1. Cis and trans linkage of spin frustrated copper triangles creating Cu6 clusters
- Author
-
Xiao-Lei Li, Basharat Ali, Jinkui Tang, Frédéric Gendron, Boris Le Guennic, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences [Changchun Branch] (CAS), University of Science and Technology of China [Hefei] (USTC), Institut des Sciences Chimiques de Rennes (ISCR), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Physics ,cis and trans ,010405 organic chemistry ,chemistry.chemical_element ,Linkage (mechanical) ,010402 general chemistry ,01 natural sciences ,Copper ,0104 chemical sciences ,law.invention ,Crystallography ,chemistry ,law ,Copper triangles ,[CHIM.COOR]Chemical Sciences/Coordination chemistry ,Spin frustration ,Cis–trans isomerism ,Spin-½ ,Cu 6 cluster - Abstract
International audience; Two C 3-symmetric guanidine-based copper triangles bridged by acetates in a cis manner and by chloride anions in a trans manner, respectively gave rise to two antiferromagnetically coupled hexanuclear Cu II compounds, namely [Cu 6 L 2 Cl(µ-OAc)(DMF) 3 ]·DMF (Cu 6) and [Cu 6 L 2 (µ-Cl) 2 (DMF) 4 ] (Cu 6 Cl) (where L stands for fully deprotonated tris (2-hydroxybenzylidene) triaminoguanidinium chloride, H 5 L). The experimental magnetic data of the two compounds were analyzed theoretically. A relatively good agreement with the experimental data was obtained when using the wavefunction theory (CASSCF) in combination with DFT (B3LYP) calculations for the very strong antiferromagnetic coupling within the Cu 3 triangles (J avg = − 300 cm −1 for Cu 6 and J avg = − 250 cm −1 for Cu 6 Cl), leading to spin-frustrated systems. It is worth mentioning that the electronic structure of each Cu II center remains very similar in each complex with a Kramers ground state well separated from the first excited state (over 12000 cm −1) and weakly anisotropic (g∥ ≈ 2.40 and g⊥ ≈ 2.10).
- Published
- 2020