By reduction of tribenzoylenebenzene 4 with lithium in 2-methyltetrahydrofuran (MTHF) an ion pair and a cluster with S = 1 were obtained whereas with potassium or sodium in MTHF in the presence of dicyclohexano-18-crown-6 (or a solvent of strong solvating power such as diglyme or hexamethyl-phosphoric triamide), different species with S greater than or equal to 1/2 were detected. The ESR spectra of the randomly oriented pluri-anions in glassy matrix showed the existence of triplet species assigned to a dianion [4(2(.-))(M+)(2)] and aggregates [4(.-)(M+)(n)4(.-)] and quartet species [4(2(.-))(M+)(3)4(.-)]. The quartet species was attributed to intermolecular high-spin clusters with the relatively small zero-field splitting parameter D and vanishing E value. Further reduction led to the formation of a more persistent species with a quartet ground state characterized by the zero-field parameters D = + 0.0215 cm(-1) and E = 0 cm(-1), assigned to a triradical-trianion [4(3(.-))(M+)(3)], generated by three-electron doping per a single tribenzoylenebenzene molecule. The observed H-1-ENDOR spectra and INDO calculations also confirmed the above identification. 4(3(.-)) is a stable pluri-anionic high-spin molecule in solution.