations in SCSC fashion. Further, the memory device using the hybrid POM as active layer exhibits uncommon performance, which can keep resistive switching silent in the low temperature range of 30–150 °C, but show nonvolatile memory behavior in the high temperature range of 150–270 °C. Particularly, the silent and working states at three special temperatures (30, 150 and 270 °C) can be monitored by chromism. The correlation between structure and resistive switching property of the material has been discussed. The work demonstrates that crystalline inorganic‐organic hybrid POMs are promising materials for making memristors with superior performance. [ABSTRACT FROM AUTHOR]

The development of new‐type memristors with special performance is of great interest. Herein, an inorganic‐organic hybrid crystalline polyoxometalate (POM) with usual dynamic structures is reported and used as active material for fabricating memristor with unique temperature‐regulated resistive switching behaviors. The hybrid POM not only exhibits tunable thermochromic properties, but also thermal‐induced reversible aggregation and disaggregation reactions, leading to reversible structural transformations in SCSC fashion. Further, the memory device using the hybrid POM as active layer exhibits uncommon performance, which can keep resistive switching silent in the low temperature range of 30–150 °C, but show nonvolatile memory behavior in the high temperature range of 150–270 °C. Particularly, the silent and working states at three special temperatures (30, 150 and 270 °C) can be monitored by chromism. The correlation between structure and resistive switching property of the material has been discussed. The work demonstrates that crystalline inorganic‐organic hybrid POMs are promising materials for making memristors with superior performance. [ABSTRACT FROM AUTHOR]

The hybridization of 1,4-bis(isoquinoline)butane (BIQBT2+) cation with iodobismuthate under different solvents produce two isomers α-[(BIQBT)(BiI4)2]n (α-1, in CH3OH/H2O mixed solvent, Triclinic system with P-1 space group) and β-[(BIQBT)(BiI4)2]n (β-1, in CH3OH, Monoclinic system with P21/c space group). The 1-D (BiI4)nn− chains are constructed from the opposite edge-sharing BiI6 octahedra. The (BIQBT)2+ in α-isomer adopts the planar configuration, and that in β-isomer presents the chair-like configuration, as a result, different packing modes (intercalating quasi-3-D mode for α-1 and interlocking 2-D mode for β-1) are observed. Interestingly, from α-1 to β-1, distortion degree of BiI6 octahedron and π–π stacking interaction decrease, but hydrogen bonds number increase. Consequently, due to different packing mode, photoluminescence/thermochromisms can be found in α-1, but those of β-1 are vanished, Theoretical calculation was conducted to disclose the structure/thermochromism correlation. [ABSTRACT FROM AUTHOR]

Considering the low conversion and long reaction time in scaling up reaction in batch reactor, the organocatalyzed epoxidation reaction of styrene was intensified under continuous flow conditions using a commercial fluidic reactor (Corning Advanced Flow G1 Reactor). After investigating the effect of reaction temperature, catalyst amount, MeCN/t-BuOH ratio, FO/FAB (buffer solution amount), total feed flow rate and operating mode on the epoxidation reaction, the optimal reaction conditions were identified under continuous flow conditions. Upon optimization, high conversion and excellent selectivity with short reaction time (3.17 min) can be obtained. We successfully developed a process for the rapid and continuous epoxidation of styrene using an organocatalyst with hydrogen peroxide as the oxidant. Compared with the batch conditions, the continuous flow reactor can exhibit unique advantages including high-speed, safety, continuousness and absence of amplifying effect, which will be significant for the industrial production of epoxides. [ABSTRACT FROM AUTHOR]

Host‐guest encapsulation of functional organic dye into a porous metal‐organic framework can give rise to the development of new functional materials. In this work, by intercalating the stilbazolium‐type dye (DEAST)I (4′‐diethylamino‐N‐methyl stilbazolium) into four lanthanide layered metal‐organic complexes (Ln‐LMOCs), i. e. {[Ln(BTB)(H2O)2]⋅3(DMF)⋅2(H2O)}n (Ln=La (1), Nd (2), Sm (3), Er (4)), four responsive (DEAST)I@Ln‐LMOC composites have been prepared, serving as multifunctional performance platform. The core–shell structures of (DEAST)I@Ln‐LMOC composites have been fully characterized by IR, UV/Vis, PXRD, SEM, TEM, TGA and ESR. Significantly, after intercalation of dyes, the (DEAST)I@Ln‐LMOC composites exhibit enhanced luminescent sensing properties in detecting Fe3+ with much higher water stabilities. The luminescent sensing behavior stems from the fluorescence resonance energy transfer (FRET) from the π‐electron‐rich BTB ligands to the Fe3+, and their higher water stabilities are induced by electrostatic interactions and lower porosity. Specially, the characteristic emissions of Sm3+ will not be affected after the encapsulation guest dyes, which provide a theoretical guide for the modulation of luminescence devices. Finally, better ion conductivities and diminished photocurrents can be achieved after the embedding of the functional organic dye. In all, the formation of (DEAST)I@Ln‐LMOC composites with core–shell structures can be utilized as a multifunctional platform with good stability. [ABSTRACT FROM AUTHOR]

The combination of hexacyanoferrate anions with protonated N,N′-dipyridyl-naphthalene diimide tectons resulted in a novel cuboid 3-D H-bonded anion-coordinated framework. Induced by anion–π interactions, such a unique framework is further catenated into an unprecedented five-fold interpenetrated D–A hybrid heterostructure with 1-D hexacyanoferrate polyanions and naphthalene diimide aggregates as electron donors and acceptors, respectively. The photophysical and photochemical properties have also been discussed. [ABSTRACT FROM AUTHOR]

Bio-resistive memory devices with good environmental robustness are important for the next generation of biodegradable electronic devices. In this field, the facile achievement of both resistive switching performance and environmental robustness is still challengeable. Herein, resistive switching active oxidized multi-walled carbon nanotube (O-MWCNT) has been doped into chitosan (CS) to produce twisted O-MWCNT-CS biocomposites based on strong -COO-/NH 3 + electrostatic interaction. The FTO/O-MWCNT-CS(8%)/Ag biomemorizer can exhibit good resistive switching performance with high ON/OFF ratio (104.51) and low setting voltage (0.86 V). Besides, this biomemorizer possesses good environmental robustness with thermal (200 °C) and ionizing irradiation tolerance (UV exposure for 72 h). Ag conductive filament formation and rupture account for the resistive switching behavior. Specially, the conduction pathways provided by O-MWCNT and its good radical scavenging ability are the reason for the facile realization of resistive switching performances even under large layer thickness. The facile carboxylation on MWCNT and robust O-MWCNT-CS biocompoiste together with good environmental robustness render the promising applications as green, stable and biodegradable electronic devices. [Display omitted] • Oxidized multi-walled carbon nanotube was doped into chitosan to produce biocomposite with strong -COO-/NH 3 + interactions.. • The biomemorizer exhibits good resistive switching performance (ON/OFF ratio:104.51, V Set : 0.86 V). • This biomemorizer possesses good thermal/irradiating robustness (200 °C, UV exposure for 72 h). • The conduction pathways and radical scavenging ability account for the good resistive switching performances. [ABSTRACT FROM AUTHOR]

Four (triphenyl)phosphonium‐based quaternary phosphorus salts with different substituents (varying from methyl to n‐butyl) were selected to be structural directed agents (SDAs) to construct four iodocuprate(I) hybrids via solution method, i.e., [(PPh3Me)(Cu3I4)]n (1), [(PPh3Et)(Cu3I4)]n (2), (PPh3iPr)2(Cu2I4) (3), [(PPh3nBu)(Cu3I4)]n (4). The inorganic iodocuprates in 1, 2 and 4 are 1‐D (Cu3I4)nn– chains constructed from Cu5I11 units, but (Cu2I4)2– in 3 is a di‐nuclear cluster. Interestingly, the strength of Cu···Cu and π–π stacking interactions are weakened with the lengthening of alkyl groups on P‐atom. The best water stability of 4 can be ascribed to the better hydrophobicity of n‐butyl group, which deters the dispersing of organic and inorganic moieties and as a result, inhibit hydrolysis reaction. Furthermore, all compounds exhibit typical reversible luminescent thermochromic behaviors, among which 4 exhibits blue emission and the quenching of higher energy (HE) zone in 1 and 2 are led by strong π–π stacking interactions. Besides, effective and repeatable photocurrent responses can be detected in these compounds. In all, by systematically introducing alkyl groups into (triphenyl)phosphonium as SDAs to prepare hybrid iodocuprates, we can find that the longer alkyl groups can achieve stronger tunable PL materials with enhanced water stabilities. Four iodocuprate(I) hybrids have been prepared by using quaternary phosphorus salts as SDAs. The weakening of Cu···Cu and π–π stacking interactions with the lengthening of alkyl groups on the P‐atom is relative to their water stabilities and luminescent thermochromic behaviors. The proper length of alkyl group on (triphenyl)phosphonium in hybrid iodocuprates can achieve strong blue PL materials with enhanced water stability. [ABSTRACT FROM AUTHOR]

The mono-substituted bipyridinium derivative 1-(3-carboxybenzyl)-4,4′-bipyridinium (cbpy) and polyiodide were adopted to construct two new lead-carboxylate hybrids: [Pb(cbpy)I3·I3]n (1) and {[Pb(cbpy)2](I3)4·I2}n (2), in which interesting halogen bonds were detected. Specifically, the hybrids demonstrate efficient photocatalytic degradation of organic dyes and excellent photocurrent response, and the mechanisms of degradation have been discussed and verified using theoretical calculations. [ABSTRACT FROM AUTHOR]

Diphenyliodonium cations were firstly introduced into halobismuthate system to synthesize two new hybrids, i. e. (DPI) 4 (Bi 2 I 10 ) ( 1 ) and (DPI) 4 (Bi 2 Br 10 )·H 2 O ( 2 ) (DPI = diphenyliodonium). Two hybrids are isostructures containing (Bi 2 X 10 ) 4- halobismuthate dimmers and diphenyliodonium cations. Hypervalent I(III)⋯X interactions and C H⋯X (X I, Br) hydrogen bonds stabilize the structures and contribute to the structural extending from 0-D clusters to 2-D layer/1-D chain. The broader absorption spectra and lower energy gap of 1 were led by strong I⋯I interactions. Two compounds display thermochromism behaviors, whose mechanisms were verified by theoretical calculations. [ABSTRACT FROM AUTHOR]

Four mononuclear Cu(i)–halide complexes containing phosphines and pyridine ligands with strong electron donor substituents, [CuCl(PPh3)2(4-NMe2py)] (1), [CuI(PPh3)2(4-NH2py)] (2), [CuI(POP)(4-NH2py)] (3), and [CuI(POP)(4-NMe2py)]·0.5(Et2O) (4), (PPh3 = triphenylphosphine, 4-NMe2py = 4-(dimethylamino)pyridine, POP = bis[(2-diphenyl-phosphino)phenyl]ether, 4-NH2py = 4-aminopyridine, Et2O = diethyl ether) were synthesized and studied with regard to their structural, photophysical properties and theoretical calculations. The complexes exhibit pure blue thermally activated delayed fluorescence (λmax = 442 (1), 436 (2), 464 (3), and 448 nm (4)) in crystalline at room temperature. Emission lifetime analyses and density functional theory (DFT) calculations show that the blue-light emission at room temperature is the singlet (metal + halide)-to-ligand charge transfer state, (1(M + X)LCT), while that at 77 K is the state of 3(M + X)LCT transition character, owing to the small singlet–triplet energy gaps (ΔE = 660–1680 cm−1). X-ray diffraction structure analysis, photophysical studies and theoretical calculations suggest that the much larger torsion angle between the N-heterocyclic rings and N–Cu–X planes of complex 3 than that of 1, 2 and 4 might causes the bathochromic shift of luminescence, although these complexes containing similar heterocycle ligands. [ABSTRACT FROM AUTHOR]

The searching for green memristor with good environmental robustness will be significant for next generation biodegradable devices. In this work, bio-compatible and non-toxic polydopamine (PDA) was prepared by self-polymerization of dopamine in simple aqueous solution, which was protonated by different acid concentrations (3–12 M HCl) and further fabricated as memory devices with structures of FTO/PDA/Ag. The ON/OFF ratio are enhanced gradually from 2.80 × 102 (PDA-3 M), 8.39 × 102 (PDA-6 M), 5.18 × 103 (PDA-9 M) to 2.41 × 104 (PDA-12 M). The lower conjugated degree, the closer lattice packing and the less radicals after acid treatment are the reasons for the enhanced bipolar resistive switching performances of protonated PDA-based memristor. The resistive switching mechanism is the conductive filament with three processes of Ohm, space charge limited conduction (SCLC) and trap-filled limited (TFL). In addition, the FTO/PDA-12 M/Ag exhibit good environmental robustness, including thermal (100 °C) and ionizing irradiation (UV exposure for 96 h). In all, the facial protonation treatment and the simple sandwich device structures together with good environmental robustness endow its promising applications in as green, stable and biodegradable next generation electron devices. The enhanced bipolar resistive switching performance and good environmental robustness can be achieved in protonated polydopamine based memristor, which is assigned to the lower conjugated degree, the closer lattice packing and the less radicals after acid treatment. [Display omitted] • Bio-compatible polydopamine was protonated by different acid concentrations and further fabricated as memory devices. • The reasons for the enhanced bipolar resistive switching performances of protonated PDA-based memristor was discussed. • The FTO/PDA-12 M/Ag exhibits good thermal (100 °C) and ionizing irradiation (UV exposure for 96 h) robustness. [ABSTRACT FROM AUTHOR]

The first transition-metal-bridged polyniobotungstate-based 3D framework has been hydrothermally synthesized, which is constructed from bi-[CuII(en)2(H2O)]-decorating [Nb3W3O19]5− polyoxoanions linked together by CuI ions. Interestingly, the 3D polyniobotungstate framework can undergo a solid–liquid reaction with KI solution to generate a 1D copper halide of [Cu(en)2][CuI2]2 in a single-crystal-to-single-crystal process. [ABSTRACT FROM AUTHOR]

A new halocadmium/methyl viologen hybrid (MV)(CdI)(CdI) ( 1) (MV = methyl viologen) has been structurally determined. In 1, two kinds of dimeric halocadmium clusters constructed from edge/vertex-sharing CdI tetrahedra respectively, i.e., CdI and CdI dimmers were observed, which were templated by methyl viologen cation (MV). A highly interesting feature of 1 is the presence of mixed type dimeric halocadmium clusters in one crystal lattice templated by one kind of cation. 1 displays photoluminescences, and its thermochromism behavior is observed, whose mechanism was verified by theoretical calculations. [ABSTRACT FROM AUTHOR]

• Memory devices fabricated with protonated g-C 3 N 4 can exhibit enhanced memory performances, in which acid concentration is crucial. • g-C3N4 treated with 8 M HCl presents the best resistive switching performance, which might be relative to its texture without violent tortuosity. • The protonated g-C 3 N 4 -based memory devices present good environmental robustness, including temperature and ionizing irradiation. • The high tolerant temperature (454 °C) can also be enhanced by doping BN for heat dissipation. Memory devices with simple sandwich structures using the g-C 3 N 4 treated by different concentration acids as active layers have been fabricated, which exhibit enhanced non-volatile bipolar switching performances and good environmental robustness. [Display omitted] The searching for new memory that can work under harsh conditions will be significant for their application in some important fields such as geothermal, oil and aerospace industries. In this work, memory devices with simple sandwich structures using the g-C 3 N 4 treated by different concentration acids as active layers have been fabricated, which exhibit non-volatile behaviors and bipolar switching characteristics. Protonation treatment can enhance the memory performance efficiently compared with un-protonized device. Among them, the device containing g-C 3 N 4 treated with 8 M HCl presents the best resistive switching performance with ON/OFF ratio of 104 and good retention capability, which might be relative to its texture without violent tortuosity. In addition, the protonated g-C 3 N 4 -based memory devices exhibit good environmental robustness, including temperature and ionizing irradiation. Specially, its high tolerant temperature (454 °C) can also be assisted by doping BN for heat dissipation. Their good thermal/irradiating stabilities are assigned to the strong bond energy of C N double bonds localized π-conjugated tri-s-triazine rings. In all, the facial protonation treatment without any functionalization or supporting, the simple sandwich device structure and good environmental robustness endow their promising applications in aerospace and outdoor environment. [ABSTRACT FROM AUTHOR]

Two new two- and three-dimensional transition-metal-organic frameworks, namely, [Ni(imbz)] ( 1), [Cu(imbz)·4HO] ( 2), (imbz = 4-(imidazole-1-yl)-benzoic acid), have been hydrothermally synthesized and structurally determined. Compound 1 is a 2-D (4, 4)-network framework consisting of square grid with dimensions of ca. 11.4158(11) × 11.4158(11) Å, and 2 exhibits a 3-D framework encapsulating four guest solvent waters. Interestingly, both compounds exhibit tunable photoluminescences upon thermochromisms, i.e., upon heating, two compounds undergo color changes from blue to green (for 1) and dark blue to light blue (for 2) accompanied by a reduction or disappear of the fluorescent intensities. Graphical Abstract: Two new two- and three-dimensional transition-metal-organic frameworks exhibiting tunable photoluminescences upon thermochromisms have been structurally determined. They present 2-D (4, 4)-network framework and 3-D framework encapsulating four guest solvent waters.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Two new heterometallic inorganic-organic hybrids containing polynuclear halobismuthates anions and ruthenium complex cations, i.e., [Ru(tpy)][(BiICl)·I] ( 1), [Ru(bipy)(bipyo](BiI) ( 2), (tpy = 2,2′:6′,2″-terpyridine, bipy = 2,2′-bipyridine, bipyo = 2,2′-bipyridine-6-olato) have been structurally determined. These hybrids are the rare examples of mixed-metal halobismuthates containing photochemically active coordination cations, and 1 consists of mixed halo atoms. C-H···I hydrogen bonds among halobismuthates clusters and [Ru(tpy)]/[Ru(bipy)(bipyo] countercations contribute to the formation of a 3-D network. Moreover, their absorption spectra and photoluminescence have also been discussed, and their absorption edges fall in the range of those of semiconductors. Graphical Abstract: Two new heterometallic inorganic-organic hybrids containing polynuclear halobismuthates anions and ruthenium complex cations have been structurally determined, which represent the rare examples of mixed-metal halobismuthates containing photochemically active coordination cation and mixed halo atoms. C-H···I hydrogen bonds contribute to the formation of a 3-D network, and their absorption spectra and photoluminescence have also been discussed.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

A new bimetallic inorganic-organic hybrid {[Ru(phen)](PbI)} (phen = 1,10-phenanthroline) ( 1) with its (PbI) polymeric iodoplumbate templated by ruthenium complex [Ru(phen)], has been structurally determined. 1 is the rare example of mixed-metal iodoplumbate containing photochemically active coordination cation. The 1-D (PbI) chain is constructed from edge-sharing of neighboring 2 × 3 PbI units. C-H···I hydrogen bonds among (PbI) inorganic anions and [Ru(phen)] counteractions contribute to the formation of a 2-D layer. Moreover, its absorption spectrum and photoluminescence have also been discussed. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The combination of N , N ′-dipyridyl-tetrachloroperylene diimide (4Cl-DPPDI) buliding blocks with lead iodides in the presence of hydrogen iodides led to a novel D-A hybrid heterostructure with segregated iodoplumbate anions and 2-D H-bonded 4Cl-DPPDI networks as electron donors and acceptors. Due to the compact anion-π interactions as well as small energy gaps between the donors and acceptors, persistent and stable radical anions are generated in such a unique complex triggered by natural-light irradiation, which thus exhibits a panchromatic absorption. Induced by the compact anion-π interactions and small energy gaps between the donor and acceptor components, persistent radical anions are photogenerated in a novel D-A hybrid heterostructure, which thus exhibits a panchromatic absorption. Image 1 • A novel D-A hybrid heterostructure composed of perylene diimide dyes and iodoplumbate anions have been synthesized. • In the structure, the iodoplumbate anions and perylene diimide networks acted as electron donors and acceptors, respectively. • The donor and acceptor components in the heterostructure are interconnected through the anion-π interactions. • Due to the compact connections, persistent and stable radical anions are triggered by natural-light irradiation. • The generation mechanism of these persistent and stable radical anions was studied through theoretical calculation. [ABSTRACT FROM AUTHOR]