Multifunctional properties of {CuLn} systems involving nitrogen-rich nitronyl nitroxide: single-molecule magnet
Hongdao Li1, Pei Jing2, Jiao Lu2
1Department of Chemistry and Chemical Engineering, Taiyuan Institute of Technology, Taiyuan 030008, China. lihong.dao@163.com and Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry and Tianjin Key Laboratory of Metal and Molecule-based Material Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China. songzj@mail.nankai.edu.cn.
Abstract:
A series of nitrogen-rich nitronyl nitroxide radical PPNIT (1)-based (PPNIT = 2-(1-(pyrazin-2-yl)-1H-pyrazole)-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide) 3d-4f ring-shaped tetranuclear clusters [Ln2Cu2(hfac)10(PPNIT)2(H2O)2]·CHCl3 (LnIII = Gd 2, Tb 3, Dy 4; hfac = hexafiuoroacetylacetonate) with multifunctional properties were isolated. The magnetic behavior, luminescence and heat capacity of the 3d-4f complexes were investigated, displaying interesting multiple properties of the molecular materials. The Gd derivative shows a magnetocaloric effect with the maximum entropy change (-ΔSm) of 15.3 J kg-1 K-1 at 2 K for ΔH = 70 kOe. The Tb cluster exhibits spin glass behavior and the characteristic fluorescence emission of the TbIII ion, while the Dy cluster exhibits SMM behaviour, and the heat capacity has been investigated. Notably, in nitronyl nitroxide radical-metal systems, the investigation of diverse properties is still scarce so far. This work can pave the way towards the synthesis of multifunctional materials that combine SMM behavior, and optical or/and thermodynamic properties.
Related Concept Videos
01:25Applications Of NMR In Biology
03:02Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
01:07Nuclear Magnetic Resonance (NMR): Overview
NMR spectroscopy generates a spectrum where the characteristic absorption frequencies of the sample are...
02:42Valence Bond Theory
01:15Insensitive Nuclei Enhanced by Polarization Transfer (INEPT)
01:16Other Nuclides: 31P, 19F, 15N NMR
While fluorine-19 and phosphorous-31 have high natural abundances (100%) and positive gyromagnetic ratios, nitrogen-15 has a low natural abundance and a negative gyromagnetic ratio. However, nitrogen-15 is still preferred over nitrogen-14 (which has a...