Introduction of an ethylenedithio group into an amphiphilic bis(tetrathiafulvalene) annulated macrocycle results in the formation of organogels which produce nanodot‐array structures in Langmuir–Blodgett films (see picture). Chemical oxidation of the sulphur‐containing π‐electron system afforded size‐controllable electrically conducting nanodot structures.

Amphiphilic bis(tetrathiafulvalene) [bis(TTF)] macrocycles with four alkyl chains were fabricated as novel electrically active Langmuir-Blodgett (LB) films. Two TTF units were linked via [24]crown-8, [21]crown-7, and [18]crown-6 macrocycles, forming charge-transfer (CT) salts with 2,3,5,6-tetrafluoro-7,7,8,8-tetracyano-p-quinodimethane (F4-TCNQ) at the air-water interface and on solid substrates. The CT salt of the amphiphilic bis(TTF)-macrocycle having a [24]crown-8 ring system formed a uniform surface morphology on mica. Using single-crystal X-ray structural analysis, the layer structure between the hydrophobic chains and the one-dimensional pi-pi stack of the CT salt was confirmed. Our results show that the bis(TTF)-macrocycle was folded at the flexible [24]crown-8 moiety, forming intramolecular pi-pi dimer structures and one-dimensional intermolecular pi-pi stacks with F4-TCNQ dimers. The open-shell electronic structure of the LB films was determined by electronic spectra, electrical conductivity, and electron spin resonance analyses. Asymmetry was introduced into the bis(TTF)-macrocycle by changing the ring size from [24]crown-8 to [21]crown-7. The surface morphology of the CT salts with F4-TCNQ was established as two-dimensional round-shape domains on mica. Further reduction of the macrocyclic ring from [21]crown-7 to [18]crown-6 resulted in a CT salt of the bis(TTF)-macrocycle with F4-TCNQ with a leaf-shape domain morphology and a typical dimension of approximately 1 microm2 on mica. In general, decreasing the macrocyclic ring size from [24]crown-8 to [21]crown-7 or [18]crown-6 affected the inter- and intramolecular interactions and the surface morphologies of LB films.

Einführen einer Ethylendithio‐Einheit in einen amphiphilen Makrocyclus mit zwei anellierten Tetrathiafulvalen‐Ringen führt zu Organogelen, die in Langmuir‐Blodgett‐Filmen Nanopunktanordnungen bilden (siehe Bild). Chemische Oxidation des schwefelhaltigen π‐Elektronensystems liefert elektrisch leitende Nanopunktstrukturen von regulierbarer Größe.

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 5 mN m−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 ratio of 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 film of 1a–Br2TCNQ exhibited a broad absorption at ca. 3 × 103 cm−1, which is characteristic of 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 × 10−2 S cm−1) was two orders of magnitude higher than that of 1a–F4TCNQ (3.9 × 10−4 S cm−1).