INFRARED-SPECTROSCOPY OF CO ON NACL(100) .4. BAND-SHAPE ANALYSIS

被引：84

作者：

DISSELKAMP, R ^{[1
]}

CHANG, HC ^{[1
]}

EWING, GE ^{[1
]}

机构：

[1] INDIANA UNIV,DEPT CHEM,BLOOMINGTON,IN 47405

来源：

SURFACE SCIENCE | 1990年 / 240卷 / 1-3期

基金：

美国国家科学基金会;

关键词：

D O I：

10.1016/0039-6028(90)90742-Q

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The infrared bandshape of monolayer CO on NaCl(100) at 4 K is slightly asymmetric and its bandwidth of 0.09 cm-1 is the narrowest observed for any surface molecule. From a variety of experiments we know that this band profile is determined by heterogeneous rather than homogeneous broadening. We offer an explanation for the experimentally observed bandshape by proposing that irregularities in the surface of the cleaved NaCl crystals give rise to many distinct two-dimensional domains of physisorbed CO. A first-order perturbation calculation, which generates the infrared cross-section as a function of domain size, has been used to estimate that on the order of 10(5) molecules reside in an average size domain. The accuracy of the calculation, whose Hamiltonian represents the intermolecular potential among CO molecules by electric multipole coupling, will be discussed. We use the same coupling Hamiltonian to explore the effect of submonolayer coverages, isotopic dilution, and surface heterogeneities on the infrared spectroscopy of CO on NaCl(100). Our calculations can account for some, but not all, of the observed spectroscopic data.

引用

页码：193 / 210

页数：18

共 61 条

[1] SCF AND CI CALCULATIONS OF THE ONE-ELECTRON PROPERTIES OF CARBON-MONOXIDE AS A FUNCTION OF INTER-NUCLEAR DISTANCE [J].