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1.
Xiaoling Wang Panpan Xu Xia Bao Fengwu Wang Yonghong Chen Yijun Wei 《无机化学与普通化学杂志》2013,639(1):176-180
Abstract. Two radical–LnIII–radical complexes, [Ln(hfac)3(NITPh‐Ph)2] [Ln = Gd ( 1 ) and Ho ( 2 ), hfac = hexafluoroacetylacetonate; and NITPh‐Ph = 4′‐biphenyl‐4, 4, 5, 5‐tetramethylimidazoline‐1‐oxyl‐3‐oxide] were synthesized and characterized by X‐ray diffraction, elemental analysis, magnetic measurements, as well as IR and UV/Vis spectroscopy. X‐ray crystal structure analysis revealed that the structures of both complexes are isomorphous, the central LnIII ions are coordinated by six oxygen atoms from three hfac ligand molecules and two oxygen atoms from nitronyl radicals. The temperature dependencies of the magnetic susceptibilities were studied. They showed that in the GdIII complex, ferromagnetic interactions between GdIII and the radicals and antiferromagnetic interactions between the radicals coexist in this system (with JRad–Gd = 0.1 cm–1, JRad–Rad = –0.309 cm–1). 相似文献
2.
Structural and Magnetic Properties of 2p‐3d‐4f Hetero‐Tri‐Spin Chains Comprising [{Cu(hfac)2‐Radical}2] Dimers and Ln(hfac)3 (hfac=hexafluoroacetylacetonate)
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A new family of 2p‐3d‐4f hetero‐tri‐spin complexes [Ln(hfac)3{Cu(hfac)2(NIT‐3 PyPh)}2] (Ln=Gd ( 1 ), Tb ( 2 ), Dy ( 3 ), Ho ( 4 ); NIT‐3 PyPh=2‐[4‐(3‐pyridinylmethoxy)phenyl]‐4,4,5,5‐tetramethylimidazoline‐1‐oxyl‐3‐oxide; hfac=hexafluoroacetylacetonate) have been synthesized. Four complexes possess a 1D chain structure in which two radical ligands join two Cu(hfac)2 molecules to form a [{Cu(hfac)2‐rad)}2] dimer cycle and the dimer rings are linked by Ln(hfac)3 units. Magnetic studies show that ferromagnetic exchange couplings exist between the coordinated NO groups of radical ligands and metal ions. Field‐induced slow relaxation of the magnetization was observed in the Tb and Dy compounds. 相似文献
3.
Three unprecedented nitronyl nitroxide radical‐bridged 3d–4f clusters, [Ln2Cu2(hfac)10(NIT‐3py)2(H2O)2](LnIII=Y, Gd, Dy), have been obtained from the self‐assembly of Ln(hfac)3, Cu(hfac)2, and the radical ligand. The Dy complex shows a slow relaxation of magnetization, representing the first nitronyl nitroxide radical‐based 3d–4f cluster with single‐molecule magnet behavior. 相似文献
4.
Dr. Fabrice Pointillart Dr. Thomas Cauchy Dr. Olivier Maury Yann Le Gal Dr. Stéphane Golhen Dr. Olivier Cador Dr. Lahcène Ouahab 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(39):11926-11941
The tetrathiafulvalene‐amido‐2‐pyridine‐N‐oxide ( L ) ligand has been employed to coordinate 4f elements. The architecture of the complexes mainly depends on the ionic radii of the lanthanides. Thus, the reaction of L in the same experimental protocol leads to three different molecular structure series. Binuclear [Ln2(hfac)5(O2CPhCl)( L )3] ? 2 H2O (hfac?=1,1,1,5,5,5‐hexafluoroacetylacetonate anion, O2CPhCl?=3‐chlorobenzoate anion) and mononuclear [Ln(hfac)3( L )2] complexes were obtained by using rare‐earth ions with either large (LnIII=Pr, Gd) or small (LnIII=Y, Yb) ionic radius, respectively, whereas the use of TbIII that possesses an intermediate ionic radius led to the formation of a binuclear complex of formula [Tb2(hfac)4(O2CPhCl)2( L )2]. Antiferromagnetic interactions have been observed in the three dinuclear compounds by using an extended empirical method. Photophysical properties of the coordination complexes have been studied by solid‐state absorption spectroscopy, whereas time‐dependent density functional theory (TD‐DFT) calculations have been carried out on the diamagnetic YIII derivative to build a molecular orbital diagram and to reproduce the absorption spectrum. For the [Yb(hfac)3( L )2] complex, the excitation at 19 600 cm?1 of the HOMO→LUMO+1/LUMO+2 charge‐transfer transition induces both line‐shape emissions in the near‐IR spectral range assigned to the 2F5/2→2F7/2 (9860 cm?1) ytterbium‐centered transition and a residual charge‐transfer emission around 13 150 cm?1. An efficient antenna effect that proceeds through energy transfer from the singlet excited state of the tetrathiafulvalene‐amido‐2‐pyridine‐N‐oxide chromophore is evidence of the YbIII sensitization. 相似文献
5.
Structure and Magnetic Investigation of a Series of Rare Earth Heterospin Monometallic Compounds of Nitronyl Nitroxide Radical
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Yuxiao Wang Zhe Fan Xiaoying Yin Shuping Wang Shutao Yang Jianjun Zhang Lina Geng Shikao Shi 《无机化学与普通化学杂志》2016,642(2):148-154
Five rare earth heterospin complexes [Ln(hfac)3(NITptBuPh)2], [LnIII = Eu ( 1 ), Tb ( 2 ), Dy ( 3 ), Ho ( 4 ), Er ( 5 )] (hfac = hexafluoroacetylacetonate), were synthesized with the radical ligand NITptBuPh [2‐(4′‐tert‐butylphenyl)‐4, 4,5, 5‐tetramethylimidazoline‐1‐oxyl‐3‐oxide]. These complexes exhibit similar structures. All of them crystallize in the monoclinic space group P21/c, and consist of discrete mononuclear molecules. The central LnIII ion is eight‐coordinate with a distorted dodecahedral environment. The NITptBuPh radical acts as monodentate ligand towards LnIII ion through the NO group. The magnetic studies suggested weak antiferromagnetic interactions between LnIII ion and radicals in 1 , 3 , 4 , and 5 , but weak ferromagnetic interaction in 2 . 相似文献
6.
Hetero‐tri‐spin [2p‐3d‐4f] Chain Compounds Based on Nitronyl Nitroxide Lanthanide Metallo‐Ligands: Synthesis,Structure, and Magnetic Properties
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Mei Zhu Peng Hu Yungai Li Xiufeng Wang Prof. Licun Li Prof. Daizheng Liao V. M. L. Durga Prasad Goli Prof. S. Ramasesha Dr. Jean‐Pascal Sutter 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(41):13356-13365
Employing nitronyl nitroxide lanthanide(III) complexes as metallo‐ligands allowed the efficient and highly selective preparation of three series of unprecedented hetero‐tri‐spin (Cu?Ln‐radical) one‐dimensional compounds. These 2p–3d–4f spin systems, namely [Ln3Cu(hfac)11(NitPhOAll)4] (LnIII=Gd 1Gd , Tb 1Tb , Dy 1Dy ; NitPhOAll=2‐(4′‐allyloxyphenyl)‐4,4,5,5‐tetramethylimidazoline‐1‐oxyl‐3‐oxide), [Ln3Cu(hfac)11(NitPhOPr)4] (LnIII=Gd 2Gd , Tb 2Tb , Dy 2Dy , Ho 2Ho , Yb 2Yb ; NitPhOPr=2‐(4′‐propoxyphenyl)‐4,4,5,5‐tetramethyl‐imidazoline‐1‐oxyl‐3‐oxide) and [Ln3Cu(hfac)11(NitPhOBz)4] (LnIII=Gd 3Gd , Tb 3Tb , Dy 3Dy ; NitPhOBz=2‐(4′‐benzyloxyphenyl)‐4,4,5,5‐tetramethyl‐imidazoline‐1‐oxyl‐3‐oxide) involve O‐bound nitronyl nitroxide radicals as bridging ligands in chain structures with a [Cu‐Nit‐Ln‐Nit‐Ln‐Nit‐Ln‐Nit] repeating unit. The dc magnetic studies show that ferromagnetic metal–radical interactions take place in these hetero‐tri‐spin chain complexes, these and the next‐neighbor interactions have been quantified for the Gd derivatives. Complexes 1Tb and 2Tb exhibit frequency dependence of ac magnetic susceptibilities, indicating single‐chain magnet behavior. 相似文献
7.
Chien Thang Pham Thu Ha Nguyen Thi Nguyet Trieu Kenji Matsumoto Hung Huy Nguyen 《无机化学与普通化学杂志》2019,645(17):1072-1078
The bifunctional ligand 2,6‐dipicolinoylbis(N,N‐diethylthiourea) (H2L) readily reacts with mixtures of Zn(CH3COO)2 and LnCl3 in MeOH at ambient temperature with formation of trinuclear heterobimetallic complexes [Zn2Ln(L)2(OAc)3] ( 1a – 1f ) (Ln = Ce, Nd, Sm, Gd, Dy, Er). The X‐ray single‐crystal diffraction and structural studies of the complexes revealed their isostructural nature, in which two doubly‐charged ligands {L2–} bind two Zn2+ ions with the terminal acylthiourea sites and one Ln3+ ion with the central 2,6‐pyridinedicarboxamide site. In the complexes, the coordination numbers of LnIII and ZnII ions are 9 and 5, respectively. Magnetic properties of the complexes were studied by temperature‐dependent dc magnetic measurements. The observed μeff values at room temperature are all closed to the calculated values. Fitting χM and M data of [Zn2Gd(L)2(OAc)3] ( 1d ) shows a giso value of 1.94. 相似文献
8.
Trinuclear [CoIII2–LnIII] (Ln=Tb,Dy) Single‐Ion Magnets with Mixed 6‐Chloro‐2‐Hydroxypyridine and Schiff Base Ligands
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Prof. Dr. Cai‐Ming Liu Prof. Dr. De‐Qing Zhang Prof. Dr. Xiang Hao Prof. Dao‐Ben Zhu 《化学:亚洲杂志》2014,9(7):1847-1853
The Schiff base ligand N1,N3‐bis(3‐methoxysalicylidene)diethylenetriamine (H2valdien) and the co‐ligand 6‐chloro‐2‐hydroxypyridine (Hchp) were used to construct two 3d–4f heterometallic single‐ion magnets [Co2Dy(valdien)2(OCH3)2(chp)2] ? ClO4 ? 5 H2O ( 1 ) and [Co2Tb(valdien)2(OCH3)2(chp)2] ? ClO4 ? 2 H2O ? CH3OH ( 2 ). The two trinuclear [CoIII2LnIII] complexes behave as a mononuclear LnIII magnetic system because of the presence of two diamagnetic cobalt(III) ions. Complex 1 has a molecular symmetry center, and it crystallizes in the C2/c space group, whereas complex 2 shows a lower molecular symmetry and crystallizes in the P21/c space group. Magnetic investigations indicated that both complexes are field‐induced single‐ion magnets, and the CoIII2–DyIII complex possesses a larger energy barrier [74.1(4.2) K] than the CoIII2–TbIII complex [32.3(2.6) K]. 相似文献
9.
Three new homodinuclear lanthanide(III) complexes [Ln2(L)6(2,2′‐bipy)2] [Ln = TbIII ( 1 ), SmIII ( 2 ), EuIII ( 3 ); HL = 3‐hydroxycinnamic acid (3‐HCA); 2,2′‐bipy = 2,2′‐bipyridine] were synthesized and characterized by IR spectroscopy, elemental analyses, and X‐ray diffraction techniques. Complexes 1 – 3 crystallize in triclinic system, space group P$\bar{1}$ . In all complexes the lanthanide ions are nine‐coordinate by two nitrogen atoms from the 2,2′‐bipy ligand and seven oxygen atoms from one chelating L ligands and four bridging L ligands, forming distorted tricapped trigonal prismatic arrangements. The lanthanide(III) ions are intramolecularly bridged by eight carboxylate oxygen atoms forming dimeric complexes with Ln ··· Ln distances of 3.92747(15), 3.9664(6), and 3.9415(4) Å for complexes 1 – 3 , respectively. The luminescent properties in the solid state of HL ligand and EuIII complex are also discussed. 相似文献
10.
Daniel N. Huh Sierra R. Ciccone Samuel Bekoe Saswata Roy Joseph W. Ziller Filipp Furche William J. Evans 《Angewandte Chemie (International ed. in English)》2020,59(37):16141-16146
Lanthanide triflates have been used to incorporate NdIII and SmIII ions into the 2.2.2‐cryptand ligand (crypt) to explore their reductive chemistry. The Ln(OTf)3 complexes (Ln=Nd, Sm; OTf=SO3CF3) react with crypt in THF to form the THF‐soluble complexes [LnIII(crypt)(OTf)2][OTf] with two triflates bound to the metal encapsulated in the crypt. Reduction of these LnIII‐in‐crypt complexes using KC8 in THF forms the neutral LnII‐in‐crypt triflate complexes [LnII(crypt)(OTf)2]. DFT calculations on [NdII(crypt)]2+], the first NdII cryptand complex, assign a 4f4 electron configuration to this ion. 相似文献
11.
Unprecedented Sensitization of Visible and Near‐Infrared Lanthanide Luminescence by Using a Tetrathiafulvalene‐Based Chromophore
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Min Feng Dr. Fabrice Pointillart Dr. Boris Le Guennic Bertrand Lefeuvre Dr. Stéphane Golhen Dr. Olivier Cador Dr. Olivier Maury Dr. Lahcène Ouahab 《化学:亚洲杂志》2014,9(10):2814-2825
Ligand L was synthesized and then coordinated to [Ln(hfac)3] ? 2 H2O (LnIII=Tb, Dy, Er; hfac?=1,1,1,5,5,5‐hexafluoroacetylacetonate anion) and [Ln(tta)3]?2 H2O (LnIII=Eu, Gd, Tb, Dy, Er, Yb; tta?=2‐thenoyltrifluoroacetonate) to give two families of dinuclear complexes [Ln2(hfac)6( L )] ? C6H14 and [Ln2(tta)6( L )] ? 2 CH2Cl2. Irradiation of the ligand at 37 040 cm?1 and 29 410 cm?1 leads to tetrathiafulvalene‐centered and 2,6‐di(pyrazol‐1‐yl)‐4‐pyridine‐centered fluorescence, respectively. The ligand acts as an organic chromophore for the sensitization of the infrared ErIII (6535 cm?1) and YbIII (10 200 cm?1) luminescence. The energies of the singlet and triplet states of L are high enough to guarantee an efficient sensitization of the visible EuIII luminescence (17 300–14 100 cm?1). The EuIII luminescence decay can be nicely fitted by a monoexponential function that allows a lifetime estimation of (0.49±0.01) ms. Finally, the magnetic and luminescence properties of [Yb2(hfac)6( L )] ? C6H14 were correlated, which allowed the determination of the crystal field splitting of the 2F7/2 multiplet state with MJ=±1/2 as ground states. 相似文献
12.
Huilu Wu Yuchen Bai Yanhui Zhang Guolong Pan Jin Kong Furong Shi Xiaoli Wang 《无机化学与普通化学杂志》2014,640(10):2062-2071
The Schiff base N,N′‐bis(salicylidene)‐1,5‐diamino‐3‐oxapentane (H2L) and its lanthanide(III) complexes, PrL(NO3)(DMF)(H2O) ( 1 ) and Ho2L2(NO3)2 · 2H2O ( 2 ), were synthesized and characterized by physicochemical and spectroscopic methods. Single crystal X‐ray structure analysis revealed that complex 1 is a discrete mononuclear species. The PrIII ion is nine‐coordinate, forming a distorted capped square antiprismatic arrangement. Complex 2 is a centrosymmetric dinuclear neutral entity in which the HoIII ion is eight‐coordinate with distorted square antiprismatic arrangement. The DNA‐binding properties of H2L and its LnIII complexes were investigated by spectrophotometric methods and viscosity measurements. The results suggest that the ligand H2L and its LnIII complexes both connect to DNA in a groove binding mode; the complexes bind more strongly to DNA than the ligand. Moreover, the antioxidant activities of the LnIII complexes were in vitro determined by superoxide and hydroxyl radical scavenging methods, which indicate that complexes 1 and 2 have OH · and O2– · radical scavenging activity. 相似文献
13.
Xiao‐Qing Zhao Yi‐Yan Wang Dong‐Xu Bao Fen‐Hang Zhang Wei Wu Fu‐Sen Xu Qiu‐Hong Zhang Yun‐Chun Li 《应用有机金属化学》2019,33(11)
Six novel decanuclear clusters with formula of {[Fe8Ln2(O)4(OH)4(EtO)2(dhbp)4(dhbpH)2(piv)6]·4EtOH} (Ln = Y ( 1 ), Gd ( 2 ), Tb ( 3 ), Dy ( 4 ), Ho ( 5 ), Er ( 6 ), dhbpH2 = 6,6′‐dihydroxyl‐2,2′‐bipyridine, Hpiv = pivalic acid, EtOH = ethanol) have been synthesized and characterized. Single‐crystal and powder X‐ray diffraction analyses reveal that complexes 1 – 6 are isostructural and show a sandwich‐like FeIII8LnIII2 structure, in which the [Ln2] unit is sandwiched by two planar [Fe4] units. Magnetic properties of complexes 1 – 6 have been investigated and display dominant antiferromagnetic interactions, thereinto, complexes 4 and 6 display weak ferromagnetic behaviors associated with LnIII ions, while others are antiferromagnetic‐like features. Furthermore, complex 4 (FeIII8DyIII2) shows temperature/frequency‐dependent ac signals with an energy barrier of 4.1 K, indicating that complex 4 should be a single‐molecule magnet (SMM) 相似文献
14.
The Building Block [FeIII(pzphen)(CN)4]– and its Lanthanide Complexes: Synthesis,Crystal Structure,and Magnetic Properties
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Jian‐Qing Tao Wen‐Wen Ju Zhou Zhou Li‐Yong Jia Ning‐Ning Chen Yun‐Shan Xue Jun Wang Xing‐Cai Huang 《无机化学与普通化学杂志》2016,642(24):1466-1471
The cyanide building block [FeIII(pzphen)(CN)4]– and its four lanthanide complexes [{FeIII(pzphen)(CN)4}2LnIII(H2O)5(DMF)3] · (NO3) · 2(H2O) · (CH3CN) [Ln = Nd ( 1 ), Sm ( 2 ), DMF = dimethyl formamide] and [{FeIII(pzphen)(CN)4}2LnIII(NO3)(H2O)2(DMF)2](CH3CN) [Ln = Gd ( 3 ), Dy ( 4 )] were synthesized and structurally characterized by single‐crystal X‐ray diffraction. Compounds 1 and 2 are ionic salts with two [FeIII(pzphen)(CN)4]– cations and one LnIII ion, but compounds 3 and 4 are cyano‐bridged FeIII‐LnIII heterometallic 3d‐4f complexes exhibiting a trinuclear structure in the same conditions. Magnetic studies show that compound 3 is antiferromagnetic between the central FeIII and GdIII atoms. Furthermore, the trinuclear cyano‐bridged FeIII2DyIII compound 4 displays no single‐molecular magnets (SMMs) behavior by the alternating current magnetic susceptibility measurements. 相似文献
15.
Amir Zaïm Dr. Homayoun Nozary Dr. Laure Guénée Dr. Céline Besnard Dr. Jean‐François Lemonnier Prof. Dr. Stéphane Petoud Prof. Dr. Claude Piguet 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(23):7155-7168
Herein, we discuss how, why, and when cascade complexation reactions produce stable, mononuclear, luminescent ternary complexes, by considering the binding of hexafluoroacetylacetonate anions (hfac?) and neutral, semi‐rigid, tridentate 2,6‐bis(benzimidazol‐2‐yl)pyridine ligands ( Lk ) to trivalent lanthanide atoms (LnIII). The solid‐state structures of [Ln( Lk )(hfac)3] (Ln=La, Eu, Lu) showed that [Ln(hfac)3] behaved as a neutral six‐coordinate lanthanide carrier with remarkable properties: 1) the strong cohesion between the trivalent cation and the didentate hfac anions prevented salt dissociation; 2) the electron‐withdrawing trifluoromethyl substituents limited charge‐neutralization and favored cascade complexation with Lk ; 3) nine‐coordination was preserved for [Ln( Lk )(hfac)3] for the complete lanthanide series, whilst a counterintuitive trend showed that the complexes formed with the smaller lanthanide elements were destabilized. Thermodynamic and NMR spectroscopic studies in solution confirmed that these characteristics were retained for solvated molecules, but the operation of concerted anion/ligand transfers with the larger cations induced subtle structural variations. Combined with the strong red photoluminescence of [Eu( Lk )(hfac)3], the ternary system LnIII/hfac?/ Lk is a promising candidate for the planned metal‐loading of preformed multi‐tridentate polymers. 相似文献
16.
Pei Jing Dr. Lu Xi Jiao Lu Jing Han Xiaohui Huang Chaoyi Jin Junfang Xie Prof. Licun Li 《化学:亚洲杂志》2021,16(7):793-800
Four biradical-Ln complexes with different transition metal ions, namely [LnM(hfac)5(NITPh-PyPzbis)] (MII=MnII and LnIII=Gd 1 , Dy 2 ; MII=NiII and LnIII=Tb 3 , Dy 4 ), were prepared by the reaction of Ln(hfac)3 ⋅ 2H2O, Mn(hfac)2 ⋅ 2H2O or Ni(hfac)2 ⋅ 2H2O with NITPh-PyPzbis biradical (hfac=hexafluoroacetylacetonate, NITPh-PyPzbis=5-(3-(2-pyridinyl)-1H-pyrazol-1-yl)-1,3-bis(1’-oxyl-3’-oxido- 4’,4’,5’,5’-tetramethyl-4,5-hydro-1H-imidazol-2-yl)benzene). In complexes 1 – 4 , the NITPh-PyPzbis biradical chelates one LnIII ion by means of its aminoxyl moieties and the transition metal ion is introduced through the two N donors from the pyridyl pyrazolyl moiety. Magnetic investigations indicate that complex 4 displays visible maxima in frequency/temperature-dependent χ′′ signals with two-step relaxation processes, but complex 2 exhibits no slow magnetization relaxation. The comparison of structure parameters of both Dy complexes indicates that the symmetries of coordination spheres of two Dy ions are D2d for 2 and C2v for 4 , which thus probably results in different magnetic relaxation behaviors. This work provides new insight for improving properties of Ln-biradical based SMMs. 相似文献
17.
《无机化学与普通化学杂志》2018,644(5):293-300
Three dinuclear lanthanide complexes [Ln2(H2L)2(NO3)4] [Ln = Dy ( 1 ), Tb ( 2 ), and Gd ( 3 )] [H3L = 2‐hydroxyimino‐N′‐[(2‐hydroxy‐3‐methoxyphenyl)methylidene]‐propanohydrazone] were solvothermally synthesized by varying differently anisotropic rare earth ions. Single‐crystal structural analyses demonstrate that all the three complexes are crystallographically isostructural with two centrosymmetric LnIII ions aggregated by a pair of monodeprotonated H2L– anions. Weak intramolecular antiferromagnetic interactions with different strength were mediated by a pair of phenoxo bridges due to superexchange and/or single‐ion anisotropy. Additionally, the DyIII‐based entity shows the strongest anisotropy exhibits field‐induced single‐molecule magnetic behavior with two thermally activated relaxation processes. In contrast, 3 with isotropic GdIII ion has a significant cryogenic magnetocaloric effect with the maximum entropy change of 25.7 J · kg–1 · K–1 at 2.0 K and 70.0 kOe. 相似文献
18.
Dr. Lu Xi Chaoyi Jin Hongwei Song Xiaotong Wang Junfang Xie Prof. Yue Ma Prof. Jinkui Tang Prof. Licun Li 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(65):e202202239
In spite of achievement of a lot of Ln-radical SMMs, how to improve magnetic behavior of Ln-radical system remains challenging. Here, two series of Ln-radical complexes have successfully been built using an imino nitroxide biradical, namely, [Ln2(hfac)6(ImPhPyobis)2] (LnIII=Gd 1 , Tb 2 , Dy 3 ) and [Ln2Cu2(hfac)10(ImPhPyobis)2] (LnIII=Gd 4 , Dy 5 ; hfac=hexafluoroacetylacetonate and ImPhPyobis=5-(4-oxypyridinium-1-yl)-1,3-bis(1’-oxyl-4’,4’,5’,5’-tetramethyl-4,5-hydro-1H-imidazol-2-yl)benzene). For these biradical-metal complexes, two imino nitroxide biradicals bind two Ln(III) ions via their oxygen atoms coming from 4-oxypyridinium units to produce a binuclear {Ln2O2} unit. Those imino nitroxide groups are free for complexes 1 – 3 , however one of imino nitroxide groups of the biradical is ligated to the copper(II) ion for complexes 4 and 5 . The distinct magnetic relaxation behaviors are observed for two Dy derivatives, as revealed by ac magnetic studies: complex 3 presents one magnetic process with the effective energy barrier(Ueff) of 74.0 K while complex 5 exhibits dual relaxation processes with Ueff values for the fast- and slow-relaxation being 20.2 K and 30.9 K, respectively, which implies that the second coordination sphere of Dy ion plays a critical role for magnetic relaxation. 相似文献
19.
Syntheses,Crystal Structures,and Photophysical Properties of Heteronuclear Zinc(II)/Cadmium(II)‐Lanthanide(III) Coordination Complexes based on Benzoic Acid
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Yu‐Xian Chi Yu‐Qian Liu Xiao‐Shuang Hu Xiao‐Yun Tang Yu‐Juan Liu Jing Jin Shu‐Yun Niu Guang‐Ning Zhang 《无机化学与普通化学杂志》2016,642(1):73-80
The heteronuclear d‐f coordination complexes [Er2Zn2(C6H5COO)10(phen)2] (1), [Ho2Zn2(C6H5COO)10(phen)2] ( 2 ), [Pr3Zn6(C6H5COO)21(phen)3] ( 3 ), [ErCd(C6H5COO)5(phen)·H2O] ( 4 ), [Ho2Cd3(C6H5COO)12(phen)2] ( 5 ), [EuCd2(C6H5COO)7(phen)2] ( 6 ) (C6H5COOH = benzoic acid;phen = 1,10‐phenanthroline) were synthesized by hydrothermal methods, and their structures were studied by single‐crystal X‐ray diffraction. Complexes 1 , 2 , 4 , and 5 crystallize in the triclinic space group P$\bar{1}$ and complexes 3 and 6 in the monoclinic space group C2/c. The room temperature IR, UV/Vis/NIR absorption, and emission spectra of the six complexes were determined and assigned. In the visible and NIR regions, the emission spectra of complexes show characteristic bands of corresponding LnIII ions, which are attributed to the sensitization from the d block (Zn/Cd‐ligand section) and ligands. In comparison with isolated LnIII ions, the NIR emission bands of complexes 1 – 5 exhibit shifting, broadening and splitting, which are also present in their UV/Vis/NIR absorption spectra. Thus, the two spectra of complexes can evidence each other. 相似文献
20.
The Syntheses,Structures, and Magnetic Properties of Four 2D Lanthanide(III)‐naphthalenedicarboxylic Complexes
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Ying‐Bing Lu Lei‐Peng Chen Shi‐Yong Zhang Ping Lian Yong‐Rong Xie 《无机化学与普通化学杂志》2015,641(14):2408-2413
Four Ln‐NDC coordination polymers [Ln(NDC)(HNDC)(H2O)] (Ln = La ( 1 ), Pr ( 2 ), Nd ( 3 ), Sm ( 4 ), H2NDC = 1,4‐naphthalenedicarboxylic acid) were hydrothermally synthesized and structurally characterized by elemental analyses, IR spectroscopy, and single‐crystal X‐ray diffraction. Compounds 1 – 4 are isomorphous, and their structures display a layer constructed from a Ln‐organic chain and NDC2– ligand, in which the H2NDC ligands adopt two different acidity‐dependent types and coordination modes: HNDC1– with μ‐η1:η1 and NDC2– with μ‐η1:η2:η1:η2. The 3D supramolecular networks of 1 – 4 are mainly controlled by hydrogen bonds interactions. The magnetic susceptibilities of complexes 2 – 4 reveal overall antiferromagnetic interactions between the LnIII ions. In addition, thermogravimetric analysis of compound 2 is described. 相似文献