Abstract
The supramolecular self-assembly of a push-pull dye is investigated using scanning tunneling microscopy (STM) at the liquid–solid interface. The molecule has an indandione head, a bithiophene backbone and a triphenylamine–bithiophene moiety functionalized with two carboxylic acid groups as a tail. The STM images show that the molecules adopt an “L” shape on the surface and form chiral Baravelle spiral triangular trimers at low solution concentrations. The assembly of these triangular chiral trimers on the graphite surface results in the formation of two types of chiral Kagomé nanoarchitectures. The Kagomé-α structure is composed of only one trimer enantiomer, whereas the Kagomé-β structure results from the arrangement of two trimer enantiomers in a 1:1 ratio. These Kagomé lattices are stabilized by intermolecular O-H···O hydrogen bonds between carboxylic acid groups. These observations reveal that the complex structure of the push-pull dye molecule leads to the formation of sophisticated two-dimensional chiral Kagomé nanoarchitectures. The subsequent deposition of coronene molecules leads to the disappearance of the Kagomé-β structure, whereas the Kagomé-α structure acts as the host template to trap the coronene molecules.
Highlights
“Push-pull” dyes are promising building blocks to fabricate photoactive devices. These dyes are donor–acceptor single compounds; i.e., they possess one electron-rich section as well as one electron-poor section, giving them an intense and tunable absorption band in the visible spectrum. This specific molecular structure has been successfully exploited to enhance the properties of organic solar cells and precious-metal-free dye-sensitized solar cells[22,23]
scanning tunneling microscopy (STM) reveals that the N,N-di(4-benzoic acid)-4-(5′
Two Kagomé nanoarchitectures coexist on the surface (Fig. 7). These structures share the same building block. This building block has a triangular shape, and it is composed of three molecules adopting a Baravelle spiral triangular arrangement
Summary
Engineering novel organic/inorganic interfaces through the self-assembly of functionalized molecules[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18] is the focus of intense research interest for developing new applications in nanotechnology. “Push-pull” dyes are promising building blocks to fabricate photoactive devices These dyes are donor–acceptor single compounds; i.e., they possess one electron-rich section as well as one electron-poor section, giving them an intense and tunable absorption band in the visible spectrum. This specific molecular structure has been successfully exploited to enhance the properties of organic solar cells and precious-metal-free dye-sensitized solar cells[22,23]. Double hydrogen bonds (O-H···O) are expected to appear between neighboring molecules possessing carboxylic groups This strategy has been successfully used to stabilize the formation of porous and compact nanoarchitectures in a highly predictable fashion[35,36,37,38,39,40,41]. “push-pull” dyes usually have a complex structure with low symmetry
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call