Crystal and molecular structure stabilized by weak interaction in unique 3,5-diiodo-L-tyrosinato copper(II) complex – synthesis, experimental and theoretical studies

• Published in: Materials science & engineering. B, Solid-state materials for advanced technology Vol. 262; p. 114723
• Main Authors: Wojciechowska, Agnieszka, Rojek, Tomasz, Malik−Gajewska, Magdalena, Jerzykiewicz, Maria, Wysokiński, Rafał, Gągor, Anna, Rytlewski, Piotr, Staszak, Zbigniew, Duczmal, Marek
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01-12-2020; Elsevier BV
• Subjects: Amino acids; Coordination compounds; Copper; Copper compounds; Copper(II); Crystal structure; DFT calculation; Diamines; Diiodo−L−tyrosine; Magnetic; Magnetic methods; Molecular structure; Spectroscopies (FT-IR, Raman, Q-band EPR, NIR-Vis-UV); Stacking; System effectiveness; Tensors; Thermal stability; Weak interaction; DFT calculation; Diiodo−L−tyrosine; Magnetic; Weak interaction; Spectroscopies (FT-IR, Raman, Q-band EPR, NIR-Vis-UV); Thermal stability; Copper(II)
• ISSN: 0921-5107; 1873-4944
• DOI: 10.1016/j.mseb.2020.114723

[Display omitted]
•A novel, hybrid 3,5-diiodo-L-tyrosinato copper(II) complex was synthesized.•The structure is stabilized by π···π, metal···π, π···I non-covalent interactions.•The structural, spectroscopic, thermal and magnetic properties were investigated.•The exchange pathway occurs in the zig - zag chain.
The ternary Cu(II)/amino-acid/diamine systems have large positive logK values than binary Cu/amino systems, suggesting stabilization due to the effective stacking interaction between aromatic diamine and the aromatic side group of the amino acid. Thus, a hybrid 3,5-diiodo-L−tyrosinato copper(II) complex with an aromatic diamine, of formula [Cu(L−I2TyrO-)(H2O)(phen)]∙2H2O (1) was characterized in depth by using X-ray, TG/DTG, DSC, FT-IR, Raman, Q-band EPR, NIR-Vis-UV, magnetic methods and the theoretical calculations. The crystal structure is stabilized by weak π···π stacking, metal···π and intra- and intermolecular π···I non-covalent interactions. The computed interaction energies of Cg(1)∙∙∙Cg(2), Cg(3)∙∙∙I and Cg(1)∙∙∙Cu ranging from 0.69 kcal/mol− -2.20 kcal/mol. The weak interactions shift the bands assigned as ν(C-I) to higher frequency in the FT-IR spectrum. The g tensor is axial with g|| (2.239) > g⊥ (2.057) indicating that the unpaired electron residues in the dx2–y2 orbital. The exchange pathway occurs in the zig-zag chain with d(Cu···Cu) = 9.429 Å.