Proton transfer and a dielectric phase transition in the molecular conductor (HDABCO+)2(TCNQ)3

Tomoyuki Akutagawa; Sadamu Takeda; Tatsuo Hasegawa; Takayoshi Nakamura

doi:10.1021/ja0377697

Proton transfer and a dielectric phase transition in the molecular conductor (HDABCO+)2(TCNQ)3

J Am Chem Soc. 2004 Jan 14;126(1):291-4. doi: 10.1021/ja0377697.

Authors

Tomoyuki Akutagawa¹, Sadamu Takeda, Tatsuo Hasegawa, Takayoshi Nakamura

Affiliation

¹ Research Institute for Electronic Science, Hokkaido University, Sapporo 060-0812, Japan. takuta@imd.es.jokudai.ac.jp

PMID: 14709094
DOI: 10.1021/ja0377697

Abstract

One-dimensional dielectric (N.H.N)( infinity ) hydrogen-bonding chains of monoprotonated 1,4-diazabicyclo[2.2.2]octane (HDABCO(+)) were introduced into an electrically conducting 7,7,8,8-tetracyano-p-quinodimethane (TCNQ) salt as the countercation structure. Room-temperature electrical conductivity was approximately 10(-)(3) S cm(-)(1), with a semiconductive behavior. The temperature-dependent dielectric constants of (HDABCO(+))(2)(TCNQ)(3) indicated a dielectric transition at 306 K. A large deuterium isotope effect for the dielectric transition (DeltaT = 70 K) was observed for the deuterated salt, (DDABCO(+))(2)(TCNQ)(3). Thermally activated order/disorder of the protons or deuteriums within the one-dimensional hydrogen-bonding chains of (HDABCO(+))( infinity ) and (DDABCO(+))( infinity ) affected the dielectric responses in the TCNQ-based semiconductors.