The synthesis and nonlinear optical characterization of new electrooptic (EO) materials useful for terahertz (THz) applications is presented. Semiempirical calculations were used to guide the development of a series of chromophores on the basis of 2-dicyanomethylen-3-cyano-4,5,5-trimethyl-2,5-dihydrofuran acceptors acting as guests in polymer films used in the generation of THz radiation via optical rectification. Amorphous films, 65-250 mum thick, with EO coefficients as high as 52 pm/V at 785 nm were used to generate sub-picosecond pulses with bandwidths up to 3 THz. (C) 2003 Wiley Periodicals, Inc. J Polym. Sci Part B: Polym Phys 41: 2492-2500, 2003