三维孔道结构(H_3NCH_2CH_2NH_3)_2(H_3NCH_2CH_2NH_2)[V~Ⅲ(H_2O)_2(V~ⅣO)_8(OH)_4(H(P,B)O_4)_4 ((P,B)O_4)_4(H_2O)_2]·3H_2O的水热合成及晶体化学研究——(2)晶体结构与晶体化学  

Hydrothermal Synthesis and Crystal Chemistry of a Vanadium Borophosphate (H_3NCH_2CH_2NH_3)_2(H_3NCH_2CH_2NH_2)[V~Ⅲ(H_2O)_2(V~ⅣO)_8(OH)_4(H(P,B)O_4)_4 ((P,B)O_4)_4(H_2O)_2]·3H_2O with Three-dimensional Open Framework ——(2)Crystal Structure and Crysta

作　　者：杨赞中[1] 廖立兵[1] 杜洪兵 

机构地区：[1]中国地质大学材料科学与工程学院 [2]人工晶体研究院,北京100018

出　　处：《人工晶体学报》2005年第2期270-277,共8页Journal of Synthetic Crystals

基　　金：国家自然科学基金(No. 40272024);山东省自然科学基金(No. 20042X25)资助项目

摘　　要：在单晶X射线衍射实验的基础上,对孔道结构化合物V9P8 en的类质同象物V9 (P,B)8 en的晶体结构和晶体化学进行了深入研究。结果表明,该化合物的晶体学数据为:P2 (1) /n,a=1. 43134 (9 )nm,b=1. 01256 ( 6 )nm,c=1. 83156(12)nm,β=90. 280(2)°,V=2. 6545(3)nm3,Z=2,R=0. 0540,wR2=0. 1551。结构中,沿着三个结晶轴方向发育复杂而规整的三维孔道,最大孔径达1. 83nm(∥b轴),质子化乙二胺和水分子居于孔道中。硼部分替代四面体配位的磷,替代率为B8∶P8 =0. 1838∶7. 8162;其中B与{P—OH}位P的替代量大于与[P-O]位P的替代量。相对于V9P8 en来说,V9 (P,B)8 en的晶胞参数发生了变化,导致b轴增长( 1. 0150→1. 0256nm)和c轴缩短(1. 8374→1. 8316nm),同时β角变小(90. 39→90. 278 (2)°)。二者的化学计量比也不同,体现在结构与孔容的关系、电荷平衡、满足亲水疏水作用的结晶水的数量及有机模板分子的赋存状态等方面都有差异。Extensive studies have been devoted to the synthesis and characterization of V-P-O compounds because of not only their relevance to catalytic and adsorptive properties, but also their rich and complex structural chemistry. In order to elucidate the influence of chemical component on the framework stability of VPO system, the crystal structure of the allomer (H_3NCH_2CH_2NH_3)_2(H_3NCH_2CH_2NH_2)[V~Ⅲ(H_2O)_2(V~ⅣO)_8(OH)_4(H(P,B)O_4)_4((P,B)O_4)_4(H_2O)_2]·3H_2O (V_9(P,B)_8-en for short) of V_9P_8-en was characterized by X-ray single crystal diffraction method (R=(0.0540) for the data [I>2sigma(I)]). Results show that V_9(P,B)_8-en crystallized in the monoclinic space group P2(1)/n with lattice parameters of a=1.43134(9)nm, b=1.01256(6)nm, c=1.83156(12)nm, β=90.280(2)°, V=2.6545(3)nm^3, Z=2. The structure consists of complex 3-dimensional intercrossing channels including a very large tunnel of 1.83nm in diameter, in which both protonated ethylenediamine and water species are occluded. It has been demonstrated that element B substitutes partially for P in tetrahedron (the atomic ratio of B:P is 0.1838:7.8162), and the substituted quantity of P in[HPO_4]is bigger than in[PO_4] by refining the site occupancy of V and P atoms. Compared with V_9P_8-en, the crystal parameters, contents in pores and charges between template and framework for V_9(P,B)_8-en change to some extent. The successful elucidation of these differences between the two compounds can be helpful for the investigation of the structural stability mechanism of open framework vanadium phosphates.

关 键 词：孔道结构 钒硼磷酸盐 晶体结构 晶体化学 乙二胺 计算方法 表征方法 各向同性 水热合成反应 

分 类 号：O74[理学—晶体学]