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A computational (ZINDO) investigation is employed to estimate the molecular hyperpolarizability () of a (TTF−NH2)8(TTF tetrathiafulvalene) octameric stack at various fractional (0 < < 1) oxidation states of TTF. While the neutral (TTF−NH2)8octamer exhibits a modest (7.6 × 10-30cm5esu-1) static 0value, in relation to a nearly centrosymmetric electronic structure, the formal (TTF−NH2)0.25oxidation state leads to a giant (03891 × 10-30cm5esu-1per octamer) NLO response. This effect is related to the appearance of an extremely intense HOMO → LUMO-based low-lying transition, occurring at 1260 nm upon fractional oxidation, thus providing new and unexpected interest in TTF-donor substituted molecules. To illustrate the chemical feasibility of such species, two kinds of derivatives are synthesized:  a TTF-dimethylaniline (TTF-DMA)by using in particular a Suzuki cross-coupling reaction between iodo-TTF and p-dimethylaminophenylboronic acid and a TTF-vinyldimethylaniline (TTF-VDMA)by a Wittig-type condensation notably between TTF-carboxaldehyde and p-(dimethylamino)benzyltriphenylphosphonium bromide. Their NLO response, evaluated at 1.064 m by the Hyper Raleigh Scattering technique, leads to values around 240 × 10-30cm5esu-1, in both cases. Additionally, these monomeric species are observed to exhibit very strong multiphoton fluorescence in solution after one electron oxidation. Different routes are discussed toward a possible engineering of TTF-donor based chromophores into oligomeric stacks in the solid state. [ABSTRACT FROM AUTHOR]