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Two mononuclear Dy(III) compounds and one heteronuclear Dy(III)–K(I) compound, [Dy(tmpd)3(4,4′-dmpy)] (1), [KDy2(tmpd)8]·C5H6N (2) and [Dy(tmpd)3(dppz)] (3) (4,4′-dmpy = 4,4′-dimethyl-2,2′-bipyridyl, tmpd = 4,4,4-trifluoro-1-(4-methylphenyl)butane-1,3-dione, and dppz = dipyrido[3,2-a:2′,3′-c]phenazine), were synthesized by changing the organic bases and auxiliary ligands. The coordination environments of compounds 1 and 3 are different DyN2O6 configurations resulting from steric effects of different auxiliary ligands, while 2 has KF6O6 and DyO8 coordination environments because of the introduction of an organic base (CH3OK). The Dy(III) ions in compounds 1 and 2 have a triangular dodecahedral (D2d) configuration and square antiprismatic (D4d) configuration, respectively. Compound 3 contains two crystallographically equivalent Dy(III) ions of which the eight-coordinated geometries uniformly behave as distorted square antiprismatic (D4d) configurations. Compound 2 affords a novel Dy(III)–K(I) compound with unusually coordinated fluorine atoms of trifluoromethyl groups of β-diketone ligands. 2 is a centrosymmetric structure in which the central K(I) ion is located at the middle of two Dy(III) ions, resulting in an icosahedral (Ih) configuration. Magnetic investigations demonstrate that 1 and 3 display slow magnetic relaxation behaviors. The effective barriers are 94.91 K in 1 and 82.44 K in 3. The M versus H data exhibit weak butterfly-shaped hysteresis loops at 2 K for 1 and 3. The uniaxial magnetic anisotropies, magnetostructural correlations and relaxation mechanism were investigated both experimentally and theoretically. The experimental and theoretical studies indicate that compound 1 exhibits the best magnetic properties among compounds 1–3. The theoretical predictions of quantum tunneling of magnetization time and effective barriers are consistent with the corresponding experimental values. Our results indicate that the different organic bases and substituted groups of auxiliary ligands play an important role in synthetic processes, finally affording distinct structures and magnetic properties. [ABSTRACT FROM AUTHOR]

Three bismuth(III) bromide hybrids based on 2,2′-bipyridyl-1,1′-dioxide (bp2do) were obtained by a solvothermal method, namely Bi2Br6(bp2do)2 (1), Bi2Br6(bp2do)2·0.5CH3CN (2), and [PP14][BiBr4(bp2do)] (3, PP14 = 1-butyl-1-methylpiperidinium). 1 features a centrosymmetric [Bi2Br6O4] dimer, in which two identical [BiBr4O2] octahedra edge-share two Br atoms; 2 contains a [Bi2Br6O4] dinuclear unit with a unique configuration, in which a [BiBr4O2] octahedron face-shares one Br and two O atoms with a [BiBr3O4] pentagonal-bipyramid. Moreover, the metal–ligand linking mode adopted in 2 has not been reported before. The choice of organic solvents could induce different Bi–Br–bp2do geometries with a dimer in 1 and a dinuclear unit in 2. Introduction of ionic liquid cations resulted in the ionic compound 3 featuring a mononuclear [BiBr4(bp2do)] unit. A more rigid environment with more hydrogen bonds leads to visible green phosphorescence with long lifetime for 3 under UV light. The three compounds possess similar phosphorescence peaks at 77 K, which originates from inorganic-to-organic charge transfer (IOCT) as confirmed by density functional theory (DFT) calculations. [ABSTRACT FROM AUTHOR]

Two chlorobismuthate hybrids incorportating ionic liquid cations (ILCs) with second-level room-temperature phosphorescence (RTP), namely [Emim]BiCl4(bp2do) (1) and [Emmim]BiCl4(bp2do) (2) (Emim = 1-ethyl-3-methylimidazolium, Emmim = 1-ethyl-2,3-dimethylimidazolium, bp2do = 2,2′-bipyridyl-1,1′-dioxide), were obtained. The decrease in the number of substituents in the ILCs largely enhanced the phosphorescence quantum yield (QY) from 2.31% for 2 to 25.05% for 1, owing to the more compact structure of 1. The two compounds possess uncommonly different temperature-dependent emission peak shifting behaviors, which could be ascribed to whether the electron-phonon interactions or the exciton localization at high energy is dominant. Density functional theory (DFT) calculations show that the optical absorptions for both compounds originate from inorganic moiety to organic moiety charge transfer (IOCT). X-ray scintillation was observed for both compounds, which is the first report on inorganic–organic halobismuthate hybrids. Finally, 1 with higher QY was fabricated into a luminescent thin flim, letters and a bendable round wafer with polyacrylonitrile (PAN). This work provides new insight on RTP materials and X-ray scintillation materials involving bismuth halides. [ABSTRACT FROM AUTHOR]

Solvent responsive magnets comprise a class of molecule-based materials where lattice solvent driven structural transformation leads to the switching of magnetic properties. Herein, we present a special type of magnet where single-crystal to single-crystal (SCSC) transformations within mononuclear DyIII compounds result in the switching of DyIII single-molecule magnets (SMMs). This structural transformation involves lattice solvents which leads to significant changes in the color and magnetic properties. Additionally, the relaxation dynamics of mononuclear DyIII compounds are perceptibly fine-tuned by the modification of β-diketonate ligands. The uniaxial magnetic anisotropies, magneto-structural correlations and the relaxation mechanism were investigated by magnetic studies and ab initio calculations. These experimental and theoretical studies indicate that compound 2 exhibits the best magnetic properties in compounds 1–4. The experimental observation is supported by the theoretical prediction of QTM time (τ ZeeQTM) as theτ ZeeQTM of 2 is remarkably longer than those of the other three compounds by an order of magnitude. This means that, compared with 1, 3, and 4, the magnetic relaxation of 2 is significantly slower. Meanwhile, 2 has the largest value of axial ESP (the axial electrostatic potential), which supports the smallest gXY value in these compounds, resulting in better SMM properties. The present results offer a systematic synthesis regulation to change the magnetization dynamics and further understand magneto-structural correlations for DyIII SMMs. [ABSTRACT FROM AUTHOR]

By utilizing a flexible fluorinated bis(triazole) ligand 1,4-bis(1,2,4-triazole-1-ylmethyl)-2,3,5,6-tetrafluorobenzene (Fbtx), a thermally and chemically stable cobalt(II)-containing tungstovanadate-based metal–organic framework (MOF) {[Co3(Fbtx)5(V2W18O62)(H2O)2]·26H2O}n (denoted as CZU-5) was synthesized and structurally characterized. The X-ray structural analysis revealed that CZU-5 features a three-dimensional (3-D) self-penetrated α-polonium cubic structure, which results from a 3-D 4-fold interpenetrated diamondoid [Co(Fbtx)]n network connected by the Wells–Dawson-type tungstovanadate clusters. Unexpectedly, the introduction of vanadium atoms as heteroatoms into the Dawson-type anion in polyoxometalate (POM)-based coordination polymers has not been reported to date. For the first time, the POM-based material was demonstrated to be an effective catalyst for the solvent-free ring-opening polymerization of ε-caprolactone. Moreover, the CZU-5 catalyst could be recycled up to five times with the retention of both catalytic activity and crystal structure. [ABSTRACT FROM AUTHOR]

Based on a multidentate Schiff-base ligand, N,N′-bis(2-hydroxy-5-methyl-3-formylbenzyl)-N,N′-bis-(pyridin-2-ylmethyl)ethylenediamine (H2L), two binuclear DyIII compounds, with formulas [Dy2(L)(NO3)3(CH3O)] (1) and [Dy2(L)(NO3)3(CH3CH2O)] (2), have been synthesized under different solvent systems. The DyIII ions in 1 and 2 adopt monocapped square antiprism coordination geometries, while different structural distortions can be observed. The two DyIII ions in 1 and 2 are bridged by two phenoxide atoms of one L2− ligand and one bridged CH3O−/CH3CH2O− oxygen node, leading to an approximate fusiform Dy2O3 core. The different DyIII–Obridged node distances, DyIII–Obridged node–DyIII angles and DyIII⋯DyIII distances can be observed. Magnetic studies reveal that 1 and 2 display slow magnetic relaxation behaviours under a zero direct-current field with the effective energy barriers (Ueff) of 114.17 K and 171.23 K, respectively. Furthermore, compound 2 possesses the highest Ueff in nine-coordinated Dy2 compounds. The M versus H data exhibit weak butterfly-shaped hysteresis loops at 2 K for 2. The rare CH3O−/CH3CH2O−-bridged nine-coordinated binuclear DyIII single-molecule magnets (SMMs) significantly regulate and enhance the Ueff of compounds 1 and 2. To deeply understand their different magnetic behaviours, the magnetic anisotropies and magnetic interactions of 1 and 2 were studied by ab initio calculations. These findings demonstrate an efficient approach for regulating and enhancing the magnetic anisotropy barriers using a bridged CH3O− anion or CH3CH2O− anion. [ABSTRACT FROM AUTHOR]

Herein, a zero-dimensional (0D) hybrid organic–inorganic metal halide (OIMH) [BPy]6[Pb3Br12] (BPB, BPy = N-butylpyridinium) as a room-temperature phosphorescent (RTP) material is synthesized. Through molecular sensitization, its RTP quantum efficiency can be increased by a maximum of 14-fold. A white-light-emitting device is obtained via a solvent-free and eco-friendly melting method. [ABSTRACT FROM AUTHOR]

The different hydrogen bond interactions in two organic–inorganic hybrid manganese halide compounds, namely [A]2[MnBr4] (A = N-butyl-N-methylpyrrolidinium ([P14]+) for (1) and N-butyl-N-methylpiperidinium ([PP14]+) for (2)), lead to distinct photoluminescence quantum yields (81% for 1; 55% for 2). Further applications of luminescent 1 are also developed. [ABSTRACT FROM AUTHOR]

Quasi-two-dimensional (Q-2D) perovskites ((RNH3)2MAn−1PbnI3n+1, RNH3 represents the organic spacer (mostly phenethylammonium (PEA) and n-butylammonium (BA)) and MA = methylammonium) have shown great potential for application in solar cells due to their intrinsic stability, where the organic spacer dominantly determines the Q-2D perovskite ambient stability and device performance. Current studies merely concentrate on unary organic spacer Q-2D perovskites, either using BA or PEA. Herein, for the first time, we have successfully designed and fabricated (PEA1−xBAx)2MA3Pb4I13 binary spacer-based Q-2D perovskite films, and demonstrated that the device using binary organic spacer-based Q-2D perovskite films has substantially better performance than that using either of the unary organic spacer-based Q-2D perovskite films. The (PEA0.8BA0.2)2MA3Pb4I13 binary spacer device yields a maximum power conversion efficiency of 15.7%, which outperforms the efficiency record (12–14%) for unary spacer (PEA or BA) Q-2D perovskite devices. In particular, a peak open-circuit voltage of 1.21 V is achieved due to a non-radiative recombination loss of ∼100 mV, the lowest reported loss value for Q-2D perovskite devices. The high device performance results from binary-spacer-induced intensified film surface quality, preferable vertical orientation of crystals and improved film optoelectronic properties as well as obviously decreased device recombination losses. These findings open up a new avenue for the rational design of Q-2D perovskite materials with polynary organic spacer. [ABSTRACT FROM AUTHOR]

Herein, two indium-based metal organic frameworks (In-MOFs), namely [(CH3)2NH2][In(bpdc)2]·(DMF)2 (1) and [(CH3)2NH2]3[(In3Cl2)(bpdc)5]·(H2O)5(DMF)2.5 (2, bpdcH2 = 4,4′-biphenyldicarboxylic acid), have been synthesized and characterized. By introducing a Cl− ion as a terminal ligand to break the symmetrical coordination environment of a typical InO8 dodecahedron as that in a three dimensional (3D) compound 1 with a 4-connected and four-fold interpenetrating dia net topology, a chiral 2D compound 2 with unique double-helical chains along the c axis is generated. Fluorescence (FL) measurements indicate that both compounds demonstrate excellent FL sensing behaviour towards CS2, a trace amount of Fe3+ ions and nitro-containing explosives. Notably, the layered 2 exhibits a unique “turn on” FL sensing behaviour towards thiol molecules, e.g., cysteine and 1-butylmercaptan, by exfoliating 2 into a few-layer FL material. The detection mechanism was investigated in detail by multiple characterizations including but not limited to EDS, SEM and AFM. The [(CH3)2NH2]+ cations in 2 can be replaced by an Eu3+ ion to generate 2@Eu3+ which exhibits a new characteristic sharp red emission of Eu3+. More importantly, 2@Eu3+ can serve as a convenient ratiometric FL sensor for temperature, demonstrating obvious color changes from weak purple to red under UV light as the temperature increases. Furthermore, cationic green- and red-light emitting dyes incorporated with 2@dyes emit white light with 17.28% quantum yield. [ABSTRACT FROM AUTHOR]

Vanadium dioxide (VO2) is emerging as the most promising candidate for next-generation smart windows. However, the applications of VO2-based films encounter the bottleneck of its optimal thermochromic property being unable to be retained as the modulating phase transition temperature approaches the ambient temperature. Joule heating is an effective approach to maintain the infrared switching ability of pristine VO2 films, but the accompanied energy consumption and its effects on the infrared switching ability of flexible VO2 films are still unexplored. Here, we fabricated flexible VO2 nanoparticle films via a scalable blade-coating process and investigated the effects of Joule heating on the infrared switching of flexible VO2 films. Infrared switching triggered by Joule heating can be effectively managed by the input voltages with high stability and exhibited no obvious degradation even after 10 000 bending cycles, suggesting excellent flexibility. Importantly, we found that maximum infrared switching ability could be sustained with a dramatically reduced power, 15% of the threshold power (224 mW cm−2), by utilizing the hysteresis behaviour of the as-prepared VO2 films. This study provides a practical strategy for utilizing hysteresis behaviour to maintain the optimal infrared switching ability of flexible VO2 films with low energy consumption, substantially promoting the development of flexible smart devices. [ABSTRACT FROM AUTHOR]

Six phosphomolybdate compounds based on the sandwich-type cluster [M(P4Mo6X31)2] (M = Na, Mn, Na/Cu; X = O or OH) have been solvothermally synthesized by using various organic/inorganic cations as templates, namely, (H3AEP)4[Na(P4Mo6O31H5.5)2]·4H2O (1), (Me2NH2)7[NaMn(H2O)][Mn(P4Mo6O31H6)2]·5H2O (2), (H4tpc)0.5(H4tpb)0.5(H0.5bpp)[Na2.5(H2O)][Na(P4Mo6O31H8)2]·2H2O (3), (Me2NH2)6.5[Na4(H2O)8][Cu0.25Na0.75(P4Mo6O31H6.25)2] (4), (Me2NH2)1.5(NH4)4[Mn1.5Na4.5(H2O)7][Mn(P4Mo6O31H4.5)2]·3.5H2O (5), and (DMIm)4[Mn1.5Na2(H2O)8][Mn(P4Mo6O31H6.5)2]·1.5H2O (6) (AEP = 1-(2-aminoethyl) piperazine, Me2NH = dimethylamine, bpp = 1,3-bis(4-pyridyl)propane, tpb = 1,2,4,5-tetra(4-pyridyl)-benzene, tpc = a,a-1,4-dihydroxy-e,e,e,e-1,2,4,5-tetra-(4-pyridyl)cyclohexane, and [DMIm] = 1,3-dimethylimidazolium). These compounds were characterized by elemental analysis, PXRD, IR, TGA, and single-crystal X-ray diffraction. Compound 1 features a classical zero-dimensional (0D) dimeric cluster [Na(P4Mo6O31H5.5)2]. Compound 2 possesses a 1-D chain constructed from the linkage of [Mn(P4Mo6O31H6)2] dimeric clusters and M (M = Na+, Mn2+) linking metal ions. Compounds 3 and 4 are characteristic of 2-D layers, which are built up by connecting [Na(Mo6P4O31H8)2] and [M(Mo6P4O31H6.5)2] (M = Cu0.25/Na0.75) dimeric clusters, respectively, via Na+ ions. Compounds 5 and 6 feature 3D frameworks, where the dimeric clusters are interconnected by M (M = Na+, Mn2+) ions. Thus, the application of linking metal ions with different coordination modes and valence states to assemble [M(P4Mo6X31)2] clusters is promising for harvesting new phosphomolybdates. In particular, compounds 1 and 5 exhibited visible light degradation performance for Rhodamine B. [ABSTRACT FROM AUTHOR]

Photochromic [2]rotaxanes with bidirectional photoswitchability were fabricated, whose colored states exhibit remarkable visible-light and thermal stabilities as revealed by systematically spectroscopic investigations. [ABSTRACT FROM AUTHOR]

Graphite, widely employed as an anode in LIBs, is limited by a theoretical capacity of 372 mA h g−1. Progress in nanoscience and energy storage systems has brought attention to nano-sized α-Fe2O3 as next-generation anodes, providing capacities up to three times higher than graphite. However, mass-market application remains challenging due to a long-term cycling capacity loss, the intrinsic low conductivity and safety concerns regarding the “nano-nature” of α-Fe2O3 nanoparticles. Promising solution concepts include the embedding of α-Fe2O3 into conductive sp2 derived carbons with volume-buffer capabilities. This review article presents the current status of α-Fe2O3/carbon nanocomposites with superior electrochemical performance based on 2D graphene, 1D carbon nanofibers and 1D carbon nanotubes. [ABSTRACT FROM AUTHOR]

Monoclinic VO2 (M) is a key material for energy-efficient smart window applications. Fine crystalline VO2 particles with an ambient phase transition temperature are urgently required to achieve excellent properties including high luminous transmittance and solar heat shielding ability. Moreover, the anti-oxidation ability is regarded as a significant factor which determines the lifetime of VO2-based products. In this paper, well-crystallized W-doped VO2 with low phase transition temperature, excellent solar heat shielding ability and considerable anti-oxidation ability was synthesized by a solid-state reaction process. The phase transition temperature was reduced from 67.3 °C to 10.8 °C at 2.0% W doping with an efficiency of −28.1 °C per at%. Importantly, an excellent balance between the phase transition temperature and the latent heat was obtained at high doping levels (1.5–2.0%). Furthermore, W-doped VO2 particles exhibited a significantly longer exposure time (more than 5 h) at 300 °C in air than the previously reported 2 h in the literature, and the corresponding derived composite foils showed excellent luminous transmittance and solar heat shielding properties (Tlum = 49.9% and Tsol = 44.8% for 2.0% W doping). [ABSTRACT FROM AUTHOR]

Ionothermal syntheses, characterization and properties of two selenidostannate compounds with two- or three-dimensional (D) skeletons by utilizing the synergistic structure-directing effects of the ionic liquid (IL) [Bmmim]Cl (Bmmim = 1-butyl-2,3-dimethylimidazolium) and in-situ generated metal–amine complexes (MACs), namely, 2D-(Bmmim)2[Ni(teta)(en)][Sn3Se7]2 (1, teta = triethylenetetramine, en = ethylenediamine) and 3D-(Bmmim)1.5(dienH)0.5Ni(dien)2[Sn4Se9]2 (2, dien = diethylenetriamine) are presented. Single-crystal X-ray diffraction analyses revealed that compound 1 possesses a lamellar anionic [Sn3Se7]n2n− structure comprising a large ten-membered ring with a window size of 24.85 × 13.38 Å when considering the [Sn3Se4] semicube as a member. While 2 features a 3D [Sn4Se9]n2n− framework with orthogonally intersecting channels where the three different types of cations are filled. The successful isolation of these two compounds demonstrated again that the mixed SDA strategy is promising for the synthesis of novel crystalline selenidostannates. [ABSTRACT FROM AUTHOR]

A water-stable Eu-coordination polymer (CP), namely [HMIm]Eu(DHBDC)2 (1) (HMIm = 1-hexyl-3-methylimidazolium; H2DHBDC = 2,5-dihydroxytelephthalic acid), was obtained using ionothermal synthesis. 1 represents the first coordination polymer capable of qualitative and quantitative detection of Ba2+ in aqueous solutions with a fluorescent enhancement that is visible to the human eye, which can be ascribed to the formation of fluorescent compound Ba(DHBDC) (2) during the detection process. Temperature-dependent photoluminescence (PL) makes 1 a potential material for a fluorescence thermometer. Furthermore, the detection process for Ba2+ using 1 turns the one-PL transition fluorescence thermometer into a two-PL transition fluorescence thermometer, increasing the accuracy of the fluorescence thermometer. [ABSTRACT FROM AUTHOR]

The hydrothermal synthesis of VO2 (M) nanoparticles is commonly considered as a result of the transformation of intermediate phase VO2 (A) or VO2 (B). Here, we found a new intermediate phase (NH4)2V4O9 that appeared in the hydrothermal synthesis and played a crucial role in the formation of VO2 (M) nanoparticles. Then, the mechanism for the transformation of intermediate (NH4)2V4O9 to VO2 (M) was described as a self-assembly–decomposition–nucleation–growth process. Pure crystalline VO2 nanoparticles were ultimately obtained and showed excellent thermochromic properties. The phase-transition temperature Tc of VO2 (M) nanoparticles is approximately 65 °C. Furthermore, VO2 flexible foils on PET at a VO2 solid content of 1.5–2.0% show excellent optical properties with luminous transmittance (Tlum) ＞ 50% and solar energy modulation ability (ΔTsol) ＞ 15%. [ABSTRACT FROM AUTHOR]

Presented are the syntheses, characterizations and properties of a series of selenidostannate compounds directed by metal–amine complex (MAC) cations and/or [Bmmim]+ (Bmmim = 1-butyl-2,3-dimethylimidazolium). Mixtures of the ionic liquid (IL) (Bmmim)Cl and amines, such as ethylenediamine (en) and diethylenetriamine (dien), in various ratios were used to ionothermally/solvothermally prepare four selenidostannates, namely, [Mn(en)3]Sn3Se7 (1), [Mn(dien)2]Sn3Se7·H2O (2), (Bmmim)3[Mn(en)3]2[Sn9Se21]Cl (3) and (Bmmim)6[Mn(dien)2]2Sn15Se35 (4). Single-crystal X-ray diffraction analyses revealed that these compounds exhibit lamellar anionic [Sn3Se7]n2n− structures. [Sn3Se7]n2n− layers in all 1–4 possess a {63} net, considering [Sn3Se10] semi-cube unit as a 3-connected node; however, diverse multi-membered rings exist there. In compounds 1 and 2, all the [Sn3Se10] units are 3-connected nodes interlinking with each other via edge-sharing two Se atoms to produce six-membered rings. However, in compound 3, the insertion of two [Sn3Se9] units into a six-membered ring results in a novel eight-membered heart-shaped ring, which has never been observed before in the family of chalcogenidostannates. More interestingly, the [Sn3Se7]n2n− layer in compound 4 consists of mixed six- and eight-membered rings. The phase composition is strongly dependent on the ratio of IL to MAC in the syntheses, e.g., 1 and 2 were obtained with IL : MAC ratios less than 3 : 1 and 4 : 1, while 3 and 4 were obtained when the ratios were increased to 4 : 1 and 5 : 1, respectively. The structural variation from 1 to 4 clearly indicates the competitive and synergistic effects between MAC and IL cation on the formation of lamellar selenidostannates. A synthetic approach via varying the ratio of IL to MAC cation as solvent and structure-directing agent will be attractive in the synthesis of novel chalcogenidometallates. [ABSTRACT FROM AUTHOR]

Vanadium dioxide (VO2) is a key material for thermochromic smart window applications because of its Mott phase transition properties. However, the applications of VO2 have been restricted because of its drawbacks in performance, including high phase transition temperature (Tc), low luminous transmittance (Tlum), limited solar energy modulation ability (∆Tsol) and unpleasant color. Various studies have been undertaken to resolve these problems but the improvement in any one aspect is always accompanied by a deterioration of the others. This paper reports that Zr doping can simultaneously decrease Tc, increase Tlum, improve ∆Tsol and modify the color of VO2 foils. The Tc value decreased from 68.6 °C to 64.3 °C at 9.8% Zr-doping; meanwhile, the composite foils prepared from Zr-doped VO2 nanoparticles exhibited excellent luminous transmittance (up to 60.4%) and solar energy modulation ability (up to 14.1%). The experimental optical band gap was 1.59 eV for the undoped VO2, which increased to 1.89 eV at 9.8% doping. As a result, the color of the Zr-doped foils was modified to increase their luminous transmittance and lighten the yellowish color of the VO2 foil. The first-principles calculation was in good agreement with the experiment results. The W-Zr-codoped VO2 nanoparticles were prepared to further decrease the transition temperature (28.6 °C), while simultaneously maintaining the luminous transmittance (48.6%) and solar energy modulation ability (4.9%) of the derived foils. [ABSTRACT FROM AUTHOR]

Solvent responsive magnets comprise a class of molecule-based materials where lattice solvent driven structural transformation leads to the switching of magnetic properties. Herein, we present a special type of magnet where single-crystal to single-crystal (SCSC) transformations within mononuclear DyIII compounds result in the switching of DyIII single-molecule magnets (SMMs). This structural transformation involves lattice solvents which leads to significant changes in the color and magnetic properties. Additionally, the relaxation dynamics of mononuclear DyIII compounds are perceptibly fine-tuned by the modification of β-diketonate ligands. The uniaxial magnetic anisotropies, magneto-structural correlations and the relaxation mechanism were investigated by magnetic studies and ab initio calculations. These experimental and theoretical studies indicate that compound 2 exhibits the best magnetic properties in compounds 1-4. The experimental observation is supported by the theoretical prediction of QTM time (τZeeQTM) as theτZeeQTM of 2 is remarkably longer than those of the other three compounds by an order of magnitude. This means that, compared with 1, 3, and 4, the magnetic relaxation of 2 is significantly slower. Meanwhile, 2 has the largest value of axial ESP (the axial electrostatic potential), which supports the smallest gXY value in these compounds, resulting in better SMM properties. The present results offer a systematic synthesis regulation to change the magnetization dynamics and further understand magneto-structural correlations for DyIII SMMs.

The different hydrogen bond interactions in two organic-inorganic hybrid manganese halide compounds, namely [A]2[MnBr4] (A = N-butyl-N-methylpyrrolidinium ([P14]+) for (1) and N-butyl-N-methylpiperidinium ([PP14]+) for (2)), lead to distinct photoluminescence quantum yields (81% for 1; 55% for 2). Further applications of luminescent 1 are also developed.

Monoclinic VO 2 (M) is a key material for energy-efficient smart window applications. Fine crystalline VO 2 particles with an ambient phase transition temperature are urgently required to achieve excellent properties including high luminous transmittance and solar heat shielding ability. Moreover, the anti-oxidation ability is regarded as a significant factor which determines the lifetime of VO 2 -based products. In this paper, well-crystallized W-doped VO 2 with low phase transition temperature, excellent solar heat shielding ability and considerable anti-oxidation ability was synthesized by a solid-state reaction process. The phase transition temperature was reduced from 67.3 °C to 10.8 °C at 2.0% W doping with an efficiency of -28.1 °C per at%. Importantly, an excellent balance between the phase transition temperature and the latent heat was obtained at high doping levels (1.5-2.0%). Furthermore, W-doped VO 2 particles exhibited a significantly longer exposure time (more than 5 h) at 300 °C in air than the previously reported 2 h in the literature, and the corresponding derived composite foils showed excellent luminous transmittance and solar heat shielding properties (T lum = 49.9% and T sol = 44.8% for 2.0% W doping).

Ionothermal syntheses, characterization and properties of two selenidostannate compounds with two- or three-dimensional (D) skeletons by utilizing the synergistic structure-directing effects of the ionic liquid (IL) [Bmmim]Cl (Bmmim = 1-butyl-2,3-dimethylimidazolium) and in-situ generated metal-amine complexes (MACs), namely, 2D-(Bmmim)2[Ni(teta)(en)][Sn3Se7]2 (1, teta = triethylenetetramine, en = ethylenediamine) and 3D-(Bmmim)1.5(dienH)0.5Ni(dien)2[Sn4Se9]2 (2, dien = diethylenetriamine) are presented. Single-crystal X-ray diffraction analyses revealed that compound 1 possesses a lamellar anionic [Sn3Se7]n(2n-) structure comprising a large ten-membered ring with a window size of 24.85 × 13.38 Å when considering the [Sn3Se4] semicube as a member. While 2 features a 3D [Sn4Se9]n(2n-) framework with orthogonally intersecting channels where the three different types of cations are filled. The successful isolation of these two compounds demonstrated again that the mixed SDA strategy is promising for the synthesis of novel crystalline selenidostannates.

A water-stable Eu-coordination polymer (CP), namely [HMIm]Eu(DHBDC)2 (1) (HMIm = 1-hexyl-3-methylimidazolium; H2DHBDC = 2,5-dihydroxytelephthalic acid), was obtained using ionothermal synthesis. 1 represents the first coordination polymer capable of qualitative and quantitative detection of Ba(2+) in aqueous solutions with a fluorescent enhancement that is visible to the human eye, which can be ascribed to the formation of fluorescent compound Ba(DHBDC) (2) during the detection process. Temperature-dependent photoluminescence (PL) makes 1 a potential material for a fluorescence thermometer. Furthermore, the detection process for Ba(2+) using 1 turns the one-PL transition fluorescence thermometer into a two-PL transition fluorescence thermometer, increasing the accuracy of the fluorescence thermometer.

Presented are the syntheses, characterizations and properties of a series of selenidostannate compounds directed by metal-amine complex (MAC) cations and/or [Bmmim](+) (Bmmim = 1-butyl-2,3-dimethylimidazolium). Mixtures of the ionic liquid (IL) (Bmmim)Cl and amines, such as ethylenediamine (en) and diethylenetriamine (dien), in various ratios were used to ionothermally/solvothermally prepare four selenidostannates, namely, [Mn(en)3]Sn3Se7 (1), [Mn(dien)2]Sn3Se7·H2O (2), (Bmmim)3[Mn(en)3]2[Sn9Se21]Cl (3) and (Bmmim)6[Mn(dien)2]2Sn15Se35 (4). Single-crystal X-ray diffraction analyses revealed that these compounds exhibit lamellar anionic [Sn3Se7]n(2n-) structures. [Sn3Se7]n(2n-) layers in all 1-4 possess a {6(3)} net, considering [Sn3Se10] semi-cube unit as a 3-connected node; however, diverse multi-membered rings exist there. In compounds 1 and 2, all the [Sn3Se10] units are 3-connected nodes interlinking with each other via edge-sharing two Se atoms to produce six-membered rings. However, in compound 3, the insertion of two [Sn3Se9] units into a six-membered ring results in a novel eight-membered heart-shaped ring, which has never been observed before in the family of chalcogenidostannates. More interestingly, the [Sn3Se7]n(2n-) layer in compound 4 consists of mixed six- and eight-membered rings. The phase composition is strongly dependent on the ratio of IL to MAC in the syntheses, e.g., 1 and 2 were obtained with IL:MAC ratios less than 3:1 and 4:1, while 3 and 4 were obtained when the ratios were increased to 4:1 and 5:1, respectively. The structural variation from 1 to 4 clearly indicates the competitive and synergistic effects between MAC and IL cation on the formation of lamellar selenidostannates. A synthetic approach via varying the ratio of IL to MAC cation as solvent and structure-directing agent will be attractive in the synthesis of novel chalcogenidometallates.