LAUSR

Abstract The electronic, spectral and structural properties of a molecular machine composed of a phenylene rotator encased by two trityl stators and two acetylides as axis are investigated theoretically to evaluate the rotational dynamics by DFT method. The changes in these properties and intramolecular rotation barriers caused by substituting F, CN, NO2, and NH2 on the central phenylene were also investigated. The potential energy surface calculations showed that the activation barrier of phenylene rotation is lower than 1 kcal/mol, for all considered systems. The results of the computational method were in good agreement with previously reported experimental results. The dynamical features of the studied molecules suggest that this kind of structure can act as a molecular machine at room temperature in the living organisms. The displacement of phenylene hydrogen atoms with polar groups improves this property and it is expected that these compounds may be helpful in drug delivery.