Tuning the self-assembly of 5-amino [6]helicene on solid surfaces

HUGO ASCOLANI; MARTEEN VAN DER MEIJDEN; LUCILA J. CRISTINA; J. ESTEBAN GAYONE; RICHARD M. KELLOGG; JAVIER D. FUHR; MAGALÍ LINGENFELDER

Leuven

Congreso; Chirality at the Nanoscale; 2015

p { margin-bottom: 0.21cm; direction: ltr; color: rgb(0, 0, 0); widows: 2; orphans: 2; }p.western { font-family: "Times New Roman",serif; font-size: 12pt; }p.cjk { font-family: "Times New Roman",serif; font-size: 12pt; }p.ctl { font-family: "Times New Roman",serif; font-size: 12pt; }a:link { color: rgb(0, 0, 255); }Scanning tunneling microscopy (STM) studies have shown that chiralexpression can be explored in great detail for molecules adsorbed onmetal surfaces. Particularly interesting model systems are helicenes,compounds with ortho-condensed aromatic rings presenting axialchirality. Here we report the investigation of 5-amino[6]helicene(AH) under ultra-high vacuum (UHV) and compare the self-assembly onCu (100) and Au(111). AH represents an interesting model system forthe study of the interplay of van der Waals (vdW) and H bondinggroups and their influence on the chiral footprint of the enantiopureadsorbates on a solid surface. The chief difference between the twoanalysed surfaces is found in the origin of the molecule?surfaceinteraction. While the C6 rings-surface interaction dominates in thecase of Cu(100), the amino?surface interaction is crucial onAu(111). In both cases, it is significant that the amino group doesnot induce polar interactions via hydrogen bonding but rather thatthe maximization of vdW interactions drives the self-assembly [1].Further studies of (MP)AH on Cu(100), Au(111) and SnCu(100) will alsobe presented.