Absolute reaction rate constants have been measured at room temperature for the ground state dichlorocarbene, CCl2 with a series of simple molecules: C2H4, NO, N2O, and halomethanes (T = 297 K). The technique of laser-induced fluorescence was employed to obtain these rate constants. The reaction Of CCl2 + CH2O2 was theoretically studied using a high-level ab initio calculation in order to gain an insight into the mechanism for the reactions CCl2 + halomethanes. (C) 2004 Elsevier B.V. All rights reserved.