The first ferromagnetic (2J = 1.60 cm-1) binuclear copper(II) complex, [Cu(LBPh3)]2, which contains the self-assembly O-bridged and B−N bonded ligand LBPh3 (=N-(salicylidene)-N‘-(1-BPh3)-imidazol-2-ylmethylene)-1,3-propanediamine), has been prepared. The X-ray structure of [Cu(LBPh3]2 reveals that in an unusual formation of B−N bonding the boron atom bonds to the nitrogen atom of the imidazolate moiety of the ligand. The copper(II) atoms are bridged by self-assembly of chelated oxygen atoms.