Two Polyoxometalate-Based Hybrid Compounds Modified by Iron Schiff Base Complexes: Syntheses, Crystal structures, Cyclic Voltametric Studies and Nonlinear Optical Properties.

Two new polyoxometalate (POM)-based hybrid compounds modified by a Schiff base, [Fe(DAPSC)(H O) ] [HPMo Mo O ] ⋅ 5H O (1) and [Fe(DAPSC)(H O)] [HPV Mo Mo O ] ⋅ 6H O (2), (DAPSC=2,6-diacetylpyridine bis-(semicarbazone)), have been successfully constructed from typical Keggin POMs, iron ions, and DAPSC ligands under hydrothermal condition. Structural analysis demonstrates that the Fe-Schiff base ligand units are free from polyacid anions in compound 1. While in compound 2, the Fe-Schiff base ligand units are bridged with polyacid anions via Fe-O bonds to emerge a stable double-supported skeleton.

Polyoxometalate-Based Metal-Organic Frameworks with Unique High-Nuclearity Water Clusters.

The maximum exposure of polyoxometalates (POMs) is of great significance to enhance the catalytic performance of HKUST-1 with incorporated Keggin-type POMs. Herein, two phosphovanadomolybdates were encapsulated into the HKUST-1 via a hydrothermal method to obtain two polyoxometalate-based metal-organic frameworks, formulated as [Cu(BTC)(HO)][HPMoVO]@(HO) () and [Cu(BTC)(HO)][HPMoVO]@(HO) (). Single-crystal X-ray diffraction analysis indicates that two compounds contain unique high-nuclearity water clusters without organic counter cations.

Two new isolated Zn-ε-Keggin clusters modified by conjugated organic ligands with decent electrocatalytic and third-order NLO properties.

Two new bifunctional isolated hybrid compounds, [ε-PMoV8MoVI4O37(OH)3Zn4][iql]4·6H2O (1) and [ε-PMoV8MoVI4O38(OH)2Zn4][bipy]3[(CH3COO)(bipy)2Zn]·2H2O (2) (where iql = isoquinoline and bipy = 2,2'-bipyridine), based on Zn-ε-Keggin were successfully synthesized by self-assembly under hydrothermal conditions. It is interesting to note that acetate in 2 acted as a linker connecting the ε-Keggin anion with the one Zn atom (Zn5) and enabled the ε-Keggin anion to coordinate with more bipy ligands, culminating with a larger isolated system, which is the first reported isolated cluster of Zn5PMo12. Meanwhile, compounds 1-2 show great electrochemical behaviors and excellent electrocatalytic activity for the degradation of NaNO2.

An Unprecedented Bird Nest Molybdenum(V) Cobalto-Phosphate Nanosized Wheel Constructed from the [H (Mo O )(Co O) Co (PO ) (py) (EtOH) (H O) ] Anion.

An unprecedented bird-nest high-nuclear molybdenum(V) cobalto-phosphate nanosized wheel modified by imidazole (im) and pyridine (py), {[H (Mo O )(Co O) Co (PO ) (py) (EtOH) (H O) ]- @[(Him) (Hpy)]}(N-Et-py)(H PO )(py) (EtOH)⋅12 H O (1), has been successfully synthesized by self-assembly. The anionic huge wheel consists of two rare {Co O} squares, four {Co } tetramers, four {Mo } tetramers and four {Mo } dimers, linked by bridging oxygen atoms and [PO ] groups and encloses two imidazolium cations and a protonated pyridium for charge balance. Surprisingly, 1 represents the first twisted wheel-shaped cluster with a record high-nuclear molybdenum(V) cobalto-phosphate.

Two 3D Mn-based coordination polymers: synthesis, structure and magnetocaloric effect.

Two three-dimensional (3D) coordination polymers, namely Mn (CHCOO)(HCOO)(IN)(CHO)(HO) and Mn Mn (μ-O)(CHCOO)(IN)(HO) (abbreviated as and respectively; HIN = isonicotinic acid), were synthesized by the reaction of Mn(CHCOO)·4HO and isonicotinic acid under solvothermal conditions. Magnetic studies revealed that antiferromagnetic interactions may be present in compounds and . Moreover, the values of -Δ (26.

Two 2D Layered PMo Clusters with Potential Bifunctional Properties: Proton Conduction and CO Photoreduction.

Two hourglass-type molybdophosphate hybrids with the formulas [Cd(HO)DABT][Cd(HPMoO)]·19HO () and (CHOH)(CHN)[Co(HPMoO)]·HO () (DABT= 3,3'-diamino-5,5'-bis(1H-1,2,4-triazole)) have been successfully designed and synthesized via a hydrothermal method. Structure analysis revealed that the inorganic moieties in compounds and are made up of hourglass-type {M[PMo]} (M = Cd/Co) structure, which were constructed by two (PMo) units with single transition metal (TM) (Cd/Co) atom as the central metal. The {M[PMo]} (M = Cd/Co) structures were then further connected by TM to constitute a 2D layered structure.

Synthesis, crystal structures and magnetic properties of two heterometallic {LnCr} (Ln = Gd and Tb) complexes with one-dimensional wave chain structure.

Two isomorphic heterometallic 3d-4f cluster-based materials, formulated [GdCr(IN)(μ-O)(μ-OH)(μ-O)(HO)]·13HO (1) and [TbCr(IN)(μ-O)(μ-OH)(μ-O)(HO)]·13HO (2) (abbreviation: {LnCr}: Ln = Gd (1); Tb (2); HIN = isonicotinic acid), were achieved by hydro-/solvothermal method through using the ligand HIN. X-ray diffraction analysis illustrates eight lanthanide ions (Ln = Gd, Tb) and four transition-metal ions (Cr) of {LnCr} were constructed from two classical "drum-like" {LnCr} structures associated by organic ligands HIN, displaying a one-dimensional wave chain structure, which is rare. The magnetic properties of {GdCr} were inspected and showed the existence of antiferromagnetic coupling interactions between contiguous metal ions.

Lewis Acid Dominant Windmill-Shaped V Clusters: A Bifunctional Heterogeneous Catalyst for CO Cycloaddition and Oxidation of Sulfides.

Carbon dioxide (CO) and sulfides in gasoline are the main causes of air pollution. Considerable attention has been devoted to solving the problems, and the catalytic reaction seems to be a good choice. Owing to the high density of Lewis acid (LA) active sites and large numbers of open methoxide groups, polyoxovanadates (POVs) are an undisputed option as a heterogeneous catalyst for the CO cycloaddition reaction and catalytic oxidation of sulfides.

Multifunctional Polymolybdate-Based Metal-Organic Framework as an Efficient Catalyst for the CO Cycloaddition and as the Anode of a Lithium-Ion Battery.

A three-dimensional polymolybdate-based metal-organic framework (POMOF) consisting of Zn-ε-Keggin unit and organic linker, {[PMoMoO(OH)Zn][BPE]}·[BPE] (), was successfully obtained by the hydrothermal method. Compound is composed of Zn-ε-Keggin units and BPE ligands, featuring a fascinating 5-fold interpenetrating framework with topology. The catalytic performance of compound was investigated, and experiments showed that could effectively facilitate the cycloaddition reaction of CO with epoxides as Lewis acid heterogeneous catalyst.

Cl-Templated Assembly of Novel Peanut-like LnNi Heterometallic Clusters Exhibiting a Large Magnetocaloric Effect.

Two novel and fascinating high-nuclearity lanthanide-transition (4f-3d) heterometallic clusters were obtained based on an anion-template (Cl) and ligand-controlled approach, formulated as [GdNi(CO)(CHCOO)(IDA)(CO)(μ-O)(μ-OH)(μ-O)(HO)]·Cl·20HO (abbreviated as GdNi, ) and [EuNi(CO)(CHCOO)(IDA)(CO)(μ-O)(μ-OH)(μ-O)(HO)]·Cl·23HO (abbreviated as EuNi, ), where HIDA = iminodiacetic acid and HCO = oxalic acid. Structural analysis exhibits that the compounds and were both constructed by two enticing bowl-like anion units LnNi, featuring peanut-like structures. Besides, the assembly of LnNi was templated by five Cl ions.

A huge novel polyoxometalate-based cluster FePW exhibiting prominent electrocatalytic activity for the oxygen evolution reaction and third-order NLO properties.

Two novel POM-based huge clusters modified by conjugated organic ligands (DAPSC), {FePW} and {FeMoW}, have been successfully isolated. Compound 1 consists of a novel huge inorganic building block {FePW} and four organic groups DAPSC linked by ten iron ions and four sodium ions. The DAPSC ligands enhance the electric delocalization effects of polyoxoanions, leading to strengthening of the third-order nonlinear optical (NLO) responses of compounds 1-2.

3D Enantiomorphic Mg-Based Metal-Organic Frameworks as Chemical Sensor of Nitrobenzene and Efficient Catalyst for CO Cycloaddition.

Two enantiomorphic Mg -based metal-organic frameworks, {MgL(H O) } (1-D and 1-L) (where H L=2,2'-bipyridyl-4,4'-dicarboxylic acid) have been synthesized by solvothermal reaction without any chiral auxiliary. The single-crystal X-ray measurement and the structural analysis indicate that both 1-D and 1-L possess 2-fold interpenetrated frameworks with different left- and right-handed helical chains simultaneously, which serve as chiral source, thus transmitting chirality over the whole frameworks. The fluorescence measurements reveal that they exhibit a strong quenching response to nitrobenzene and could be potentially used as a chemical sensor.

Exploring the Magnetic Interaction of Asymmetric Structures Based on Chiral V Clusters.

Polyoxovanadates (III) are important class of polyoxometalates in molecular magnetism field, and particularly the systems which contain vanadium(III) centers. To date, only very few highly reduced vanadium polynuclear complexes were reported, which remains a significant challenge to synthesize novel polyoxovanadates, owing to the characteristics of easily oxidized vanadium(III). Herein, two unprecedented petaloid chiral octanuclear polyoxovanadates, l- and d-[HN(CH)](HN(CH)NH)(HO)(Vμ-OH)(SO)·2HO (L-, D-V), have been successfully obtained by solvothermal method without any chiral auxiliary.

Polyoxometalate-Based Well-Defined Rodlike Structural Multifunctional Materials: Synthesis, Structure, and Properties.

The unpredictability of the polyoxometalate (POM) coordination model and the diversity of organic ligands provide more possibilities for the exploration and fabrication of various novel POM-based materials. In this work, a series of POM-based lanthanide (Ln)-Schiff base nanoclusters, [Ln(HO)(DAPSC)][Ln(HO)(DAPSC)][(SiWO)]·15HO (Ln = Sm, 1; Eu, 2; Tb, 3), have been successfully isolated by the reaction of classical Keggin POMs, a Ln ion, and a Schiff-base ligand [2,6-diacetylpyridine bis(semicarbazone), abbreviated as DAPSC]. Both the hindrance effect of the organic ligand and charge balance endow the cluster with fascinating structural features of discrete and linear arrangement.

Two new POM-based compounds modified by lanthanide-Schiff base complexes with interesting NLO properties.

Two POM-based lanthanide derivatives, namely {triaqua[2,6-diacetylpyridine bis(semicarbazone)-κO,N,N',N'',O']terbium(III)}-μ-oxido-[tricosa-μ-oxido-dodecaoxido-μ-phosphato-dodecamolybdenum(VI)] pentahydrate (1), [Tb(CHNO)(HO)][PMoO]·5HO, and the dysprosium(III) analogue (2), have been isolated successfully by the reaction of Keggin-POM [PMoO] (abbreviated as PMo), the Ln ion and the Schiff base 2,6-diacetylpyridine bis(semicarbazone) (DAPSC) ligand under hydrothermal conditions. [Ln(DAPSC)(HO)][PMoO]·5HO is a PMo-supported cluster featuring a lanthanide-Schiff base complex [denoted Ln-L(Schiff base)]. Single-crystal X-ray diffraction analysis reveals that the Ln ion is in a distorted tricapped trigonal prismatic arrangement, coordinated by six O atoms and three N atoms.

Exploring the Performance Improvement of Magnetocaloric Effect Based Gd-Exclusive Cluster Gd.

Despite wide potential applications of Gd-clusters in magnetocaloric effect (MCE) owing to f electron configuration of Gd(III), the structural improvement in order to enhance MCE remains difficult. A new approach of the situ hydrolysis of acetonitrile is reported, and the slow release of small ligand CHCOO is realized in the design and synthesis of high-nuclearity lanthanide clusters. A large lanthanide-exclusive cluster complex, [Gd(CO)(CHCOO)(μ-OH)(μ-OH)(HO)](NO3)Br(dmp)·30CHOH·20Hdmp (1-Gd), was isolated under solvothermal conditions.

Two Pairs of Chiral "Tower-Like" Ln Cr (Ln=Gd, Dy) Clusters: Syntheses, Structure, and Magnetocaloric Effect.

Two pairs of novel chiral chromium lanthanide compounds, formulated as l- and d-[Gd Cr (IN) (μ -OH) (μ -O) (H O) ]⋅[IN] ⋅8 H O (1 and 3), and l- and d-[Dy Cr (IN) (μ -OH) (μ -O) (H O) ]⋅[IN]⋅1.5 H O (2 and 4) (HIN=isonicotinic acid) have been successfully synthesized and characterized. Structural analysis reveals that four Ln ions and four Cr ions connect with each other and yield a "tower-like" [Ln Cr ] skeleton.

A Series of Lanthanide Compounds Constructed from Ln Rings Exhibiting Large Magnetocaloric Effect and Interesting Luminescence.

A series of lanthanide compounds, [Ln(CHOHCHOH)(SO)]· m(CHN)· nHO (Ln = Gd (1), Sm (2), Tb (3), La (5), m = 2, n = 2; Ln = Eu (4), m = 0, n = 8), which contain Ln rings by sulfate and glycol as the ligand have been synthesized and characterized. Besides, small organic amine and l-tartaric acid act as dual templating roles during the synthetic process. Magnetic investigation of compound 1 reveals the existence of weak antiferromagnetic interactions between Gd ions and the data of magnetic entropy change (-Δ S) is 36.

Three new high-nuclear transition-metal-substituted heteropolytungstates: syntheses, crystal structures, magnetic studies and NLO properties.

Three new nickel-cluster-substituted polyoxometalates (POMs), [Ni6(H2O)9(μ3-OH)3(HSiW9O34)]2·12H2O (1), [Ni(en)(H2O)3][Ni6(H2O)3(en)2L(μ3-OH)3(HSiW9O34)]2·9H2O (2) (en = ethylenediamine; L = C7H5O2 = benzoic acid) and [Ni6(L')6(CH3COO)(H2O)3(μ3-OH)3(HPW9O34)]2·9H2O (3) (L' = C5NH5 = pyridine) were successfully isolated under hydro-/solvothermal conditions. 1-3 were structurally characterized by single-crystal XRD, elemental analyses, PXRD, IR, and TGA. Compound 1 mainly consists of a pair of {Ni6SiW9} fragments and some water molecules.

Proton conductivity resulting from different triazole-based ligands in two new bifunctional decavanadates.

Triazole, similarly to imidazole, makes a prominent contribution to the proton conductivity of porous materials. To investigate the effects of triazole-based ligands in polyoxovanadates (POVs) on proton conduction, we designed and synthesized two decavanadate-based POVs, [Zn(CHN)(HO)](VO)·14HO (1) and [Zn(CHN)(HO)](VO)·8HO (2) constructed from the ligands 3-amino-1,2,4-triazole and 1-1,2,4-triazole, respectively, an aqueous solution evaporation method. Surprisingly, complex 1 obtained a superior proton conductivity of 1.