ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
The crystal structure and the optical data of the (1:1) charge-transfer (CT) complex of tetrathiafulvalene (TTF) with 2,5-dichloro-p-benzoquinone (2,5Cl2BQ) are reported, yielding a full characterization of the ground state properties. The complex crystallizes in the triclinic space group P1¯, Z=1. TTF and 2,5Cl2BQ form mixed regular stacks along the b axis. The degree of ionicity ρ is ∼0.18, and the CT integral ∼0.22 eV. A detailed analysis of the optical data yields estimates of the strength of electron–molecular vibration coupling and of intersite electron–electron interactions. The latter has also been computed in the atom-in-molecule fractional charge approximation. The TTF-2,5Cl2BQ structure and microscopic parameters at ambient conditions are found to be rather similar to those of the extensively studied complex of TTF with tetrachloro-p-benzoquinone (CA). The different behavior of the two complexes under pressure (both exhibit a neutral–ionic phase transition, but ρ changes discontinuously for TTF–CA and continuously for TTF-2,5Cl2BQ) is ascribed to the competitive role of the Madelung energy and of the CT integral.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.464577
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