- 作者: 陳志達
- 作者服務機構: Department of Chemistry, State Key Laboratory of Rare Earth Materials Chemistry and Applications, Peking University, Beijing, 100871, P.R. China
- 中文摘要: The magnetic exchange interaction and electronic structures for the nitronyl nitroxide free radical (1), (4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazolyl-1-oxyl 3-oxide), nitronyl nitroxide biradical, [BNITPhOPr] (2), (1,3-[di-2-(4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazolyl-1-oxyl 3-oxide)phenoxy]propane) and CuII-nitronyl nitroxide radical complex, [Cu(Cl2CHCO2)2(NITpPy)2(H2O)] (3), (NITpPy=2-(4-pyridyl)-4,4,5,5-tetramethyl-2-imidazoline-1-oxy 3-oxide) were studied by the broken symmetry (BS) approach within the density functional theory (DFT), combined with the spin-Hamiltonian full-matrix diagonalization method. The theoretically calculated magnetic coupling constant J values (-0.10 (2), -12.9 (3)) are approximately consistent with experimental results (-0.24 (2) and -11.5 (3)). For the complex 3, the magnetic coupling constant j (-0.85) between two terminal radical ligands is also obtained, which has not been characterized experimentally. In contrast to radical 1, the nitronyl nitroxide radicals in the biradical 2 and complex 3 behave as a more localized spin-center. However, CuII ion of the complex 3 exhibits a local-spin delocalization to the surrounding atoms. Spin population analyses suggest that the intramolecular antiferromagnetic coupling for the biradical 2 is governed by the weak spin polarization through the bridging ligand and that the antiferromagnetic coupling interaction between the CuII ion and nitronyl nitroxide radicals in the complex 3 is dominated by both the local-spin delocalization on the CuII ion and the global spin polarization mechanism.
- 英文摘要: --
- 中文關鍵字: Density functional theory; Nitronyl nitroxide; Copper(II) complex; Magnetic coupling.
- 英文關鍵字: --