The Crystal Structure of Copper Yunainate Trihydrate, Cu(C5H8O3NS)2·3H2O

Abstract

Abstract The crystal structure of copper yunainate trihydrate, Cu(C5H8O3NS)2·3H2O, has been studied by means of three-dimensional X-ray analysis. The crystal is monoclinic, with two formula units in a unit cell of the dimensions: a=15.94, b=6.33, c=8.60 Å, and β=95.6°; the space group is P21. The intensities were measured visually from equi-inclination integrating Weissenberg photographs taken with CuKα radiation around the b and c axes. The structure was elucidated by Sim’s method, and refined by the block-diagonal-matrix least-squares method, assuming anisotropic thermal motions for all the atoms. The final R factor is 9.2%. The copper atom is coordinated by imino nitrogen and carboxyl oxygen atoms of two yunainate groups, and a water oxygen atom. The first four atoms lie almost on a plane and make a square configuration of the trans type. The last one is bonded to the copper atom nearly in the direction of the normal of the plane. Thus, the coordination number of copper is five in the present crystal. Of the three sorts of water of crystallization, one is connected with the copper atom, as has already been mentioned, and the remaining two are lattice water, forming a hydrogen-bonded spiral chain around the screw axis. Further, these water molecules connect complex molecules to one another by their hydrogen bonds, forming a threedimensional hydrogen-bonded structure.