Molecular orientation in self-assembled layers of two functionalized fullerenes—Role of bromine atom at the end of alkyl chain

The IR reflection–absorption spectra of Langmuir–Blodgett (LB) layers of the functionalized fullerenes: C60-fused N-methylpyrrolidine-5-(dodecyl)thiophene (1) and C60-fused N-methylpyrrolidine-5-(12-bromododecyl)thiophene (2) were investigated. It was shown that thin films of functionalized fullerenes are ordered and characteristic parts of the molecules are oriented. Their orientation was evaluated with a simple spectroscopic method. It was stated that bromine atom at the end of aliphatic chain of the sample 2 strongly influences the chain orientation. Similarly, the sulphur atom in the thiophene ring causes some bend of its plane.