A Series of Open-Framework Aluminoborates Templated by Transition-Metal Complexes

Three new aluminoborates: from 1D tube to 3D framework

Three new aluminoborates (ABOs) KCs[Al{B5O9(OH)}{BO(OH)2} (1), K0.5Cs[Al{B5O10}1/2{BO2(OH)}] (2), and Cs1.5[Al{B5O10}1/2{BO2(OH)}] (3) have been made under solvothermal conditions. 1 features a 1D tube constructed by the alternation of [B5O9(OH)]4- clusters and AlO4 units, onto which the [BO(OH)2]- triangles are grafted. To further construct higher dimensional structures based on the structure 1, solvents were adjusted for high basicity, resulting in the formations of the 3D ABO frameworks 2 and 3. 2 and 3 are isostructural and built from [B5O10]5- clusters, AlO4 tetrahedra and [BO2(OH)]2- triangles, in which [B5O10]5- clusters are bridged by AlO4 tetrahedra to produce a 2D ABO layer with 14-membered ring (MR) windows, and the [BO2(OH)]2- triangles act as the linkers to bridge the adjacent ABO layers to form 3D ABO frameworks containing eight types of channels. UV-vis diffuse reflectance spectra indicate that 1, 2, and 3 have potential applications in deep ultraviolet (DUV) regions.

Tailoring Hybrid Aluminoborate Frameworks by Incorporating Multicomponent Cadmium-Amine Complexes with Various Conformations

Inorganic-organic hybrid aluminoborates represent a subclass of porous materials, which rely on effective construction method and structure-directing agents. Herein, we prepared a series of hybrid aluminoborates through covalent decoration of unsaturated Cd²⁺ complexes, whose formation take advantage of chelating amine and long-chain diamine as mixed ligands. These isolated compounds, that is, [Cd(en)(1,4-dab)_0.5][AlB₅O₁₀] (1a; its analogue with discrete complex [Cd(en)(dien)H₂O][AlB₅O₁₀] is denoted as 1b), [Cd(1,2-dap)_1.5(1,4-dabH)_0.5]{Al[B₅O₈(OH)₂](B₅O₁₀)_0.5} (2), and [Cd(en)(1,3-dap)][AlB₅O₁₀] (3) feature open frameworks (1a, 1b, and 3) or a sandwich-like porous layer (2) that are constructed by AlO₄ tetrahedra and [B₅O₁₀]^5-/[B₅O₈(OH)₂]^3- clusters. However, they exhibit different structural features in interconnection, channel environment, and topology as a result of diversified interactions between unsaturated complexes and aluminoborate frameworks, that is, through forming two Cd-O bonds with (i) a pair of neighboring BO₃ and AlO₄, (ii) the same AlO₄, or (iii) the same BO₃. The variation in connection mode exerts essential influence on binding effects and steric hindrance that are reflected by changes in interatomic distance, bond angle, window configuration, and interlinkage of units. In addition, the incorporation of unsaturated Cd²⁺ complexes endows these aluminoborate materials with photoluminescence function. Compound 3 with a noncentrosymmetric structure exhibits second harmonic generation (SHG) response approximately 0.7 times that of KDP. The preparation strategy for hybrid aluminoborates proposed here combines well molecular design with templating assembly, whose synergistic effect would be crucial for drawing a rational pathway for inorganic synthesis, especially with focus on structural and functional innovation.

Syntheses, structures and optical properties of two B3O7 cluster-based borates

1 is a 2D fluctuant layered borate made from two different B3O7 clusters. 2 features a 3D open framework with large 17-MR channels filled with Li-BO(OH)2-Ca chains.

Synthesis and optical properties of N→Ga coordinated gallium boroxines

Reactions of the N,C,N-chelated organogallium amide LGa(NEt₂)₂ (1), where L is {2,6-(Me₂NCH₂)₂C₆H₃}^-, with organoboronic acids RB(OH)₂ yielded molecular gallium boroxines LGa(O₃B₂R₂) (2: R = OH, 3: R = Ph, 4: R = 4-MeO-C₆H₄, 5: R = 4-CHO-C₆H₄, 6: R = Fc), neutral analogues of gallaborates. The molecular structures revealed the presence of a six-membered central GaB₂O₃ ring. The film forming properties of 5 allowed the deposition of transparent thin films by a spin coating method. The thicknesses, refractive index, energy of the optical gap (Eoptg), activation energy of surface electrical conductivity (Esa) and pre-exponential factor (σ₀) of the thin layers of 5 were measured and they are close to those found for related oxygen glass. Finally, GBO 5 was also used as an additive to printing ink and a thin film of 5 was prepared by the gravure printing technique.

Four Inorganic-Organic Hybrid Borates: From 2D Layers to 3D Oxoboron Cluster Organic Frameworks

Four inorganic-organic hybrid borates, K[B₆O₉(OH)(en)]·H₂O (1, en = ethylenediamine), K[B₆O₉(OH)(1,3-dap)]·H₂O (2, 1,3-dap = 1,3-diaminopropane), K[B₆O₉(OH)(1,6-dah)_0.5]·H₂O (3, 1,6-dah = 1,6-diaminlhexane) and [(1,3-dap)Cd@B₅O₈(OH)]·0.5H₂O (4), were made under solvothermal conditions. 1 and 2 are isostructural and feature a 2D layer built by B₆O₉(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 B₆O₉(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.

Two Chiral Metal Complex Templated Aluminoborates Constructed from Three Types of Oxoboron Clusters

The two acentric aluminoborates (ABOs) [M(dap)₃]₂{Al[B₅O₇(OH)₃][B₅O₈(OH)₂][B₆O₉(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 P2₁. Both feature unprecedented 2D wavelike layers built by three kinds of oxoboron (B-O) clusters ([B₅O₇(OH)₃]^2-, [B₅O₈(OH)₂]^3-, and [B₆O₉(OH)₂]^2-) and AlO₄ tetrahedra. In the frameworks of 1 and 2, AlO₄ and [B₆O₉(OH)₂]^2- units are strictly alternating into 1D chains. Further, [B₅O₈(OH)₂]^3- clusters link adjacent chains to form 2D wavelike layers. In addition, the [B₅O₇(OH)₃]^2- units as the hanging clusters are supported on two sides of the wavelike layers through AlO₄ 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 KH₂PO₄ (KDP) and belong to the class of wide-band-gap semiconductors.

From [B6O13]8− to [GaB5O13]8− to [Ga{B5O9(OH)}{BO(OH)2}]2−: synthesis, structure and nonlinear optical properties of new metal borates

By tuning the synthetic conditions, a 3D gallo-borate with a high second-harmonic generation response was obtained.

Three Inorganic-Organic Hybrid Gallo-/Alumino-Borates with Porous-Layered Structures Containing [MB4O10(OH)] (M = Al/Ga) Cluster Units

Three inorganic-organic hybrid gallo-/alumino-borates [Ga₂B₇O₁₄(OH)]·H₂dah (1, dah = 1,6-diaminohexane), K₂[Ga₂B₇O₁₄(OH)(en)_0.5] (2, en = ethylenediamine), and K₂[Al₂B₇O₁₄(OH)(en)_0.5]·H₂O (3) were synthesized under solvothermal conditions. Compound 1 features a 3D porous-layered structure built by the alternation of [GaB₄O₁₀(OH)]^6-, [B₃O₆]^3- clusters and GaO₄ tetrahedra, in which the novel [GaB₄O₁₀(OH)]^6- cluster is first observed. Compounds 2 and 3 are isostructural and made by [MB₄O₁₀(OH)]^6-, [B₃O₆(en)_0.5]^3- clusters and MO₄ 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.

Syntheses and structures of a new 2D layered borate and a novel 3D porous-layered aluminoborate

Two new layered and porous-layered borates ([H₂dap][B₇O₁₁(OH)] (1, dap = 1,2-propanediamine) and [H₃O]K_3.52Na_3.48{Al₂[B₇O₁₃(OH)][B₅O₁₀][B₃O₅]}[CO₃] (2)) have been solvothermally made. 1 features a 2D layer made of the [B₇O₁₃(OH)]^6- cluster, in which H₂dap is located in the windows of the layers. The fundamental building block (FBB) [B₇O₁₃(OH)]^6- cluster in 1 represents a new type of FBB of the hepta-borate family. 2 is a novel aluminoborate with a 3D porous-layered structure formed by three types of oxoboron clusters, [B₇O₁₃(OH)]^6-, [B₅O₁₀]^5- and [B₃O₇]^5-, respectively. The strict alternation of the different oxoboron clusters and AlO₄ tetrahedra leads to the abundant channel systems of the structure. 2 is the first aluminoborate (ABO) containing three types of oxoboron clusters and the first 3D porous-layered ABO with seven types of channels. UV-vis diffuse reflectance spectra reveal that both of them are wide band-gap semiconductors and have potential applications in UV regions.

Trinuclear Cd3O14 hexaborate and two nickel borates based on molten salt synthesis and precursor synthesis: structure, characterization, and properties

In this work, different synthetic methods were used to prepare metal borates. One cadmium borate Cd3[B6O9(OH)2]2·2NO3·4H2O (1) and two nickel borate Ni0.8Mn0.2{B6O7(OH)3[O(CH2)2NH2]3} (2), [Ni(1-MI)6]·[B5O6(OH)4]2·2DMF (3, 1-MI = 1-methylimidazole, DMF = N,N-dimethylformamide) species were successfully prepared. The structures of these three compounds were confirmed via single crystal powder X-ray diffraction (SCPXRD), elemental analysis, FTIR, PXRD, and ICP studies. Compound 1 was prepared via molten salt synthesis, and compounds 2 and 3 were prepared via precursor synthesis, which is a synthetic method that uses a certain polyanionic cluster as a reagent. Compound 1 shows a novel three-dimensional (3D) structure, in which the [B6O11(OH)2] units acting as the basic polyanionic cluster form a two-dimensional (2D) anionic structure. In addition, the unexpected Cd3O14 clusters are connected with the 2D structures, leading to the 3D structure. The crystal structure of 2 is packed with very large neutral Ni0.8Mn0.2{B6O7(OH)3[O(CH2)2NH2]3} oxo-metal-boron clusters. The crystal structure of 3 consists of a [B5O6(OH)4]- cluster, a DMF molecule, and a [Ni(1-MI)6]2+ complex. In particular, 2 was successfully constructed using the same hexaborate cluster as its precursor. However, 3 only contains Ni2+ cations when a neutral NixMn1-x[B6O7(OH)6] cluster was used as an initial reagent, and it shows an ability to select a certain metal cation during the self-assembly process. Moreover, compounds 1, 2, and 3 exhibit different wide band gaps of 3.06 eV (1), 3.95 eV (2), and 4.24 eV (3).

Research and Development of Zincoborates: Crystal Growth, Structural Chemistry and Physicochemical Properties

Borates have been regarded as a rich source of functional materials due to their diverse structures and wide applications. Therein, zincobrates have aroused intensive interest owing to the effective structural and functional regulation effects of the strong-bonded zinc cations. In recent decades, numerous zincoborates with special crystal structures were obtained, such as Cs₃Zn₆B₉O₂₁ and AZn₂BO₃X₂ (A = Na, K, Rb, NH₄; X = Cl, Br) series with KBe₂BO₃F₂-type layered structures were designed via substituting Be with Zn atoms, providing a feasible strategy to design promising non-linear optical materials; KZnB₃O₆ and Ba₄Na₂Zn₄(B₃O₆)₂(B₁₂O₂₄) with novel edge-sharing [BO₄]^5- tetrahedra were obtained under atmospheric pressure conditions, indicating that extreme conditions such as high pressure are not essential to obtain edge-sharing [BO₄]^5--containing borates; Ba₄K₂Zn₅(B₃O₆)₃(B₉O₁₉) and Ba₂KZn₃(B₃O₆)(B₆O₁₃) comprise two kinds of isolated polyborate anionic groups in one borate structure, which is rarely found in borates. Besides, many zincoborates emerged with particular physicochemical properties; for instance, Bi₂ZnOB₂O₆ and BaZnBO₃F are promising non-linear optical (NLO) materials; Zn₄B₆O₁₃ and KZnB₃O₆ possess anomalous thermal expansion properties, etc. In this review, the synthesis, crystal structure features and properties of representative zincoborates are summarized, which could provide significant guidance for the exploration and design of new zincoborates with special structures and excellent performance.

A series of new vanadium(iii) chalcogenido-antimonates: an unusual seven-coordinate nitro-selenidovanadium(iii) complex

A series of new vanadium(iii) chalcogenidoantimonates [VIII(dap)2SbQ3] (Q = S (1), Se (2); dap = 1,2-diaminopropane), [H2dien][VIII2(en)2(dien)2(μ2-O)][SbSe4]2 (3, en = ethylenediamine; dien = diethylenetriamine) and [VIII(dien)2SbSe4] (4) have been solvothermally synthesized and structurally characterized. Both 1 and 2 contain neutral vanadium(iii)-centered complexes [VIII(dap)2SbQ3], where the [SbQ3]3- anion acts as a chelating ligand to complex [VIII(dap)2]3+, but they exhibit different molecular conformations. 3 consists of selenidoantimonate anions [SbSe4]3-, the protonated H2dien2+ cation, and the dinuclear complex [VIII2(en)2(dien)2(μ2-O)]4+ based on two [VIII(en)(dien)]3+ units bridged by one μ2-O group. 4 contains neutral [VIII(dien)2SbSe4] moieties with seven coordinated vanadium centres, which offers a rare example of high coordination of a nitro-selenidovanadium(iii) complex, mainly because the vanadium(iii) ion has a regular octahedral configuration based on the structures in the solid state. The optical, magnetic and photoelectronic properties of all compounds have been investigated, and the density functional theory calculation of 4 has also been studied.

Linking 1D Transition-Metal Coordination Polymers and Different Inorganic Boron Oxides To Construct a Series of 3D Inorganic-Organic Hybrid Borates

Three inorganic-organic hybrid borates, M(1,4-dab)[B₅O₇(OH)₃] [M = Zn (1), Cd (2), 1,4-dab = 1,4-diaminobutane)] and Co(1,3-dap)[B₄O₇] (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 P2₁/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 P4₃2₁2; 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.

Extending Unique 1D Borate Chains to 3D Frameworks by Introducing Metallic Nodes

Two novel alkali/alkaline-earth borates, Ba₆ [B₆ O₉ (OH)₆ ]₂ (H₃ BO₃ ) (1) and Li₇ MAlB₁₂ O₂₄ (M=Ba, Sr, Ca) (2 a-c), with 1D and 3D structures have been made hydrothermally and characterized. 1 features a rare 1D anionic chain built by hexaborate clusters of B₆ O₁₁ (OH)₆ ; each made of six BO₄ /BO₂ (OH)₂ tetrahedra. The anionic chains are embedded in the channels of a Ba₆ -based wheel-cluster open-framework. On the basis of the structural analyses of 1, by incorporating Al atoms as the linkers and tuning the reaction conditions, the novel anhydrous 3D aluminoborates (ABOs) 2 a-c have been successfully obtained, constructed from B₆ O₁₄ -based cluster chains and AlO₆ octahedra. The 3D ABO framework and 3D Ba-O-Li network are interpenetrated to give a final dense structure. The study not only realized the expansion of the structure from the 1D chain of 1 to the 3D dense ABOs 2 a-c, but also obtained the first 3D AlO₆ -containing ABOs made under hydrothermal conditions. Different from the previously known 4-connected zeolite-type ABOs, alternately arranged from AlO₄ tetrahedra and oxo-boron clusters, the AlO₆ octahedra in 2 a-c as the linkers join to six 1D B₆ O₁₄ -based cluster chains to produce 3D ABOs. The optical diffuse reflectance spectra reveal that 2 a-c have wide range transparency. In addition, the thermal property analysis proves that 2 a-c are congruently melting compounds and possess high thermostability.

Two hybrid transition metal triphosphonates decorated with a tripodal imidazole ligand: synthesis, structures and properties

Two transition-metal triphosphonates with pillar-layered structures were synthesized and characterized. The luminescence, magnetic and proton conductive properties were investigated.

A novel supramolecular magnesoborate framework with snowflake-like channels built by unprecedented huge B69 cluster cages

A novel magnesoborate with a 3D supramolecular framework has been made under solvothermal conditions, showing wonderful snowflake-like motif channels assembled from unprecedented B₆₉ cluster cage units.

A series of inorganic-organic hybrid cadmium borates with novel Cd-centred [Cd@B14O20(OH)6](2-) clusters

Four novel inorganic-organic hybrid cadmium borates, namely [EAH]2{(py)2Cd@[B14O20-(OH)6]} (1, py = pyridine, EA = ethylamine), [PAH]2{(py)2Cd@[B14O20(OH)6]} (2, PA = propylamine), [pyH]2{(py)2Cd@[B14O20(OH)6]} (3) and {(AImH)2Cd@[B14O20(OH)6]} (4, AIm = 1-(3-aminopropyl)imidazole) have been solvothermally synthesized and characterized by elemental analysis, thermogravimetric analysis, IR spectroscopy, UV-Vis-NIR spectroscopy, fluorescence spectroscopy, powder X-ray diffraction, and single-crystal X-ray diffraction, respectively. They represent the first hybrid cadmium borates that exhibit 3D supramolecular open-frameworks with different topologies. All the networks are formed by the unprecedented Cd-centred cluster [Cd@B14O20(OH)6](2-), and further link each other via a multipoint H-bond system. UV-Vis-NIR spectral investigation reveals that these borates are wide-band-gap semiconductors. Moreover, they display strong fluorescence emission around 430 nm, making them excellent candidates for optoelectronic applications as blue materials.

Three iodocuprate hybrids symmetrically modulated by positional isomers and the chiral conformation of N-benzyl-methylpyridinium

The successful synthesis and structural analysis of three novel iodocuprate frameworks, [N-Bz-2-MePy]₂[Cu₅I₇] (1), [N-Bz-3-MePy]₂[Cu₅I₇] (2), and [N-Bz-4-MePy][Cu₄I₅] (3), exhibit an excellent structural directing effect of the conformationally chiral N-Bz-MePy⁺.

A zeolite CAN-type aluminoborate with gigantic 24-ring channels

A well crystalline chiral aluminoborate with extra-large 24-ring channels was solvothermally made by using amines as templates. It exhibits a rare zeolite CAN-type net with very low framework density and high nonframework volume by incorporating B₅O₁₀ clusters and AlO₄ tetrahedra.

Octahedron-based gallium borates (Ga-PKU-1) with an open framework: acidity, catalytic dehydration and structure–activity relationship

The octahedron-based Ga-PKU-1 catalyst with an open framework acted as an efficient solid acid catalyst for isopropanol decomposition.

Na₂B₁₀O₁₇·H₂en: a three-dimensional open-framework layered borate co-templated by inorganic cations and organic amines

A layered borate Na2B10O17·H2en (1, en = ethylenediamine) with three-dimensional microporosity within the layers has been synthesized under solvothermal conditions by using organic amines and inorganic cations as the templates. Its framework displays a unique 5-connected net constructed by B5O11 cluster and emits blue luminescence.

Zn(1,3-DAP)[B4O7]: a rare chiral zeolitic framework constructed of four-connected [B4O9] clusters with a single-stranded helical channel

A zinc borate Zn(1,3-DAP)[B₄O₇] (1) was prepared. 1 possessed a rare chiral zeolitic framework based on a [B₄O₉] cluster. The combination of a [B₄O₉] cluster and Zn(1,3-DAP)O₃ chain produced a helical ribbon motif and gave rise to a single-stranded helical channel.

Series of open-framework aluminoborates containing [B5O10] clusters

Three new open-framework aluminoborates (ABOs), Rb₂AlB₅O₁₀·4H₂O (1), [C₅N₂H₁₆]AlB₅O₁₀ (2, C₅N₂H₁₆ = N-ethyl-1,3-diaminopropane) and [H₂dap][(CH₃)₂NH]AlB₅O₁₀ (3, dap = 1,2-diaminopropane) have been made under solvothermal conditions and characterized. The fluorescence and NLO properties were also studied.

Syntheses, structures, and properties of six cobalt(ii) complexes based on a tripodal tris(4-(1H-1,2,4-triazol-1-yl)phenyl)amine ligand

Six new cobalt(ii) metal–organic frameworks based on the tripodal tris(4-(1H-1,2,4-triazol-1-yl)phenyl)amine (TTPA) ligand with different aromatic carboxylate auxiliary ligands have been synthesized and structurally characterized in detail. All the complexes show optical semiconductive properties.

Cotemplating synthesis of a rare borate Ni(en)3·Hen·[B9O13(OH)4]·H2O with a chiral polyanonic chain constructed from two different clusters

Ni(en)3·Hen·[B9O13(OH)4]·H2O was prepared under the cotemplating effect of [Ni(en)3](2+) and Hen(+). It was the first example of a cotemplated borate with an unusual chiral polyanionic chain, which was constructed from [B5O8(OH)2] and [B4O7(OH)2] clusters.