稀土正硼酸盐的晶体结构与温(压)致相变研究

稀土正硼酸盐(REBO3)晶体是一类潜在的紫外发光和非线性光学应用方面的材料,其中方解石结构的LuBO3:Ce3+晶体的光输出可达到26000 Ph·Mev-1,几乎是BGO(Bi4Ge3O12)的3倍,是PbWO4的135倍,并且该晶体表现出显著的闪烁特性和物力稳定性,例如快的衰减时间(~33 ns)及不易潮解等;但是由于方解石结构相、球霰石结构相以及高温球霰石结构相间存在相变反应,使得大尺寸的纯LuBO3单晶难于生长。因此,在晶体的生长过程中迫切需要明确各结构间的相互关系,并且为了进一步优化和拓展其应用空间,还需要深入了解其组成-结构-性能的相互关系。主要对各种稀土正硼酸盐的晶体结构和结构间的转变进行了总结与分析。     

稀土硼酸盐中影响Dy^3＋发光的因素

60年代初对ABO_3型稀土硼酸盐的合成、结构和性质的研究已有报道。80年代侧重稀土和金属离子硼酸盐发光规律的研究。 Srivastava曾对GdBO_3中pr~(3+)的光谱及Gd~(3+)对Pr~(3+)的敏化、郭风瑜,李有谟     

氯柱硼镁石的硼酸溶液中硼氧配阴离子的FT-IR光谱分析

硼有ＢＯ3平面三角形和ＢＯ4四面体两种配位类型 ,在晶体和水溶液中硼以聚合硼氧配阴离子形式存在。硼氧配阴离子存在形式及其相互作用受溶液温度、ｐＨ值、总硼浓度及金属阳离子存在等多种因素的影响。可见 ,硼酸盐水溶液要比一般盐水溶液复杂。振动光谱能有效地用于鉴定和表征固体硼酸盐 ,至今对水溶液硼酸盐结构的研究却较少。由于多数硼酸盐在室温水中的溶解度较小 ,溶液中硼浓度低 ,加之溶剂水对ＩＲ辐射具有明显吸收作用 ,致使硼酸盐水溶液红外光谱中多聚硼氧配阴离子特征峰被减弱、模糊甚至被湮灭。近年来 ,Ｊ .Ｍａｘ[1 ] 等在对盐…     

蝎型钒氧配合物的合成、结构及量子化学研究

设计合成了两种新型的以聚类吡唑硼酸盐为配体的钒氧配合物VO(acac)[HB(pz)3](1)和VO(acac)[HB(3,5-Me2pz)3]·CH3CN(2). 运用元素分析、 红外光谱和紫外光谱对所合成的配合物进行了表征, 并用X射线衍射测定了它们的晶体结构. 同时, 采用量子化学的Hartree Fock方法和自然轨道分析方法(NBO), 使用3-21G*(6d, 7f)基组计算得到了两个分子体系的分子轨道、原子电荷以及键级, 并对其结构进行了分析.     

锂离子电池硼酸盐电极材料的研究进展

硼酸盐作为新一代锂离子电池电极材料,其具有摩尔质量小、资源丰富、环境友好和理论比容量高等优点.本文对LiFeBO3、LiMnBO3和LiCoBO3等硼酸盐正极材料以及Fe3BO6、FeBO3、Cr3BO6、Co2B2O5、Cu3B2O6和VBO3等硼酸盐负极材料的结构、制备方法、电化学性能的研究现状进行了综述,并对存在的主要问题提出了改进方法.     

有机杂化硼酸盐[Ni(dien)_2][B_5O_6(OH)_4]_2的水热合成及晶体结构

硼酸盐不仅结构丰富,而且在矿物学、催化、非线性光学材料、激光材料、隔热隔声材料等方面具有重要的应用, 从而促使人们在研究与探索硼酸盐晶体材料方面作了大量工作,制备出许多性能优良的晶体材料.     

Co(en)3[B4O5(OH)4]Cl·3H2O和[Ni(en)3][B5O6(OH)4]2·2H2O的合成、结构以及热力学性质

利用水热法合成了两种过渡金属配合物为模板剂的含水硼酸盐晶体Co(en)3[B4O5(OH)4]Cl·3H2O(1) 和 [Ni(en)3][B5O6(OH)4]2·2H2O (2),并通过元素分析、X射线单晶衍射、红外光谱及热重分析对其进行了表征。化合物1晶体结构的主要特点是在所有组成Co(en)33+, [B4O5(OH)4]2–, Cl– 和 H2O之间通过O–H…O、O–H…Cl、N–H…Cl和N–H…O四种氢键连接形成网状超分子结构。化合物2晶体结构的特点是[B5O6(OH)4]–阴离子通过O–H…O氢键连接形成沿a方向有较大通道的三维超分子骨架,模板剂[Ni(en)3]2+阳离子和结晶水分子填充在通道中。     

硼酸盐润滑油添加剂的研究现状和进展

综述了国内外硼酸盐润滑油添加剂的研究现状,介绍了针对其合成和作用机制研究的进展,并对其前景进行了展望.指出硼酸盐已成为近年来绿色润滑油添加剂研究领域的热点之一,有机硼酸盐润滑油添加剂克服了无机硼酸盐分散稳定性差的弱点,代表了综合性能优良的硼酸盐润滑油添加剂的发展方向.     

Li2O﹒2B2O3-H2O过饱和溶液20℃结晶动力学研究

盐水溶液中存在过饱和现象，硼酸盐溶液的过饱和即是一例．其中，镁础酸盐体系过饱和溶液在不同浓度和温度条件下的液固相关系曾有多次报道［‘－’］；给出过许多有益的结果，也探讨了镁硼酸盐的结晶反应机理并拟合出相应的结晶动力学方程．这些工作对认识盐水溶液过饱和现象有重要意义．为了更广泛地认识和了解不同棚酸盐水溶液中的过饱和现象，本文采用动力学方法，首先对Li20·2B203－HZO过饱和溶液结晶过程进行了研究．1实验初始反应溶液中Li。O／BZO。（摩尔比）为1／2，按此配比计算并称取需要量的Li0H·H。O（A．R．）、H。…     

核苷酸与β-环糊精及硼酸盐的络合作用在高效毛细管电泳分离核苷酸中的应用

核苷酸和β-环糊精(β-CD)及硼酸盐之间存在络合作用，可应用于核苷酸的高效毛细管电泳分离，在10mmol/L β-CD和20mmol/L硼酸盐存在时，实现了8种单磷酸核苷酸的分离测定；讨论了pH值、β-CD浓度、硼酸盐浓度及分离电压对分离和络合作用的影响。     

水合铵硼氧酸盐及其饱和溶液的FTIR和Raman光谱研究

研究了NH₄B₅O₈·4H₂O和(NH₄)₂B₈O₁₃·6H₂O及其饱和溶液于20℃的FTIR和Raman光谱,对振动频率进行了归属.根据振动光谱特征,预测(NH₄)₂B₈O₁₃·6H₂O中所含基本结构单元为[B₇O ₁₁(OH)·B(OH)₃]^2-.首次将Raman光谱中516cm^-1处的强散射峰归属为这一多聚硼氧配阴离子的对称脉冲振动峰,并对以上2种铵硼氧酸盐饱和溶液中硼氧配阴离子的存在形式{B(OH)₃,[B₃O₃(OH)₄]^-和[B₅O₆(OH)₄]^-}和相互作用机理进行了探讨.     

单离子导体聚合硼酸锂盐的研究进展

目前商业化锂离子电池常用的锂盐LiPF6,对水极其敏感,热稳定性差,尤其是在高温条件下的应用存在着一定的安全隐患.种类多且环境友好的新型有机硼酸锂盐越来越受到人们的重视.本文综述了近年来几种锂盐的合成方法,电化学性能,各自存在的优点和不足以及本课题组在聚合硼酸锂盐方向取得的系列研究进展,并对锂盐和聚合物电解质的发展方向进行了展望.     

Esterification of borate with NAD+ and NADH as studied by electrospray ionization mass spectrometry and 11B NMR spectroscopy

This paper describes for the first time the direct measurement of boric acid (B(OH)(3)) and borate (B(OH)(4) (-)) adduction to NAD(+) and NADH by electrospray ionization mass spectrometry (ESI-MS) and (11)B NMR spectroscopy. The analysis demonstrates that borate binds to both cis-2,3-ribose diols on NAD(+) forming borate monoesters (1 : 1 addition), borate diesters (1 : 2 addition) and diborate esters (2 : 1 addition), whereas, only borate monoesters were formed with NADH. MS in the negative ion mode showed borate was bound to a cis-2,3-ribose diol and not to the hydroxyl groups on the phosphate backbone of NAD(+), and MS/MS showed that the 1 : 1 addition monoester contained borate bound to the adenosine ribose. Boron shifts of borate monoesters and diesters with NAD(+) were observed at 7.80 and 12.56 ppm at pH 7.0 to 9.0. The esterifications of borate with NAD(+) and NADH were pH dependent with maximum formation occurring under alkaline conditions with significant formation occurring at pH 7.0. Using ESI-MS, the limit of detection was 50 micro M for NAD(+) and boric acid (1 : 1) to detect NAD(+)-borate monoester at pH 7.0. These results suggest esterification of borate with nicotinamide nucleotides could be of biological significance.     

硼原子的键合形式对硼酸盐晶体非线性光学行为的影响

在几种具有典型复杂结构的硼酸盐晶体中 ,从硼原子的键合形式出发讨论了不同键合情况下的B—O键对硼酸盐晶体的非线性光学行为的具体影响。结果表明 ,晶体中B—O键的键合形式是制约硼酸盐晶体非线性光学行为的重要因素。     

Cyano- and isocyanotris(trifluoromethyl)borates: syntheses, spectroscopic properties, and solid state structures of K[(CF3)3BCN] and K[(CF3)3BNC

A two step synthesis to the isocyanotris(trifluoromethyl)borate anion, [(CF3)3BNC]-, and its isomerization to the cyanotris(trifluoromethyl)borate anion, [(CF3)3BCN]-, at temperatures above 150 degrees C are presented. In the first step (CF3)3BNCH was obtained by reacting (CF3)3BCO with hydrogen cyanide followed by deprotonation of the HCN adduct with Li[N(SiMe3)2] in toluene. The thermal behavior of K[(CF3)3BNC] and K[(CF3)3BCN] were investigated by differential scanning calorimetry (DSC), and K[BF4] was identified as a major solid decomposition product. The enthalpy of the isocyanide-cyanide rearrangement, deltaH(iso) = -35 +/- 4 kJ mol(-1), was obtained from DSC measurements, and the activation energy, E(a) = 180 +/- 20 kJ mol(-1), from kinetic measurements. The isomerization was modeled as an intramolecular reaction employing DFT calculations at the B3LYP/6-311+G(d) level of theory yielding a reaction enthalpy of deltaH(iso) = -36.1 kJ mol(-1) and an activation energy of E(a) = 155.7 kJ mol(-1). The solid-state structures of K[(CF3)3BNC] and K[(CF3)3BCN] were determined by single-crystal X-ray diffraction. Both salts are isostructural and crystallize in the orthorhombic space group Pnma (no. 62). In the crystals the borate anions possess C(s) symmetry, while for the energetic minimum C3 symmetry is predicted by DFT calculations. The borate anions have been characterized by IR and Raman spectroscopy as well as by NMR spectroscopy. The assignment of the IR and Raman bands is supported by their calculated wavenumbers and intensities. The spectroscopic and structural properties of both borate anions are compared to the properties of the isoelectronic borane carbonyl (CF3)3BCO and the [B(CF3)4]- anion as well as to those of other related species.     

Synthesis,structure characterization,photoluminescence properties and TD–DFT calculations for two new borates

Due to their rich structural chemistry and wide variety of applications, borate materials have provided a rich area of research. In a continuation of this research, diethylammonium bis(2‐oxidobenzoato‐κ²O¹,O²)borate, C₄H₁₂N⁺·BO₄(C₇H₄O)₂⁻, (1), and propylammonium bis(2‐oxidobenzoato‐κ²O¹,O²)borate, C₃H₁₀N⁺·BO₄(C₇H₄O)₂⁻, (2), have been synthesized by the reaction of boric acid with salicylic acid under ambient conditions. In both structures, the B atom exhibits a slightly distorted tetrahedral environment formed by the bidentate coordination of two salicylate anions via the O atoms of the central carboxylate and oxide groups. In the crystals of salts (1) and (2), mixed cation–anion layers lying parallel to the (101) plane are formed through N—H…O, C—H…O and C—H…π/N—H…O hydrogen‐bonding interactions, resulting, in each case, in a two‐dimensional supramolecular architecture in the solid state. The photoluminescence properties of the salts were studied using the as‐synthesized samples and reveal that salts (1) and (2) both display a strong blue‐light emission, with maxima at 489 and 491 nm, respectively. In DFT/TD–DFT (time‐dependent density functional theory) studies, the blue emission appears to be derived from an intramolecular charge transfer (ICT) excited state. In addition, IR and UV–Vis spectroscopies were used to investigate the title salts.     

Styrylpyridinium borate salts as dye photoinitiators of free‐radical polymerization

Styrylpyridinium borate salts photoinitiate free‐radical polymerization. The rate of photopolymerization depends on the ΔG^o of electron transfer between a borate anion and a styrypyridinium cation. This latter value was estimated for a series of styrylpyridinium borate salts, and the relationship between the rate of polymerization and the free energy of activation gives the dependence predicted by the classical theory of electron transfer. This relation was independently observed for the two series of styrylpyridinium borate salts tested—one for the photoredox pair with an iodine atom and the second without. Styrylpyridinium borate salts were stable at ambient temperature in the formulations prepared for the photopolymerization experiments. Photopolymerization initiated by the photoredox pairs tested proceeded by the conventional mechanism in which bimolecular termination occurs by a reaction between two macroradicals. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1433–1440, 2002     

Borate Hydrides as a New Material Class: Structure,Computational Studies,and Spectroscopic Investigations on Sr5(BO3)3H and Sr5(11BO3)3D

The unprecedented borate hydride Sr₅(BO₃)₃H and deuteride Sr₅(¹¹BO₃)₃D crystallizing in an apatite-related structure are reported. Despite the presence of hydride anions, the compound decomposes only slowly in air. Doped with Eu²⁺, it shows broad-band orange-red emission under violet excitation owing to the 4f⁶5d–4f⁷ transition of Eu²⁺. The observed ¹H NMR chemical shift is in good agreement with previously reported ¹H chemical shifts of ionic metal hydrides as well as with quantum chemical calculations and very different from ¹H chemical shifts usually found for hydroxide ions in similar materials. FTIR and Raman spectroscopy of different samples containing ¹H, ²H, ^natB, and ¹¹B combined with calculations unambiguously prove the absence of hydroxide ions and the sole incorporation of hydride ions into the borate. The orange-red emission obtained by doping with Eu²⁺ shows that the new compound class might be a promising host material for optical applications.     

The First Mixed Calcium Zinc Borate with a Flexible [B8O17] Fundamental Building Block and Short UV Cutoff Edge

The first mixed calcium zinc borate with a new fundamental building block (FBB) [B₈O₁₇], Ca_1.13Zn_0.87B₈O₁₄ has been successfully synthesized. It exhibits two independent interpenetrating three-dimensional B−O anion networks constructed by [B₈O₁₇] groups, enriching the structural diversity of B−O configurations. In particular, the UV-Vis-NIR diffuse-reflectance spectrum shows that it has a short UV cutoff edge (<195 nm).     

盐卤硼酸盐化学──ⅩⅩⅧ.氯柱硼镁石的激光拉曼光谱

本文研究了氯柱硼镁石硼酸和硼砂的晶体和它们在水溶液中的激光拉曼光谱，并与某些阴酸盐的谱图进行对比．初步提出硼氧配阴离子的聚合形式，为进行氯柱硼镁石结构分析提供实验依据．