Photoisomerization of Self-Assembled Monolayers of Azobiphenyls: Simulations Highlight the Role of Packing and Defects
Artikel i vetenskaplig tidskrift, 2016

We present surface hopping simulations of the photodynamics of self-assembled monolayers (SAMs) of 4'-(biphenyl-4-ylazo)-biphenyl-4-thiol (ABPT) on Au(111). We show that trans -> cis photoisomerization is suppressed because of steric hindrance in a well-ordered SAM. Photoisomerization is instead viable in the presence of defects. Two particularly important defects are the boundaries between domains of trans-ABPT molecules leaning in different directions (a line defect) and single cis molecules embedded in a SAM of trans (a point defect). Our findings explain the cooperative behavior observed during the photoisomerization of a trans-ABPT SAM, leading to large domains of pure cis and trans isomers. The line and point defects are predicted to produce different patterns of cis-ABPT molecules during the early stages of the photoconversion.


Valentina Cantatore

Kemi och kemiteknik, Energi och material, Oorganisk miljökemi

G. Granucci

Universita di Pisa

G. Rousseau

Universite Paris-Sud XI


G. Padula

Universita di Pisa

M. Persico

Universita di Pisa

Journal of Physical Chemistry A

1089-5639 (ISSN) 1520-5215 (eISSN)

Vol. 7 4027-4031