Langmuir-blodgett films of charge-transfer complexes: Ethylenedithio- substituted amphiphilicbis-ttf macrocycle and F4TCNQ or Br 2TCNQ

Toru Endo, Tomoyuki Akutagawa, Teppei Kajiwara, Keiko Kakiuchi, Yoko Tatewaki, Shin Ichiro Noro, Takayoshi Nakamura

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

Charge-transfer (CT) complexes between ethylenedithio-substituted bis-TTF macrocycle 1a, as an amphiphilic electron donor, and 7, 7, 8, 8-tetracyano-p-quinodimethane (TCNQ) derivatives, as electron acceptors, were fabricated as Langmuir-Blodgett (LB) films. For the 1a-F4TCNQ LB film deposited at a surface pressure of 5mNm-1 onto a substrate surface, the stoichiometry between the donor and acceptor was determined as 1:2 using XPS measurements. In contrast, a donor/acceptor ratioof 1:0.3 was observed for the 1a-Br2TCNQ LB film, indicating that a fraction of Br2TCNQ was lost during the LB film formation process. Similarity of the round-shaped domains that cover the surfaces of the 1a-Br2TCNQ and neutral 1a LB films indicates the presence of neutral 1a within the 1a-Br2TCNQ LB film. For the (1a2+)(F4TCNQ-)2 LB film, the presence of a CN-stretching frequency signifies the formation of a fully ionic electronic ground state. The LB filmof 1a-Br2TCNQ exhibited a broad absorption at ca. 3 x 103cm-1, which is characteristicof an intermolecular CT transition for a partial CT state. 1a-Br2TCNQ LB film consisted of neutral 1a and CT complex of 1a-Br2TCNQ. The room temperature conductivity of the 1a-Br2TCNQ LB film (1.2 x 10 -2 S cm-1) was two orders of magnitude higher than that of 1a-F4TCNQ (3.9 x 10-4Scm-1).

Original languageEnglish
Pages (from-to)968-974
Number of pages7
JournalBulletin of the Chemical Society of Japan
Volume82
Issue number8
DOIs
Publication statusPublished - 2009 Aug 25
Externally publishedYes

ASJC Scopus subject areas

  • Chemistry(all)

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