Tetranuclear Cu(I)complex,Cu4(imdt)(NO3)4.6H2O(imdt=1,3-imidazolidine-2-thione),was synthesized by areaction of Cu(NO3)2with imdt in water.It crystallizes in monoclinic crystal system,space group C2/c(No.15),with a =3.1418(3)nm,b =0.94332(6) nm,c =2.3027(2) nm,β=119.773(3)°,V =5.9236(9) nm3,Z =4,Mr=1529.68.mol-1,Dc.=1.715g.cm-3,μ=1.815 mm-1,F(000) =3144,R1=0.028,wR2=0.065.The crystal structure consists of tetranuclear[Cu4(imdt)9]4 +cation,in which Cu(I)is coordinated with four S atoms from four imdt ligands to form a distorted tetrahedral geometryand imdt ligands exhibit three coordination modes of terminal monodentate S-donating andμ2—S andμ4—S bridging coordina-tion.