A New Approach to Bond Valence Parameters for Pb(II)—halide Bonds

HU Sheng-Zhi, 厦门大学化学系, 物理化学研究所, 福建 厦门 361005, Institute of Physical Chemistry, Department of Chemistry, Xiamen University, Xiamen 361005, Fujian Province, P. R. China
2007 Wuli huaxue xuebao  
导出铅(II)-卤素键价参数的一条新途径 胡盛志 (厦门大学化学系, 物理化学研究所, 福建厦门 361005) 摘要: 基于精确的晶体结构数据并设定 B=0.037nm 以拟合经验参数 R 0 是通常采用的键价参数推导方法. 与 此相反, 作者提出从分子气相电子衍射的键长设定经验参数 R 0 , 然后从晶体结构数据拟合经验参数 B. 以 Pb(II)-卤素键为例,PbX 2 气相电子衍射 Pb-X(X=F,Cl,Br,I)键长分别为 0.2036,0.2447,0.2598 和 0.2804nm, 经拟合 到最佳 B 值分别为 0.0382,0.040,0.040,0.0386nm, 与普适参数 B 值 0.037nm 有一定的差距. 所提出的键价参 数不仅得到比较理想的键价值和计算结果, 而且保留了键价参数 R 0 作为单价键长明确的物理意义. 关键词:键价参数; 单价键长; 电子衍射; 铅(II)卤化物 中图分类号: O641 ANewApproachtoBondValenceParametersforPb(II)-halideBonds HUSheng鄄Zhi
more » ... HUSheng鄄Zhi (InstituteofPhysicalChemistry,DepartmentofChemistry,XiamenUniversity,Xiamen 361005,FujianProvince,P.R.China) Abstract: Thevaluesofbondvalenceparameters R 0 forthebondsofmaingroupmetalhalidesareusuallyobtained bysystematicanalysisofthecrystalstructuredatabyassuming B=0.037nm.Inthiswork,conversely,thevaluesof B wereproposedtobefittedwithcrystalstructuredataonassumingthevaluesof R 0 equaltothebondlengthsof r g accuratelydeterminedbygaseouselectrondiffraction.Asanexample,thenewsetsof R 0 /B forthePb(II)-X(X=F,Cl, Br,I)bondswereobtainedandfittedas0.2036/0.0382,0.2447/0.040,0.2598/0.040,and0.2804/0.0386,respectively. Comparedwiththevaluesof R 0 =0.203,0.253,0.264,and0.278nmbasedon B=0.037nmforPb(II)-Xbondsreported intheliterature,thesenewparameterswerenotonlyaccurateandreliableforbondvalencecalculations,butalso revealedthephysicalmeaninginherentinevery R 0 asunitvalencebondlength.
doi:10.3866/pku.whxb20070532 fatcat:x5dc65c3yre4tprhwzgicgeqrq