含羟基基团取代的氮氧自由基构筑的三个双核稀土化合物的结构及磁性表征（英文）

以三氟乙酰丙酮(tfac)为共配体的稀土配合物分别与5-溴-2-羟基苯取代的自由基配体和5-硝基-2-羟基苯取代的自由基配体进行反应,合成3个稀土-自由基配合物[Ln_2(tfac)_4(NIT-5Br-2PhO)_2](Ln=Gd (1),Dy (2))和[Dy_2(tfac)_4(NIT-5NO_2-2PhO)_2](3)(NIT-5Br-2PhOH=2-(2′-hydroxy-5′-bromophenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide,NIT-5NO_2-2PhOH=2-(2′-hydroxy-5′-nitrophenyl)-4,4,5,5-tetra-methylimidazoline-1-oxyl-3-oxide)。单晶结构分析表明这3个化合物中的稀土离子均通过自由基配体上的羟基氧基团连接为双核的结构。配合物1的直流磁化率表征揭示了Gd(Ⅲ)离子间的反铁磁耦合对其磁行为起主要作用。     

两个双核稀土-自由基化合物的合成、结构及磁性

以乙酰丙酮为共配体的稀土配合物与2-羟基苯取代的自由基配体进行反应得到2个新颖的稀土-自由基配合物[Ln₂（acac）₄（NIT-PhO）₂]（Ln=Tb（1）,Y（2）;acac=乙酰丙酮,NIT-PhOH=2-（2''-hydroxyphenyl）-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide）。2个配合物的结构相同,均是通过2个自由基配体上的羟基氧原子桥联2个稀土离子构成双核结构。直流磁化率的研究表明配合物2具有弱的反铁磁性质。     

氮氧自由基-稀土配合物

氮氧自由基-稀土配合物具有特殊的光学和磁学性质,是分子磁性材料及其它多功能材料设计中的关注热点,具有广阔的应用前景.本文总结了该类配合物的结构特点,综述了已有的氮氧自由基-稀土配合物的磁学性质和光学性质,概括了影响这些配合物性质的一些因素.     

稀土双核配合物的合成与磁性

稀土离子存在于许多磁性材料中,但至今稀土双核配合物的合成及磁性研究很少,建立磁性-结构间的关系对新型分子磁性材料的设计有重要意义。稀土双核配合物的磁性研究也为研究f轨道参与磁相互作用提供第一手材料。我们曾合成了一系列以氯冉酸二价阴离子为桥联配体的过渡金属双核配合物,本文合     

三个镧系金属氮氧自由基配合物的合成、结构及磁性

以氮氧自由基为配体,合成了3例氮氧自由基-稀土三自旋单核配合物[Ln（hfac）₃（NIT-Ph-4-Br）₂]（Ln=Gd（1）,Tb（2）,Dy（3）,hfac=六氟乙酰丙酮,NIT-Ph-4-Br=4,4,5,5-四甲基-2-（4''-溴）-咪唑啉-3-氧化-1-氧基自由基。单晶结构分析表明3个配合物均属单斜晶系P2₁/c空间群,配合物中的Ln（Ⅲ）离子为八配位模式,并且拥有相似的自由基-稀土-自由基单核结构。对配合物的磁性测试结果表明,配合物1中自由基与Gd（Ⅲ）离子之间存在着铁磁相互作用,自由基与自由基之间存在着反铁磁相互作用;配合物2,3中,稀土离子与自由基之间存在弱的反铁磁相互作用。     

三个镧系金属氮氧自由基配合物的合成、结构及磁性

以氮氧自由基为配体,合成了3例氮氧自由基-稀土三自旋单核配合物[Ln（hfac）₃（NIT-Ph-4-Br）₂]（Ln=Gd（1）,Tb（2）,Dy（3）,hfac=六氟乙酰丙酮,NIT-Ph-4-Br=4,4,5,5-四甲基-2-（4''-溴）-咪唑啉-3-氧化-1-氧基自由基。单晶结构分析表明3个配合物均属单斜晶系P2₁/c空间群,配合物中的Ln(Ⅲ)离子为八配位模式,并且拥有相似的自由基-稀土-自由基单核结构。对配合物的磁性测试结果表明,配合物1中自由基与Gd(Ⅲ)离子之间存在着铁磁相互作用,自由基与自由基之间存在着反铁磁相互作用;配合物2,3中,稀土离子与自由基之间存在弱的反铁磁相互作用     

金属-氮氧自由基层状配合物磁性体系

介绍了金属与氮氧自由基所形成的层状体系的结构特点、磁耦合特征及其发展前景。     

基于氮氧自由基的新型稀土配合物的合成、结构及光谱性质

合成了一种新型的氮氧自由基-稀土配合物[Dy（hfac）3（H2O）2]·（NITMePy）(1, CCDC:846691, hfac=六氟乙酰丙酮,NITMePy=2-（2-吡啶基-3-甲基）-4,4,5,5-四甲基氧化咪唑啉-3氧化-1-氧基自由基),其结构和光谱性质经元素分析、红外光谱和紫外光谱表征。结果表明：配...     

一维氮氧自由基-银配合物的合成及结构表征

用二氰化银盐(Ag(CN)2-)和氮氧自由基反应合成了一种新的一维配合物[Ag(im2-py)(CN)]n(im2-py=2-(2′-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl)。利用X-射线单晶衍射、元素分析、红外和紫外光谱进行了表征。晶体结构分析表明,配合物晶体属正交晶系,空间群P212121,晶胞参数:a=9.6074(6),b=9.8668(8),c=14.8589(14),V=1408.5(2)3,Z=4,R1=0.0594,wR2=0.121。配合物晶体结构中,每个Ag(Ⅰ)采用四配位的变形四面体构型,每个氰根阴离子通过单齿配位模式连接两个Ag(Ⅰ)离子形成一维链状结构,一维链状结构通过分子间的C-H…O和C-H…N氢键作用扩展为二维网状结构。     

一价金的氮氧自由基配合物的合成、结构及其磁性

本文合成了一个含一价金的氮氧自由基配合物(PPh₃)Au(p-NN) (1)[p-NN=2-(对-乙炔基苯基)-4，4，5，5-四甲基-2-咪唑啉基氧自由基]，并用X射线衍射单晶结构分析测定了它的结构。由于三苯基膦具有较大的位阻效应，因此配合物中不存在明显的分子内或分子间Au…Au相互作用。磁化率研究表明，相邻分子间的O…O相互作用使之形成二聚体，因而导致了分子之间的反铁磁相互作用。     

Synthesis, Crystal Structure and Magnetic Properties of a Co(Ⅱ) Complex Containing 2'-(1'- Methyl)benzimidazolyl-substituted Nitronyl Nitroxide

A new complex [Co(NIT-1'-MeBzIm)<,2>Cl<,2>] (NIT-1'-MeBzIm = 2-{2'-[(1'-methyl)- benzimidazolyl] }-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) has been prepared and structurally characterized by X-ray diffraction method.The complex crystallizes in the monoclinic system, space group C2/c, Z = 4.Crystal data: C<,30>H<38>Cl<,2>CoN<,8>O<,4>, M<,r> = 704.51, a = 17.074(3), b = 21.350(3), c = 11.6962(19) (A), β= 108.879(2)°, V= 4034.3(11) (A)<'3>, D<,c> = 1.160 g/cm<'3>,μ(MoKα) = 0.597 mm<'-1>, F(000) = 1468, R = 0.0422 and wR = 0.1141 for 2577 observed reflections with I > 2σ(I).X-ray analysis reveals that the Co(Ⅱ) ion is six-coordinated with a distorted octahedral geometry.Temperature dependenee of susceptibility measurements shows the existence of antiferromagnetic interactions between the Co(Ⅱ) ion and the radicals (J= -52.88 cm<'-1>).     

两个氮氧双自由基桥连的稀土一维链的晶体结构、磁性和荧光性能

选用1,2-二苯氧基乙烷取代的氮氧双自由基(BNPhOEt)与稀土金属反应,得到了2例氮氧双自由基-稀土配合物[Ln(hfac)3(BNPhOEt)]·C6H14(Ln=Tb(1)、Ho(2);hfac=六氟乙酰丙酮),其均为2p-4f一维链状结构.磁性研究表明,在配合物1和2中分别存在铁磁和反铁磁耦合.此外,对2个配...     

邻位噻吩基取代咪唑类氮氧自由基的合成

合成了未见报道的邻位噻吩基取代咪唑类氮氧自由基———NITS[2-(2′-噻吩基)-4,4,5,5-四甲基咪唑啉-3-氧化-1-氧基自由基]。NITS的晶体属单斜晶系,C2/c空间群,a=23.78(3),b=8.435(10),c=12.297(14),β=103.680(19)°,Z=8。NITS的电学性质经电子顺磁谱表征,并首次利用电化学分析探讨了其反应机理。     

A New One-dimensional Dicyanamide Bridged Zinc(II) Complex Containing Nitronyl Nitroxide Radicals:Synthesis,Crystal Structure and Magnetic Properties

A new one-dimensional dicyanamide bridged zinc(II) complex containing nitronyl nitroxide radicals Zn(NO3)(NIT-1'-MeBzIm)(dca)n·(H2O)n(NIT-1'-MeBzIm = 2-{2'-(l'-me-thyl)benzimidazolyl}-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, dca = dicyanamide anion) has been prepared and structurally characterized by single-crystal X-ray diffraction.The complex crystallizes in triclinic, space group P1, with a = 7.428(3), b = 9.839(3), c = 16.708(6), α = 93.270(4), β = 101.642(4), γ = 100.632(4)°, C17.5H21N8O5.5Zn, Mr = 496.79, V = 1169.7(7) 3, Dc = 1.411 g/cm3, μ(MoKα) = 1.096 mm-1, Z = 2, F(000) = 512, R = 0.0583 and wR = 0.1663 for 4295 observed reflections with I > 2σ(I).X-ray analysis reveals that the zinc(II) ion is six-coordinated with a distorted octahedral geometry.These units develop as 1D species where dicyanamide ligands bridge zinc(II) ions.In addition, molecules are linked by π-π piling interactions to form 1-D double-chains.Magnetic investigation indicates that the weak intramolecular interactions are antiferromagnetic with J =-0.27 cm?1, where the spin Hamitonian is defined as H =-2∑i,jJi,jSiS within the complex.     

Ferro-and Antiferromagnetic Properties of Metal Complexes with Pyridine-Substituted Nitronyl Nitroxide Radicals

The synthesis, crystal structure and magnetic properties of the non-transition metals; Cd(II), Zn(II), Hg(II), Mg(II) and the transition metals; Co(II), Ni(II), Cu(II) complexes with 2-(4-pyridyl)-4,4,5,5-tetra-methylimidazolinyl-l-oxy-3-oxide (NITpPy) are presented. The compounds of free radical NITpPy, HgCl₂(NITpPy), and Zn(acac)₂(NITpPy) crystallize in the same monoclinic system of space group C2/c. The magnetic properties of the temperature-dependent magnetic susceptibility of NITpPy and its metal complexes are discussed according to the Heisenberg model. A weak ferromagnetic coupling in NITpPy and a weak antiferromagnetic coupling in the metal complexes have been revealed.     

Triphenylamine Derivatives Containing Nitronyl Nitroxide and Iminyl Nitroxide‐Syntheses,Characterization, Crystal Structures and Magnetic Studies

New triphenylamine derivatives 1, 2, 3, and 4 were synthesized and characterized by IR, FAB‐MS, EPR and EA. All of them displayed similar absorption and fluorescence spectra except compound 1, for which a possible explanation was proposed. Quasi‐reversible oxidation waves at about 0.76 V (vs. SCE) and 1.1 V for nitronyl nitroxide and iminyl nitroxide respectively as well as irreversible one at about 1.5 V for triphenylamine group were detected with cyclic voltammetry for compounds 1, 2, 3 and 4. Crystal structures of 2 and 4 were determined by X‐ray diffraction analysis. Their crystal data are as follows: for 2: monoclinic, C2/c, a = 1.69914 (4), b = 1.37435(5), c = 1.24621(5) ran, β= 106.553(2)°, V = 2.7896(2) nm³ Z = 4; for 4: orthorhombic, Pbca, a = 1.95970(6), b = 1.33096(4), c = 4.84691(14) nm, V = 12.6421(7) nm³, Z = 8. Magnetic studies indicated that all of them showed antiferromagnetic properties in solid state, but with strong intermolecular spin‐spin coupling as indicated by the relatively large values of 6, in particular for 4 (θ = ?12 K). Possible spin‐spin interaction mechanism was suggested based on the crystal structures of 2 and 4.     

Synthesis, Crystal Structure and Magnetic Properties of a New Zn(II)-Nitronyl Nitroxide Complex

A new complex [Zn(NIT-1'-MeBzIm)Cl2(H2O)] (NIT-1'-MeBzIm = 2-{2'-[(l'- methyl)benzimidazolyl]}-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) has been prepared and structurally characterized by X-ray diffraction method. Crystal data: monoclinic, space group P21/n, Z = 4, C15H21Cl2N4O3Zn, Mr = 441.63, a = 7.2225(10), b = 30.849(4), c = 8.8758(13) , β = 103.904(2)°, V = 1919.6(5) 3, Dc = 1.528 g/cm3, μ(MoKα) = 1.579 mm1, F(000) = 908, R = 0.0436 and wR = 0.1029 for 2456 observed reflections with I > 2σ(I). X-ray analysis reveals that the Zn(II) ion is four-coordinated with a distorted tetrahedron. There also exist H-bonds, π-π piling interactions and weak intermolecular contacts between the NO groups which form a mutual stagger 3-D network configuration. Magnetic investigation reveals that there exists intermolecular antiferro- and ferromagnetic interactions in the title complex.