Scanning tunneling microscopy (STM) can identify the alignment of individual molecules at a surface, and can also induce reaction one molecule-at-a-time. In a recent STM study we have shown that low-energy electron-induced reaction of CF3 on Cu(110) at 4.6 K breaks the C-F bond lying along the copper row, producing opposed directed recoil of an F-atom and CF2 [1]. These energetic products can be ‘projectiles’ engaged in directed collision at selected impact parameter with a second adsorbate, the ‘target’ [1-2]. In the present case the target is another CF3 molecule adsorbed on the same copper row as the projectile, exclusively giving-zero-impact parameter collision dynamics. Here we show that if the projectile is an F-atom, the collision results in umbrella inversion of the CF3 target and gives an F-atom product that recoils in the direction of, and collinear with, the F- projectile. If the projectile is CF2, the collision once again results in umbrella inversion of the CF3 target and in this case gives a CF2 product recoiling in the direction of, and collinear with, the CF2 projectile. Preliminary calculations suggest that the collinearity of projectile and product and the observed umbrella inversion of the target and can be explained as substitution by the projectile in the course of each reaction.

Directed collision of F or CF2 with CF3 gives umbrella inversion of CF3 followed by collinear ejection of F or CF2

Macromolecular Chemistry: The Second Century

[Author Benefits](https://scimeetings.acs.org/?utm_source=pubs_content_marketing&utm_medium=website&utm_campaign=0320_MCF_NPI_Launch_Spring_Homepage&ref=pubs_content_marketing)

[How to use SciMeetings](https://storage.googleapis.com/dl.morressier.com/acs/SciMeetings-ACSSpring2020-HowToGuide_M3020-Final.pdf)

[Frequently Asked Questions](https://storage.googleapis.com/dl.morressier.com/acs/SciMtng_ACSNMSp2020_FAQ_M3120_Final.pdf)

ACS Spring 2020 National Meeting & Expo

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.