Preparation, crystal structures and electrical properties of PF6 and AsF6 salts of a novel furopyrazine-extended donor (BDTFP) with a two-leg ladder type orbital overlapping mode

Structural phase transition in quasi-one-dimensional conductors (BDTFP)2X(PhCl)0.5 (X = PF6 and AsF6) [BDTFP = 5,7-bis(1,3-dithiol-2-ylidene)-5,7-dihydrofuro[3,4-b]pyrazine; PhCl = chlorobenzene]

“…The single crystals were grown using the method described by Ise et al 1 The crystal shapes are thin and needle-like, developing mostly along the c-axis with the development of the bc crystal face. The absorption spectrum in solution was measured on a HITACHI U-3500.…”

“…BDTFP {5,7-bis(1,3-dithiol-2-ylidene)-5,7-dihydrofuro [3,4-b]-pyrazine} is a new electron donor molecule synthesized by a group at Tohoku University (Scheme 1). 1 Ise et al characterized the crystal structures of the charge transfer (CT) salts (BDTFP) 2 X(PhCl) 0.5 (X ~PF 6 , AsF 6 ; PhCl ~chlorobenzene) and claimed that these CT salts can be regarded as a two-leg ladder system, based on the calculation of the overlap integrals. BDTFP molecules are stacked along the c-axis, and have a dimerized structure with an overlap integral ratio of c2/c1 0.5 (Fig.…”

Ground State and Finite Temperature Behavior of 1/4-Filled Band Zigzag Ladders

“…63 A coupled SG-MI transition occurs at T MI =175 K in (BDTFP) 2 PF 6 (PhCl) 0.5 . 57 While structurally (BDTFP) 2 PF 6 (PhCl) 0.5 appears to be ladder-like, 18,57 X-ray 58 and optical measurements 59 show that in the low-temperature phase tetramerization takes place along the stacks with the SMWM bond pattern. 58 The coupled SG-MI transitions found in these two materials are consistent with our criterion above.…”

Cooperative Density Wave and Giant Spin Gap in the Quarter-Filled Zigzag Electron Ladder

“…Several recently discovered 1/4-filled band CTS are very likely structurally zigzag ladders. These systems consist of pairs of 1D stacks of organic donor molecules with strong intrapair interchain couplings, and weak interpair couplings 16,17 . They undergo M-I transition at T M−I > 200 K, followed by an insulator-insulator (I-I) transition which is accompanied by the opening of a SG at lower temperature T SG 8,9,10,18 .…”