Two unprecedented 1D coordination polymer chains based on tetranuclear copper(II) building blocks

The reaction of copper(II) sulfate with pyridine in DMF or methanol yield two unprecedented Cu(II) coordination polymers {[Cu4(μ4-O)(py)4(SO4)4][μ-Cu(py)(DMF)2]}n(1) and {[Cu4(μ4-O)(py)4(SO4)4][μ-Cu(py)4]}n(2), respectively. Single-crystal X-ray diffraction indicated that compound 1 crystallizes in the monoclinic system, space group p2(1)/n, a=14.542(5) A, b=16.359(5) A, c=18.951(5) A, β=92.047(5)o, V=4505(2) A3, Z=4 while 2 is monoclinic C2/c, a=23.078(5) A, b=10.214(5) A, c=23.142(5) A, β=115.471(5)o, V=4925(3) A3, Z=4. Both of the two compounds consist of tetrahedral tetranuclear [Cu4(μ4-O)(py)4(SO4)4] clusters that are bridged by pentacoordinated Cu atom for 1 or hexacoordinated Cu atoms for 2 through the sulfate oxygen to form the infinite one-dimensional polymer chains. - Graphical abstract: Two unprecedented Cu(II) coordination polymers have been prepared by using solvothermal method; they consist of tetrahedral tetranuclear clusters that are bridged by unique Cu(II) atom through the sulfate oxygen to form the infinite one-dimensional polymer chains (a) for complex 1 and (b) for complex 2