title: Molecular and crystal structure diversity, and physical properties of tetrathiafulvalene derivatives substituted with various aryl groups through sulfur bridges.
abstract: A library of tetrathiafulvalene (TTF) derivatives (TTF-1-TTF-47) bearing aryl groups attached through sulfur bridges has been created. The peripheral aryl groups exert a significant influence on both the electronic and crystallographic properties of the resulting TTFs. These TTFs display broad absorption bands at 400-500 nm caused by intramolecular charge-transfer transitions between the aryl groups and central TTF core, and their first redox potentials increase with increasing electron-withdrawing ability of the aryl groups. In their crystal structures (22 examples), the central TTF cores adopt various conformations, including chair, half-chair, boat, and planar conformations. Moreover, the peripheral aryl groups exhibit multiple alignment modes with respect to the central TTF core, caused by their rotation about the two C-S bonds of the sulfur bridges. The packing motifs of these TTFs depend on both the nature of the aryl groups and their spatial alignment modes. Driven by intermolecular van der Waals forces and π-π interactions between the aryl groups and between the aryl groups and the TTF core, these TTFs adopt various packing structures. As a typical example, TTF-14, an achiral molecule, adopts a helical chain stack through intermolecular atomic close contacts. Moreover, the molecular geometries and packing motifs of these TTFs are sensitive to environmental variation, as exemplified by TTF-28, which adopts three distinct crystal modifications with diverse molecular geometries and stacking modes under different crystallization conditions. This work indicates that these TTFs are potential candidates as electronic materials, as well as functional building blocks for supramolecular assembly.
authors.affiliation: State Key Laboratory of Applied Organic Chemistry & School of Chemistry and Chemical Engineering, Lanzhou University, 222 Tianshui Southern Road, Lanzhou 730000 (P.R. China), Fax: (+86) 0931-8915557.
authors.forename: Jibin
authors.initials: J
authors.lastname: Sun
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Lu
authors.forename: Jiafeng
authors.initials: J
authors.lastname: Shao
authors.forename: Xuexiang
authors.initials: X
authors.lastname: Li
authors.forename: Shangxi
authors.initials: S
authors.lastname: Zhang
authors.forename: Baolin
authors.initials: B
authors.lastname: Wang
authors.forename: Jinlian
authors.initials: J
authors.lastname: Zhao
authors.forename: Yongliang
authors.initials: Y
authors.lastname: Shao
authors.forename: Ran
authors.initials: R
authors.lastname: Fang
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Wang
authors.forename: Wei
authors.initials: W
authors.lastname: Yu
authors.forename: Xiangfeng
authors.initials: X
authors.lastname: Shao
keywords: TTF derivatives; electrochemistry; helical chains; photochemistry; polymorphism