硼酸镁过饱和溶液稀释和酸化过程中的Raman光谱

用纯水和恒沸点盐酸对六硼酸镁过饱和水溶液进行稀释和酸化,使用激光Raman光谱记录反应过程。对光谱峰进行归属。讨论了溶液中含硼量和pH值对硼氧配阴离子存在形式的影响,对多聚硼氧配阴离子在溶液中的存在形式及其相互作用机理进行了初步探讨。     

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…     

四水五硼酸铯及其饱和溶液的振动光谱分析

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。振动光谱[1]能有效地用于鉴定和表征固体硼酸盐,。近年来,ＦＴ ＩＲ和Ｒａｍａｎ光谱已用于研究硼酸盐水溶液的结构[2 5],但仅对溶解度较大的硼酸盐才能获得基团特征振动频率。Ｒａ ｍａｎ光谱有利于测量高含硼水溶液中的样品而没有在ＦＴ ＩＲ光谱中的来自于水的干扰,硼酸盐水溶液中的硼氧配阴离子存在形式可以通过差示ＦＴ ＩＲ光谱技术[6]来研究。本文采用这两种物理测试技术,研究了易溶性水合五硼酸铯及其饱和溶液,分别对其ＦＴ Ｉ…     

水合硼氧酸盐结晶过程中液相的红外光谱

使用差示红外光谱的方法记录了MgB4O7.9H2O,NaB5O8.5H2O,MgB6O10.7H2O和MgB6O10.7.5H2O过饱和水溶液结晶析出相应固相时液相中多聚硼氧配阴离子的变化。结果得出,硼氧酸盐水溶液的红外光谱在800－1000cm^-1波数范围内,存在多种多聚硼氧配阴离子的特征峰,并对振动光谱频率进行了归属。870,810cm^-1为三硼氧配阴离子特征峰;844cm^-1为四硼氧配阴离子特征峰;929cm^-1为五硼氧配阴离子特征峰;959cm^-1为六硼氧配阴离子的特征峰。     

MgO·3B2O3·3.5H2O的合成、表征及其溶液Raman光谱分析

硼是具有独特化学行为的稀有亲氧元素，在自然界中主要是以无机硼氧酸和硼氧酸盐形式存在。在硼酸盐晶体中，硼以聚合硼氧配阴离子形式存在，其中配位数为３和４的硼原子比可以有所不同，这使得硼酸盐种类繁多，结构复杂多样。至今，人们在自然界和实验室已发现了４种六硼酸镁盐犤１，２犦：MgO·３B２O３·nH２O（n＝７．５，７，６，５），它们的分子结构中都含有犤B６O７（OH）６犦２－基团。最近，我们在硼酸盐化学系列研究中，利用复盐氯柱硼镁石在沸点温度下的硼酸溶液中的相转化，合成了一种新的六硼酸镁盐MgO·３B２O３·３．…     

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.     

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．     

NaB5O8·5H2O过饱和溶液中硼氧配阴离子的FT-IR光谱分析

研究了NaB₅O₈·5H₂O过饱和水溶液及其在稀释和酸化过程中的FT-IR光谱,并与已知固体五硼酸盐对比进行光谱频率的归属,提出五硼酸盐过饱和水溶液中硼氧配阴离子的存在形式及其相互转化机理。     

过饱和硼酸盐水溶液的Raman光谱

制备了MgO·2B₂O₃-H₂O,Na₂O·5B₂O₃-H₂O和MgO·3B₂O₃-H₂O的过饱和水溶液.采用激光喇曼光谱研究了这些过饱和水溶液,并对光谱频率进行了归属.讨论了过饱和水溶液中硼氧配阴离子的存在形式和相互作用机理.     

Li2B4O7-MgCl2(B)-H2O体系热力学性质的等压研究及离子相互作用模型

采用等压法测定了298.15 K下Li-Mg-Cl-borate-H2O体系离子强度范围为0.0581～0.6320 mol*kg-1, MgCl2不同离子浓度分数的等压摩尔平衡浓度、水活度,计算了Li2B4O7和MgCl2混合溶液的饱和水蒸汽压、渗透系数等热力学性质.考虑了在不同的总硼浓度范围的硼酸(H3BO3)和硼氧配阴离子[B(OH)-4, B3O3(OH)-4, B4O5(OH)2-4]的不同生成反应平衡.由实验结果对修正的Pitzer渗透系数方程进行了参数化研究,提出了一简化的参数化模型,减少了模型的经验参数量,获得了锂、镁、氯离子与硼物种组合之间、及不同硼氧配阴离子之间的组合相互作用参数,用该模型计算的渗透系数值与实验结果取得合理的一致性,从而将离子作用模型扩展到对含硼、锂、镁的复杂体系的表述.对完善含锂、硼的盐湖卤水体系的热力学模型和盐湖资源的综合开发利用具有重要意义.     

FT-IR spectroscopy of supersaturated aqueous solutions of magnesium borate

FT-IR spectra of supersaturated aqueous solution of magnesium borate, its acidized solutions with azeotropic hydrochloric acid, and its diluted solutions with water have been recorded. The FT-IR spectra of borate in solution are obtained by difference, subtracting the FT-IR spectrum of water from that of the magnesium borate supersaturated aqueous solution. All of the results showed that various polyborate anions in the supersaturated aqueous solutions exist. The bands of symmetric pulse vibration of the corresponding polyborate anions were indicated and some assignments were tentatively given.     

Raman spectroscopic analysis of supersaturated aqueous solution of MgO.B2O3-32%MgCl2-H2O during acidification and dilution

Raman spectra of supersaturated aqueous solution of MgO.B2O3-32%MgCl2-H2O during acidification/alkalization and dilution have been studied. The assignments of the recorded Raman shift are given. The main existing forms of polyborate anions and their interaction in borate aqueous solution have been proposed through spectroscopic analysis. The experimental results indicate that the higher concentration of cation are beneficial not only to the dissolution of boric acid but also to the polymerization of polyborate anions. The existing forms and interaction among them also depend on the concentration of boron and the pH value in solution.     

FT-IR and Raman spectroscopic analysis of hydrated cesium borates and their saturated aqueous solution

Hydrated cesium borates have been synthesized by the reaction of Cs(2)CO(3) with H(3)BO(3) aqueous solution. After reaction equilibria were reached, liquid and solid phases were separated and the FT-IR difference and Raman spectra of each phase were recorded, respectively. The assignments of the recorded FT-IR absorption frequencies and Raman shift are given. The main polyborate anions and their interaction in borate aqueous solution have been proposed. The relations between the existing forms of polyborate anions and the crystallizing solid phases, Cs(2)B(4)O(7).5H(2)O and CsB(5)O(8).4H(2)O, have been gained.     

FT-IR spectroscopic study of phase transformation of chloropinnoite in boric acid solution at 303 K

The dissolution and transformation of chloropinnoite in boric acid solution at 303 K has been studied using FT-IR difference spectroscopic technique. After equilibrium was reached, liquid and solid phases were separated and FT-IR spectra of each phase were recorded, FT-IR spectroscopic analysis of solid phases indicated that the transformation products, with the increase of boron-concentration in solution, were 2MgO x 3B2O3 x 15H2O (inderite), 2MgO x 3B2O3 x 15H20 (kumakovite), MgO x 3B2O3 x 7.5H2O, and MgO x 3B2O3 x 7H2O, respectively. The main polyborate anions and their interaction in each borate saturated aqueous solution have been proposed according to the FT-IR difference spectra of borate in liquid phase, and some assignments were tentatively given firstly. The relations between the existing forms of polyborate anions and the crystallizing solid phases have been gained.     

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.     

Investigations of kinetics and mechanism of chloropinnoite in boric acid aqueous solution at 303 K by Raman spectroscopy

Raman spectroscopy of dissolution and transformation of chloropinnoite in 4.5% (wt.%) boric acid aqueous solution at 303 K has been recorded. The Raman spectra of kinetics process have been obtained. The phase transformation product is 2MgO.3B2O3.15H2O (kurnakovite). The main polyborate anions and their interaction in aqueous solution have been proposed according to the Raman spectrum. Some assignments were tentatively given and the relations between the existing forms of polyborate anions and the crystallizing solid phases have been gained. A mechanism of dissolution and crystallization reactions and the formation condition of kurnakovite in Qinghai-Tibet plateau were proposed and discussed.     

Volumetric properties of aqueous electrolytes at high temperature. III. B(OH)3−NaBx(OH)3x+1−NaOH mixtures up to 523 K

The densities of aqueous solutions resulting from the partial neutralization of boric acid with sodium hydroxide were measured as a function of concentration, between 375 K and 523 K at pressures close to saturation. The speciation in this system is complex, di- and triborate ions are present in addition to the monoborate ion. The concentration dependence of the apparent partial molar volume of the mixture can be described using the Pitzer equation only if the formation of the polyborate species in the concentrated solutions is taken into account. The partial molar volumes at infinite dilution for the diborate and triborate anions, obtained by assuming ideal mixing, are reported in the range of temperature studied.