n Noorani - Department of Chemistry, Payame Noor University, P.O. Box ۱۹۳۹۵-۳۶۹۷ Tehran, Iran
h Rahemi - Department of Chemistry, Nazhand Institute of High Educations, ۵۷۱۵۹-۱۶۵, Ira n

EPR sp ectroscopy represents one of t he most powerful experimental methods for investigating electro nic and stru ctural features of system s containing unpaired electrons, suc h as radic als, coordination compounds and paramagnetic sites in solids [۱, ۲ ]. Since, t he Copper(II)hydrogen malonate dihydrate c omplex, [Cu(C۳H۲O۴)×۲H۲O]+۲, has the d۹ configur ation, it possesses an unpaired elec tron, and c an interact with an applied magnetic field, making it EPR active. Th erefore, our other principal goal will be studyi ng changes of the EPR g tensor parameters in the ۴.۲–۲۹۵ K temperat ure range [۳ ] using the available solid state bond lengths an d bond angles of the complex.Methods :All calc ulations were carried o ut at the level of den sity functio nal theory (DFT) usin g Gaussian ۰۳ package of program . All structu res were fully optimized with the G aussian ۰۳ W program at the B۳LYP/۶-۳۱۱G, ۶-۳۱G**, BWP۹۱/۶-۳ ۱G**levels. The optimized structural paramete rs are saved for the ne xt step of calculations. After the optimization, g values were calculated using the NMR/GIAO method [۴,۵].

Copper( II)hydrogen malonate dihydrate com plex, DFT, EPR, NMR/GIAO