The novel (E,E)-dioxime,7,8-bis(hydroxyimino)-1,14-bis(monoazacrown-6)-benzo[f]-4,11-dioxa-1,14-diazadecane[7,8-g]quinoxaline (H2L), has been synthesized by the reaction of 6,7-diamino-1,12-bis(monoazacrown-6)benzo[f]-4,9-dioxa-1,12-diazadecane (4) which has been prepared by the reduction of 6,7-dinitro-1,12-bis(mono-azacrown-6)benzo[f]-4,9-dioxa-1,12-diazdecane (3) and cyanogendi-N-oxide. Mononuclear Ni-II and Cu-II complexes of H2L have a metal:ligand ratio of 1:2 and the ligand coordinates through two hydroxyimino nitrogen atoms, as do most of the (E,E)-dioximes. The hydrogen-bridged Ni-II was converted into its BF2+ capped anologue by the reaction with BF3 center dot Et2O. The reaction of the Cu-II complex with 2,2'-dipyridyl as an end-cap ligand gave the homotrinuclear complex. Structures for the ligand and its complexes are proposed in accordance with elemental analysis, magnetic susceptibility measurements, H-1, C-13-n.m.r, IR and MS spectral data.