^(113)Cd MAS NMR谱表征纳米CdO,CdS在NaY的β笼内形成的构型  

Characterization of Configuration of CdO, CdS in NaY β-Cage by Using ^(113)Cd MAS NMR

作　　者：张永潮[1] 戚明[1] 薛志元[1] 李全芝[2] 

机构地区：[1]复旦大学分析测试中心,上海200433 [2]复旦大学化学系,上海200433

出　　处：《化学学报》2001年第2期253-256,共4页Acta Chimica Sinica

基　　金：国家自然科学基金 ( 2 97330 70 )资助项目

摘　　要：通过2 9Si,2 7Al和113CdMASNMR谱 ,观察到如下结果 :( 1)在NaYβ笼内形成的CdO和CdS簇 ,它们的113Cd化学位移分别为 115 .0和 10 0 .0这些值接近于体相CdO的化学位移 83 .5 ,而远离体相CdS的化学位移 5 83 .8,因此它们的构型应归属为体相CdO的立方岩盐构型 ,而不属于体相CdS的配位数为 4的闪锌矿构型 .( 2 )CdO -NaY硫化时 ,NaY的骨架脱铝原子 ,脱铝原子使 β笼的窗口扩大 ,这有利于直径大于 β笼窗口的硫原子 (或H2 S)进入 β笼对CdO[或Cd(OH)The geometry structure of the guest clusters Cd(OH) +,CdO and CdS located at β cage of Y zeolite was investigated by 113Cd MAS NMR. The results show that there is a chemical shift at 115.0,114.4 and 100.0 in the 113Cd MAS NMR spectrum of CdO-NaY,CdS10-NaY and CdS20-NaY(sulphuration time for CdO-NaY is 10 min,20 min respectively), respectively. These chemical shift values are close to the value of 83.5 which is the resonance signal of cubic halite type of bulk CdO with coordination number of 6, and deviate from the value of 583.8 which is the 113Cd chemical shift of cubic sphalerite of bulk CdS with coordination number of 4. These results illustrate that the corrdination environment of the Cd 2+ ions located at β cage of Y zeolite is similar to that of bulk CdO with the cubic halite structure. It is also noted that the chemical shift value for CdO-NaY sample decreases with the increase of sulphuration time due to the oxygen atom with larger electronegativity being gradually substituted by sulphur atom. The phenomenon is identical with that substitute of selenium for sulphur of CdS or tellurium for selenium of CdSe. In addition, the 29Si and 27Al MAS NMR results show that several aluminum ions were removed from framework of zeolite NaY in the period of preparation of guest cluster with ion exchange and sulfidation treatment bringing about the formation of framework defect position.It is of benefit to sulfur atoms with larger atomic diameter from α cage smoothly entering into β cage of Y zeolite and sulfate the CdO or Cd(OH) + clusters to Cd(O,S) clusters.

关 键 词：氧化镉 硫化镉 纳米材料 光敏材料 分子筛笼 原位红外光谱 立方岩盐结构 构型 

分 类 号：O657.2[理学—分析化学]