A. Marzotto, D. A. Clemente, L. Pasimeni
Oct 1, 1988
Citations
1
Influential Citations
6
Citations
Journal
Journal of Crystallographic and Spectroscopic Research
Abstract
The crystal and molecular structure of tetrapropylammonium-2,3-dichloro-5,6-dicyano-p-benzoquinone (TPA+ DDQ−) has been determined from single-crystal X-ray diffraction analysis. The crystals are monoclinic, space groupP21/n, witha=13.297(5),b=12.851(4),c=13.099(5) Å,β=101.34(2)°, andZ=4. The compound consists of discrete (DDQ)22− anion dimers and two TPA+ cations inserted between the (DDQ)22− dimers, with an infinite stack running along b of the type ⋯(DDQ)22−[(C3H7)4N+] (DDQ)22−2[(C3H7)4N+]⋯The (DDQ)22− anion is formed by two DDQ− anions dimerized through a crystallographic center of symmetry; each DDQ− moiety is nearly planar and exhibits molecular dimensions similar to those found in analogous compounds. The comparison between the (DDQ)22− anion and a neutral DDQ molecule clearly shows that bond lengths are markedly influenced by the 2-anionic charge. Tetrapropylammomum cation assumes a distorted tetrahedral configuration as observed in TEA+ DDQ− (TEA+=tetraethylammonium cation). The data are discussed in connection with the electrical conductivity of “organic metals”.