高等学校化学学报

高等学校化学学报 ›› 1997, Vol. 18 ›› Issue (7): 1000.

• 论文 • 上一篇    下一篇

磷酸铝分子筛骨架结构及其稳定性的模拟计算(Ⅱ)──骨架结构中各类键长、键角的取值及其分布

李宝宗, 徐文国, 裘式纶, 庞文琴, 徐如人   

  1. 吉林大学化学系无机合成与制备化学开放研究实验室, 长春 130023
  • 收稿日期:1997-01-09 出版日期:1997-07-24 发布日期:1997-07-24
  • 通讯作者: 庞文琴.
  • 作者简介:李宝宗, 男, 34岁, 博士研究生.
  • 基金资助:

    国家攀登计划;国家自然科学基金;国家教委博士点基金;吉林大学无机会成与制备化学开放研究实验室资助

Simulated Calculation of Aluminophosphate Molecular Sieves Structure and Stability (Ⅱ) ──Bond Lengths, Bond Angles and Distribution of Framework Structure

LI Bao-Zong, XU Wen-Guo, QIU Shi-Lun, PANG Wen-Qin, XU Ru-Ren   

  1. Key Laboratory of Inorganic Synthesis & Preparative Chemistry, Department of Chemistry, Jilin University, Changchun 130023
  • Received:1997-01-09 Online:1997-07-24 Published:1997-07-24

PDF (PC)

被引次数

4

摘要： 应用晶格能极小化技术计算了19种磷酸铝分子筛的骨架晶格能. 从计算结果发现这些磷酸铝分子筛彼此间的晶格能相差很小,而与磷酸铝致密相块磷铝矿(Berlinite)相差48～127kJ/mol. 据此可以解释磷酸铝分子筛骨架结构的多样性和相似性. XRD数据表明在它们的结构中包含很短的AI－O键(0. 1478nm)、P－O键(0. 1348nm)和很长的AI－O键(0. 1942nm)、P－O键(0. 1678nm),O－T－O键角有大的分布范围(O－AI－O键角为98. 62°～122. 27°和O－P一O键角为92. 36°～122. 86°),平均AI—O一P键角在153°左右,并且具有更大的分布范围(114°～180°). 量子化学AMI计算结果表明,在AI—O一P键角由114°变化至180°而引起的能量改变很小(仅22. 97kJ/mol),当AI一O一P键角为137. 74°时能量最低.

关键词: 磷酸铝分子筛, 晶格能极小化, 键长, 键角, 结构与性质

Abstract: The lattice energy of a series of aluminophosphate molecalar sieves was deter-mined by using the lattice energy minimization method.The results were compared to thelattice energy of dense polymorphs of AlPO4. All AlPO4 molecular sieves frameworks are on-ly 48-127 kJ/mol less stable than berlinite.This may explain the structural diversity andsimilarity observed for aluminophosphate molecular sieves.These XRDdata of the AlPO4molecular sieves contain a very short Al-Obond length(0.1478 nm) and P-Obond length(0.1348 nm), very long Al-Obond length (0.1942 nm)and P-Obond length (0.1678nm), and a large range of O-Al-Oangles(98.62°-122.27°) and O-P-Oangles (92.36°-122.86°), an averge Al-O-Pangle is closes to 153° and a larger range of Al-O-Pan-gles (114.80°-180°).AM1 molecular Orbital calculation have shown that there is a smallbarrier (22.97 kJ/mol) to variation in the Al-O-Pangle between 114°and 180°, and thereis the lowest energy for angles 137.74°.

Key words: Aluminophosphate molecular sieves, Lattice energy minimization, Bond length-es, Bond angles, Structure and property

中图分类号: 

TrendMD: