The reaction between the tetrakis(2-pyridyl-N-oxidemethylthio)-tetrathiafulvalene ligand (L) and Ln(hfac)(3)center dot 2H(2)O precursors (where hfac(-) = 1,1,1,5,5,5-hexafluoroacetylacetonate anion and Ln = Tb-III (1), Dy-III (2), Er-III (3), and Yb-III (4) and (4b)) leads to the formation of five tetranuclear complexes of formula [Ln(4)(hfac)(12)(L)(2)]center dot xCHCl(3).yC(6)H(14) (n = 1, x = 2, y = 0 for (1), (2), and (4), n = 1, x = 4 for (3), and n = 2, x = 2.5, y = 1 for (4b)). Their X-ray structures reveal that the surrounding of each Ln(III) center is filled by two N-oxide groups coming from two different ligands L. These tetranuclear complexes have the highest nuclearity which is reported until now for coordination compounds of lanthanide involving TTF-based ligands. Direct current (dc) measurements highlight the paramagnetic behavior of the compounds with a significant crystal field effect. The temperature dependences of static magnetic measurements for 4 have been fitted. The ground state corresponds to M-J = +/- 5/2 while the first excited state (M-J = +/- 3/2) was localized at +214 cm(-1) which was well correlated with the luminescence transition. UV-visible absorption properties have been experimentally measured and rationalized by time-dependent density functional theory (TD-DFT) calculations. Upon irradiation at 77 K and room temperature, in the range 24390-20835 cm(-1), both compounds 3 and 4 display a metal-centered luminescence attributed to I-4(13/2) -> I-4(15/2) (6660 cm(-1)) and F-2(5/2) -> F-2(7/2) (signal centered around the value of 9966 cm(-1)) transitions, respectively. The observed six transitions could be attributed to the M-J state splitting due to the existence of two Yb1 and Yb2 ions with slightly different polyhedra in 4.