We report the synthesis and properties of two series of homologous donor-acceptor (D-A) chromophores in which N, N-dimethylanilino (DMA) or N,N-dihexylanilino (DHA) donors and dicyanovinyl acceptors are separated by up to four CϵC triple-bond spacers or up to three C=C doublebond spacers. The intramolecular charge-transfer (CT) interactions of the new D-A oligoynes and the known all-trans D-A oligoenes were investigated by X-ray crystallography, electrochemistry, UV/Vis spectroscopy, and theoretical calcu-

Chiral and achiral push-pull chromophores have been prepared by cascades of sequential [2+2] cycloadditions of tetracyanoethene (TCNE) and tetrathiafulvalene (TTF) to different oligoynes. Thermal [2+2] cycloaddition of TCNE to donor-substituted alkynes, followed by electrocyclic ring-opening of the initially formed cyclobutenes, affords donor-substituted 1,1,4,4-tetracyanobuta-1,3-dienes (TCBDs). Similarly, TTF reacts with electron-deficient CϵC bonds to give the corresponding buta-1,3-diene derivatives, 1,2-bis(1,3-dithiol-2-ylidene)ethanes. Thus, achiral [AB]-type oligomers were synthesized from N,N-dialkylanilino (DAA)-substituted tetraynes and hexaynes and chiral [AB]-type oligomers from alkyne-substituted 1,1Ј-binaphthalenes. The [AB]-type oligomers exhibit complex conformational equilibria in solution, as revealed by 1 H and 13 C NMR spectroscopy. Therefore, the circular dichroism (CD) spectra of the chiral [AB]-type oligo-

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