The magnetic coupling interactions of the nitronyl nitroxide radicals bound to diamagnetic(YⅢ) and paramagnetic(GdⅢ) rare earth ions in two model magnetic systems based on novel rare earth organic radical complexes ...The magnetic coupling interactions of the nitronyl nitroxide radicals bound to diamagnetic(YⅢ) and paramagnetic(GdⅢ) rare earth ions in two model magnetic systems based on novel rare earth organic radical complexes Ln(hfac)3(NITPhOCH3)2(Ln=YⅢ 1,GdⅢ 2;hafc = hexafluoroacetylacetonate;NIT-PhOCH3 = 4'-methoxyo-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) have been investigated by density functional theory(DFT).The magnetic coupling mechanisms were also explored from the viewpoint of molecular orbital and spin density populations.DFT calculations show that the empty 4d-orbitals of YⅢ and 5d-orbitals of GdⅢ play an important role in the antiferromagnetic coupling between the two nitronyl nitroxide radical ligands,and that the ferromagnetic coupling between the GdⅢ ion and the radical magnetic centers can be attributed to the nearly complete localization of the isotropic 4f-shell and singly occupied magnetic orbital(π) of the nitronyl nitroxide.展开更多
A new coordination polymer, [（C（18）H（16）N4O（18）Y2）（H2O）]n, has been hydrothermally synthesized by reacting yttrium（Ⅲ） nitrate with 5-aminonicotinic acid and ammonium oxalate at a molar ratio of 1：1：1, a...A new coordination polymer, [（C（18）H（16）N4O（18）Y2）（H2O）]n, has been hydrothermally synthesized by reacting yttrium（Ⅲ） nitrate with 5-aminonicotinic acid and ammonium oxalate at a molar ratio of 1：1：1, and its structure was determined by X-ray crystallography with the following data： monoclinic system, space group C2/c, a = 13.4507（10）, b = 11.5829（9）, c = 16.3448（9） ？, a= 89.983（6）, β = 109.056（6）, g = 90.047（6）°, Z = 4, V = 2406.92（14） ？~3, F（000） = 1536, Dc = 2.13079 g/cm^3, R = 0.0284（1695） and w R = 0.0787（2014）. In the asymmetric unit of the compound, each Y（Ⅲ） ion is bonded to eight oxygen atoms from 5-aminonicotinic acid and oxalate groups and terminal-coordinated water molecule, resembling a highly distorted tricapped trigonal geometry. Adjacent three yttrium atoms are bridged by three identically independent oxalate groups in a side-by-side manner to form brickwall-like 2D sheets, and these sheets are further linked through π-π stacking interactions to generate a 3D supramolecular network. The photoluminescent property of the complex was investigated and the iodine capture studies show that the porous frameworks have reversible absorption ability for iodine molecule.展开更多
Yttrium(Ⅲ)oxide or so-called diyttrium trioxide(Y_2O_3)is an excellent candidate ceramic material for optoelectronic applications.Structural,electrical conductivity,and dielectric relaxation properties of bulk yttri...Yttrium(Ⅲ)oxide or so-called diyttrium trioxide(Y_2O_3)is an excellent candidate ceramic material for optoelectronic applications.Structural,electrical conductivity,and dielectric relaxation properties of bulk yttrium(Ⅲ)oxide were studied.X-ray diffraction(XRD)results indicate that the yttrium(Ⅲ)oxide compound has a crystalline cubic phase.Fourier transform infrared(FTIR)technique was used to ascertain the chemical structure of the yttrium(Ⅲ)oxide compound.Impedance spectroscopy was used to analyze frequency-dependent electrical properties as a function of temperature in the range of 303-423 K and frequency range of 0.1 Hz-2 MHz.Impedance spectroscopy parameters such as dielectric constant,dielectric loss,loss factor,electric modulus,and complex impedance of the yttrium(Ⅲ)oxide compound were studied.The Nyquist plot describes the complex impedance of the yttrium(Ⅲ)oxide for different temperatures.The universal Jonscher's power law was used for the analysis of the complex electrical conductivity of the yttrium(Ⅲ)oxide compound.It is found that the real(σ')and imaginary(σ")parts of the complex conductivity increase with increasing frequency.The exponent frequency(s)equals unity,which confirms that the predominant conduction mechanism is a nearly constant loss(NCL)mechanism.DFT/TD-DFT studies using B3LYP/LanL2DZ level of theory were used to provide comparable theoretical data and electronic energy gap of HOMO→LUMO.展开更多
A new binuclear cage-like yttrium(Ⅲ) complex Y2(TMBA)6(phen)2(1) with yttrium nitrate, 2,4,6-trimethylbenzoic acid(TMBA) and 1,10-phenanthroline(phen) was synthesized. It crystallizes in the triclinic space group P1 ...A new binuclear cage-like yttrium(Ⅲ) complex Y2(TMBA)6(phen)2(1) with yttrium nitrate, 2,4,6-trimethylbenzoic acid(TMBA) and 1,10-phenanthroline(phen) was synthesized. It crystallizes in the triclinic space group P1 with a = 11.9086(15), b = 12.4843(17), c = 14.2101(18) ?, α = 104.977(4), β = 111.750(4), γ = 95.874(5)o, V = 1848.8(4) ?3, Dc = 1.363 g/cm3, Z = 1, μ(Mo Ka) = 1.627, F(000) = 788, the final GOOF = 1.039, R = 0.0353 and w R = 0.0826. The whole molecule consists of two yttrium ions bridged by four 2,4,6-trimethylbenzoic acid anions. The Y(Ⅲ) ion is coordinated by eight atoms to give a distorted square antiprism coordination geometry. The TG analysis and fluorescent properties of 1 were studied.展开更多
基金Supported by the 973 Project (Grant No. 2006CB601102)the National Natural Science Foundation of China (Grant No. 20973052)
文摘The magnetic coupling interactions of the nitronyl nitroxide radicals bound to diamagnetic(YⅢ) and paramagnetic(GdⅢ) rare earth ions in two model magnetic systems based on novel rare earth organic radical complexes Ln(hfac)3(NITPhOCH3)2(Ln=YⅢ 1,GdⅢ 2;hafc = hexafluoroacetylacetonate;NIT-PhOCH3 = 4'-methoxyo-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) have been investigated by density functional theory(DFT).The magnetic coupling mechanisms were also explored from the viewpoint of molecular orbital and spin density populations.DFT calculations show that the empty 4d-orbitals of YⅢ and 5d-orbitals of GdⅢ play an important role in the antiferromagnetic coupling between the two nitronyl nitroxide radical ligands,and that the ferromagnetic coupling between the GdⅢ ion and the radical magnetic centers can be attributed to the nearly complete localization of the isotropic 4f-shell and singly occupied magnetic orbital(π) of the nitronyl nitroxide.
基金supported by the Project of Guangdong Province Quality Engineering "Comprehensive Reform Pilot of Applied Chemistry Specialty"Guangdong Higher Education Letter(No.[2014]97)+1 种基金the Project of Scientific and Technological Innovation Special Fund of Guangdong University Students(No.pdjh2017b0372)the Training Programs of Innovation for Undergraduates of 2017(No.201714278030)
文摘A new coordination polymer, [（C（18）H（16）N4O（18）Y2）（H2O）]n, has been hydrothermally synthesized by reacting yttrium（Ⅲ） nitrate with 5-aminonicotinic acid and ammonium oxalate at a molar ratio of 1：1：1, and its structure was determined by X-ray crystallography with the following data： monoclinic system, space group C2/c, a = 13.4507（10）, b = 11.5829（9）, c = 16.3448（9） ？, a= 89.983（6）, β = 109.056（6）, g = 90.047（6）°, Z = 4, V = 2406.92（14） ？~3, F（000） = 1536, Dc = 2.13079 g/cm^3, R = 0.0284（1695） and w R = 0.0787（2014）. In the asymmetric unit of the compound, each Y（Ⅲ） ion is bonded to eight oxygen atoms from 5-aminonicotinic acid and oxalate groups and terminal-coordinated water molecule, resembling a highly distorted tricapped trigonal geometry. Adjacent three yttrium atoms are bridged by three identically independent oxalate groups in a side-by-side manner to form brickwall-like 2D sheets, and these sheets are further linked through π-π stacking interactions to generate a 3D supramolecular network. The photoluminescent property of the complex was investigated and the iodine capture studies show that the porous frameworks have reversible absorption ability for iodine molecule.
基金supported by Taif University Researchers,Taif University,Taif,Saudi Arabia(grant numbers TURSP-2020/22)。
文摘Yttrium(Ⅲ)oxide or so-called diyttrium trioxide(Y_2O_3)is an excellent candidate ceramic material for optoelectronic applications.Structural,electrical conductivity,and dielectric relaxation properties of bulk yttrium(Ⅲ)oxide were studied.X-ray diffraction(XRD)results indicate that the yttrium(Ⅲ)oxide compound has a crystalline cubic phase.Fourier transform infrared(FTIR)technique was used to ascertain the chemical structure of the yttrium(Ⅲ)oxide compound.Impedance spectroscopy was used to analyze frequency-dependent electrical properties as a function of temperature in the range of 303-423 K and frequency range of 0.1 Hz-2 MHz.Impedance spectroscopy parameters such as dielectric constant,dielectric loss,loss factor,electric modulus,and complex impedance of the yttrium(Ⅲ)oxide compound were studied.The Nyquist plot describes the complex impedance of the yttrium(Ⅲ)oxide for different temperatures.The universal Jonscher's power law was used for the analysis of the complex electrical conductivity of the yttrium(Ⅲ)oxide compound.It is found that the real(σ')and imaginary(σ")parts of the complex conductivity increase with increasing frequency.The exponent frequency(s)equals unity,which confirms that the predominant conduction mechanism is a nearly constant loss(NCL)mechanism.DFT/TD-DFT studies using B3LYP/LanL2DZ level of theory were used to provide comparable theoretical data and electronic energy gap of HOMO→LUMO.
基金Supported by Natural Science Foundation of Hunan Province (2019JJ60021)Industry and Research Key Project of Hengyang City (2019jhzx1093,2018kKJ016)。
文摘A new binuclear cage-like yttrium(Ⅲ) complex Y2(TMBA)6(phen)2(1) with yttrium nitrate, 2,4,6-trimethylbenzoic acid(TMBA) and 1,10-phenanthroline(phen) was synthesized. It crystallizes in the triclinic space group P1 with a = 11.9086(15), b = 12.4843(17), c = 14.2101(18) ?, α = 104.977(4), β = 111.750(4), γ = 95.874(5)o, V = 1848.8(4) ?3, Dc = 1.363 g/cm3, Z = 1, μ(Mo Ka) = 1.627, F(000) = 788, the final GOOF = 1.039, R = 0.0353 and w R = 0.0826. The whole molecule consists of two yttrium ions bridged by four 2,4,6-trimethylbenzoic acid anions. The Y(Ⅲ) ion is coordinated by eight atoms to give a distorted square antiprism coordination geometry. The TG analysis and fluorescent properties of 1 were studied.
