Figures from "Formation of Ordered, Anisotropic Organic Monolayers on the Si(001) Surface", by R.J. Hamers, J.S. Hovis, S. Lee, H. Liu, and J. Shan, Journal of Physical Chemistry, vol. 101, no. 9, pp. 1489-1492 (February 1997).

Figure 1

Schematic illustration of reactions between a Si=Si dimer and a cyclopentene molecule:
(1a) starting species;
(1b) reaction via 2+2 cycloaddition reaction, leaving Si=Si dimer sigma bond intact;
(1c) reaction involving insertion into Si=Si dimer bond, with breaking of Si=Si dimer sigma and pi bonds.


Figure 2

STM images of cyclopentene-exposed Si(001) surfaces:

(2a) image showing ordered molecular adsorption onto a single terrace;
(2b) high-resolution image showing the translational ordering and consistent elongated appearance of individual molecules;
(2c) image obtained on 4-°-miscut vicinal Si(001) substrate showing that the molecular orientation of cyclopentene is retained across double-height steps. Arrows indicate positions of double-height steps.


Figure 3

Anisotropy of infrared absorption of cyclopentene layer on Si(001) for s-polarized light:

(3a) definition of polarization directions;
(3b) s-polarized infrared absorption spectra for the two primary polarization directions in the Si-H and C-H spectral regions.