An electron acceptor molecule of tetracyanoquinodimethane (TCNQ) derivative; trifluoromethyl-TCNQ (CF(3)TCNQ) was synthesized and its crystal structure was determined. CF(3)TCNQ was found to be a strong electron acceptor comparable to 2,5-difluoro-TCNQ. The adiabatic electron affinity and molecular on-site Coulomb energy of CF(3)TCNQ were estimated to be 2.96-3.05 eV and 4.74 eV, respectively. The acidity of dihydro-CF(3)TCNQ in N,N-dimethylformamide/H2O was estimated to be pK(1) = 5.30 and pK(2) = 8.20. The molecular and crystal structures and molecular orbitals of CF(3)TCNQ are described.