https://research.bangor.ac.uk/portal/files/8375980/Coord_Chem_Rev_2016.pdf

Recent advances in crystalline hydrated borates with non-metal or transition-metal complex cations

A new borate LiBa3 (OH)[B9 O16 ][B(OH)4 ], which combines the uniform porosity of open-frameworks with the extraordinary NLO properties of borates, has been obtained under hydrothermal conditions by using mixed lithium and barium ions as templates. The framework displays an acs-type net with large 21-ring channels. The second harmonic generation (SHG) measurement shows that it is a type I phase-matchable material with a strong SHG signal intensity about 3.1 times that of KDP (KH2 PO4 ). UV/Vis-NIR diffuse reflectance analysis indicates that the compound has a wide transparency range with the short-wavelength absorption edge below 200 nm. These characteristics reveal that the compound is a promising deep-UV nonlinear optical material.

Deep-Ultraviolet Nonlinear Optics in a Borate Framework with 21-Ring Channels

Under solvothermal conditions, a chair open-framework borate, Na2B9O15(H2O)(H3O) (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 B3O7 and B6O13 with three-ring units. The second harmonic generation (SHG) signal intensity of 1 is similar to that of KH2PO4 (KDP) and gradually increased with larger particle size. Compound 1 is a potential UV NLO material for its short wavelength absorption edge.

An Ultraviolet Nonlinear Optic Borate with 13-Ring Channels Constructed from Different Building Units.

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.

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

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.

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

A series of open-framework aluminoborates (ABOs), namely, [Zn2(en)5][Al2B10O20] (1), [Zn(en)(dien)][AlB5O10] (2), [Zn(en)3][AlB7O12 (OH)2] (3), [Zn(en)2][AlB5O10] (4), K7{AlO0.5[BO2(OH)]Zn@[B12O21(OH)3]}⋅H2O (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@[B12O21(OH)3] ({BZn@B12}) clusters with Al2O7 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 KH2PO4. Compounds 1–2 are type I phase-matchable materials. UV/Vis spectroscopy indicates that compounds 1–5 are wide-band-gap semiconductors.

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

Two new borate clusters, [C4H11N2O][C4H9N2][B5O6(OH)4]2 (1), [Cd(dien)2][B5O6(OH)4]2 (2, dien = diethylenetriamine), have been obtained under solvothermal conditions and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, powder X-ray diffraction and single-crystal X-ray structural analysis, respectively. Crystal data for 1: monoclinic, P21/c, a = 18.6975(5) A, b = 15.3413(8) A, c = 9.6691(3) A, β = 90.462(3)°, Z = 4. Crystal data for 2: triclinic, P-1, a = 8.6107(4) A, b = 9.3504(4) A, c = 18.9631(4) A, α = 103.798(4), β = 91.940(4)°, γ = 94.134(4)°, Z = 2. They all consist of [B5O6(OH)4]− clusters and further extend to 3-D frameworks via extensive hydrogen-bonding interactions. Interestingly, a novel in situ organic reaction between ethylenediamine and CH3COO− group has been observed during the formation of compound 1.

Two New Borates Containing [B5O6(OH)4] Clusters, Accompanying a Novel In Situ Organic Reaction Between Ethylenediamine and CH3COO− Group

A DNA triplex has the advantages of improved nanostructure stability and pH environment responsiveness compared with single-stranded and double-stranded nucleic acids. However, sequence stability and low design efficiency hinder the application of DNA triplexes. Therefore, a DNA triplex design approach (TripDesign) based on interaction forces is proposed. First, we present the stacking force constraint, torsional stress constraint, and G-quadruplex motif constraint and then use an improved memetic algorithm to design triplex sequences under combinatorial constraints. Finally, to quantify the process of triplex formation, we also explore the minimum length of the triplex-forming oligos (TFOs) required to form the triplex and the factors that produce depletion in cyclic pH-jump experiments. The experimental results show that the sequences produced by TripDesign have high stability and reversibility, and the proposed approach achieves efficient and automatic sequence design. In addition, this study characterizes multiple basic parameters of DNA triplex formation and promotes the wider application of DNA triplexes in nanotechnology.

TripDesign: A DNA Triplex Design Approach Based on Interaction Forces.

With the rapid development of DNA nanotechnology, the reasonable construction and precise control of complex DNA nanostructures have become active research areas. The continuous breakthroughs in the field of dynamic DNA nanotechnology have provided a number of innovative ideas and techniques for building programmable DNA nanostructures. In this study, we report a mechanism of antibody-mediated four-way branch migration. This mechanism utilizes an antibody, which has the property of specifically binding to an antigen, as the input to the DNA molecular system, promoting four-way branch migration by activating toehold domains. The antibody-mediated four-way branch migration mechanism is then used for the assembly of DNA tiles. Specifically, the tiles are attached to the ends of the four-way branch, and the two tiles are connected by four-way branch migration. Experiments demonstrate the feasibility of this assembly strategy. Our study provides a novel idea for realizing the assembly of nanostructures, simply by attaching structures such as tiles, proteins, quantum dots, etc. to the ends of the four-way branches. It also provides more possibilities for the development of future medical detection.

Yuan Liu

Papers

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

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

Two New Borates Containing [B5O6(OH)4] Clusters, Accompanying a Novel In Situ Organic Reaction Between Ethylenediamine and CH3COO− Group

TripDesign: A DNA Triplex Design Approach Based on Interaction Forces.

DNA tile self-assembly driven by antibody-mediated four-way branch migration.