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1.
Heterotrimetallic Coordination Polymers: {CuIILnIIIFeIII} Chains and {NiIILnIIIFeIII} Layers: Synthesis,Crystal Structures,and Magnetic Properties
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Dr. Maria‐Gabriela Alexandru Dr. Diana Visinescu Prof. Marius Andruh Dr. Nadia Marino Dr. Donatella Armentano Dr. Joan Cano Prof. Francesc Lloret Prof. Miguel Julve 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(14):5429-5446
The use of the [FeIII(AA)(CN)4]? complex anion as metalloligand towards the preformed [CuII(valpn)LnIII]3+ or [NiII(valpn)LnIII]3+ heterometallic complex cations (AA=2,2′‐bipyridine (bipy) and 1,10‐phenathroline (phen); H2valpn=1,3‐propanediyl‐bis(2‐iminomethylene‐6‐methoxyphenol)) allowed the preparation of two families of heterotrimetallic complexes: three isostructural 1D coordination polymers of general formula {[CuII(valpn)LnIII(H2O)3(μ‐NC)2FeIII(phen)(CN)2 {(μ‐NC)FeIII(phen)(CN)3}]NO3 ? 7 H2O}n (Ln=Gd ( 1 ), Tb ( 2 ), and Dy ( 3 )) and the trinuclear complex [CuII(valpn)LaIII(OH2)3(O2NO)(μ‐NC)FeIII(phen)(CN)3] ? NO3 ? H2O ? CH3CN ( 4 ) were obtained with the [CuII(valpn)LnIII]3+ assembling unit, whereas three isostructural heterotrimetallic 2D networks, {[NiII(valpn)LnIII(ONO2)2(H2O)(μ‐NC)3FeIII(bipy)(CN)] ? 2 H2O ? 2 CH3CN}n (Ln=Gd ( 5 ), Tb ( 6 ), and Dy ( 7 )) resulted with the related [NiII(valpn)LnIII]3+ precursor. The crystal structure of compound 4 consists of discrete heterotrimetallic complex cations, [CuII(valpn)LaIII(OH2)3(O2NO)(μ‐NC)FeIII(phen)(CN)3]+, nitrate counterions, and non‐coordinate water and acetonitrile molecules. The heteroleptic {FeIII(bipy)(CN)4} moiety in 5 – 7 acts as a tris‐monodentate ligand towards three {NiII(valpn)LnIII} binuclear nodes leading to heterotrimetallic 2D networks. The ferromagnetic interaction through the diphenoxo bridge in the CuII?LnIII ( 1 – 3 ) and NiII?LnIII ( 5 – 7 ) units, as well as through the single cyanide bridge between the FeIII and either NiII ( 5 – 7 ) or CuII ( 4 ) account for the overall ferromagnetic behavior observed in 1 – 7 . DFT‐type calculations were performed to substantiate the magnetic interactions in 1 , 4 , and 5 . Interestingly, compound 6 exhibits slow relaxation of the magnetization with maxima of the out‐of‐phase ac signals below 4.0 K in the lack of a dc field, the values of the pre‐exponential factor (τo) and energy barrier (Ea) through the Arrhenius equation being 2.0×10?12 s and 29.1 cm?1, respectively. In the case of 7 , the ferromagnetic interactions through the double phenoxo (NiII–DyIII) and single cyanide (FeIII–NiII) pathways are masked by the depopulation of the Stark levels of the DyIII ion, this feature most likely accounting for the continuous decrease of χM T upon cooling observed for this last compound. 相似文献
2.
Six‐Coordinate Lanthanide Complexes: Slow Relaxation of Magnetization in the Dysprosium(III) Complex
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Dr. Bo Na Xue‐Jing Zhang Prof. Dr. Wei Shi Prof. Dr. Yi‐Quan Zhang Prof. Dr. Bing‐Wu Wang Chen Gao Prof. Dr. Song Gao Prof. Dr. Peng Cheng 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(48):15975-15980
A series of six‐coordinate lanthanide complexes {(H3O)[Ln(NA)2]?H2O}n (H2NA=5‐hydroxynicotinic acid; Ln=GdIII ( 1?Gd ); TbIII ( 2?Tb ); DyIII ( 3?Dy ); HoIII ( 4?Ho )) have been synthesized from aqueous solution and fully characterized. Slow relaxation of the magnetization was observed in 3?Dy . To suppress the quantum tunneling of the magnetization, 3?Dy diluted by diamagnetic YIII ions was also synthesized and magnetically studied. Interesting butterfly‐like hysteresis loops and an enhanced energy barrier for the slow relaxation of magnetization were observed in diluted 3?Dy . The energy barrier (Δτ) and pre‐exponential factor (τ0) of the diluted 3?Dy are 75 K and 4.21×10?5 s, respectively. This work illustrates a successful way to obtain low‐coordination‐number lanthanide complexes by a framework approach to show single‐ion‐magnet‐like behavior. 相似文献
3.
Philipp R. Matthes Jörn Nitsch Ana Kuzmanoski Prof. Claus Feldmann Dr. Andreas Steffen Prof. Todd B. Marder Prof. Klaus Müller‐Buschbaum 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(51):17369-17378
A series of 12 dinuclear complexes [Ln2Cl6(μ‐4,4′‐bipy)(py)6], Ln=Y, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, ( 1 – 12 , respectively) was synthesized by an anhydrous solvothermal reaction in pyridine. The complexes contain a 4,4′‐bipyridine bridge and exhibit a coordination sphere closely related to luminescent lanthanide MOFs based on LnCl3 and 4,4‐bipyridine. The dinuclear complexes therefore function as a molecular model system to provide a better understanding of the luminescence mechanisms in the Ln‐N‐MOFs ${\hbox{}{{\hfill 2\atop \hfill \infty }}}$ [Ln2Cl6(4,4′‐bipy)3] ? 2(4,4′‐bipy). Accordingly, the luminescence properties of the complexes with Ln=Y, Sm, Eu, Gd, Tb, Dy, ( 1 , 4 – 8 ) were determined, showing an antenna effect through a ligand–metal energy transfer. The highest efficiency of luminescence is observed for the terbium‐based compound 7 displaying a high quantum yield (QY of 86 %). Excitation with UV light reveals typical emission colors of lanthanide‐dependent intra 4f–4f‐transition emissions in the visible range (TbIII: green, EuIII: red, SmIII: salmon red, DyIII: yellow). For the GdIII‐ and YIII‐containing compounds 6 and 1 , blue emission based on triplet phosphorescence is observed. Furthermore, ligand‐to‐metal charge‐transfer (LMCT) states, based on the interaction of Cl? with EuIII, were observed for the EuIII compound 5 including energy‐transfer processes to the EuIII ion. Altogether, the model complexes give further insights into the luminescence of the related MOFs, for example, rationalization of Ln‐independent quantum yields in the related MOFs. 相似文献
4.
Lanthanide coordination polymers with the formula [Ln(pydc)2]·H2O (Ln = La, 1 ; Nd, 2 ; pydc = 3,4‐pyridinedicarboxylate) and [Ln(pydc)(ina)(H2O)2] (Ln = Sm, 3 ; Eu, 4 ; Tb, 5 ; Dy, 6 ; pydc = 3,4‐pyridinedicarboxylate, ina = isonicotinate) were synthesized by treating LnIII nitrates with 3,4‐pyridinedicarboxylic acid under hydrothermal conditions. Single‐crystal and powder X‐ray diffraction studies indicate that these lanthanide coordination polymers adopt two different structures. The lighter lanthanide compounds 1 and 2 consist of extended two‐dimensional layer structures with the thickness of ca. 1.7 nm. While the heavier lanthanide compounds 3 ‐ 6 have pydc‐bridged double chain structures with one chelating carboxylate group of ina ligand and two water molecules on each metal center. Interestingly, decarboxylation occurred and pydc was partially transformed into ina in the hydrothermal reactions of 3 ‐ 6 . The fluorescence activities of compounds 4 and 5 are reported. 相似文献
5.
Systematic Investigation of Reaction‐Time Dependence of Three Series of Copper–Lanthanide/Lanthanide Coordination Polymers: Syntheses,Structures, Photoluminescence,and Magnetism
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Dr. Ju‐Wen Zhang Xiao‐Min Kan Bin‐Qiu Liu Guo‐Cheng Liu Dr. Ai‐Xiang Tian Prof. Xiu‐Li Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(45):16219-16228
Three series of copper–lanthanide/lanthanide coordination polymers (CPs) LnIIICuIICuI(bct)3(H2O)2 [Ln=La ( 1 ), Ce ( 2 ), Pr ( 3 ), Nd ( 4 ), Sm ( 5 ), Eu ( 6 ), Gd ( 7 ), Tb ( 8 ), Dy ( 9 ), Er ( 10 ), Yb ( 11 ), and Lu ( 12 ), H2bct=2,5‐bis(carboxymethylmercapto)‐1,3,4‐thiadiazole acid], LnIIICuI(bct)2 [Ln=Ce ( 2 a ), Pr ( 3 a ), Nd ( 4 a ), Sm ( 5 a ), Eu ( 6 a ), Gd ( 7 a ), Tb ( 8 a ), Dy ( 9 a ), Er ( 10 a ), Yb ( 11 a ), and Lu ( 12 a )], and LnIII2(bct)3(H2O)5 [Ln=La ( 1 b ), Ce ( 2 b ), Pr ( 3 b ), Nd ( 4 b ), Sm ( 5 b ), Eu ( 6 b ), Gd ( 7 b ), Tb ( 8 b ), and Dy ( 9 b )] have been successfully constructed under hydrothermal conditions by modulating the reaction time. Structural characterization has revealed that CPs 1 – 12 possess a unique one‐dimensional (1D) strip‐shaped structure containing two types of double‐helical chains and a double‐helical channel. CPs 2 a – 12 a show a three‐dimensional (3D) framework formed by CuI linking two types of homochiral layers with double‐helical channels. CPs 1 b – 9 b exhibit a 3D framework with single‐helical channels. CPs 6 b and 8 b display visible red and green luminescence of the EuIII and TbIII ions, respectively, sensitized by the bct ligand, and microsecond‐level lifetimes. CP 8 b shows a rare magnetic transition between short‐range ferromagnetic ordering at 110 K and long‐range ferromagnetic ordering below 10 K. CPs 9 a and 9 b display field‐induced single‐chain magnet (SCM) and/or single‐molecule magnet (SMM) behaviors, with Ueff values of 51.7 and 36.5 K, respectively. 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.
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
8.
Damir Barisic David Schneider Ccilia Maichle‐Mssmer Reiner Anwander 《Angewandte Chemie (International ed. in English)》2019,58(5):1515-1518
The half‐open rare‐earth‐metal aluminabenzene complexes [(1‐Me‐3,5‐tBu2‐C5H3Al)(μ‐Me)Ln(2,4‐dtbp)] (Ln=Y, Lu) are accessible via a salt metathesis reaction employing Ln(AlMe4)3 and K(2,4‐dtbp). Treatment of the yttrium complex with B(C6F5)3 and tBuCCH gives access to the pentafluorophenylalane complex [{1‐(C6F5)‐3,5‐tBu2‐C5H3Al}{μ‐C6F5}Y{2,4‐dtbp}] and the mixed vinyl acetylide complex [(2,4‐dtbp)Y(μ‐η1:η3‐2,4‐tBu2‐C5H4)(μ‐CCtBu)AlMe2], respectively. 相似文献
9.
Reversible SC‐SC Transformation involving [4+4] Cycloaddition of Anthracene: A Single‐Ion to Single‐Molecule Magnet and Yellow‐Green to Blue‐White Emission
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Xin‐Da Huang Yan Xu Kun Fan Prof. Dr. Song‐Song Bao Prof. Dr. Mohamedally Kurmoo Prof. Dr. Li‐Min Zheng 《Angewandte Chemie (International ed. in English)》2018,57(28):8577-8581
In search of magneto‐optic materials, the mononuclear compounds LnIII(depma)(NO3)3(hmpa)2 (Ln=Dy, Gd) were synthesized. The anthracene moieties undergo [4+4] dimerization when irradiated at 365 nm without loss of crystallinity. The Dy compound switches from a single‐ion to a single‐molecule magnet with doubling of the spin reversal barrier energy and from yellow‐green to blue‐white emission. The dimerization is reversed by heating at 100 °C or partially on light irradiating at 254 nm. The results suggest that lanthanide phosphonates with anthracene are promising smart materials displaying synergistic magneto‐optic property. 相似文献
10.
Synthesis and Cytotoxicity of Arene‐Ru Compounds Containing 4‐Nitroaniline or 2‐Halogenated 4‐Nitroaniline
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An‐Liang Chen Fen Huang Mao‐Lin Hu Zhi‐Min Jin Qian Miao Bei Tian 《无机化学与普通化学杂志》2017,643(16):1045-1048
The compounds [(η6‐p‐cymene)RuCl2(4‐nitroaniline)] and [(η6‐p‐cymene)RuCl2(2‐halogen‐4‐nitroaniline)] were synthesized and characterized by various means. The [(η6‐p‐cymene)RuCl2(4‐nitroaniline)] and [(η6‐p‐cymene)RuCl2(2‐fluoro‐4‐nitroaniline)] compounds were determined by X‐ray diffraction, appearing in a distorted piano‐stool type of arrangement with similar bond lengths and angles around the ruthenium. The compounds exhibited moderate to strong in vitro cytotoxicity against A549 and MCF‐7 human cancer cells. Substitution of heavy halogen atom on the ortho position of para‐nitroaniline weakened the cytotoxicity against both of MCF‐7 and A549, except the cases of fluorine substitution for hydrogen atom regarding A549 and bromine substitution for chlorine atom regarding MCF‐7, which showed minor deviation. 相似文献
11.
The reaction of tricyanometallate precursor, (Bu4N)[(pzTp)Fe(CN)3] with Cu(ClO4)2·6H2O in the presence of the tetradentate ligand tris(2‐pyridylmethyl)amine (TPyA) afford the dinuclear compound fac‐{[FeIII(pzTp)(CN)2(μ‐CN)]CuII(TPA)}·Et2O·ClO4 ( 1 ) (pzTp = tetrakis(pyrazolyl)borate). The molecular structure was determined by single‐crystal X‐ray diffraction. In compound 1 , the FeIII ion is coordinated by three cyanide carbon atoms and three nitrogen atoms of pzTp anions. Whereas, the CuII ion is surrounded by one cyanide nitrogen atom and four nitrogen atoms from the TPyA ligand. Magnetic measurements indicate the intramolecular ferromagnetic coupling is observed for compound 1 , and it has S = 1 ground states. 相似文献
12.
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
13.
Dr. Victor E. Pushkarev Dr. Alexander Yu. Tolbin Fedor E. Zhurkin Dr. Nataliya E. Borisova Dr. Stanislav A. Trashin Prof. Larisa G. Tomilova Prof. Nikolay S. Zefirov 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(29):9046-9055
Phthalocyanine compounds of novel type based on a bridged bis‐ligand, denoted “intracavity” complexes, have been prepared. Complexation of clamshell ligand 1,1′‐[benzene‐1,2‐diylbis(methanediyloxy)]bis[9(10),16(17),23(24)‐tri‐tert‐butylphthalocyanine] (clam,tBuPc2H4, 1 ) with lanthanide(III) salts [Ln(acac)3] ? n H2O (Ln=Eu, Dy, Lu; acetylacetonate) led to formation of double‐deckers clam,tBuPc2Ln ( 2 a – c ). Formation of high molecular weight oligophthalocyanine complexes was demonstrated as well. The presence of an intramolecular covalent bridge affecting the relative arrangement of macrocycles was shown to result in specific physicochemical properties. A combination of UV/Vis/NIR and NMR spectroscopy, MALDI‐TOF mass‐spectrometry, cyclic voltammetry, and spectroelectrochemistry provided unambiguous characterization of the freshly prepared bis‐phthalocyanines, and also revealed intrinsic peculiarities in the structure–property relationship, which were supported by theoretical calculations. Unexpected NMR activity of the paramagnetic dysprosium complex 2 b in the neutral π‐radical form was observed and examined as well. 相似文献
14.
Synthesis, Crystal Structure, Vibrational Spectra, and Normal Coordinate Analysis of (n‐Bu4N)2[PtX4(ox)], X = Cl, Br By oxidation of (n‐Bu4N)2[PtX2(ox)], X = Cl, Br, with Cl2 or Br2 in dichloromethane (n‐Bu4N)2[PtCl4(ox)] ( 1 ) and (n‐Bu4N)2[PtBr4(ox)] ( 2 ) are formed. The crystal structure of [(C5H5N)2CH2][PtCl4(ox)] (monoclinic, space group C2/m, a = 15.562(1), b = 13.779(1), c = 10.168(1)Å, ß = 128.099(9)°, Z = 4) reveals complex anions with nearly C2v point symmetry. The bond lengths in the Cl′‐Pt‐O˙ axes are Pt‐Cl′ = 2.287 and Pt‐O˙ = 2.048 and in the Cl‐Pt‐Cl axis Pt‐Cl = 2.314Å. The oxalato ligand is nearly plane with an O‐C‐C‐O torsion angle of 0.5°. In the vibrational spectra the PtX stretching vibrations are observed at 328 and 353 ( 1 ) and 201 and 212 cm—1 ( 2 ). The PtX′ modes appear at 360 and 343 ( 1 ) and 227 and 238 cm—1 ( 2 ). The PtO˙ stretching vibrations are coupled with internal modes of the oxalato ligands and appear in the range of 400—800 cm—1. Based on the molecular parameters of the X‐ray determination ( 1 ) and estimated data ( 2 ) the IR and Raman spectra are assigned by normal coordinate analysis. The valence force constants are fd(PtCl) = 2.08, fd(PtCl′) = 2.29, fd(PtBr) = 1.56, fd(PtBr′) = 2.02 and fd(PtO˙) = 2.46 ( 1 ) and 2.35 mdyn/Å ( 2 ). Taking into account increments of the trans influence a good agreement between observed and calculated frequencies is achieved. The NMR shifts are δ(195Pt) = 5623.0 ( 1 ) and 4536.1 ( 2 ). 相似文献
15.
Dr. Min‐Xia Yao Qi Zheng Kang Qian Prof. Dr. You Song Prof. Dr. Song Gao Prof. Dr. Jing‐Lin Zuo 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(1):294-303
By using the node‐and‐spacer approach in suitable solvents, four new heterotrimetallic 1D chain‐like compounds (that is, containing 3d–3d′–4f metal ions), {[Ni(L)Ln(NO3)2(H2O)Fe(Tp*)(CN)3] ? 2 CH3CN ? CH3OH}n (H2L=N,N′‐bis(3‐methoxysalicylidene)‐1,3‐diaminopropane, Tp*=hydridotris(3,5‐dimethylpyrazol‐1‐yl)borate; Ln=Gd ( 1 ), Dy ( 2 ), Tb ( 3 ), Nd ( 4 )), have been synthesized and structurally characterized. All of these compounds are made up of a neutral cyanide‐ and phenolate‐bridged heterotrimetallic chain, with a {? Fe? C?N? Ni(? O? Ln)? N?C? }n repeat unit. Within these chains, each [(Tp*)Fe(CN)3]? entity binds to the NiII ion of the [Ni(L)Ln(NO3)2(H2O)]+ motif through two of its three cyanide groups in a cis mode, whereas each [Ni(L)Ln(NO3)2(H2O)]+ unit is linked to two [(Tp*)Fe(CN)3]? ions through the NiII ion in a trans mode. In the [Ni(L)Ln(NO3)2(H2O)]+ unit, the NiII and LnIII ions are bridged to one other through two phenolic oxygen atoms of the ligand (L). Compounds 1 – 4 are rare examples of 1D cyanide‐ and phenolate‐bridged 3d–3d′–4f helical chain compounds. As expected, strong ferromagnetic interactions are observed between neighboring FeIII and NiII ions through a cyanide bridge and between neighboring NiII and LnIII (except for NdIII) ions through two phenolate bridges. Further magnetic studies show that all of these compounds exhibit single‐chain magnetic behavior. Compound 2 exhibits the highest effective energy barrier (58.2 K) for the reversal of magnetization in 3d/4d/5d–4f heterotrimetallic single‐chain magnets. 相似文献
16.
[Fe2(μsb‐CO)(CO)3(NO)(μ‐PtBu2)(μ‐Ph2PCH2PPh2)]: Synthesis, X‐ray Crystal Structure and Isomerization Na[Fe2(μ‐CO)(CO)6(μ‐PtBu2)] ( 1 ) reacts with [NO][BF4] at —60 °C in THF to the nitrosyl complex [Fe2(CO)6(NO)(μ‐PtBu2)] ( 2 ). The subsequent reaction of 2 with phosphanes (L) under mild conditions affords the complexes [Fe2(CO)5(NO)L(μ‐PtBu2)], L = PPh3, ( 3a ); η‐dppm (dppm = Ph2PCH2PPh2), ( 3b ). In this case the phosphane substitutes one carbonyl ligand at the iron tetracarbonyl fragment in 2 , which was confirmed by the X‐ray crystal structure analysis of 3a . In solution 3b loses one CO ligand very easily to give dppm as bridging ligand on the Fe‐Fe bond. The thus formed compound [Fe2(CO)4(NO)(μ‐PtBu2)(μ‐dppm)] ( 4 ) occurs in solution in different solvents and over a wide temperature range as a mixture of the two isomers [Fe2(μsb‐CO)(CO)3(NO)(μ‐PtBu2)(μ‐dppm)] ( 4a ) and [Fe2(CO)4(μ‐NO)(μ‐PtBu2)(μ‐dppm)] ( 4b ). 4a was unambiguously characterized by single‐crystal X‐ray structure analysis while 4b was confirmed both by NMR investigations in solution as well as by means of DFT calculations. Furthermore, the spontaneous reaction of [Fe2(CO)4(μ‐H)(μ‐PtBu2)(μ‐dppm)] ( 5 ) with NO at —60 °C in toluene yields a complicated mixture of products containing [Fe2(μ‐CO)(CO)4(μ‐H)(μ‐PtBu2)(μ‐dppm)] ( 6 ) as main product beside the isomers 4a and 4b occuring in very low yields. 相似文献
17.
Guo FS Liu JL Leng JD Meng ZS Lin ZJ Tong ML Gao S Ungur L Chibotaru LF 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(8):2458-2466
A family of linear Dy3 and Tb3 clusters have been facilely synthesized from the reactions of DyCl3, the polydentate 3‐methyloxysalicylaldoxime (MeOsaloxH2) ligand with auxiliary monoanionic ligands, such as trichloroacetate, NO3?, OH?, and Cl?. Complexes 1 – 5 contain a nearly linear Ln3 core, with similar Ln???Ln distances (3.6901(4)–3.7304(3) Å for the Dy3 species, and 3.7273(3)–3.7485(5) Å for the Tb3 species) and Ln???Ln???Ln angles of 157.036(8)–159.026(15)° for the Dy3 species and 157.156(8)–160.926(15)° for the Tb3 species. All three Ln centers are bridged by the two doubly‐deprotonated [MeOsalox]2? ligands and two of the four [MeOsaloxH]? ligands through the N,O‐η2‐oximato groups and the phenoxo oxygen atoms (Dy‐O‐Dy angles=102.28(16)–106.85(13)°; Tb‐O‐Tb angles=102.00(11)–106.62(11)°). The remaining two [MeOsaloxH]? ligands each chelate an outer LnIII center through their phenoxo oxygen and oxime nitrogen atoms. Magnetic studies reveal that both Dy3 and Tb3 clusters exhibit significant ferromagnetic interactions and that the Dy3 species behave as single‐molecule magnets, expanding upon the recent reports of the pure 4f type SMMs. 相似文献
18.
Synthesis, Crystal Structure, Vibrational Spectra, and Normal Coordinate Analysis of cis‐ and trans‐(n‐Bu4N)2[PtF2(ox)2] and (n‐Bu4N)2[PtF4(ox)] By treatment of trans‐(n‐Bu4N)2[PtCl2(ox)2] and (n‐Bu4N)2[PtCl4(ox)] with XeF2 in propylene carbonate cis‐ and trans‐(n‐Bu4N)2[PtF2(ox)2] ( 1 , 2 ) and (n‐Bu4N)2[PtF4(ox)] ( 3 ) are formed which have been isolated by ion exchange chromatography on diethylaminoethyl cellulose. The crystal structure of trans(n‐Bu4N)2[PtF2(ox)2] ( 2 ) (tetragonal, space group P42/n, a = 15.5489(9), b = 15.5489(9), c = 17.835(1)Å, Z = 4) und Cs2[PtF4(ox)] ( 3 ) (monoclinic, space group C2/m, a = 14.5261(7), b = 6.2719(4), c = 9.6966(9)Å, β = 90.216(8)°, Z = 4) reveal complex anions with nearly D2h and C2v point symmetry. The average bond lengths in the symmetrical coordinated axes are Pt—F = 1.93 ( 2 , 3 ) and Pt—O = 1.987 ( 2 ) and in the F•—Pt—O′‐axes Pt—F• = 1.957 and Pt—O′ = 1.977Å ( 3 ). The oxalato ligands are nearly planar with a maximum displacement of the ring atoms of 0.05 ( 2 ) und 0.01Å ( 3 ) to the calculated best planes. In the vibrational spectra the symmetric and antisymmetric PtF stretching vibrations are observed at 583 and 586 ( 2 ) and 576 and 568 cm—1 ( 3 ). The PtF• modes appear at 565 and 562 ( 1 ) and 560 cm—1 ( 3 ). The PtO and PtO′ stretching vibrations are coupled with internal modes of the oxalato ligands and appear in the range of 400—800 cm—1. Based on the molecular parameters of the X‐ray determinations ( 2 , 3 ) and estimated data ( 1 ) the IR and Raman spectra are assigned by normal coordinate analysis. The valence force constants are fd(PtF) = 3.55 ( 2 ) and 3.38 ( 3 ), fd(PtF•) = 3.23 ( 1 ) and 3.20 ( 3 ), fd(PtO) = 2.65 ( 1 ) and 2.84 ( 2 ) and fd(PtO′) = 2.97 ( 1 ) and 3.00 mdyn/Å ( 3 ). Taking into account increments of the trans influence a good agreement between observed and calculated frequencies is achieved. The NMR shifts are δ(195Pt) = 8485 ( 1 ), 8597 ( 2 ) and 10048 ppm ( 3 ), δ(19F) = —350 ( 2 ) and —352 ( 3 ) and δ(19F•) = —323 ( 1 ) and —326 ppm ( 3 ) with the coupling constants 1J(PtF) = 1784 ( 2 ) and 1864 ( 3 ) and 1J(PtF•) = 1525 ( 1 ) and 1638 Hz ( 3 ). 相似文献
19.
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
20.
Two C3‐Symmetric Dy3III Complexes with Triple Di‐μ‐methoxo‐μ‐phenoxo Bridges,Magnetic Ground State,and Single‐Molecule Magnetic Behavior
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Dr. Mikko M. Hänninen Prof. Dr. Antonio J. Mota Dr. Daniel Aravena Prof. Dr. Eliseo Ruiz Prof. Dr. Reijo Sillanpää Dr. Agustín Camón Dr. Marco Evangelisti Prof. Dr. Enrique Colacio 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(27):8410-8420
Two series of isostructural C3‐symmetric Ln3 complexes Ln3 ? [BPh4] and Ln3 ? 0.33[Ln(NO3)6] (in which LnIII=Gd and Dy) have been prepared from an amino‐bis(phenol) ligand. X‐ray studies reveal that LnIII ions are connected by one μ2‐phenoxo and two μ3‐methoxo bridges, thus leading to a hexagonal bipyramidal Ln3O5 bridging core in which LnIII ions exhibit a biaugmented trigonal‐prismatic geometry. Magnetic susceptibility studies and ab initio complete active space self‐consistent field (CASSCF) calculations indicate that the magnetic coupling between the DyIII ions, which possess a high axial anisotropy in the ground state, is very weakly antiferromagnetic and mainly dipolar in nature. To reduce the electronic repulsion from the coordinating oxygen atom with the shortest Dy?O distance, the local magnetic moments are oriented almost perpendicular to the Dy3 plane, thus leading to a paramagnetic ground state. CASSCF plus restricted active space state interaction (RASSI) calculations also show that the ground and first excited state of the DyIII ions are separated by approximately 150 and 177 cm?1, for Dy3 ? [BPh4] and Dy3 ? 0.33[Dy(NO3)6], respectively. As expected for these large energy gaps, Dy3 ? [BPh4] and Dy3 ? 0.33[Dy(NO3)6] exhibit, under zero direct‐current (dc) field, thermally activated slow relaxation of the magnetization, which overlap with a quantum tunneling relaxation process. Under an applied Hdc field of 1000 Oe, Dy3 ? [BPh4] exhibits two thermally activated processes with Ueff values of 34.7 and 19.5 cm?1, whereas Dy3 ? 0.33[Dy(NO3)6] shows only one activated process with Ueff=19.5 cm?1. 相似文献