variscite

• 分子结构分类: 无机化合物 - 混合金属/非金属化合物 - 后过渡金属氧阴离子化合物
• 英文名称: variscite
• 英文别名: variscite AlPO4*2H2O；Aluminum;phosphate;hydrate；aluminum;phosphate;hydrate
• 化学式: Al*2H₂O*O₄P
• 分子量: 157.983
• InChiKey: FIQKTHSUXBJBCQ-UHFFFAOYSA-K

计算性质

• 辛醇/水分配系数(LogP)：
  -4.03
• 重原子数：
  7
• 可旋转键数：
  0
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.0
• 拓扑面积：
  87.2
• 氢给体数：
  1
• 氢受体数：
  5

反应信息

• 作为反应物：
  描述：

  variscite 以 neat (no solvent) 为溶剂， 生成 monoaluminum phosphate
  参考文献：
  名称：

  Kinetics and thermodynamics of thermal decomposition of synthetic AlPO4·2H2O

  摘要：

  利用 TG-DTG-DTA 技术研究了 AlPO4-2H2O 在动态空气气氛中不同加热速率下的非等温脱水动力学。该结果为制备 AlPO4 提供了重要的理论支持。AlPO4-2H2O 在 80-150 ℃ 范围内发生两步分解反应。用基辛格法计算的 AlPO4-2H2O 第二次脱水反应的活化能为 69.68 kJ mol-1 ，阿夫拉米指数值为 1.49。结果证实了结晶水的消除，这与晶体生长机理有关。用活化复合物理论计算了脱水反应的热力学函数（ΔH*、ΔG*和ΔS*）。脱水步骤中的这些数值表明，它与热量的引入直接相关，是一个非自发过程。

  DOI：

  10.1007/s10973-009-0292-0
• 作为产物：
  描述：

  monoaluminum phosphate 在 moist air 作用下， 以 neat (no solvent) 为溶剂， 生成 variscite
  参考文献：
  名称：

  A Combined Experimental and Theoretical Evaluation of the Structure of Hydrated Microporous Aluminophosphate AlPO₄-18

  摘要：

  Water adsorption in the microporous aluminophosphate AlPO4-18 is studied by a combination of solid-state NMR, X-ray diffraction, and density functional theory calculations. The change of the framework structure upon hydration is moderate, and NMR gives local information on the environment of Al and P atoms. The structural distribution of water molecules in the channels has been explored by a combination of first-principle molecular dynamics simulations and of static geometry optimizations. Two starting points have been considered for the calculations. If the structure of the dehydrated aluminophosphate is used, the simulation result is not satisfactory with an incomplete hydration and no agreement with NMR results. Starting from a partial refinement of the aluminophosphate framework for the hydrated system, a structure with six tetrahedral and six octahedral Al atoms in the unit cell is obtained, involving twelve water molecules coordinated to Al atoms and twelve others in the channels, and in good agreement with experimental data.

  DOI：

  10.1021/jp050670x

文献信息

• Synthesis of AlPO4 and kinetics of thermal decomposition of AlPO4·H2O-H4 precursor
  作者：B. Boonchom、S. Youngme、T. Srithanratana、C. Danvirutai

  DOI：10.1007/s10973-007-8420-1

  日期：2008.2

  The thermal decomposition of aluminum phosphate monohydrate AlPO4·H2O-H4 was investigated in air using TG-DTG/DTA. The AlPO4·H2O-H4 decomposes in one step and final decomposition product (AlPO4) was studied by X-ray powder diffraction, FTIR and FT-Raman spectroscopy. The activation energies of dehydration reaction of AlPO4·H2O-H4 were calculated through the isoconversional methods of Ozawa and Kis

  使用TG-DTG / DTA在空气中研究了磷酸铝一水合物AlPO 4 ·H 2 O-H4的热分解。AlPO 4 ·H 2 O-H4一步分解，并通过X射线粉末衍射，FTIR和FT-拉曼光谱研究了最终的分解产物（AlPO 4）。通过小泽和基辛格-赤平-Sunose（KAS）的等转化方法计算了AlPO 4 ·H 2 O-H4脱水反应的活化能，并通过比较方法估算了可能的转化函数。计算出的AlPO 4 ·H 2分解的活化能发现通过不同方法和技术得到的O-H4是一致的。可以更好地描述AlPO 4 ·H 2 O-H4脱水反应的动力学模型是F n模型，它是简单的 n 阶反应，相应的函数是 f （α）=（1-α）2.75和 g （α ）＝-[1-（1-a）-1.75 /(1.75）]。
• Study of kinetics and thermodynamics of the dehydration reaction of AlPO4 · H2O
  作者：Banjong Boonchom、Samart Kongtaweelert

  DOI：10.1007/s10973-009-0113-5

  日期：2010.2

  The kinetics and thermodynamics of the thermal dehydration of aluminum phosphate monohydrate, AlPO4 · H2O were studied using thermogravimetry (TG-DTG-DTA) at four heating rates in dry air atmosphere. The activation energies of the dehydration step of AlPO4 · H2O were calculated through the methods of Friedman (FR) and Flynn–Wall–Ozawa (FWO) and the possible conversion function has been estimated through the Achar and Li–Tang equations. The independent activation energies on extent of conversions and the better kinetic model of the dehydration reaction for AlPO4 · H2O indicate single kinetic mechanism and the F 2.05 model as a simple n-order reaction of “chemical process or mechanism no-invoking equation”, respectively. The positive values of ΔH# and ΔG# for the dehydration reaction show that it is endothermic and non-spontaneous process and it is connected with the introduction of heat. The kinetic and thermodynamic functions calculated for the dehydration reaction by different techniques and methods were found to be consistent.

  在干燥空气环境中，使用热重分析（TG-DTG-DTA）以四种加热速率研究了磷酸铝一水合物（AlPO4·H2O）的热脱水的动力学和热力学。通过Friedman（FR）和Flynn-Wall-Ozawa（FWO）的方法计算了AlPO4· 脱水步骤的活化能，并通过Achar和Li-TAng方程估计了可能的转换函数。AlPO4· 的转化程度上的独立活化能和更好的脱水反应动力学模型分别表明了单一动力学机制和F 2.05模型是“化学过程或机制无调用方程”的简单n阶反应。脱水反应的ΔH#和ΔG#的正值表明它是吸热和非自发过程，并且与热量的引入有关。通过不同的技术和方法计算的脱水反应的动力学和热力学函数是相一致的。
• Effect of niobia as an additive in phosphate-bonded alumina
  作者：C. Fredericci、S. Folgueras-Dominguez

  DOI：10.1016/0025-5408(95)00164-6

  日期：1996.2

  In this work a study was carried out on the Alsub 2}Osub 3}/Nbsub 2}Osub 5}/Hsub 3}POsub 4} system. A-2 alumina from Alcoa (Brazil) was used and the Alsub 2}Osub 3}/Nbsub 2}Osub 5}/Hsub 3}POsub 4} system with an Alsub 2}Osub 3}/Psub 2}Osub 5} molar ratio of 20.3, pressed at 20 and 60 MPa and thermally treated at 110, 300, 500, 800, 1,000, 1,200, 1,400 and 1,600 C, was studied. An attempt

  在这项工作中，对 Alsub 2}Osub 3}/Nbsub 2}Osub 5}/Hsub 3}POsub 4} 系统进行了研究。使用来自 Alcoa（巴西）的 A-2 氧化铝，Alsub 2}Osub 3}/Nbsub 2}Osub 5}/Hsub 3}POsub 4} 系统与 Al sub 2}Osub 3}/Psub 2}Osub 5} 摩尔比为 20.3，在 20 和 60 MPa 下压制并在 110、300、500、800、1,000、1,200、1,400 和 1,600 C 下热处理，进行了研究。尝试将机械性能与孔隙率以及热处理过程中形成的相联系起来。X 射线衍射 (XRD)、红外光谱 (IRS) 和魔角旋转磷核磁共振 (sup 31}P MAS NMR) 用于相位检测。非晶AlPOsub 4}被认为是低温结合相。所研究的系统在 1,400
• Britton, H. T. S., Journal of the Chemical Society
  作者：Britton, H. T. S.

  DOI：——

  日期：——
• Gmelin Handbuch der Anorganischen Chemie, Gmelin Handbook: Al: MVol.B2, 14, page 344 - 347
  作者：

  DOI：——

  日期：——