The DFT Calculations of Structures and EPR Parameters for the Dinuclear Paddle-Wheel Copper(II) Complex {Cu 2 (μ 2 -O 2 CCH 3 ) 4 }(OCNH 2 CH 3 ) as Powder or Single Crystal

• Published in: Zeitschrift für Naturforschung A
• Main Authors: Ding, Chang-Chun, Wu, Shao-Yi, Xu, Yong-Qiang, Zhang, Li-Juan, Zhang, Zhi-Hong, Zhu, Qin-Sheng, Wu, Ming-He, Teng, Bao-Hua
• Format: Article in Journal/Newspaper
• Language: English
• Published: Walter de Gruyter GmbH 2017
• Subjects: Physical and Theoretical Chemistry; General Physics and Astronomy; Mathematical Physics; Orca
• Online Access: http://dx.doi.org/10.1515/zna-2017-0236; https://www.degruyter.com/view/journals/zna/72/11/article-p985.xml; https://www.degruyter.com/document/doi/10.1515/zna-2017-0236/xml; https://www.degruyter.com/document/doi/10.1515/zna-2017-0236/pdf

Abstract Density functional theory (DFT) calculations of the structures and the Cu 2+ g factors ( g x , g y and g z ) and hyperfine coupling tensor A ( A x , A y and A z ) were performed for the paddle-wheel (PW)-type binuclear copper(II) complex {Cu 2 (μ 2 -O 2 CCH 3 ) 4 }(OCNH 2 CH 3 ) powder and single crystal. Calculations were carried out with the ORCA software using the functionals BHandHlyp, B3P86 and B3LYP with five different basis sets: 6-311g, 6-311g(d,p), VTZ, def-2 and def2-TZVP. Results were tested by the MPAD analysis to find the most suitable functional and basis sets. The electronic structure and covalency between copper and oxygen were investigated by the electron localisation function and the localised orbital locator as well as the Mayer bond order for the [CuO 5 ] group. The optical spectra were theoretically calculated by the time-dependent DFT module and plotted by the Multiwfn program for the [CuO 5 ] group and reasonably associated with the local structure in the vicinity of the central ion copper. In addition, the interactions between the OCNH 2 CH 3 , NH 3 and H 2 O molecules and the uncoordinated PW copper(II) complex were studied, and the corresponding adsorption energies, the frequency shifts with respect to the free molecules and the changes of the Cu–Cu distances were calculated and compared with the relevant systems.