Single-Component Conductors: A Sturdy Electronic Structure Generated by Bulky Substituents.
While the introduction of large, bulky substituents such as tert-butyl, -SiMe3, or -Si(isopropyl)3 has been used recently to control the solid state structures and charge mobility of organic semiconductors, this crystal engineering strategy is usually avoided in molecular metals where a maximized overlap is sought. In order to investigate such steric effects in single component conductors, the ethyl group of the known [Au(Et-thiazdt)2] radical complex has been replaced by an isopropyl one to give a novel single component molecular conductor denoted [Au(iPr-thiazdt)2] (iPr-thiazdt: N-isopropyl-1,3-thiazoline-2-thione-4,5-dithiolate). It exhibits a very original stacked structure of crisscross molecules interacting laterally to give a truly three-dimensional network. This system is weakly conducting at ambient pressure (5 S·cm(-1)), and both transport and optical measurements evidence a slowly decreasing energy gap under applied pressure with a regime change around 1.5 GPa. In contrast with other conducting systems amenable to a metallic state under physical or chemical pressure, the Mott insulating state is stable here up to 4 GPa, a consequence of its peculiar electronic structure.
Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS-Université de Rennes 1, Matière Condensée et Systèmes Electroactifs (MaCSE) , Campus de Beaulieu, Bâtiment 10A, 35042 Rennes cedex, France.
Agathe
A
Filatre-Furcate
Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS-Université de Rennes 1, Matière Condensée et Systèmes Electroactifs (MaCSE) , Campus de Beaulieu, Bâtiment 10A, 35042 Rennes cedex, France.
Nathalie
N
Bellec
Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS-Université de Rennes 1, Matière Condensée et Systèmes Electroactifs (MaCSE) , Campus de Beaulieu, Bâtiment 10A, 35042 Rennes cedex, France.
Olivier
O
Jeannin
Laboratoire de Physique des Solides UMR 8502 CNRS-Université Paris-Sud, Université Paris-Saclay , F.91405 Orsay cedex, France.
Pascale
P
Auban-Senzier
Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS-Université de Rennes 1, Matière Condensée et Systèmes Electroactifs (MaCSE) , Campus de Beaulieu, Bâtiment 10A, 35042 Rennes cedex, France.
Marc
M
Fourmigué
Materials Research and Technology Department, Luxembourg Institute of Science and Technology (LIST) , 5 avenue des Hauts-Fourneaux, L-4362 Esch/Alzette, Luxembourg.|Institut de Ciència de Materials de Barcelona (ICMAB-CSIC) , Campus de la UAB, E-08193 Bellaterra, Spain.
Jorge
J
Íñiguez
Institut de Ciència de Materials de Barcelona (ICMAB-CSIC) , Campus de la UAB, E-08193 Bellaterra, Spain.
Enric
E
Canadell
GREMAN UMR 7347 CNRS, Université F. Rabelais , Parc de Grandmont, 37200 Tours, France.
Benjamin
B
Brière
GREMAN UMR 7347 CNRS, Université F. Rabelais , Parc de Grandmont, 37200 Tours, France.
Vinh
V
Ta Phuoc
Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS-Université de Rennes 1, Matière Condensée et Systèmes Electroactifs (MaCSE) , Campus de Beaulieu, Bâtiment 10A, 35042 Rennes cedex, France.
Dominique
D
Lorcy