A highly correlated conformational motion of a tube-like fully conjugated hydrocarbon

By comparing the matrix infrared spectrum (Ar, 12 K) with theoretically calculated spectra (B3LYP/6-31G∗), the structure of the tube-like hydrocarbon 1 has been determined to be a fast equilibrium of two D2d symmetrical structures. The previously assumed higher symmetrical D4h structure was found to be the transition state of this conformational interconversion. The conformational process involves the correlated and simultaneous pincer-like movement of the four relatively rigid anthracene units. Two pincers are always closed and two are open. Changing the state of one of the pincers reverses the state of the other three pincers. Upon suitable substitution, the molecular framework meets the requirements to be used as a logic gate.