The dispersed fluorescence spectra following the excitation of several (A) over tilde <--(X) over tilde vibronic bands of HCCl and DCCl at visible wavelengths were successfully acquired in a discharge supersonic free jet expansion using an intensified charge-coupled device detector. The dispersed fluorescence spectra reveal more details of the (X) over tilde (1)A' state vibrational structure in these molecules than previous reports. Dispersed fluorescence spectra of all four isotopomers ((HCCl)-Cl-35, (HCCl)-Cl-37, (DOCl)-Cl-35, and (DCCl)-Cl-37) were obtained. These dispersed fluorescence spectra exhibit the vibrational structures up to approximate to6000, cm(-1) above the zero-point level and determine the vibrational structures of (HCCl)-Cl-37 and (DCCl)-Cl-37. Complete vibrational parameters including fundamental frequencies, anharmonicities, and coupling constants were determined for the HCCl/DCCl (X) over tilde (1)A' state. Furthermore, perturbations from the background triplet state (a) over tilde (3)A" and emission to triplet state levels were observed in the spectra. The singlet-triplet energy gap from the zero-point level could be determined to be 2167 cm(-1) (6.20+/-0.05 kcal/mol) in HCCl and to be 2187 cm(-1) (6.25+/-0.05 kcal/mol) in DCCl. Additionally, some of the (A) over tilde <--(X) over tilde excitation spectrum are reported for HCCl and DCCl. (C) 2004 American Institute of Physics.