[Cu 2 (L)(O 2 CMe)].(C 3 H 7 NO) (L=1,3-bis(2,hydroxy-3-meythoxybenzlidene)propan-2-ol) was synthesized and its crystal structure determined. (C 2 1 H 2 2 N 2 O 7 Cu 2 ).(C 3 H 7 NO) monoclinic, space group P2 1 /c, a=9.7670(10), b=21.059(2), c=12.5750(10)A, β=92.308(8) o , V=2584.4(4)A 3 , Z=4. The Cu(II) ions are linked by the alkoxide oxygen of the Schiff base ligand on the oxygen atoms of the acetate ion. The Cu...Cu distance and Cu-O-Cu angle are 3.154(2)A and 107.0(2) o , respectively. Temperature-dependent magnetic susceptibility measurements of the complex show an intramolecular antiferromagnetic coupling in the dimeric Cu(II) core. The super-exchange coupling constant (-2J) is 185.4 cm - 1 . Ab initio restricted Hartree-Fock (RHF) and semi-empirical extended Huckel molecular orbital calculations were performed for the explanation of the significant differences in antiferromagnetic interactions between homologous μ-alkoxo and acetate bridged dicopper(II) complexes. Ab initio restricted RHF calculations have shown that the acetate bridge and alkoxide bridge contribute to the magnetic interaction countercomplementary to reduce antiferromagnetic interaction.