A novel 1D coordination polymer based on rhombus [Cu4O4] building block: Synthesis, crystal structure and magnetic properties

A novel 1D polymer [Cu3(μ3-OH)2(μ2–H2O)2(H2O)2(Agly)2]·(ClO4)2 was synthesized through the self-assembly of Cu2+ and acetylglycine (Agly) in aqueous solution and characterized by X-ray structure analysis. The compound crystallizes in the monoclinic P2(1)/c space group (a=5.4762(1) Å, b=15.6136(1) Å, c=13.9036(5) Å, β=98.584(1)°, Z=2) and represents the first 1D coordination polymer with tetranuclear rhombus-like [Cu4O4] unit as building block. It should be noted that the rhombus are sharing two vertices and the structure can also be viewed as a zigzag chain based on [Cu3] building blocks. Agly ligand adopts η2-coordinated mode and is used to connect two copper ions. With the help of hydrogen bonds, the 1D chains are further linked into ‘∞’ like channels in which counter-anions ClO4− are located. The magnetic susceptibility measurements (1.8–300 K) agree with a moderately strong antiferromagnetic interaction between the Cu centers with a J value of −40(2) cm−1.