A New Mn(Ⅱ) Coordination Polymer:Synthesis, Structure and Magnetic Property

摘要

cqvip:A new 2D compound,{[Mn6 L3(H2O)8]·0.69(C3 H7 NO)·3.31H2O}n(1,H4 L=1,1’-(1,4-phenylenebis(methylene))bis-(1H-pyrazole-3,5-dicarboxylic acid)),was synthesized and characterized by IR,TGA and X-ray single-crystal/powder diffraction.Compound 1 crystallizes in monoclinic system,space group C2/c with a=26.468(5),b=19.750(4),c=13.660(3)A,β=92.73(3)°,V=7132(2)A^3,Z=4,Mr=1824.12,Dc=1.699 g/cm3,F(000)=3705,R=0.042 and w R=0.117 for 8965 observed reflections(I>2σ(I)).In compound 1,all of the Mn(II)atoms are six-coordinated and take the octahedral geometry of[MnNO5].The 2D compound consists of secondary building unit[Mn3(μ2-O)(R-COO)3](SBU),in which two of the Mn^2+ions exhibit the same coordinated environments while another Mn^2+ion has a different one.The SBUs further connect with each other to form a 1 D inorganic chain which is connected with L^4-ligands to construct a 2D layer.Finally,strong O–H···O hydrogen bonds among the rich carboxyl molecules and O atoms from free DMF and guest water molecules connect the two-dimensional coordination network into a three-dimensional framework.Variable temperature magnetic measurements indicate the antiferromagnetic behavior in the Mn3 core in compound 1.