Haloperoxidase‐like Compounds: Synthesis,Structure and Properties of Two New Oxidovanadium‐Poly(pyrazolyl)borate‐Carboxylate Complexes

Two new oxidovanadium (IV) complexes: TpVO(L₁) ( 1 ) and Tp*VO(pzH*)(L₂) ( 2 ) [Tp = hydrotris(pyrazolyl)borate, HL₁ = 5‐methyl‐1H‐pyrazole‐3‐carboxylic acid, Tp* = hydrotris(3,5‐dimethylpyrazolyl)borate, pzH* = 3,5‐dimethylpyrazole, HL₂ = 5‐phenyl‐1H‐pyrazole‐3‐carboxylic acid] have been synthesized and characterized by elemental analysis and IR spectroscopy. The single‐crystal structures of the complexes shows that the vanadium ion is in a distorted octahedral environment with a N₄O₂ donor set in each complex. Additionally, hydrogen bonding interaction exits in both complexes. Interestingly, the molecules of 1 are held together to form a 1D hydrogen bonded polymer along the b axis, whereas complex 2 is a hydrogen bonded dimer. In addition, the catalytic activities of complexes 1 and 2 in bromination reactions in phosphate buffer with phenol red as a trap were evaluated primary by UV/Vis spectroscopy. Furthermore, ab initio calculations of complexes 1 and 2 were performed.     

A new polytype of orthoboric acid,H3BO3‐3T

The crystal structure of H₃BO₃‐3T, a new trigonal polytype of orthoboric acid, consists of sheets of hydrogen‐bonded B(OH)₃ mol­ecules similar to those found in the triclinic structure of orthoboric acid, H₃BO₃‐2A. In each case, van der Waals forces connect the sheets. However, the stacking sequences of the sheets differ between the two polymorphs. In H₃BO₃‐3T (space group P3₂), the sheets are stacked in the repeating sequence ABC…, whereas in H₃BO₃‐2A (space group ), the sheets are stacked in the repeating sequence AB….     

Pb2BO3Cl: A Tailor‐Made Polar Lead Borate Chloride with Very Strong Second Harmonic Generation

A meticulously designed, polar, non‐centrosymmetric lead borate chloride, Pb₂BO₃Cl, was synthesized using KBe₂BO₃F₂ (KBBF) as a model. Single‐crystal X‐ray diffraction revealed that the structure of Pb₂BO₃Cl consists of cationic [Pb₂(BO₃)]⁺ honeycomb layers and Cl^? anions. Powder second harmonic generation (SHG) measurements on graded polycrystalline Pb₂BO₃Cl indicated that the title compound is phase‐matchable (type I) and exhibits a remarkably strong SHG response, which is approximately nine times stronger than that of potassium dihydrogen phosphate, and the largest efficiency observed in materials with structures similar to KBBF. Further characterization suggested that the compound melts congruently at high temperature and has a wide transparency window from the near‐UV to the mid‐IR region.     

A Facile Synthetic Route to a New SHG Material with Two Types of Parallel π‐Conjugated Planar Triangular Units

A new SHG material, namely, Pb₂(BO₃)(NO₃), which contains parallel π‐conjugated nitrate and borate anions, was obtained through a facile hydrothermal reaction by using Pb(NO₃)₂ and Mg(BO₂)₂?H₂O as starting materials. Its structure contains honeycomb [Pb₂(BO₃)]_∞ layers with noncoordination [NO₃]^? anions located at the interlayer space. Pb₂(BO₃)(NO₃) shows a remarkable strong SHG response of approximately 9.0 times that of potassium dihydrogen phosphate (KDP) and the material is also phase‐matchable. The large SHG coefficient of Pb₂(BO₃)(NO₃) arises from the synergistic effect of the stereoactive lone pairs on Pb²⁺ cations and parallel alignment of π‐conjugated BO₃ and NO₃ units. Based on its unique properties, Pb₂(BO₃)(NO₃) may have great potential as a high performance NLO material in photonic applications.     

Packing considerations of 10‐oxa‐9‐boraphenanthrene derivatives

The crystal structures of three products of the reaction of 2‐phenylphenol and BCl₃ have been determined. The structures show intriguing packing patterns and an interesting case of pseudosymmetry. In addition, one of the two polymorphs has a primitive monoclinic crystal system, but it is twinned and emulates an orthorhombic C‐centred structure. Tris(biphenyl‐2‐yl) borate, C₃₆H₂₇BO₃, ( III ), crystallizes with only one molecule in the asymmetric unit. The dihedral angles between the planes of the aromatic rings in the biphenyl moieties are 50.47 (13), 44.95 (13) and 42.60 (13)°. The boron centre is in a trigonal planar coordination with two of the biphenyl residues on one side of the BO₃ plane and the remaining biphenyl residue on the other side. One polymorph of 10‐oxa‐9‐boraphenanthren‐9‐ol, C₁₂H₉BO₂, ( V a ), crystallizes with two almost identical molecules (r.m.s. deviation of all non‐H atoms = 0.039 Å) in the asymmetric unit. All non‐H atoms lie in a common plane (r.m.s. deviation = 0.015 Å for both molecules in the asymmetric unit). The two molecules in the asymmetric unit are connected into dimers via O—H...O hydrogen bonds. A second polymorph of 10‐oxa‐9‐boraphenanthren‐9‐ol, ( V b ), crystallizes as a pseudo‐merohedral twin with two almost identical molecules (r.m.s. deviation of all non‐H atoms = 0.035 Å) in the asymmetric unit. All non‐H atoms lie in a common plane (r.m.s. deviation = 0.012 Å for molecule 1 and 0.014 Å for molecule A). Each of the two molecules in the asymmetric unit is connected into a centrosymmetric dimer via O—H...O hydrogen bonds. The main difference between the two polymorphic structures is that in ( V a ) the two molecules in the asymmetric unit are hydrogen bonded to each other, whereas in ( V b ), each molecule in the asymmetric unit forms a hydrogen‐bonded dimer with its centrosymmetric equivalent. 9‐[(Biphenyl‐2‐yl)oxy]‐10‐oxa‐9‐boraphenanthrene, C₂₄H₁₇BO₂, ( VI ), crystallizes with four molecules in the asymmetric unit. The main differences between them are the dihedral angles between the ring planes. Apart from the biphenyl moiety, all non‐H atoms lie in a common plane (r.m.s. deviations = 0.026, 0.0231, 0.019 and 0.033 Å for molecules 1, A, B and C, respectively). This structure shows pseudosymmetry; molecules 1 and A, as well as molecules B and C, are related by a pseudo‐translation of about in the direction of the b axis. Molecules 1 and B, as well as molecules A and C, are related by a pseudo‐inversion centre at ,,. Neither between molecules 1 and C nor between molecules A and B can pseudosymmetry be found.     

catena‐Poly[sodium(I)‐μ‐tetra­ethoxy­borato]

The title compound, [Na(C₈H₂₀BO₄)]_n, has twofold crystallographic symmetry, with the Na⁺ cations bound by four O atoms [Na—O = 2.251 (3) Å]. The tetra­ethoxy­borate anion acts as a bridging ligand to form one‐dimensional polymers running along the twofold crystal axis. The crystal was treated as a racemic twin.     

[Bis(3,5‐dimethylpyrazol‐1‐yl‐κN2)hydro(pyrazol‐1‐yl‐κN2)borato][(3,5‐dimethylpyrazol‐1‐yl‐κN2)dihydro(pyrazol‐1‐yl‐κN2)borato]nickel(II)

The title compound, [Ni(C₈H₁₂BN₄)(C₁₃H₁₈BN₆)] or Bp′Tp′Ni^II, where Bp′ is (3,5‐dimethylpyrazol‐1‐yl)dihydro(pyrazol‐1‐yl)borate and Tp′ is bis(3,5‐dimethylpyrazol‐1‐yl)hydro(pyrazol‐1‐yl)borate, contains a divalent Ni^II centre bound by the chelating N atoms of the polysubstituted pyrazolylborate ligands. It is shown to lack a strong agostic B—H...Ni interaction, implying that the sixth coordination site is unoccupied in the solid state. This square‐pyramidal complex is the only known crystal structure where the Ni^II centre is pentacoordinated while bonded exclusively to pyrazolyl units. This is of interest with respect to electrochemical and catalytic properties.     

Preparation and mechanism of polyurethane prepolymer and boric acid co‐modified phenolic foam composite: Mechanical properties,thermal stability,and flame retardant properties

In this work, a new kind of co‐modified phenolic foam was synthesized with polyurethane prepolymer (PUP) and H₃BO₃ by a simple preparation method. Firstly, in order to determine the optimal amount of PUP, the effects of different PUP additions on the mechanical properties, foam microstructure, and pulverization rate of phenolic foam were investigated. Then H₃BO₃ was added to toughened phenolic foam, in order to reduce its fire hazard. The results showed that the mechanical properties of the PFPUP8 phenolic foam composite were the best when the PUP content was 8 wt%. It had a small and regular cell structure, and its pulverization ratio was reduced by 80% compared with that of pristine phenolic foam. Meanwhile, the flame retardant properties of PFPUP8 were improved in different degrees with an increase in the amount of H₃BO₃. Particularly, when the addition of H₃BO₃ was 10 wt%, the peak heat release rate, the total heat release, and the total smoke release values of PFPUP10B were decreased by 35.4%, 42.4%, and 45.2%, respectively, compared with those of PFPUP8. The value of the limit oxygen index was increased by 33.1%. Besides, the addition of H₃BO₃ had no adverse effect on the mechanical properties and pulverization ratio of PFPUP8. In addition, the specific mechanisms of toughening, flame retardant, and smoke suppression are also discussed in this paper on the basis of an investigation into the thermal properties of the toughened flame retardant foam composites by thermogravimetric analysis in N₂ atmosphere.     

Oxonium Ions Substituting Cesium Ions in the Structure of the New High‐Pressure Borate HP‐Cs1−x(H3O)xB3O5 (x=0.5–0.7)

The new high‐pressure borate HP‐Cs_1?x(H₃O)_xB₃O₅ (x=0.5–0.7) was synthesized under high‐pressure/high‐temperature conditions of 6 GPa/900 °C in a Walker‐type multianvil apparatus. The compound crystallizes in the monoclinic space group C2/c (Z=8) with the parameters a=1000.6(2), b=887.8(2), c=926.3(2) pm, β=103.1(1)°, V=0.8016(3) nm³, R1=0.0452, and wR2=0.0721 (all data). The boron–oxygen network is analogous to those of the compounds HP‐MB₃O₅, (M=K, Rb) and exhibits all three structural motifs of borates—BO₃ groups, corner‐sharing BO₄ tetrahedra, and edge‐sharing BO₄ tetrahedra—at the same time. Channels inside the boron–oxygen framework contain the cesium and oxonium ions, which are disordered on a specific site. Estimating the amount of hydrogen by solid‐state NMR spectroscopy and X‐ray diffraction led to the composition HP‐Cs_1?x(H₃O)_xB₃O₅ (x=0.5–0.7), which implies a nonzero phase width.     

Pb2BO3I: A Borate Iodide with the Largest Second‐Harmonic Generation (SHG) Response in the KBe2BO3F2 (KBBF) Family of Nonlinear Optical (NLO) Materials

Borate halides are an ideal materials class from which to design high‐performance nonlinear optical (NLO) materials. Currently, borate fluorides, chlorides, and bromides are extensively investigated while borate iodide materials discovery remains rare because of the perceived synthetic challenges. We report a new borate iodide, Pb₂BO₃I, synthesized by a straightforward hydrothermal method. The Pb₂BO₃I chemical formula conceals that the compound exhibits a structure similar to the well‐established KBe₂BO₃F₂ (KBBF), which we show supports the highest second‐harmonic generation (SHG) at 1064 nm in the KBBF family, 10 × KH₂PO₄ (KDP), arising from the inclusion of Pb²⁺ and I^? and the crystal chemistry. Our work shows that KBBF‐related compounds can be synthesized incorporating iodide and exhibit superior NLO responses.     

Synthesis, Characterization and Thermochemistry of 2MgO：B2O3：1.5H2O

Introduction　　 2MgO·B2 O3(Mg2 B2 O5)and 2MgO·B2 O3·H2 Omightbepreparedaswhiskermaterials .12MgO·B2 O3·H2 OnamedszaibelyiteisamagnesiumboratemineralwithastructuralformulaofMg2 [B2 O4 (OH) 2 ].2 Itisdifficulttosynthesizethiscompoundinthelaboratory .Recently ,weobtainedasimilarcompound 2MgO·B2 O3·1 5H2 Owhenwetriedtopreparewhiskerof 2MgO·B2 O3·H2 Obythephasetransformationof 2MgO·2B2 O3·MgCl2 ·14H2 OinH3BO3solutionunderhydrothermalcondition .Itishope fultopreparewh…     

Bis(acetonitrile‐κN)bis[hydridotris(3,5‐dimethylpyrazol‐1‐yl‐κN2)borato]di‐μ3‐sulfido‐tetra‐μ2‐sulfido‐di‐μ2‐thiocyanato‐κ2N:S;κ2S:N‐tetracopper(I)ditungsten(VI)

Reactions of (Et₄N)[Tp*WS₃] [Tp* is hydridotris(3,5‐dimethylpyrazol‐1‐yl)borate] with CuSCN in MeCN in the presence of melamine afforded the title neutral dimeric cluster [Cu₄W₂(C₁₅H₂₂BN₆)₂(NCS)₂S₆(C₂H₃N)₂] or [Tp*W(μ₂‐S)₂(μ₃‐S)Cu(μ₂‐SCN)(CuMeCN)]₂, which has two butterfly‐shaped [Tp*WS₃Cu₂] cores bridged across a centre of inversion by two (CuSCN)⁻ anions. The S atoms of the bridging thiocyanate ligands interact with the H atoms of the methyl groups of the Tp* units of a neighbouring dimer to form a C—H...S hydrogen‐bonded chain. The N atoms of the thiocyanate anions interact with the H atoms of the methyl groups of the Tp* units of neighbouring chains, affording a two‐dimensional hydrogen‐bonded network.     

Synthesis of Alumina‐Coated Natural Graphite for Highly Cycling Stability and Safety of Li‐Ion Batteries

The natural graphite (NG) uniformly coated with alumina ceramics (Al₂O₃) was successfully synthesized through sol‐gel method. The aluminum plastic film soft‐packed battery prepared using Al₂O₃‐coated NG as anode material exhibits excellent cycle performance and safety performance. The cycling retention of AN‐1 is 84.95% after 200 cycles at a rate of 1 C in a potential window ranging from 3.0 to 4.35 V, which is much greater than 75.07% of NG under the same test conditions. The result of the nail penetration tests shows that the successful nail penetration rate of the NG used as anode is 0%, while that of Al₂O₃ coated samples AN‐1 is 100%. The test results show that the Al₂O₃ coating could act as a solid electrolyte to suppress side reactions, improve cycle stability, and prevent a thermal runaway under mechanical abuse.     

1‐[5‐(4,5‐Dimethyl‐1,3,2‐dioxaborolan‐2‐yl)thiophen‐2‐yl]ethanone and 4‐(4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolan‐2‐yl)benzaldehyde

In both title compounds, C₁₀H₁₃BO₃S, (I), and C₁₃H₁₇BO₃, (II), the molecules adopt nearly planar conformations. The crystal packing of (I) consists of a supramolecular two‐dimensional network with a herringbone‐like topology formed by self assembly of centrosymmetric pairs of molecules linked via dipole–dipole interactions. The crystal structure of (II) consists of a supramolecular two‐dimensional network built up from centrosymmetric pairs of molecules viaπ–π interactions. These pairs of molecules are self‐organized in an offset fashion related by a symmetry centre, generating supramolecular ribbons running along the [101] direction. Neighbouring ribbons are stacked via complementary van der Waals and hydrophobic methyl–methyl interactions.     

Seven 5‐benzylamino‐3‐tert‐butyl‐1‐phenyl‐1H‐pyrazoles: unexpected isomorphisms,and hydrogen‐bonded supramolecular structures in zero,one and two dimensions

5‐Benzylamino‐3‐tert‐butyl‐1‐phenyl‐1H‐pyrazole, C₂₀H₂₃N₃, (I), and its 5‐[4‐(trifluoromethyl)benzyl]‐, C₂₁H₂₂F₃N₃, (III), and 5‐(4‐bromobenzyl)‐, C₂₀H₂₂BrN₃, (V), analogues, are isomorphous in the space group C2/c, but not strictly isostructural; molecules of (I) form hydrogen‐bonded chains, while those of (III) and (V) form hydrogen‐bonded sheets, albeit with slightly different architectures. Molecules of 3‐tert‐butyl‐5‐(4‐methylbenzylamino)‐1‐phenyl‐1H‐pyrazole, C₂₁H₂₅N₃, (II), are linked into hydrogen‐bonded dimers by a combination of N—H...π(arene) and C—H...π(arene) hydrogen bonds, while those of 3‐tert‐butyl‐5‐(4‐chlorobenzylamino)‐1‐phenyl‐1H‐pyrazole, C₂₀H₂₂ClN₃, (IV), form hydrogen‐bonded chains of rings which are themselves linked into sheets by an aromatic π–π stacking interaction. Simple hydrogen‐bonded chains built from a single N—H...O hydrogen bond are formed in 3‐tert‐butyl‐5‐(4‐nitrobenzylamino)‐1‐phenyl‐1H‐pyrazole, C₂₀H₂₂N₄O₂, (VI), while in 3‐tert‐butyl‐5‐(3,4,5‐trimethoxybenzylamino)‐1‐phenyl‐1H‐pyrazole, C₂₃H₂₉N₃O₃, (VII), which crystallizes with Z′ = 2 in the space group P, pairs of molecules are linked into two independent centrosymmetric dimers, one generated by a three‐centre N—H...(O)₂ hydrogen bond and the other by a two‐centre N—H...O hydrogen bond.     

Poly[di‐μ2‐methano­lato‐di‐μ2‐tetra­methoxy­borato‐disodium(I)]

In the polymeric title compound, [Na₂(C₄H₁₂BO₄)₂(CH₄O)₂]_n, the two independent sodium cations are bound by five O atoms. All the O atoms of one tetra­methoxy­borate anion bind cations, forming a tetra­meric cluster around a tetra­gonal inversion centre [Na—O = 2.2777 (18)–2.3907 (16) Å]. Two methanol O atoms bridge the two Na atoms [Na—O = 2.3590 (15)–2.4088 (18) Å] and provide the hydrogen‐bonding H atoms. The second tetra­methoxy­borate anion provides two O atoms to one Na atom [mean Na—O = 2.31 (2) Å] and two O atoms as donors for crosslinking hydrogen bonds to adjacent tetra­mers, which complete the three‐dimensional packing. The crystal was a treated as a racemic twin.     

The hydrogen‐bonding patterns of 3‐phenylpropylammonium benzoate and 3‐phenylpropylammonium 3‐iodobenzoate: generation of chiral crystals from achiral molecules

The crystal structures and hydrogen‐bonding patterns of 3‐phenylpropylammonium benzoate, C₉H₁₄N⁺·C₇H₅O₂⁻, (I), and 3‐phenylpropylammonium 3‐iodobenzoate, C₉H₁₄N⁺·C₇H₄IO₂⁻, (II), are reported and compared. The addition of the I atom on the anion in (II) produces a different hydrogen‐bonding pattern to that of (I). In addition, the supramolecular heterosynthon of (II) produces a chiral crystal packing not observed in (I). Compound (I) packs in a centrosymmetric fashion and forms achiral one‐dimensional hydrogen‐bonded columns through charge‐assisted N—H...O hydrogen bonds. Compound (II) packs in a chiral space group and forms helical one‐dimensional hydrogen‐bonded columns with 2₁ symmetry, consisting of repeating R₄³(10) hydrogen‐bonded rings that are commonly observed in ammonium carboxylate salts containing chiral molecules. This hydrogen‐bond pattern, which has been observed repeatedly in ammonium carboxylate salts, thus provides a means of producing chiral crystal structures from achiral molecules.     

Producing highly linear polyethylenes by using t‐butyl‐functionalized 2,6‐bis(imino)pyridylchromium(III) chlorides

A new family of t‐butyl substituted chromium(III) chloride complexes ( Cr1 – Cr6 ), bearing 2‐(1‐(2,6‐dibenzhydryl‐4‐t‐butylphenylimino)ethyl)‐6‐(1‐(arylimino)ethyl)pyridine (aryl = 2,6‐Me₂C₆H₃ Cr1 , 2,6‐Et₂C₆H₃ Cr2 , 2,6‐i‐Pr₂C₆H₃ Cr3 , 2,4,6‐Me₃C₆H₂ Cr4 and 2,6‐Et₂‐4‐MeC₆H₂ Cr5 ) or 2,6‐bis(1‐(2,6‐dibenzhydryl‐4‐t‐butylphenylimino)ethyl)pyridine ( Cr6 ), has been synthesized by the reaction of CrCl₃·6H₂O in good yield with the corresponding ligands ( L1 – L6 ), respectively. The molecular structures of Cr2 and Cr6 were characterized by X‐ray diffraction highlighted a distorted octahedral geometry with the coordinated N,N,N ligand and three bonded chlorides around the metal center. On activation with modified methylaluminoxane or triisobutyl aluminum, most of the chromium precatalysts exhibit good activities toward ethylene polymerization and produce linear polyethylenes with high‐molecular weight. In addition, an in‐depth catalytic evaluation of Cr2 was conducted to investigate how cocatalyst type and amount, reaction temperature, and run time affect the catalytic activities and polymer properties. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 1049–1058     

Charge‐assisted hydrogen bonding in salts of 2‐amino‐1H‐benzimidazole with 3‐phenylpropynoic acid and oct‐2‐ynoic acid

The 100 K structures of two salts, namely 2‐amino‐1H‐benzimidazolium 3‐phenylpropynoate, C₇H₈N₃⁺·C₉H₅O₂⁻, (I), and 2‐amino‐1H‐benzimidazolium oct‐2‐ynoate, C₇H₈N₃⁺·C₈H₁₁O₂⁻, (II), both have monoclinic symmetry (space group P2₁/c) and display N—H...O hydrogen bonding. Both structures show packing with corrugated sheets of hydrogen‐bonded molecules lying parallel to the [001] direction. Two hydrogen‐bonded ring motifs can be identified and described with graph sets R²₂(8) and R⁴₄(16), respectively, in both (I) and (II). Computational chemistry calculations performed on both compounds show that the hydrogen‐bonded ion pairs are more energetically favourable in the crystal structure than their hydrogen–bonded neutral molecule counterparts.     

Proton‐stabilized three‐dimensional anionic framework in H[Zn6O2(BO3)3]

A three‐dimensional anionic framework built up from [ZnO₄] tetra­hedra and planar [BO₃] groups, stabilized by H atoms, has been found for hydrogen zinc oxide borate, H[Zn₆O₂(BO₃)₃]. Boron and one of the borate O atoms are on 18e (2) positions. Triple units of [ZnO₄] tetra­hedra sharing a common oxygen vertex on a 12c (3) site and strong asymmetrical linear hydrogen bonds with the H atom [on a 12c (3) position] disordered over a twofold axis are specific structural features of this zincoborate. There is evidence that the reported Zn₄O(BO₃)₂ [Harrison, Gier & Stuky (1993). Angew. Chem. Int. Ed. Engl. 32 , 724–726] corresponds to this structure.