Copper(II) Complexes of Spirohydantoins. Synthesis, Quantum-Chemical, and Spectroscopic Study

A series of new Cu(II) complexes with important physiologically active cycloalkane-5-spirohydantoines are synthesized reacting as a result of CuCl2 · 2H2O interaction with the ligands in alkaline water medium. Their structures were studied using spectroscopic (IR and EPR) methods. For comparison, ab initio calculations of the structure and IR spectra of the corresponding Cu(II) complexes were also performed. It was proven that with cyclopentane-5-spirohydantoins, distorted (flattened) tetrahedral structure is realized Cu(L−H)2(H2O)2, while with the higher cycloalkane-5-spirohydantoins linear Cu(II) complexes of the type CuL−H(OH) are formed.