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1.
FT-IR and Raman spectroscopic analysis of hydrated cesium borates and their saturated aqueous solution 总被引:2,自引:0,他引:2
Zhihong L Bo G Mancheng H Shuni L Shuping X 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2003,59(12):2741-2745
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. 相似文献
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Investigations of kinetics and mechanism of chloropinnoite in boric acid aqueous solution at 303 K by Raman spectroscopy 总被引:1,自引:0,他引:1
Xiaoping L Shiyang G Shuping X 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2004,60(12):2725-2728
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. 相似文献
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过饱和硼酸盐水溶液的Raman光谱 总被引:14,自引:3,他引:14
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. 相似文献
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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.… 相似文献
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Raman spectroscopic analysis of supersaturated aqueous solution of MgO.B2O3-32%MgCl2-H2O during acidification and dilution 总被引:1,自引:0,他引:1
Zhihong L Bo G Shuni L Mancheng H Shuping X 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2004,60(13):3125-3128
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. 相似文献
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Yongzhong J Shiyang G Shuping X Jun L 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2000,(7):1291-1297
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. 相似文献
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The crystallization processes of hydrated Mg-borates, boric, magnesium hydroxide and Mg-oxychloride from MgO-B2O3-18%MgCl2-H2O supersaturated solution at 20℃ have been studied by kinetic method. The crystallization solid phases were characterized by X-ray powder diffraction, IR spectra, thermal analysis and chemical analysis. The liquid-solid phase diagram of ther-modynamic nonequilibrium state has been given. In this phase diagram, there exist eight crystallization fields, boric acid(H3BO3), trigomagneborite(MgO · 3B2O3 · 7.5H2O, MgO · 3B2O3 · 7H2O), hungchaoite(MgO ·2B2O3 ·9H2O), inderite(2MgO ·3B2O3 · 15H2O), chloropinnoite(2MgO ·2B2O3 · MgCl2 · 14H2O), magnesium hydroxide(Mg(OH)2) and magnesium oxychloride (5Mg(OH)2 · MgCl2·8H2O). 相似文献
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水合铵硼氧酸盐及其饱和溶液的FTIR和Raman光谱研究 总被引:1,自引:0,他引:1
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. 相似文献
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2MgO·2B2O3·MgCl2·14H2O在60℃水中的溶解及相转化动力学研究 总被引:4,自引:0,他引:4
用动力学方法研究了2MgO·2B2O3·MgCl2·14H2O在60℃水中的溶解及相转化过程.通过对不同时间取出液相的化学分析及不同阶段分离出固相所作鉴定结果表明:该复盐呈不同步溶解,中间产物是MgO·B2O3·4H2O和Mg(OH)2,最终转化产物是柱硼镁石(MgO·B2O3·3H2O).提出了溶解及相转化机理,给出了溶解和转化结晶动力学方程 相似文献
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A new borate [H2EG][B7O10(OH)3] (1) based on [B14O20(OH)6]4- polyborate anions has been solvothermally synthesized in the presence of H2EG as a template (EG = ethylene glycol). The structure was determined by single-crystal X-ray diffraction and further characterized by FFIR, elemental analysis and thermogravimetric analysis. Compound 1 crystallizes in the triclinic system, space group Pi, with a = 8.5095(4), b = 8.8694(4), c = 10.0756(4) A, a = 95.094(2), β = 96.936(2), γ = 116.844(2)°, V = 664.66(5) A3. The structure of 1 consists of [B14O20(OH)6]4- moiety, which could be regarded as the largest isolated polyborate anion so far. The anions are interlinked via hydrogen bonding to form a 3D supramolecular network, whereas the diprotonated [H2EG]2+ are filled in the free space of inorganic borate network and interact with the inorganic framework by extensive hydrogen bonds. It is noteworthy that the EG acts not only as a solvent, but also as a template. 相似文献
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对氯柱硼镁石(2MgO•2B2O3•MgCl2•14H2O)在4.5%H3BO3水溶液40 ℃的溶解及相转化过程进行了动力学研究.对不同时间取出的液相的化学分析及不同阶段分离固相的鉴定结果表明,该复盐在溶解阶段出现与前所报导不同的同步溶解,最终产物是库水硼镁石(2MgO•3B2O3•15H2O).提出了库水硼镁石的形成条件和溶解及相转化动力学机理,利用单纯形优化法配合Runge-Kutta微分方程组数值解法对实验数据进行处理,给出了转化结晶动力学方程. 相似文献
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氯柱硼镁石在87 ℃水中的溶解及相转化动力学 总被引:2,自引:0,他引:2
对氯柱硼镁石(2MgO•2B2O3•MgCl2•14H2O)在87 ℃水中的溶解转化进行了动力学考察.通过对不同时间取出液样的化学分析和不同阶段分离的固相IR和XRD鉴定表明:其高温区溶解转化不同于低温,氯柱硼镁石很快溶脱掉MgCl2,形成晶形的MgO•B2O3•4H2O中间产物,最终转化产物柱硼镁石(MgO•B2O3•3H2O),是由MgO•B2O3•4H2O脱水后从溶液中大量析出的.提出了溶解及相转化机理,拟合出转化结晶动力学方程. 相似文献
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The nonmetal cation polyborate salt of stoichiometry [H(2)en](2)[B(11)O(18)(OH)]·7H(2)O is obtained from the reaction of 1,2-diaminoethane and boric acid (1:5 ratio) in H(2)O/MeOH. An X-ray crystallographic study of the product reveals that the polyborate moiety is composed of two isolated hydrated polyborate anions: [B(4)O(5)(OH)(4)](2-) and [B(7)O(9)(OH)(5)](2-). The structure is templated by the cations with the anions forming a supramolecular H-bonded network, augmented by additional H-bonds involving the waters of crystallization and the cations. 相似文献
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Ratnakaram YC Kumar AV Naidu DT Rao JL 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2005,61(9):2169-2179
An investigations of the optical absorption and fluorescence spectra of 0.2 mol% Er2O3 in mixed alkali borate glasses of the type 67.8B2O3 x xLi2O(32-x)Na2O, 67.8B2O3 x xLi2O(32-x)K2O and 67.8B2O3 x xNa2O(32-x)K2O (where x = 8, 12, 16, 20 and 24) are presented. The glasses were obtained by quenching melts consisting of H3BO3, Li2CO3, Na2CO3, K2CO3 and Er2O3 (950-1100 degrees C, 1.5-2 h) between two brass plates. Spectroscopic parameters like Racah (E1, E2 and E3), spin-orbit (xi(4f)) and configuration interaction (alpha) parameters are deduced as function of x. Using Judd-Ofelt theory, Judd-Ofelt intensity parameters (omega2, omega4 and omega6) are obtained. Radiative and non-radiative transition rates (A(T) and W(MPR)), radiative lifetimes (tauR), branching ratios (beta) and integrated absorption cross-sections (sigma) have been computed for certain excited states of Er3+ in these mixed alkali borate glasses. Emission spectra have been studied for all the three Er3+ doped mixed alkali borate glasses. The present paper throws light on the trends observed in the intensity parameters, radiative lifetimes, branching ratios and emission cross-sections as a function of x in these borate glasses, keeping in view the effect of mixed alkalies in borate glasses. 相似文献