EFFECT OF SUBSTITUTION ON THE STRUCTURES AND OPTOELECTRONIC PROPERTIES OF MERCURY-CONTAINING DIETHYNYLFLUORENE

Abstract

We report on a quantum-chemical study of the electronic and optical properties of Mercury(II) complexes HgTFT (1) and its electron-withdrawing substitutent HgTFOT (2), HgTFCNT (3) [where TFT = diethynylfluorenyl, TFOT = diethynylfluorenone and TFCNT = diethynyl-(9-(dicyanomethylene)fluorene)]. Our theoretical calculations indicate that the substitution of - CO , - C ( CN )2 for - CH in HgTFT significantly decreases the bond length alternation and increases the electron affinity, which would qualify HgTFOT 2 and HgTFCNT 3, especially 3, as candidates for n-type electrical conductors. The vertical transition energy associated with the low-lying excited state has been examined within the time-dependent DFT formalism for mercury diethynylfluorenyl derivatives. It is found that the electron-withdrawing substitutions lead to remarkable red shift in transition energy and alter the corresponding charge transfer manner.