Search

A novel antimonotungstate (AT)-based heterometallic framework {[Er(H 2 O) 6 ] 2 [Fe 4 (H 2 pdc) 4 (B-β-SbW 9 O 33 ) 2 ]}·50H 2 O ( 1 , H 2 pdc = pyridine-2,5-dicarboxylic acid) was obtained through a synergistic strategy of in situ-generated transition-metal-encapsulated polyoxometalate (POM) building units and the substitution reaction. Its structural unit is composed of a tetra-Fe III -substituted Krebs-type [Fe 4 (H 2 pdc) 4 (B-β-SbW 9 O 33 ) 2 ] 6- subunit and two [Er(H 2 O) 6 ] 3+ cations. This subunit can be regarded as a product of carboxylic oxygen atoms of H 2 pdc ligands replacing active water ligands in the [Fe 4 (H 2 O) 10 (B-β-SbW 9 O 33 ) 2 ] 6- species. Apparently, the substitution action of carboxylic oxygen atoms of H 2 pdc ligands for active water ligands, together with the coordination function of Er 3+ ions, plays a connection role in the architecture of the three-dimensional (3-D) heterometallic framework. Based on the stability and high redox activity of 1 , a glassy carbon electrode modified by 1 is used for the construction of an electrochemical biosensor (ECBS). Thus, such 1 -based ECBS can sensitively detect the KRAS gene (a key genetic marker for identifying the occurrence of malignant tumors) and displays a low detection limit (0.106 pM), high selectivity, and reproducibility. This work not only provides a feasible approach to prepare novel multicomponent POM-based heterometallic frameworks but also establishes a new platform for biosensing the KRAS gene and extends the application scope of POM-based functional materials.

Two borates, Na 2 K[B 5 O 8 (OH) 2 ]·H 2 O ( 1 ) and Na 4 K 2 [{B 5 O 8 } 2 {B 3 O 5 }{BO 2 (OH) 2 }]·2H 2 O ( 2 ) have been designed and made under solvothermal conditions. Compound 1 exhibits a 2D fluctuant layer based on the [B 5 O 10 (OH) 2 ] 7- clusters, containing two types of 9-membered ring (MR) channels and showing a four-connected sql topology net. By modifying the reactants and reaction temperature, compound 2 was obtained from compound 1 . The addition of boron-containing components not only increased their concentration but also enriched the B-O fragment while higher temperatures promoted greater condensation of the anionic clusters. Compound 2 crystallizes in the acentric space group Pc and is composed of two types of [B 5 O 11 ] 7- clusters, [B 3 O 7 ] 5- clusters and [BO 2 (OH) 2 ] 3- tetrahedra. The two kinds of [B 5 O 11 ] 7- clusters form a 2D layer similar to 1 , which is further connected by the chain built from the [B 3 O 7 ] 5- clusters and decorated by [BO 2 (OH) 2 ] 3- groups to produce a 3D layer-pillared framework. Notably, compound 2 is the first layer-pillared borate containing three types of B-O clusters and six types of channels. Second harmonic generation (SHG) measurements reveal that compound 2 displays a moderate SHG response of about 1.1 times that of KH 2 PO 4 (KDP).

Birefringent crystals, which can modulate and polarize light, play a vital role in the development of optical sensors and optoelectronic devices. Herein, we synthesized a new birefringent crystal [(C 10 N 2 H 10 )(HI 2 O 6 )(HIO 3 )(IO 3 )] with large birefringence by integrating the large π-conjugated 4,4'-bipyridine group with two types of iodates anions ([IO 3 ] - and [HI 2 O 6 ] - ) characterized by high polarizability anisotropy and strong stereochemically active lone pairs (SCALP). The crystal exhibits a large measured birefringence of 0.171 at 550 nm, surpassing most organic-inorganic hybrid iodate birefringent materials reported in the literature. Theoretical analyses reveal that the optical properties of the crystal arise primarily from the synergistic interactions between the π-conjugated 4,4'-bipyridine group and I-O groups. This research presents an effective method for the strategic integration of large π-conjugated organic cations into iodates, facilitating the design of novel birefringent materials and encouraging further exploration of superior birefringent substances.

A high-nuclear Co-added polyoxometalate (CoAP) was synthesized via a hydrothermal reaction: H 14.5 K 9 Na 7.5 -{[Co 8 (μ 2 -OH)(μ 3 -OH) 2 (H 2 O) 2 (Co(H 2 O)GeW 6 O 26 )( B -α-GeW 9 O 34 ) 2 ][BO(OH) 2 ][Co 12 (μ 2 -OH)(μ 3 -OH) 5 (H 2 O) 3 (Co(H 2 O)GeW 6 O 26 )(GeW 6 O 26 )( B -α-GeW 9 O 34 )]}·46H 2 O ( 1 ). The polyoxoanion of 1 contains a large Co 20 cluster gathered by lacunary GeW 6 O 26 and GeW 9 O 34 subunits. 1 represents a one-dimensional (1D) chain formed by adjacent polyoxoanions coupling through a CoO 6 double bridge, showing the first example of a high-nuclear CoAP-based inorganic chain. 1 served as an efficient electrocatalyst in oxygen evolution reactions (OERs).

Two metal borate-carbonates, M 6 [Cd 2 (CO 3 ) 2 (B 12 O 18 )(OH) 6 ] [M = K ( 1 ), Rb ( 2 )], were obtained under surfactant-thermal conditions. In 1 and 2 , each cyclic [(B 12 O 18 )(OH) 6 ] 6- anion captures two CdCO 3 in two sides of the rings and finally forms the unusual (CdCO 3 ) 2 @[(B 12 O 18 )(OH) 6 ] cluster. Both 1 and 2 show moderate birefringence. Density functional theory calculations indicate that carbonate groups have a major contribution to electron-related optical transition.

It is still challenging to construct novel photochromic and photomagnetic materials in the field of molecular materials. Herein, the 2,4,6-tris-2-pyridyl-1,3,5-triazine (TPTz) molecule was found to display photochromic properties under room temperature light irradiation. Two mononuclear structures, [Ni(H 2 O)(TPTz)(C 2 O 4 )]·2H 2 O ( 1 ; C 2 O 4 2- = oxalate) [Ni(H 2 O)(TPTz)(C 2 O 4 )]·0.5H 2 O ( 2 ), and one chain compound [Ni(TPTz)(H 2 -HEDP)]·2H 2 O ( 3 ; HEDP = hydroxyethylidene diphosphonate) were obtained by assembling TPTz with polydentate O-ligands (oxalate and phosphonate) and the paramagnetic Ni 2+ ions. The electron-transfer (ET)-dominated photochromism was observable in 1 and 2 after light irradiation with the photogeneration of relatively stable radicals, and the resultant photochromism was demonstrated via UV-vis, photoluminescence, X-ray photoelectron spectra, electron paramagnetic resonance spectra, and molecular orbital calculations. Due to the denser stacking interactions between the adjacent organic molecules, 2 exhibited a faster photochromic rate than 1 . Compared with 1 and 2 , compound 3 did not show photochromic behavior, which was deciphered by the theoretical calculations for all of the compounds. Importantly, the magnetic couplings appeared between photogenerated radicals and paramagnetic Ni 2+ ions, resulting in a scarcely photomagnetic phenomenon of 1 and 2 in the Ni-based electron transfer photochromic materials. This work enriches the available kind of ligands for the design of ET photochromic materials, putting forward a method to tune the electron transfer photochromic efficiency in the molecular materials.

The reaction of [ A -α-GeW 9 O 34 ] 10- with Ni 2+ in the presence of inorganic boron sources yielded three unprecedented sandwiched Ni-added polyoxometalates (NiAPs): K 6 Na 7 H 7 [({Ni 8 (μ 6 -O)(OH) 2 }@{B 3 O 6 (OH) 3 } 2 )@( B-α- GeW 9 O 34 ) 2 ]·16H 2 O ( 1 ), K 4 Na 4 H 12 [({Ni 8 (μ 6 -O)}@{B 4 O 8 (OH) 3 } 2 )@( B-α- GeW 9 O 34 ) 2 ]·16H 2 O ( 2 ), and K 10 Na 6 [({Ni 8 (μ 6 -O)}@ {B 6 O 9 (OH) 5 } 2 )@( B-α- GeW 9 O 34 ) 2 ]·12H 2 O ( 3 ). The common feature of 1 - 3 is that a rare double-layered {Ni 8 }@{B n } 2 ( n = 3,4,6) cluster is inlaid in their sandwich belts. The {Ni 8 } cluster is composed of two cubane {Ni 4 } clusters by six bridging oxygen atoms and sharing a μ 6 -O atom. The numbers of boron atoms in the {Ni 8 }@{B n } 2 ( n = 3,4,6) clusters of 1 - 3 are different, namely, {Ni 8 }@{B 3 } 2 , {Ni 8 }@{B 4 } 2 , and {Ni 8 }@{B 6 } 2 clusters. To the best of our knowledge, such architectures containing a double-layered {Ni 8 }@{B n } 2 ( n = 3,4,6) cluster in the sandwich belts are the first observed in POM chemistry. Furthermore, 2 was investigated as an efficient heterogeneous catalyst for the Knoevenagel condensation of various aldehydes with malononitrile at room temperature.

An optically anisotropic alkali-earth-metal gallium fluoroiodate, Ba 2 [GaF 5 (IO 3 F)] ( 1 ), was ingeniously obtained by integrating fluoride and fluoroiodate functional units under moderate hydrothermal conditions. It features a three-dimensional (3D) structure constructed by the highly polarizable fluoroiodate unit [IO 3 F] and the fluoride groups [GaOF 5 ] and [BaO 3 F x ] ( x = 6, 7). The compound is stable at temperatures up to 500 °C. With the synergistic interaction between [IO 3 F] and the fluoride groups, the mixed-metal fluoroiodate induces a short ultraviolet cutoff edge at about 230 nm, a medium measured birefringence of 0.068 @ 550 nm, and a wide optical transparent window (0.34-11.9 μm), indicating that 1 has potential applications as a birefringent material from near-UV to mid-infrared. Theoretical calculations prove that the optical characteristics of the compound are mainly attributed to [IO 3 F] and the fluoride functional groups. This work demonstrates that the presence of various specific functional groups in compounds will help to develop promising inorganic functional materials possessing good optical performance.

Birefringent crystals can modulate and detect the polarization of light and are important optical functional materials. The birefringence is positively correlated to the anisotropy of the structure. By partially substituting sulfate anion with large electronegative fluorine in the parent compound Y 2 (SO 4 ) 3 ·8H 2 O, a new fluorinated rare-earth sulfate YSO 4 F·H 2 O with enhanced anisotropy was achieved. YSO 4 F·H 2 O features a dense 3D structure constructed by the polarizable [YOF] polyhedra and [SO 4 ] tetrahedra. The diffuse reflectance spectrum reveals that it has a short UV absorption edge of below 200 nm. The substitution of the F - ion enhances the optical anisotropy, making the material exhibit an enhanced birefringence (0.0357 at 546 nm), which is 5.1 times that of the parent compound and is also larger than most deep-UV birefringent sulfates. It is expected that this work may shed useful insights in the exploration of deep-UV birefringent materials with enhanced optical performances..

An acentric aluminoborate (ABO), Na 1.5 Cs 0.5 [Al{BO 3 }{B 9 O 15 (OH) 3 } 1/3 ] ( 1 ), has been made under solvothermal conditions. The alternations of AlO 4 tetrahedra and BO 3 triangles first build up the 2D ABO layer with 6-MR (membered-ring) windows. The fanlike B 9 O 15 (OH) 3 cluster adorns the layer through Al-O-B linkages, producing a pair of unclosed channels with 7-MR aperture on the lateral side of the layers. The novel B 9 O 15 (OH) 3 cluster represents the largest oxoboron cluster in the acentric ABO family. 1 not only shows a moderate second-harmonic-generation response of 1.2 times that of potassium dihydrogen phosphate but also has a short cutoff edge below 200 nm, indicating its potential applications in deep-UV regions.

A novel 40Ni-added germanotungstate, Cs 8 K 14 Na 3 H 3 {[Ni 6 (OH) 3 (H 2 O) 6 (B-α-GeW 9 O 34 )] 2 [Ni 8 (μ 6 -O)(μ 2 -OH) 2 (μ 3 -OH) 2 (H 2 O)B 2 O 3 (OH) 2 (B-α-GeW 9 O 34 ) 2 ]} 2 ·84H 2 O ( 1 ), was made by the reaction of the trivacant [A-α-GeW 9 O 34 ] 10- ({GeW 9 }) precursor with Ni 2+ cations and B 5 O 8 - , and systematically investigated by Fourier-transform infrared spectroscopy, elemental analysis, thermogravimetric analysis, and powder X-ray diffraction. Single crystal X-ray analysis indicates that the polyoxoanion of 1 is a novel octamer constructed by {Ni 6 GeW 9 } and {Ni 8 (GeW 9 ) 2 } structural building units via Ni-O═W linkages. The magnetic behavior shows the existence of overall ferromagnetic interactions among the Ni 2+ centers in compound 1 . Photocatalytic H 2 production studies have implied that 1 can work as a heterogeneous catalyst for hydrogen production with decent robustness and recyclability.

A new high-nuclear Ti-oxo-cluster-added poly(polyoxometalate) Cs 2 Na 19 H 12 [(Cs@Ti 12 O 18 )@{( A -α-SiW 9 O 34 ) (P 2 W 15 O 56 ) 3 }]·29H 2 O ( 1 ) has been made by reacting two types of trivacant precursors with TiOSO 4 under hydrothermal conditions. The polyoxoanion of 1 contains one Keggin-type [ A -α-SiW 9 O 34 ] 10- and three Dawson-type [P 2 W 15 O 56 ] 12- fragments that synergistically induce the Ti 4+ ions to aggregate at vacant sites, resulting in a large {Ti 12 }-oxo-cluster cavity sealing a Cs + ion. It is worth noting that the {Ti 12 } cluster is built by three edge-shared Ti 3 O 13 ({Ti 3 } 1 ) cores and one corner-shared Ti 3 O 15 ({Ti 3 } 2 ) core bridged via 6 μ 2 -O, which has never been seen before in polyoxometalate chemistry. Significantly, 1 represents the first example of [ A -α-SiW 9 O 34 ] 10- and [P 2 W 15 O 56 ] 12- simultaneously participating in making poly(polyoxometalate).

Micro-organic pollutants, particularly organic dyes and personal care products (PPCPs), are widely present in wastewater, and thus pose a serious risk to human health. The capture and solar-light photodegradation of micro-organic pollutants are highly challenging tasks, which require the design and synthesis of microporous materials with specific structures. As we know, organic dyes and PPCPs can be absorbed via π-π* stacking. In this paper, an iron-based metal-organic framework (Fe-UiO-68-terNap) containing semirigid conjugated aromatic ligands is prepared for the capture and solar-light photodegradation of multiple water contaminants. UiO-68-terNap was synthesized based on ternaphthalene with π-π* stacking, which would increase the adsorption capacities of organic micropollutants in wastewater. Additionally, the formation of Fe-O-Zr enhances the charge-separation ability resulting in the successful degradation of micropollutants in 240 min. The novel material has been elucidated by single-crystal X-ray diffraction and Fe K-edge XANES, which provide key insights at a molecular level for the design of novel materials for the capture and photodegradation of organic micropollutants.

A new birefringent crystal of Sb 4 O 3 (TeO 3 ) 2 (HSO 4 )(OH) was achieved by incorporating two stereochemically active lone pair (SCALP) cations of Sb(III) and Te(IV) into sulfates simultaneously. The Sb 3+ and Te 4+ ions display highly distorted coordination environments due to the SCALP effect. Sb 4 O 3 (TeO 3 ) 2 (HSO 4 )(OH) displays a 3D structure composed of [Sb 4 O 3 (TeO 3 ) 2 (OH)] ∞ + layers bridged by [SO 3 (OH)] - tetrahedra. It possesses a large birefringence and a wide optical transparent range, making it a new UV birefringent crystal. First-principles calculation analysis suggests that the synergistic effect of the cooperation of SCALP effect of Sb 3+ and Te 4+ cations make a dominant contribution to the birefringence. The work highlights that units with SCALP cations have advantages in generating large optical anisotropy and are preferable structural units for designing novel birefringent materials.

The photoinduced electron-transfer (ET) process plays an irreplaceable role in chemical and biological fields exemplified by enzymatic catalysis, artificial photosystems, solar energy conversion, and so forth. Searching for a new photoinduced ET system is of great importance for the development of functional materials. Herein, a series of host-guest compounds based on a magnesium metal-organic framework (Mg-MOF) as a host and pyridine derivatives as guests have been presented. Notably, strong O-H···N hydrogen bond between the oxygen atom of μ 2 -H 2 O and the nitrogen atom of pyridine enables proton delocalization between water molecule and pyridine guest. Despite the absence of photochromic modules in these host-guest compounds, long-lived charge-separated states with distinct color changes can be formed after UV-light irradiation. The substituents in pyridines and the proton delocalization ability between the host and guests have a great influence on their photoinduced ET process to endow the MOF materials with tunable photoinduced charge-separated states.

Two acentric aluminoborates (ABOs), [Zn(en) 2 Al{B 5 O 9 (OH)}{BO(OH) 2 }] ( 1 ) and [Cd(en) 2 AlB 5 O 10 ]·H 2 O ( 2 ) (en = ethylenediamine), have been solvothermally made. 1 includes a two-dimensional (2D) wavy ABO layer using B 5 O 9 (OH) clusters and AlO 3 {BO(OH) 2 } groups, in which both units can be regarded as three-connected nodes, and simplifying the ABO layer to a hcb -type network. 2 features an acentric three-dimensional (3D) porous framework with a unique unc -type network constituted by strictly alternating connected B 5 O 10 clusters and AlO 4 units. The structural transformation from a 2D layer 1 to a 3D framework 2 was achieved with the elimination of the terminal hydroxyls in layer 1 by adjusting synthetic conditions in the same solvent system. Metal-amine complexes Zn(en) 2 /Cd(en) 2 bond to the inorganic walls and are located in the cavity of frameworks 1 and 2 , respectively. Compounds 1 and 2 exhibit large second-harmonic generation (SHG) responses that are 2.2 and 2.7 times those of KH 2 PO 4 (KDP), respectively, which are among the largest powder SHG responses for all deep-ultraviolet (deep-UV) ABOs. The UV-vis diffuse reflectance spectra of 1 and 2 show a wide transparency window below 190 nm. Density functional theory (DFT) calculations indicate that the B-O units and the introduced distorted d 10 metal polyhedra played a decisive role in the optical properties of both compounds.

Three polyoxometalate-based metal-organic frameworks were synthesized by the thermal reaction of pyridyl-Anderson polyoxometalate linker and lanthanide ions. With the help of [Ru(bpy) 3 ] 2+ photosensitizer, these frameworks exhibited excellent photocatalytic sulfide oxidation performance with sulfoxide selectivity. The reactive oxygen species as well as the photooxidation mechanism were also explored.

When the N- and O-donor ligands are combined as coligands, two noncentrosymmetric (NCS) complexes of [Ni(p-bdc)(tipa)(H 2 O) 2 ] 2 ·H 2 O ( 1 ) and Ni(npdc)(tipa)H 2 O ( 2 ) [tipa = tris[4-(1 H -imidazol-1-yl)phenyl]amine, p-H 2 bdc = 1,4-benzenedicarboxylic acid, and H 2 npdc = 2,6-naphthalenedicarboxylic acid] were achieved under solvothermal conditions. For both structures, N-donor ligands are responsible for the generation of a layered structure, while the O-donor ligands are hung on the layers and are responsible for enhancing the polarity, giving rise to the NCS structures. Because of the different connection modes between the metal centers and different carboxylate ligands (p-bdc 2- in 1 and npdc 2- in 2 ), 1 and 2 show some structural differences. The p-bdc 2- ligands in 1 are suspended on the upper and lower sides of the [Ni(tipa)] n layers, while all of the npdc 2- ligands in 2 hang on one side of the [Ni(tipa)] n layers and point in the same direction, which makes the two NCS complexes show phase-matchable behavior with different second-harmonic-generation (SHG) responses of about 0.9 and 1.5 times that of KH 2 PO 4 (KDP), respectively. Theoretical studies reveal that charge transfers between Ni 2+ and carboxylate ligands make the dominant contribution to the optical properties. It is expected that a dual-ligand strategy may guide the design of novel superior-performing NCS complexes.

A novel high-nuclear Ni-substituted poly(polyoxometalate) [poly(POM)], [H 2 N(CH 3 ) 2 ] 2 Na 18 Cs 2 H 13 [(Cs 7 (H 2 O) 6 )@{(PO 4 )-@(Ni 4 (OH) 3 (WO 4 )) 3 @( B -α-PW 9 O 34 ) 3 } 2 ]·30H 2 O ( 1 ), has been successfully developed and structurally characterized. The polyoxoanion of 1 can be viewed as a unique huge sandwich structure made of an unprecedented Cs 7 (H 2 O) 6 ({Cs 7 }) cluster core encapsulated by two trimeric [(PO 4 )@(Ni 4 (OH) 3 (WO 4 )) 3 @( B -α-PW 9 O 34 ) 3 ] 21- subunits, in which the {Cs 7 } cluster presents an interesting Anderson-like arrangement and is the first example of a classical POM configuration based on the alkali metal cluster in the POM chemistry. The polyoxoanion can also be described as an unusual [(Cs 7 (H 2 O) 6 )@{(PO 4 )@(Ni 4 (OH) 3 (WO 4 )) 3 } 2 ] 19+ cluster packaged by six {PW 9 } fragments. Furthermore, investigations on the Knoevenagel condensation reaction reveal that 1 has good catalytic activity for the condensation of various aldehydes and malononitrile into corresponding products with excellent yields.

Driven by the synergistic-directing effect of the lacunary fragments, [B-α-GeW 9 O 34 ] 10- and [B-α-GeW 11 O 39 ] 8- , an unprecedented hepta-Zr-substituted polyoxometalate (POM) assembly K 2 Na 6 H 10 (Hpy) 3 [SbZr 7 O 6 (OH) 4 (B-α-GeW 9 O 34 ) 2 (B-α-GeW 11 O 39 ) 2 ]·28H 2 O ( 1 ) was made under hydrothermal condition and structurally characterized. Of which, a unique hepta-Zr cluster, [SbZr 7 O 6 (OH) 4 ] 15+ core, was built by two trilacunary [B-α-GeW 9 O 34 ] 10- fragments and two monolacunary [B-α-GeW 11 O 39 ] 8- fragments and further arranged in a mode of a vertical cross and formed a pseudo-tetrahedron geometry. Compound 1 features the first Zr 7 -cluster-substituted POM. Moreover, 1 is an effective heterogeneous catalyst for the catalytic oxidation of sulfides into the corresponding sulfones with H 2 O 2 , manifesting distinguished conversion, excellent yield, and desired recyclability.

Two mixed alkali-metal borates, K 0.5 Li[B 6 O 10 ]·0.5H 3 O ( 1 ) and [(μ 5 -OH)@(Na 4 Li)] 0.5 [B 6 O 10 ]·0.5B(OH) 3 ( 2 ), have been prepared under solvothermal conditions. Both of them are obtained in the same synthetic system and contain a B 6 O 13 8- cluster as the structural-building unit (SBU) but exhibit quite different structural features. 1 is a centric three-dimensional (3D) oxoboron (B-O) framework, where templated mixed K + and Li + cations occupied the cavities of the structure. 2 crystallizes in an acentric space group under the templating effect of a unique acentric alkali-metal cluster [(μ 5 -OH)@(Na 4 Li)] 4+ . The SBU of 2 is also the B 6 O 13 8- cluster, which acts as six-connected nodes linked together to form a 3D B-O framework, showing different characters from 1 because of two types of templates; the acentric [(μ 5 -OH)@(Na 4 Li)] 4+ clusters and the electroneutral B (OH) 3 groups fill in two different cages in the framework and further connect each other via Na-O-B bonds to build a novel two-dimensional (2D) wavy bricklike network, resulting in a 3D B-O framework interpenetrated by a 2D [(μ 5 -OH)@(Na 4 Li)]-B(OH) 3 network. As a crystal material with an acentric space group, 2 shows a good second harmonic generation response of about 2.8 times that of KDP (KH 2 PO 4 ) and has a cutoff edge below 190 nm, which suggests that 2 is a potential deep-UV NLO material.

An all-inorganic, novel bis-Sb 3 O 3 -functionalized A-type Anderson-Evans polyoxometalate, [Ni(H 2 O) 6 ]KH[NiMo 6 O 24 (Sb 3 O 3 ) 2 ]·5H 2 O ( 1 ), has been synthesized under hydrothermal conditions. The chemical composition, molecular structure, and elemental oxidation states of the resulting compound have been systematically characterized by various techniques, including single-crystal X-ray diffraction, thermogravimetric analysis, Fourier transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy. The title complex 1 has been investigated for the first time as a catalyst for visible-light-driven hydrogen production by coupling with a [Ir(coumarin) 2 (dtbbpy)][PF 6 ] photosensitizer and a triethanolamine (TEOA) sacrificial electron donor. Under minimally optimized conditions, a H 2 generation rate of as high as 10 358 μmol g -1 h -1 is achieved during a 6 h photocatalysis. Additional control experiments and spectroscopic analyses have demonstrated that complex 1 will undergo the in situ photoreduction during photocatalysis and its specific geometric structure is essential to efficient photocatalysis for H 2 production.

A chiral three-dimensional polyoxometalate cluster-organic framework (POMCOF) H 3 [(btc)Ni 6 (μ 3 -OH) 3 (H 2 O) 5 (B-α-PW 9 O 34 )]·17H 2 O ( 1 , btc = 1,2,4-benzenetricarboxylate) has been made under hydrothermal conditions in the absence of amine or chiral starting reagents. 1 shows high stability in CH 3 CN/DMF (1:3), acidic, and basic solutions with the pH ranging from 2 to 12 for 5 days. The UV-vis reflectance spectra and Mott-Schottky measurements reveal that 1 could be a suitable catalyst for photocatalysis. Visible-light-driven H 2 evolution studies have demonstrated that 1 is an ecofriendly, efficient, and recyclable catalyst with a H 2 evolution rate of 1058.24 μmol h -1 g -1 . Nonlinear optical (NLO) measurement reveals that 1 exhibits a second-harmonic generation (SHG) response of about 1.4 times that of KH 2 PO 4 (KDP), indicating that 1 is a potential NLO material as well.

A new acentric barium borate, Ba 2 B 10 O 16 (OH) 2 ·(H 3 BO 3 )(H 2 O) ( 1 ), was synthesized via a hydrothermal process. Compound 1 contains two different boron oxide units of [B 5 O 10 (OH)] 6- anions and H 3 BO 3 molecules and features 9-ring channels along the c axis in a layered structure. This barium borate is a possible deep-ultraviolet nonlinear-optical crystal for its moderate second-harmonic-generation signal and wide transparency window below 190 nm.

Four inorganic-organic hybrid borates, K[B 6 O 9 (OH)(en)]·H 2 O ( 1 , en = ethylenediamine), K[B 6 O 9 (OH)(1,3-dap)]·H 2 O ( 2 , 1,3-dap = 1,3-diaminopropane), K[B 6 O 9 (OH)(1,6-dah) 0.5 ]·H 2 O ( 3 , 1,6-dah = 1,6-diaminlhexane) and [(1,3-dap)Cd@B 5 O 8 (OH)]·0.5H 2 O ( 4 ), were made under solvothermal conditions. 1 and 2 are isostructural and feature a 2D layer built by B 6 O 9 (OH) clusters and modified by en and 1,3-dap via B-N-C linkages. By replacing en and 1,3-dap with longer and more flexible 1,6-dah, a new type of oxoboron cluster organic framework 3 was obtained, which was composed of the same B 6 O 9 (OH) cluster layers as in 1 and 2 and 1,6-dah linkers. By replacing alkali metal K with transition metal Cd under similar synthetic conditions, another type of oxoboron cluster organic framework 4 was made in which the Cd-centered wheel cluster layers and 1,3-dap linkers were connected via Cd-N-C linkages.

Three lanthanide (Ln)-functionali z ed antimonotungstate (AT) clusters with a {Sb 4 O 4 Ln 3 (H 2 O) 8 } core [H 2 N(CH 3 ) 2 ] 14 Na 8 H 16 [Sb 4 O 4 Ln 3 (H 2 O) 8 W 2 O 4 (H 2 O) 2 ( B-α- SbW 9 O 33 ) 4 ] 2 ·87H 2 O [Ln = Dy 3+ ( 1 ), Ho 3+ ( 2 ), Y 3+ ( 3 )] were synthesized in an acidic aqueous solution. Their molecular structural unit comprises two {Sb 4 O 4 Ln 3 (H 2 O) 8 }-core-incorporated tetrameric [Sb 4 O 4 Ln 3 (H 2 O) 8 W 2 O 4 (H 2 O) 2 ( B-α- SbW 9 O 33 ) 4 ] 19- polyanionic units, each of which is assembled from an unprecedented [Sb 4 O 4 Ln 3 (H 2 O) 8 W 2 O 4 (H 2 O) 2 ] 17+ heteroatom cluster surrounded by four trivacant [ B-α- SbW 9 O 33 ] 9- subunits. What is noteworthy is that a tetrahedral {Sb 4 O 4 } cluster is located at the center of the polyanionic unit, as far as we know, which is very infrequent in multi-Ln-functionalized polyoxometalate chemistry. Solid-state luminescent properties and energy migration of AT ligands to Dy 3+ and Ho 3+ cations in 1 and 2 have been intensively probed at ambient temperature. By varying the exciting wavelength from 250 to 450 nm, the emitting color could vary from blue to yellow for 1 and blue to green-yellow for 2 , separately. In addition, high catalytic activities and good reusability of 2 as a heterogeneous catalyst for oxygenation reaction of sulfides have been systematically performed.

Two novel Ti-oxo wheel cluster substituted silicotungstates (STs) [H 2 N(CH 3 ) 2 ] 9 H 9 [Ti 6 O 6 (SiW 10 O 37 ) 3 ]·11H 2 O ( 1 ) and [H 2 N(CH 3 ) 2 ] 16 H 10 [Ti 10 O 11 (SiW 10 O 37 ) 2 (SiW 9 O 35 ) 2 ]·14H 2 O ( 2 ) have been made by hydrothermal reactions. The polyoxoanion of 1 is a ring-shaped trimer where a Ti 6 O 6 ({Ti 6 }) wheel cluster is encapsulated by three divacant [SiW 10 O 37 ] 10- (SiW 10 O 37 ) fragments. However, 2 is built by two divacant SiW 10 O 37 units and two rare trivacant [SiW 9 O 35 ] 12- (SiW 9 O 35 ) fragments and further installs an unprecedented Ti 10 O 11 ({Ti 10 }) double-wheel cluster. To the best of our knowledge, 2 is rare in POM chemistry. Studies on the catalytic oxidation properties reveal that 1 exhibits high catalytic activity toward the oxidation of various sulfides using H 2 O 2 as an oxidant. Furthermore, 1 can be facilely recycled and reused for at least five cycles without obvious loss of catalytic activity.

An acentric layer-pillared borate, LiB 9 O 15 ·H 2 dap·H 2 O ( 1 , dap = 1,3-diaminopropane), cotemplated by organic and inorganic cations and build by mixed oxoboron cluster units of B 6 O 13 8- and B 3 O 7 5- , has first been made under solvothermal conditions, in which the B 6 O 13 8- clusters link each other to form 2D layers containing 9-membered ring (MR) windows, while the B 3 O 7 5- clusters join together to produce 1D chains that further perform as the pillars to connect neighboring layers, resulting in a 3D layer-pillared framework with 13- and 7-MR channels located by H 2 dap 2+ and Li + cations, respectively. Its second harmonic generation shows a response of ∼2.1 times that of KDP (KH 2 PO 4 ).

A novel Ti-W-O-cluster-substituted tungstoantimonate (TA), [H 2 N(CH 3 ) 2 ] 3 Na 4 H 9 [{Ti 6 W 4 O 18 (OH)(H 2 O) 3 }(B-α-SbW 9 O 33 ) 3 ]·20H 2 O ( 1 ), has been made by hydrothermal reactions of trivacant [B-α-SbW 9 O 33 ] 9- units, Ti 4+ cations, and WO 4 2- anions in the presence of [H 2 N(CH 3 ) 2 ]·Cl and structurally characterized. Intriguingly, the polyoxoanion of 1 is constructed from three [B-α-SbW 9 O 33 ] 9- units and a previously unobserved decanuclear heterometallic Ti-W-O cluster [Ti 6 W 4 O 18 (OH)(H 2 O) 3 ] 11+ ({Ti 6 W 4 }) that is comprised of an octahedral [Ti 6 WO 6 (H 2 O) 3 ] 18+ cluster and an edge-sharing [W 3 O 12 (OH)] 7- fragment via six W-O-Ti/W linkers. Furthermore, studies on the catalytic oxidation properties reveal that 1 possesses good catalytic activity toward the oxidation reactions of various sulfides and cyclooctene based on the environmentally friendly oxidant H 2 O 2 .

Four inorganic-organic hybrid octa-Cu cluster sandwiched polyoxotungstates (POTs), [Cu 8 (H 2 O) 2 (en) 4 (B-α-H 2 SiW 9 O 34 ) 2 ] ( 1 ), [Cu 8 (H 2 O) 2 (en) 4 (B-α-H 2 GeW 9 O 34 ) 2 ] ( 2 ), K 2 [Cu 8 (en) 4 (B-α-HSiW 9 O 34 ) 2 ]·6H 2 O ( 3 ), and K 2 [Cu 8 (en) 4 (B-α-HGeW 9 O 34 ) 2 ]·2H 2 O ( 4 ) (en = ethylenediamine), were hydrothermally made and characterized by single-crystal X-ray diffraction, infrared spectra, powder X-ray diffraction, and thermogravimetric analysis, respectively. Structure analysis reveals that the polyoxoanion of 1 / 2 is a discrete dimer built by two trivalent Keggin [B-α-XW 9 O 34 ] 10- (X = Si/Ge) fragments and one octa-Cu cluster, whereas 3 and 4 display a two-dimensional network built by octa-Cu-sandwiched POT units via substitution of coordinated water on polyanions of 1 and 2 and further expand into a three-dimensional framework via K cation bridges. Ultraviolet-visible diffuse reflectance spectra reveal that 1-4 are potential semiconductor materials. Moreover, its visible light-driven catalytic H 2 evolution activity, electrochemical properties, catalysis for oxygenation reactions of thioethers, and magnetic behaviors have been investigated in detail.

The two acentric aluminoborates (ABOs) [M(dap) 3 ] 2 {Al[B 5 O 7 (OH) 3 ][B 5 O 8 (OH) 2 ][B 6 O 9 (OH) 2 ]} (M and dap represent Co( 1 )/Ni( 2 ) and 1,2-diaminopropane, respectively) templated by chiral metal complexes (CMCs) have been solvothermally synthesized. The isostructural 1 and 2 crystallize in the chiral space group P 2 1 . Both feature unprecedented 2D wavelike layers built by three kinds of oxoboron (B-O) clusters ([B 5 O 7 (OH) 3 ] 2- , [B 5 O 8 (OH) 2 ] 3- , and [B 6 O 9 (OH) 2 ] 2- ) and AlO 4 tetrahedra. In the frameworks of 1 and 2 , AlO 4 and [B 6 O 9 (OH) 2 ] 2- units are strictly alternating into 1D chains. Further, [B 5 O 8 (OH) 2 ] 3- clusters link adjacent chains to form 2D wavelike layers. In addition, the [B 5 O 7 (OH) 3 ] 2- units as the hanging clusters are supported on two sides of the wavelike layers through AlO 4 groups, resulting in the first example of a wavelike layer ABO composed of three kinds of B-O clusters and four types of channels. 1 and 2 display second-harmonic generation (SHG) signals about ∼1.3 and ∼0.93 times that of KH 2 PO 4 (KDP) and belong to the class of wide-band-gap semiconductors.

A novel tetrahedral μ-AsO 4 -bridging hexadecanuclear Ni-substituted silicotungstate (ST) Na 21 H 10 [(AsO 4 ){Ni 8 (OH) 6 (H 2 O) 2 (CO 3 ) 2 ( A-α- SiW 9 O 34 ) 2 } 2 ]·60H 2 O ( 1 ) was made by the reactions of trivacant [ A -α-SiW 9 O 34 ] 10- ({SiW 9 }) units with Ni 2+ cations and Na 3 AsO 4 ·12H 2 O and characterized by IR spectrometry, elemental analysis, thermogravimetric analysis (TGA), and powder X-ray diffraction (PXRD). 1 contains a novel polyoxoanion [(AsO 4 ){Ni 8 (OH) 6 (H 2 O) 2 (CO 3 ) 2 ( A-α- SiW 9 O 34 ) 2 } 2 ] 31- built by four trivacant Keggin [ A-α- SiW 9 O 34 ] 10- fragments linked through an unprecedented [(AsO 4 ){Ni 8 (OH) 6 (H 2 O) 2 (CO 3 ) 2 } 2 ] 9+ cluster, where the tetrahedral AsO 4 acts as an exclusively μ 2 -bridging unit to link multiple Ni centers; such a connection mode appears for the first time in polyoxometalate chemistry. Furthermore, the electrochemical and catalytic oxidation properties of compound 1 have been investigated.

Three inorganic-organic hybrid gallo-/alumino-borates [Ga 2 B 7 O 14 (OH)]·H 2 dah ( 1 , dah = 1,6-diaminohexane), K 2 [Ga 2 B 7 O 14 (OH)(en) 0.5 ] ( 2 , en = ethylenediamine), and K 2 [Al 2 B 7 O 14 (OH)(en) 0.5 ]·H 2 O ( 3 ) were synthesized under solvothermal conditions. Compound 1 features a 3D porous-layered structure built by the alternation of [GaB 4 O 10 (OH)] 6- , [B 3 O 6 ] 3- clusters and GaO 4 tetrahedra, in which the novel [GaB 4 O 10 (OH)] 6- cluster is first observed. Compounds 2 and 3 are isostructural and made by [MB 4 O 10 (OH)] 6- , [B 3 O 6 (en) 0.5 ] 3- clusters and MO 4 tetrahedra (M = Ga/Al); their 3D porous layers are similar to those of 1 and further bridged by en linkers through the rare B-N-C covalent bonds, resulting in the 3D inorganic-organic hybrid framework. This is the first main-group metal borate with organic molecules participating in the oxoboron frameworks through B-N bonds. Optical diffuse-reflectance spectra reveal that 1 , 2 , and 3 are potential wide-band-gap semiconductors.

Three novel Zr-substituted polyoxotungstate aggregates [H 2 N(CH 3 ) 2 ] 7 NaH 2 [Zr 2 Sb 2 O 3 ( A -α-PW 9 O 34 ) 2 ]·16H 2 O ( 1 ), [H 2 N(CH 3 ) 2 ] 6 H 12 [ZrSb 4 (OH)O 2 ( A -α-PW 8 O 32 )( A -α-PW 9 O 34 )] 2 ·33H 2 O ( 2 ), and [H 2 N(CH 3 ) 2 ] 4 Na 11.5 H 4.5 [Zr 4 W 8 Sb 4 P 5 O 49 (OH) 5 ( B -α-SbW 9 O 33 ) 2 ]·53H 2 O ( 3 ) have been made in hydrothermal reactions of the [ B -α-SbW 9 O 33 ] 9- precursor with Zr 4+ cations and PO 4 3- anions in the presence of dimethylamine hydrochloride and sodium acetate buffer (pH = 4.8) and structurally characterized. Different pH values induce structural transformation from tungstoantimonate (TA) to tungstophosphate (TP). 1 is a di-Zr-substituted sandwich-type TP, the tetranuclear heterometallic [Zr 2 Sb 2 O 3 ] 8+ entity sandwiched by two [ A -α-PW 9 O 34 ] 9- moieties. 2 is a double sandwich-type structure, which can be perceived as two equivalent sandwiched [Sb 3 (PW 8 O 32 )(PW 9 O 34 )] 11- further sandwiching one [Sb 2 Zr 2 (OH) 2 O 4 ] 4+ core to form a novel large-size sandwich-type architecture. Different from 1 and 2 , 3 is a tetra-Zr-substituted sandwiched configuration, in which two [ B -α-SbW 9 O 33 ] 9- fragments sandwich a unique 21-core Sb-P-W-Zr oxo cluster ({Zr 4 W 8 Sb 4 P 5 }). Furthermore, the catalytic oxidation of aromatic thioethers by 3 as the heterogeneous catalyst has been investigated, showing high conversion and remarkable selectivity as well as excellent recyclability.

A new nonanuclear heterometal five-layer sandwich silicotungstate [H 2 N(CH 3 ) 2 ] 6 H 5 NaK{[NaMn 8 O 6 (OAc) 6 ][ A-α- SiW 9 O 34 ] 2 }·34H 2 O ( 1 ) has been made under hydrothermal reactions of MnCl 2 ·4H 2 O, KMnO 4 , trivacant [ A -α-SiW 9 O 34 ] 10- {SiW 9 } fragment, and [H 2 N(CH 3 ) 2 ]·Cl in NaOAc-HOAc buffer (pH = 4.8). The polyoxoanion of 1 is a sandwich architecture, in which the nonanuclear heterometal cluster [NaMn 8 O 6 (OAc) 6 ] 7+ made of two triangular pyramid clusters [Mn 4 O 3 (OAc) 3 ] 3+ {Mn 4 } via a hexacoordinate antitrigonal prism Na + linkage is encapsulated by two trivacant fragments of {SiW 9 }. Furthermore, magnetic measurements of compound 1 reveal the existence of antiferromagnetic exchange interactions between the metal centers.

Two multi-Ce 3+ -substituted selenotungstates (STs), [HDMEA][H 2 N(CH 3 ) 2 ] 4 H 3 Na 4 [Ce 2 (H 2 O) 6 (DMEA)W 4 O 9 (α-SeW 9 O 33 ) 3 ]·26H 2 O (1) and [H 2 N(CH 3 ) 2 ] 10 H 4 Na 10 [Ce 2 W 4 O 9 (H 2 O) 7 (α-SeW 9 O 33 ) 3 ] 2 ·63H 2 O (2), were prepared by the one-pot approach of sodium tungstate, sodium selenite, and lanthanide nitrate in an acidic water solution in the presence of N, N-dimethylethanolamine (DMEA) or dimethylamine hydrochloride (DMAHC). 1 was obained in the presence of DMEA, whereas 2 was synthesized in the presence of DMAHC. The trimeric polyoxoanion of 1 contains an unusual V-shaped [Se 3 W 29 O 103 ] 20- group embracing a prominent heterometal oxide fragment, [Ce 2 (H 2 O) 6 (DMEA)W 2 O 5 ] 8+ , and the hexameric polyoxoanion of 2 is constructed from two equivalent trimeric [Ce 2 W 4 O 9 (H 2 O) 7 (SeW 9 O 33 ) 3 ] 2 24- subunits through two -O-W-O-Ce-O- linkages. The most worthy of attention is that the polyoxoanion of 1 can be approximatively viewed as a half of the polyoxoanion of 2 because of the coordination and blocking effect of DMEA. The stability of 1 and 2 in different water pH values was studied by electrospray ionization mass spectroscopy (ESI-MS), and the results manifest that 1 and 2 are stable in pH = 3.5-7.5 and 3.5-7.0, respectively. The oxidation reactions of aromatic sulfides catalyzed by H 2 O 2 were studied when 1 or 2 worked as a catalyst, and experimental results reveal that 1 or 2 can serve as available catalysts for the oxidation of aromatic sulfides under mild conditions.

On the basis of the synergistic strategy of lacunary polyoxometalate structure-directing function and chiral ligand inducting role, two pairs of enantiomeric polyoxotungstates, (NH 4 ) 4 (TMA) 4 [Zr 4 (μ 3 -O) 2 (l-/d-mal) 2 (B-α-HSiW 10 O 37 ) 2 ] (TMA = tetramethylammonium, mal = malate (C 4 H 5 O 5 ); l-mal for 1a, d-mal for 1b) and (NH 4 ) 4 (TMA) 4 [Zr 4 (μ 3 -O) 2 (l-/d-mal) 2 (B-α-PW 10 O 37 ) 2 ] (l-mal for 2a, d-mal for 2b), and a mesomeric polyoxotungstate, (NH 4 ) 3 Na 2 K 5 [Zr 4 (μ 3 -O) 2 (l-mal)(d-mal)(B-α-SiW 10 O 37 ) 2 ] (3), were hydrothermally synthesized. 1a, 2a and 1b, 2b respectively exhibit 1-D 2 1 right- and left-hand helical chains formed by hydrogen-bonding interactions, and 3 forms a 3-D (3,10)-connected framework by Na + /K + ions with {4 18 .6 24 .8 3 }{4 3 } 2 topology. These homochiral compounds represent the first examples of enantiomerically pure Zr IV -substituted Keggin POMs. In this system, {Zr 4 (μ 3 -O) 2 (l-/d-mal) 2 } clusters transfer chirality from d- or l-mal to Keggin polyoxotungstate dimeric clusters, which was demonstrated by structural comparison between the homochiral architecture and mesomer as well as circular dichroism spectra of enantiomers. UV-vis diffuse reflectance spectra reveal that 1-3 are potential semiconductor materials. In addition, 1 and 2 exhibit second harmonic generation response with their response intensities of 0.8 times that of KDP.

Under hydrothermal conditions, three new acetate-functionalized zirconium-substituted polyoxometalates, H 4 Na 2 [Na 6 (H 2 O) 22 ][Zr 4 (μ 3 -O) 2 (OH) 2 (OAc) 2 (α-GeW 10 O 37 ) 2 ]·32H 2 O (1), H 8 K 3 Na 5 [Zr 6 (μ 3 -O) 3 (OH) 3 (OAc)(H 2 O)(β-GeW 10 O 37 ) 3 ]·20H 2 O (2), H 6 K 4 Na 12 [{Zr 5 (μ 3 -OH) 4 (OH) 2 }@{Zr 2 (OAc) 2 (α-GeW 10 O 38 ) 2 } 2 ]·22H 2 O (3), were synthesized and characterized. In 1, the sandwiched dimer [Zr 4 (μ 3 -O) 2 (OH) 2 (OAc) 2 (α-GeW 10 O 37 ) 2 ] 12- was linked to a hexameric [Na 6 (H 2 O) 22 ] 6+ cluster to form a 1D chain. In 2, the trimer was constructed from three [β 2 -GeW 10 O 37 ] 10- units and a new [Zr 6 O 3 (OH) 3 (OAc)(H 2 O)] 14+ cluster. In 3, the tetramer was built by two novel sandwich-type dimers [Zr 2 (OAc) 2 (α 2 -GeW 10 O 38 ) 2 ] 18- and one unique [Zr 5 (μ 3 -OH) 4 (OH) 2 ] 14+ core in an approximately orthogonal fashion, showing a staggered tetrahedral polyanion. Also, the electrochemistry and electrocatalytic properties of 3 were studied, exhibiting good catalytic activities toward the reduction of H 2 O 2 , BrO 3 - , and NO 2 - .

A new noncentrosymmetric mixed-alkaline borate, Li 2 CsB 7 O 10 (OH) 4 (1), was made under solvothermal conditions. This layered boron oxide framework consists of unique bird-shaped [B 7 O 12 (OH) 4 ] 7- clusters with large 14-ring pores. Its second-harmonic-generation (SHG) signal is 2.5KDP (KH 2 PO 4 ), with its short ultraviolet (UV) cutoff edge indicating that this crystal is a potential deep-UV transparent nonlinear-optical material.

Six analogue compounds with the general formula [Fe 2 ( xL) 5 (NCS) 4 ]· yMeOH ( x = o-Cl, y = 3 for compound 1; x = m-Cl, y = 5 for 2; x = p-Cl, y = 1 for 3; x = o-Me, y = 2 for 4; x = m-Me, y = 2 for 5; x = p-Me, y = 3 for 6; L = N-phenylmethylene-4-amino-1,2,4-triazole) were synthesized. The two Fe(II) ions are triply bridged by the triazole groups of three xL ligands and each Fe(II) is further capped with two NCS - groups and one more xL ligand. These compounds show regular patterns in their magnetic properties that depend on the positions the substituent groups (-Cl or -Me) ride, i.e., ortho-substituted compounds 1 and 4 undergo complete one-step spin crossover (SCO), while meta-substituted compounds 2 and 5 display incomplete one-step SCO with lower transition temperatures, and para-substituted compounds 3 and 6 are in the high-spin states in all temperature ranges. Structural analyses reveal that the molecular geometry and intermolecular interactions of these compounds, which should account for the differences in magnetic properties, are obviously depend on the positions of substituent groups (steric effect), despite them being electron-withdrawing chlorine or electron-donating methyl, whereas theoretical calculations confirm that the electronic effects of substituent groups exert no effect on the magnetic properties.

A series of alumino/galloborates, including (H 3 APEA) 6 [Al-B 5 O 10 ] 9 ·12H 2 O (1, APEA = N, N'-bis(3-aminopropyl)ethylenedi-amine), (HDETA) 2 (H 2 DETA) 2 [AlB 5 O 10 ] 3 (2, DETA = diethylenetriamine), and (H 2 EDAP)[GaB 5 O 10 ]·H 2 O (3, EDAP = N-ethyl-diaminopropane), was solvothermally synthesized and characterized in solid-state by powder X-ray diffraction, Fourier transform infrared spectroscopy, UV-vis spectroscopy, and single-crystal X-ray diffraction. All of them feature the [MB 5 O 10 ] n 2 n- (M = Al or Ga) frameworks, charge-balanced by the long chain-like amine cations. Three frameworks exhibit different interlinkage modes of {MB 5 O 10 } layers, resulting in channels varying in size and shape. The flexibility of long chain-like amine cations as well as their significant structure-directing functions in forming these crystalline products is also discussed in detail. Powder second-harmonic generation measurements showed that all three compounds present a nonlinear optical property, and compound 2 exhibits type I phase-matchable optical nonlinearity.

Two unprecedented examples of cluster organic frameworks (TBA) 3 Cu[V 6 O 13 (L) 2 ] 2 ·4DEF (2) (TBA)Ag[V 6 O 13 (L) 2 ] solvent (3) (TBA = tetrabutylammonium, H 3 L = tris(hydroxymethyl)-4-picoline, DEF = N, N'-diethylformamide) based on Lindqvist-type polyoxometalate (POM) secondary building units (SBUs) have been constructed successfully. Compounds 2 and 3 are the second cases of cluster organic frameworks based on Lindqvist-type POM cluster SBUs. Furthermore, the cluster organic framework of 2 exhibits efficient electrocatalytic activity and strong durability in oxygen reduction reaction.

Three inorganic-organic hybrid borates, M(1,4-dab)[B 5 O 7 (OH) 3 ] [M = Zn (1), Cd (2), 1,4-dab = 1,4-diaminobutane)] and Co(1,3-dap)[B 4 O 7 ] (3, 1,3-dap = 1,3-diaminopropane), which integrated characteristics of 1D coordination polymers and 1D/3D inorganic boron oxides have been obtained under solvothermal conditions. Compounds 1 and 2 are isostructural and crystallize in a centrosymmetric space group P2 1 /c; the 3D achiral structures of 1 and 2 consist of the nonhelical Zn/Cd-1,4-dap coordination polymers and 1D B-O chains. Compound 3 crystallizes in a chiral space group P4 3 2 1 2; the helical Co-1,3-dap coordination polymer chains are entrained within a 3D B-O network and finally form the chiral framework. Compounds 1-3 represent good examples of using coordination polymers to construct mixed-motif inorganic-organic hybrid borates. Compounds 1 and 2 display blue luminescence when excited with UV light.

Under solvothermal/surfactant-thermal conditions, two new open-framework borogermanate and galloborate, centrosymmetric (Hdima) 2 [Ge 5 B 3 O 15 (OH)] (1; dima = dimethylamine) and noncentrosymmetric Na 4 Ga 3 B 4 O 12 (OH) (2), were obtained and characterized. Compound 1 contains an unusual basket-shaped Ge 5 B 3 O 18 (OH) cluster and displays a 3D open-framework layered structure. Compound 2 shows an interrupted 3,4-connected network constructed by alternately linked BO 3 units and Ga 3+ ions and displays weak second-harmonic-generation response.

A family of unprecedented tellurotungstate-based organotin-rare-earth (RE) heterometallic hybrids [H 2 N(CH 3 ) 2 ] 6 H 12 Na 2 {[Sn(CH 3 )W 2 O 4 (IN)][(B-α-TeW 8 O 31 )RE(H 2 O) (Ac)] 2 } 2 ·25H 2 O [RE = Ce III (1), Pr III (2), Nd III (3), Sm III (4), Eu III (5), Gd III (6), Tb III (7); HIN = isonicotinic acid, HAc = acetic acid] were synthesized and characterized by elemental analyses, IR spectra, UV spectra, thermogravimetric analyses, powder X-ray diffraction, and single-crystal X-ray diffraction. The polyoxoanionic skeletons {[Sn(CH 3 )W 2 O 4 (IN)][(B-α-TeW 8 O 31 )RE(H 2 O) (Ac)] 2 } 2 20- of 1-7 are constructed from two symmetrical units {[Sn(CH 3 )W 2 O 4 (IN)][(B-α-TeW 8 O 31 )RE(H 2 O) (Ac)] 2 } 10- linked by two acetate connectors, which not only represent the first inorganic-organic hybrid RE-substituted tellurotungstates involving three different organic ligands, but also stand for the first samples of organotin-RE heterometallic polyoxometalate derivatives. The solid-state luminescent emission properties of 2-5 mainly display the characteristic emission bands of RE III cations, whereas during the emission procedure of 7, [B-α-TeW 8 O 31 ] 10- segments make a nonignorable contribution to the PL behavior of 7 accompanying by the occurrence of the intramolecular energy transfer from O→W LMCT energy to Tb 3+ centers. Furthermore, 4@CTAB composites with peanutlike and honeycombed morphologies were prepared by a surfactant cetyltrimethylammonium bromide (CTAB). The time-resolved emission spectra of the 4@CTAB composite with CTAB/4 = 0.033/0.05 consolidate the energy transfer from CTAB to RE III centers. Variable-temperature magnetic susceptibility measurements for 2, 3, and 4 were performed.

Under solvothermal conditions, a chair open-framework borate, Na 2 B 9 O 15 (H 2 O)(H 3 O) (1), has been synthesized. Compound 1 shows regular pores of zeolites as well as nonlinear optical (NLO) properties of borates. The large 13-ring channels of the boron oxide framework are constructed from different cluster units of B 3 O 7 and B 6 O 13 with three-ring units. The second harmonic generation (SHG) signal intensity of 1 is similar to that of KH 2 PO 4 (KDP) and gradually increased with larger particle size. Compound 1 is a potential UV NLO material for its short wavelength absorption edge.

Two three-dimensional (3D) zeolitic open-framework aluminoborates (ABOs) [Zn(ma)(en) 2 ][AlB 5 O 10 ] (1) and [Zn(ma)(en) 2 ][AlB 6 O 11 (OH)] (2) (ma = methylamine, en = ethylenediamine) were successfully made under solvothermal conditions, which represent the first examples using similar metal complex (MC) with mixed amines as the structure-directing agents in ABOs. Notice that the central atom in the MC is coordinated by mixed amines is uncommon. However, they exhibit distinctly different structures: 1 crystallizes in a centrosymmetric [Al(B 5 O 10 )] n 2n- zeolitic framework built by pentaborate (B 5 O 10 ) clusters and AlO 4 tetrahedra, exhibiting a 4-connected cag topology, while 2 contains hexaborate (B 6 O 11 (OH)) clusters and AlO 4 groups, further alternately joined to form a noncentrosymmetric [AlB 6 O 11 (OH)] n 2n- zeolitic framework with 7-/9-, 8-/10-ring helical channels and large 13-ring channels, showing a dia topology. Nonlinear optical (NLO) determination showed that 2 exhibits good second-harmonic generation response of ∼1.9 × KH 2 PO 4 and is phase-matchable, combining the short UV cutoff edge, making 2 a potential UV NLO material.

The partial replacement of Ge atoms in tetrahedral positions by a small number of B atoms leads to a new microporous borogermanate, CsB x Ge 6-x O 12 (x = 1), under solvothermal conditions. Its framework shows the highest atomic ratios of Ge/B in reported borogermanates and leads to a new type of zeolite sodalite-type net.

A step-by-step synthetic strategy, setting up a bridge between the polyoxometalate (POM) and metal halide cluster (MHC) systems, is demonstrated to construct an unprecedented composite hybrid cluster built up from one high-nuclearity cationic MHC [Cu8I6](2+) and eight Anderson-type anionic POMs [HCrMo6O18(OH)6](2-) cross-linked by a tripodal alcohol derivative.