Lydie Leung1, Tingbin Lim1, Zhanyu Ning1, John C. Polanyi1, Wei Ji2 and Chen-Guang Wang1,2
1Lash Miller Chemical Laboratories, Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, M5S 3H6, Canada.
2Department of Physics and Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-Nano Devices, Renmin University of China, Beijing 100872, China.
DOI:10.1021/acs.jpcc.5b09211 Publication Date:
Previous studies indicated that the reagent bond-direction of a bond being broken in surface reaction dominated the subsequent product recoil direction. Here we test this in an STM study of the electron-induced bond-breaking for three clearly different alignments of each of two dihalobenzene reactions on Cu(110). A strong correlation was observed between the physisorbed adsorbate bond-direction, and the subsequent recoil direction of the chemisorbed halogen-atom product. The correlation was also evident in the theoretical modelling for the case of variously aligned diiodobenzene. The theory employed the Impulsive Two-State (I2S) approach to compute the reaction dynamics following electron-attachment. This showed that the correlation between the prior bonddirection and the subsequent product angular-distribution was due to the directionality of the anti-bonding repulsion responsible for extending the molecules' carbon-halogen bond, en route to reaction. Retention of bond-direction in reaction dominated the effect of differing roughness of the surface along markedly different crystal axis'.