Synthesis and Crystal Structure of Solvated Complexes of Copper(II) with Serine and Phenanthroline and Their Solid-State-to-Solid-State Transformation into One Stable Solvate

Reactions of copper­(II) sulfate with 1,10-phenanthroline, l-serine, and a base were investigated under different solution-based and mechanochemical synthetic procedures. Six complexes with serine were obtained: [Cu­(l-ser)­(H2O)­(phen)]2SO4­·xH2O (x = 4, 6, or 10; 1·4H 2 O, 1·6H 2 O, and 1·10H 2 O), [Cu­(l-ser)­(H2O)­(phen)]­[Cu­(l-ser)­(CH3OH)­(phen)]­SO4·3H2O­·CH3OH (1·2·3H 2 O­·CH 3 OH), [Cu­(l-ser)­(CH3OH)­(phen)]2SO4­·xCH3OH (x = 2 or 2.5; 2·2CH 3 OH and 2·2.5CH 3 OH), and two without serine: [Cu­(SO4)­(phen)2]­·xH2O (x = 4.5 or 6.75; 3·4.5H 2 O and 3·6.75H 2 O) (phen = 1,10-phenanthroline, l-ser = l-serinato). The X-ray crystal structure analysis of serine-containing complexes revealed extensive hydrogen bonding and π-interactions that link complex cations, sulfate anions, and solvent molecules into three-dimensional architectures. Most of the water/methanol solvent molecules in these porous compounds are found in channels, some in pockets connected to channels, and can be exchanged in vapors of the other solvent. Along with the solvent exchange, the solvent molecule apically coordinated to copper­(II) is also exchanged in some transformations. By neat grinding, all serine-containing complexes transform into 1·6H 2 O. Quantum chemical calculations were done for compounds 1·4H 2 O and 1·6H 2 O in the gas phase and an aqueous (or methanol) surrounding. 1·6H 2 O and 3·4.5H 2 O showed pronounced antiproliferative activity toward human breast and lung tumor cell lines.