Molecular conductors with the common and robust building block (BEDT-TTF)2NP (NP = [FeNO(CN)5]2–) but different band filling

Abstract

Two new organic conductors based on BEDT-TTF radical cation salts with the [FeNO(CN) 5 ] 22 anion have been synthesized. b0-(BEDT-TTF) 2 [FeNO(CN) 5 ] (1) and b0-(BEDT-TTF) 3 [FeNO(CN) 5 ]?EG (2) have been characterized by single-crystal X-ray diffraction, electrical resistance measurements, and electronic band-structure calculations. A detailed comparison of 1 and 2 with b0-(BEDT-TTF) 4 A[FeNO(CN) 5 ] 2 (3) is reported. 2 and 3 are organic metals stable down to low temperatures while 1 is a semiconductor. Analysis of the correlation between the crystal and electronic structures as well as the transport properties of these molecular conductors suggests the possibility of changing their physical properties through chemical control of the composition of the anionic layers.