Department of Environmental Engineering, Kongju National University, Chungnam 331-717, Korea.
J Phys Chem B. 2010 Mar 11;114(9):3254-8. doi: 10.1021/jp911822e.
A CH(4)-loaded hydroquinone (HQ) clathrate was synthesized via a gas-phase reaction using the alpha-form of crystalline HQ and CH(4) gas at 12 MPa and room temperature. Solid-state (13)C cross-polarization/magic angle spinning (CP/MAS) NMR and Raman spectroscopic measurements confirm the incorporation of CH(4) molecules into the cages of the HQ clathrate framework. The chemical analysis indicates that about 69% of the cages are filled by CH(4) molecules, that is, 0.69 CH(4) per three HQ molecules. Rietveld refinement using synchrotron X-ray powder diffraction (XRD) data shows that the CH(4)-loaded HQ clathrate adopts the beta-form of HQ clathrate in a hexagonal space group R3 with lattice parameters of a = 16.6191 A and c = 5.5038 A. Time-resolved synchrotron XRD and quadrupole mass spectroscopic measurements show that the CH(4)-loaded HQ clathrate is stable up to 368 K and gradually transforms to the alpha-form by releasing the confined CH(4) gases between 368-378 K. Using solid-state (13)C CP/MAS NMR, the reaction kinetics between the alpha-form HQ and CH(4) gas is qualitatively described in terms of the particle size of the crystalline HQ.
采用气相反应，在 12 MPa 和室温条件下，使用 α-形式的结晶对苯二酚（HQ）和 CH4气体合成了 CH4负载的 HQ 包合物。固态（13）C 交叉极化/魔角旋转（CP/MAS）NMR 和拉曼光谱测量证实了 CH4分子进入 HQ 包合物骨架笼内。化学分析表明，大约 69%的笼被 CH4分子填充，即每个 HQ 分子有 0.69 个 CH4分子。利用同步加速器 X 射线粉末衍射（XRD）数据的 Rietveld 精修表明，CH4负载的 HQ 包合物采用 HQ 包合物的β形式，属于六方空间群 R3，晶格参数为 a = 16.6191 A 和 c = 5.5038 A。时间分辨同步加速器 XRD 和四极质量光谱测量表明，CH4负载的 HQ 包合物在 368 K 下稳定，并在 368-378 K 之间逐渐释放受限的 CH4气体转变为α形式。通过固态（13）C CP/MAS NMR，从结晶 HQ 的粒径方面定性描述了 α-HQ 与 CH4气体之间的反应动力学。
