2016. 57, 3 UDC 541.6:547.12 DESIGN OF A NEW ROTARY MOLECULAR MACHINE BASED ON NITROGEN INVERSION: A DFT INVESTIGATION S.S. Gorgani1, M. Samadizadeh2 1Young Researchers and Elite Club, Central Tehran Branch, Islamic Azad University, Tehran, Iran 2Faculty of Basic Science, Department of Chemistry, Islamic Azad University, Central Tehran Branch, Tehran, Iran E-mail: Mar.samadizadeh@iauctb.ac.ir Received January, 27, 2015 Ab initio calculations are employed to investigate nitrogen inversion as a configuration change that can supply an extremely useful switchable control mechanism for some complex systems. <...> In this paper, the design of a new artificial rotary molecular machine based on nitrogen inversion is discussed. <...> The introduced design of a molecular rotator is based on the reciprocating motion of a substituent due to the inversion phenomenon, leading to the rotary motion in the molecule. <...> Since simple secondary amines easily face the inversion process at room temperature, aziridine is selected as the initial driver for the molecular motion. <...> The most obvious finding from this study is that, following the displacement of the substituent attached to the aziridine nitrogen atom, two rotary motions occurr in the molecule, one clockwise and another counterclockwise with a 39.52 to 150.09 angle domain. <...> This explanation can also be applied at the molecular level. <...> For achieving this objective, it is necessary to properly arrange some molecular components to develop a system that can do useful work such as the directional rotation or shuttle-like movements [ 2 ]. <...> Since the concept of a device or machine in the macroscopic scale can be generalized to the molecular level, a molecular machine can be defined as an assembly of distinct molecular combinations. <...> Nitrogen pyramidal inversion is induced by changes in the of position nitrogen substituents and can exists in two distinct geometric configurations (Fig. 1). <...> These configurations are interchangeable by the transposition of substituents to the opposite side of the central atom, thereby the formation of a mirror image of the original molecule [ 7—10]. <...> Since the inversion speed of nitrogen in simple secondary amines without pressure is very high, and the inversion may even take place at room temperature, these amines can be unsuitable to serve as a stimulus to make a molecular machine movement. <...> Aziridine is one of the compounds which experiences <...>