화학공학소재연구정보센터
Langmuir, Vol.12, No.3, 754-757, 1996
Discotic Twin and Triple Molecules with Charge-Transfer Interactions in Langmuir-Blodgett-Films
X-ray and atomic force microscopy observations reveal features of the surface morphology of Langmuir-Blodgett (LB) films from discotic donor-acceptor molecules with strong core-to-core interactions caused by a charge-transfer (CT) complexation. The compounds are designed to be twin and triple molecules composed of chemically connected donor (triphenylene) and acceptor (trinitrofluorenone) fragments which display liquid crystalline structure in the bulk state. The LB films from these compounds possess edge-on orientation of molecules within monolayers with a smooth surface on a submicron scale but with substantial macroscopic imperfections. These imperfections are represented by the micron size fractures and ruptures apparently caused by local deformations and tensions during transfer of the discotic monolayers from the air-water interface to a solid substrate. It is suggested that this is due to the excessive rigidity of the monolayers caused by the stiffness of the columns with positional intracolumnar ordering enhanced by the strong intracolumnar CT interactions.