Convenient Preparation and Properties of 2,5-Dichloro-and 2,5-Dibromo-3,6-Dicyano-1,4-Benzoquinone(CDDQ and CBDQ): DDQ Analogs with Centrosymmetry

Abstract
The synthetic procedure of DDQ analogs with centrosymmetry, 2,5-dichloro-, and 2,5-dibromo-3,6- dicyano-1,4-benzoquinone (CDDQ and CBDQ) was improved. These compounds showed strong electron acceptor properties like DDQ and gave semiconducting charge-transfer complexes with TTF derivatives. Crystal structures of CDDQ and perylene-CDDQ were also reported.