Oxoboron Clusters Research Articles

Synthesis, structure, and oxygen reduction reaction of three copper complexes supported by ethylenediamine derivatives with outer-sphere oxoboron clusters

Three copper complex borates, [Cu(en)2]·[B4O5(OH)4]·2H3BO3 (1, en = ethylenediamine), [Cu(Eten)2]·[B5O6(OH)4]2 (2, Eten = N-ethyl ethylenediamine) and [Cu(Dmen)2]·[B10O13(OH)6] (3, Dmen = N,N-dimethyl ethylenediamine) have been successfully synthesized and structurally characterized by single-crystal X-ray diffraction, PXRD, and FTIR. Their oxoboron clusters are [B4O5(OH)4]2−, [B5O6(OH)4]− and [B10O13(OH)6]2−, respectively. Copper ion was used as the central atom, ethylenediamine and its derivatives were selected as ligand. The structure of oxoboron clusters in 1, 2 and 3 can be modulated through varying ethylenediamine derivative ligand, as well as temperature and pressure of reaction system. These copper complex borates exhibited open framework formed by the interconnection of hydrogen bonds of oxoboron clusters. Moreover, the oxygen reduction reaction activity of these borate-based catalysts was investigated. The half-wave potential values of the products after heating1–3with carbon at 600 °C (1/C-600, 2/C-600 and 3/C-600) were 0.817, 0.80 and 0.73 V, respectively.

K2 Na3 [{B6 O10 (OH)}{B3 O4 (OH)3 }] ⋅ H2 O: A Layered Borate Built by Mixed Oxoboron Clusters with Nonlinear-Optical Property.

A new acentric borate, K2 Na3 [{B6 O10 (OH)}-{B3 O4 (OH)3 }] ⋅ H2 O (1) has been made under solvothermal condition. 1 has layered structure made by B6 O13 (OH)-based chains and B3 O5 (OH)3 -bridging clusters. Second-harmonic generation (SHG) measurements reveal that 1 is a phase-matchable nonlinear optical (NLO) material, showing the SHG signal intensity of 1.8 times that of KDP (KH2 PO4 ). Besides, UV-Vis diffuse reflectance spectrum shows that 1 has the short deep UV (DUV) absorption cutoff edge of 198 nm. Thermogravimetric analysis reveals it has good thermal stability. Also 1 represents firstly mixed oxoboron clusters-made 2D layered borate with NLO property.

Multicomponent Cooperative Assembly of Nanoscale Boron-Rich Polyoxotungstates with 22 and 30 Boron Atoms

This work demonstrates that the introduction of positive lanthanide (Ln) and transition metal (TM) cations into polyoxotungstates (POTs) to stabilize negative oxoboron clusters is a feasible and ge...

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.

The tunable luminescent property and wide band gap in three 1D hybrid templated borates containing different metallic ions and oxoboron clusters

Our systematic exploration of chainlike borate in the hybrid templated borate systems has led to three new borates, namely, [GaTETA]·[B5O8(OH)2]·H2O, [InTETA]·[B5O8(OH)2]·1.5H2O, and [Cd(1,2-dap)]·[B6O11(OH)2]·H2O. The structures of the three borates were determined by single-crystal X-ray diffraction. [Cd(1,2-dap)]·[B6O11(OH)2]·H2O represents the first example of chainlike borate containing Cd2+ transition metal cations and [B6O11(OH)2] cluster. [GaTETA]·[B5O8(OH)2]·H2O is isostructural with [InTETA]·[B5O8(OH)2]·1.5H2O, whose structure features a one-dimensional (1D) polyatomic chain constructed of MO2N4 octahedron and [B5O8(OH)2] groups, such chains are further bridged by HBs resulting in a three-dimensional (3D) supermolecular network. Optical and luminescent property measurements have also been performed on the three compounds. Only fluorescence intensity of [GaTETA]·[B5O8(OH)2]·H2O decreased fiercely with temperature increase. Besides, the band gap of [GaTETA]·[B5O8(OH)2]·H2O and its isomer [InTETA]·[B5O8(OH)2]·1.5H2O and [Cd(1,2-dap)]·[B6O11(OH)2]·H2O are very distinct from each other, it may indicate that optical and luminescent property of hybrid borate can be manipulated by adjusting of polyatomic cluster and metallic ion.

Synthesis, Characterization and Optical Properties of Two Metal Borates Containing Two Types of Oxoboron Clusters

AbstractTwo metal borates, namely, Pb6O(B6O14) (1) and β‐BaAl[B4O8(OH)](H2O) (2) have been obtained and characterized. Compound 1 crystallizes into triclinic crystal system with a centrosymmetric space group of P‐1 and its structure features [Pb6O13]14− layers which are further connected by [B6O14]10− chains into a 3D framework. Compound 2 is isostructural with β‐BaGa[B4O8(OH)](H2O) and adopts a centrosymmetric space group P‐1. Its structure consists of a AlB4O10(OH) bilayers with intersecting channel systems comprised of two interconnected porous sheets. Each compound was also characterized by optical and thermogravimetric analysis and band structure calculations have been carried out based on density functional theory methods.

A new mixed alkali metal borate: LiCs[B5O8(OH)]·H2O

A new mixed alkali metal borate LiCs[B5O8(OH)]·H2O (1) has been made under solvothermal conditions and characterized by single-crystal X-ray diffraction, IR spectroscopy, diffuse-reflectance spectroscopy, powder X-ray diffraction and thermogravimetric analysis, respectively. 1 crystallizes in the monoclinic space group P21/c, a=10.1523(9)Å, b=8.4516(6)Å, c=12.2178(17)Å, β=122.522(8)°, V=883.93(14)Å3 and Z=4. 1 exhibits a novel fluctuant anionic [B5O8(OH)]n2n− layers based on the unusual B5O10(OH) oxoboron clusters, showing a four-connected spl topology net with the Schläfli symbol of {44·62}. The layers are further linked via the LiOCs chains and H-bonds to form a new 3-D structure. The cutoff edge of 1 is below 190nm and it has a band gap of 5.82eV.

Na2(H2en)[B5O8(OH)]2[B3O4(OH)]2 and Na3(HCOO)[B5O8(OH)]: Two Borates Co‐Templated by Inorganic Cations and Organic Compounds

The cooperative effect of inorganic and organic co‐templates led to two layered borates: centrosymmetric (CS) Na2(H2en)[B5O8(OH)]2[B3O4(OH)]2 (1; en = ethylenediamine) and noncentrosymmetric (NCS) Na3(HCOO)[B5O8(OH)] (2). Compound 1 features coupled layers extended by two different oxoboron clusters, which are rare in borates. The Na+ cations are located in the channel and hold the coupled layers in tight inorganic B–O–Na layers, while H2en2+ cations reside in channels between inorganic layers. Compound 2 is the first NCS borate directed by inorganic and organic species simultaneously and features acentric [B5O8(OH)]n2n– layers. It exhibits a good second harmonic generation efficiency of about 1.9 times that of potassium dihydrogenphosphate and is phase‐matchable, and the UV cutoff edge below 200 nm makes 2 a potential UV nonlinear optical material. Investigation of the fluorescence properties indicated that the new borates are potential blue fluorescent materials. In addition, structure elucidation revealed that host–guest symmetry matching plays a key role in the formation of CS 1 and NCS 2.

Novel borate supramolecular frameworks constructed from isolated B4/B5 clusters and 1-D B17-based chains

Three new borates [Cu(1,3-dap)2(H2O)2][Cu(1,3-dap)2(B(OH)3)2][B4O5(OH)4]2 (1, 1,3-dap=1,3-diaminopropane), [Cu(py)4(H2O)][B5O6(OH)4]2·3py·H2O (2, py=pyridine) and (HDMF)2[NH(CH3)3]4[NH2(CH3)2]2Mg2[B17O26(OH)4][B17O27(OH)4]·NH3 (3, DMF=N,N-dimethylformamide) have been synthesized under mild solvothermal conditions and characterized by elemental analysis, IR spectra, diffuse reflectance spectra, thermogravimetric analysis, single-crystal X-ray diffraction and powder X-ray diffraction. 1 and 2 exhibit 3-D supramolecular hydrogen-bonded architectures constructed from isolated oxoboron clusters [B4O5(OH)4]2− and [B5O6(OH)4]−, respectively. The structure of 3 features two different 1-D chains built by unprecedented [B17O26(OH)4]5− and [B17O27(OH)4]7− clusters, respectively. And the adjacent chains are alternatively linked by H-bonding to form a 3-D supramolecular framework.

Borates A Novel Twofold Interpenetrating 3D Diamondoid Borate Framework Constructed from B4and B5Clusters

Borates with extended structures and interpenetrating system built from different types of cluster units are extremely rare. In this paper, we report a novel mixed-alkali-metal borate Na3Li2[B4O7][B5O8(OH)2] (1) synthesized under solvothermal conditions, showing a three-dimensional twofold interpenetrating system constructed from two types of oxoboron clusters (B4O9 and B5O10(OH)2) setting as the first example in borates. And 1 also features an intricate 3-D Li-O−Na cationic network. In this work, we made a detailed comparison with other reported borates from 1-D chain, 2-D layer to 3-D framework containing B4 and B5 clusters and further demonstrated that such 3-D framework of 1 can be achieved by controlling the alkalinity of solution to prompt the concentration of two different oxoboron clusters with rich terminal hydroxyl groups together. Indeed, it can be regarded as a good interpretation of hydrolysis-condensation processes in dimensional transformation of borates making it possible for the rational design of various structural borates in the future. Moreover, 1 displays fluorescence emission around 472 nm, making it an appropriate candidate for optoelectronic applications.

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 deep-ultraviolet nonlinear optical alkaline-earth metal borates based on different types of oxoboron clusters.

Two non-centrosymmetric alkaline-earth metal borates, Ca2[B5O8(OH)]2[B(OH)3]·H2O (1) and Ba2[B6O9(OH)2][B3O3(OH)4]·(OH)·4H2O (2), have been synthesized under solvothermal conditions. Both of them exhibit layered structures constructed from two fundamental building blocks (FBBs), respectively. 1 features porous double-layers made by the acentric single A-layer and B-layer in a face-to-face arrangement. Ca-O layers gather the B-O double-layers together resulting in the chiral structure of 1. Compound 2 contains two different FBBs, which is rare in borate. Hexaborate B6 clusters are responsible for the expansion of inorganic B6-layers while the isolated triborate B3 clusters are arranged in supermolecular B3-layers. Ba1-B6-layers and Ba2-B3-layers are alternately arranged in the same direction generating the NCS structure of 2. Both 1 and 2 are phase-matchable materials with second-harmonic generation (SHG) responses of ∼1.3 and ∼0.8 times that of KDP (KH2PO4), respectively. UV-vis diffuse reflectance spectra reveal that they have short cut-off edges lower than 200 nm. These characteristics make them potential deep-UV NLO materials. The calculations reveal that the SHG efficiency mainly originates from the synergistic effect of the distorted MOn (M = Ca, Ba; n = 7, 10, 11) polyhedra and the asymmetric π-conjugated of BO3 units.

ChemInform Abstract: A Series of Aluminoborates Templated or Supported by Zinc‐Amine Complexes.

Abstract[Zn2(en)5][Al2B10O20] (I), [Zn(en)(dien)][AlB5O10] (II), [Zn(en)3][AlB7O12(OH)2] (III), [Zn(en)2][AlB5O10] (IV), and K7{AlO0.5[BO2(OH)]Zn@ [B12O21(OH)3]}·H2O (V) (dien: diethylenetriamine) are prepared under mild solvothermal conditions using a 8:1:1 molar mixture of H3BO3, Al(O‐iPr)3, and Zn(OH)2 in en and H2O for (I) (autoclave, 170 °C, 9 d, 57% yield) and (IV) (200 °C, 9 d, 60% yield), the same mixture plus pyridine for compound (II) (190 °C, 9 d, 46% yield) and compound (III) (180 °C, 9 d, 60% yield), and K2B4O7 replacing H3BO3 in the procedure similar to compound (III) to arrive at (V) (46% yield).

A Series of Aluminoborates Templated or Supported by Zinc-Amine Complexes.

A series of open-framework aluminoborates (ABOs), namely, [Zn2 (en)5 ][Al2 B10 O20 ] (1), [Zn(en)(dien)][AlB5 O10 ] (2), [Zn(en)3 ][AlB7 O12 (OH)2 ] (3), [Zn(en)2 ][AlB5 O10 ] (4), K7 {AlO0.5 [BO2 (OH)]Zn@[B12 O21 (OH)3 ]}⋅H2 O (5) (en=ethylenediamine, dien=diethylenetriamine) have been made under mild solvothermal conditions and characterized by single-crystal X-ray diffraction, powder X-ray diffraction, elemental analysis, IR and UV/Vis spectroscopy, thermogravimetric analysis, and nonlinear optical determination. They were classified as two types: Compounds 1-4 contain intersecting channels and exhibit various 4-connected nets built by AlO4 tetrahedra and oxo boron clusters, zinc-amine complexes act as the templates (1-3) or directly bond to the walls of the ABO (4); compound 5 exhibits a double-layer structure made by nanosized [BO2 (OH)]Zn@[B12 O21 (OH)3 ] ({BZn@B12 }) clusters with Al2 O7 dimers, the channels are within the layer. The second harmonic generation (SHG) measurement shows that the SHG responses of 1-3 are about 2.5, 1.6, and 0.5 times that of KH2 PO4 . Compounds 1-2 are type I phase-matchable materials. UV/Vis spectroscopy indicates that compounds 1-5 are wide-band-gap semiconductors.

Synthesis, Structural Characterization and Properties of Two Strontium Borates Constructed from Oxo Boron Clusters

Two strontium borates Sr2[B6O9(OH)4] (1) and Sr2B5O9(OH)·H2O (2), with acentric structures have been synthesized under hydro/solvothermal conditions. Compound 1 is reported for the first time in the strontium borates system, and it crystallizes in the monoclinic space group P21 with unit cell parameters a = 6.8445(5) A, b = 8.7033(6) A, c = 8.4632(6) A, β = 100.581(6)°, V = 495.58(6) A3 and Z = 2. Its structure consists of unusual borate layers of 3, 11-membered rings, which are interconnected via Sr–O ionic bonds and hydrogen bonds to generate a 3D supramolecular network. Compound 2 is a known strontium borate, crystallizing in the monoclinic space group C 2 with a = 10.161 (13) A, b = 7.965(4) A, c = 6.393(11) A, β = 128.0(2)°, V = 407.7(14) A3 and Z = 2. Second-harmonic generation measurements on the powder samples reveal that 1 and 2 exhibits good SHG efficiency about 1.5 and 2 times that of KDP (KH2PO4) powder respectively.

Two new organic borates with the large [B14O20(OH)6]4− oxoboron clusters

Two new borate clusters, [NH3(CH2)3NH3]2[B14O20(OH)6] (1) and [NH3(CH2)6NH3]2[B14O20(OH)6] (2), have been made under solvothermal conditions and characterized by single-crystal X-ray structural analysis. Also their IR and UV–Vis spectroscopy, thermogravimetric analysis, and elemental analysis have been investigated, respectively. Crystal data for 1: triclinic, P-1, a = 8.8049(4) A, b = 9.1585(5) A, c = 10.1912(5) A, α = 74.925(4)°, β = 80.987(4)°, γ = 67.495(5)°, Z = 1. Crystal data for 2: triclinic, P-1, a = 9.2010(4) A, b = 9.8663(4) A, c = 11.4191(4) A, α = 107.014(4)°, β = 92.514(3)°, γ = 107.265(4)°, Z = 1. The structures consist of isolated 8-membered boron ring made of the [B7O10(OH)3]2−cluster subunits. UV–Vis spectral investigation indicates that they are wide-band-gap semiconductors. Fluorescence spectroscopy indicates that they are potential blue light materials.

ChemInform Abstract: Oxo Boron Clusters and Their Open Frameworks

AbstractReview: 105 refs.

Oxo Boron Clusters and Their Open Frameworks

AbstractThis review article briefly summarizes the recent research advances in the field of crystalline oxo boron clusters and their open frameworks. By using different amine molecules and transition metal complexes or inorganic ions as the charge‐balancing agents, different oxo boron clusters, such as [B3O3(OH)4]–, [B4O5(OH)4]2–, [B5O6(OH)4]–, [B7O9(OH)5]2–, [B8O10(OH)6]2–, [B9O12(OH)6]3–, and [B14O20(OH)6]4– polyanions, have been successfully isolated and structurally characterized. These polyborate anions may act as the main building blocks to create new open‐framework compounds with layered and three‐dimensional structures. Odd ring channels and helical channels are noteworthy in open‐framework borate structures. Besides their traditional zeolitic properties, open‐framework borates exhibit interesting optical properties including photoluminescence and second harmonic generation, suggesting their potential applications in catalysis, nonlinear optics, display and lighting devices.