Towards a symmetric reversible single-molecule switch: Amino-imino-cyclo-n-enes

We propose cyclic 5- and 7-ring structures with alternating single double bonds adjacent imino amino groups as candidates for switches in molecular electronics, amino-imino tautomerisation the switching mechanism. Due to C2V-symmetric transition state, molecules exhibit a symmetric double-well potential identical energies two states, which is desirable property functioning switch. Calculations at hybrid mPW2PLYP-D2/def2-TZVP level show barriers of 1.07 0.52 eV 5-ring 7-ring, respectively (zero-point corrected: 0.97 0.41 eV, respectively). The corresponding 9-ring structure not suitable switch, due ring puckering existence multiple minima. Attachment ethyne nitrogens opposite carbon, models wires, only slightly changes barrier heights. are promising switch further investigation.