Molecular assembly structure of CCl4 in graphitic nanospaces

The X-ray diffraction of CCl4 molecules adsorbed in slit-shaped graphitic micropores was measured at 303 K. The effect of the pore width in the range of 0.75-1.13 nm on the structure of CCl4 molecular assembly in the micropores was examined. The electron radial distribution function (ERDF) analysis was applied to the diffraction data, and the ERDFs from only adsorbed molecular assembly were determined. The peak position of ERDF due to the first-nearest-neighbor coordination agreed with that of the bulk liquid, but other peaks shifted from those of the bulk liquid. The second-nearest-neighbor peak shifted to a smaller side, indicating the presence of a more dense short range structure of the molecular assembly in the micropore. The peak intensities were noticeably weaker than those of the bulk liquid, and the tendency became significant with the decrease of the pore width. These behaviors indicate a serious restriction for the molecular assembly structure in the narrow micropore. Although the bulk liquid has a clear regular coordination structure up to the fourth-nearest-neighbor range, the structure of molecular assembly in the micropores smears around the third or fourth neighbors.