ortho-tetraaryls as helical building blocks:: a study of structure, theory, electrochemistry, and optical properties

(ortho)-3,3'-Diphenyl-2,2'-bithiophene is shown to exhibit a solid-state helical conformation that is consistent with MMFF predictions of structure. The optical, electronic, and conformational properties of this compound are examined, and the results are commensurate with a helical building block capable of exhibiting redox-induced conformational changes along the long molecular axis. Such a property demonstrates promise for this tetramer to function as building block for a spring-like electromechanical actuator. (C) 2004 Elsevier Ltd. All rights reserved.