A copper(II) complex Cu(3,5-DMBA)2(phen) has been synthesized by self-assembly of 3,5-dimethylbenzoic acid, 1,10-phenanthroline and copper Perchlorate. Crystal data for this complex: Monoclinic, space group C2/c with a=2.3483(5) nm, b=0.9844(2) nm, c=1.1384(2) nm,β=103.02(3)°, V=2.5639(9) nm3 Dc=1.404 g·cm-3, Z=4, F(000)=1 124, final GooF=1.051, R1=0.035 0, wR2=0.099 8. The crystal structure shows that the copper atom is coordinated with two oxygen atoms from two 3,5-dimethylbenzoic acids and two nitrogen atoms from the 1,10-phenanthroline, ...