The structure of a copper(II) complex with water in Cu-ZSM-5 at 4 K by ENDOR

Electron spin resonance and electron nuclear double resonance were used to characterize the detailed structure of a copper complex with water molecules in Cu-ZSM-5 zeolites at 4 K. This Letter highlights the structure of the complex. It has an axial distorted octahedral symmetry. The distances between the copper ion and protons within the water molecules are 2.54 and 2.69 إ. Accordingly, the water molecules can be divided into two groups. Two water molecules at the longer distance are in the axial position and four other water molecules at the shorter distance are in the equatorial position with respect to the Cu ion.