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1.
Four new heterobimetallic coordination polymers, namely, {[Cu(aeoe)M(H2O)3 · 2H2O]2}n (M = Mn(II) (1), Co(II) (2), Ni(II) (3)) and [Cu(aeoe)Ni(H2O)3]2 (4) (H4aeoe = N′-(2-aminoterephthalic acid)-N′′-(ethylenediamine)oxamidato) have been synthesized and characterized structurally. Complexes 1-3 are allomerism and feature 1-D ladder-like chain structure constructed from neutral tetranuclear complex units through the syn-anti carboxylate bridges, whereas complex 4 is a cyclic neutral tetranuclear complex unit. Their magnetic properties are also investigated based on their structures.  相似文献   

2.
By the reactions of Cu(AcO)2·H2O and Cu(HCOO)2·4H2O with 4,4′-dimethyl-2,2′-bipyridine and 5,5′-dimethyl-2,2′-bipyridine the compounds [Cu(AcO)2(4,4′-Me2-2,2′-bipy)]·1/2H2O (1), [Cu(AcO)2(5,5′-Me2-2,2′-bipy)(H2O)] (2), [Cu(HCOO)(μ-HCOO)(4,4′-Me2-2,2′-bipy)]n·nH2O (3) and [Cu(HCOO)(μ-HCOO)(5,5′-Me2-2,2′-bipy)]n·2nH2O (4) were obtained. In the acetate complexes, 1 and 2, the geometry around copper is distorted octahedral and square pyramidal, respectively. Dimeric units of different geometry are formed in both cases through hydrogen bonds in which non-coordinated (in 1) and coordinated (in 2) water molecules are involved. The structures of 3 and 4 consist of polymeric monodimensional chains of square pyramidal copper units linked by axial-equatorial syn-anti (3) or anti-anti (4) bridging formate groups. Water molecules form hydrogen bonds with formate groups of the same chain in compound 3. In compound 4 the water molecules link the polymeric contiguous chains of complex through hydrogen bonds with oxygen atoms of formate groups and they are also linked between them, forming monodimensional water chains which run parallel to the complex chains. Sheets parallel to the ac plane are formed by alternating chains of water and polymeric complex. Magnetic properties and EPR spectra for these compounds have been studied.  相似文献   

3.
Using a phosphorus based Mannich condensation reaction the new pyridylphosphines {5-Ph2PCH2N(H)}C5H3(2-Cl)N (1-Cl) and {2-Ph2PCH2N(H)}C5H3(5-Br)N (1-Br) have been synthesised in good yields (60% and 88%, respectively) from Ph2PCH2OH and the appropriate aminopyridine. The ligands 1-Cl and 1-Br display variable coordination modes depending on the choice of late transition-metal complex used. Hence P-monodentate coordination has been observed for the mononuclear complexes AuCl(1-Cl) (2), AuCl(1-Br) (3), RuCl2(p-cymene)(1-Cl) (4), RuCl2(p-cymene)(1-Br) (5), RhCl2(Cp)(1-Cl) (6), RhCl2(Cp)(1-Br) (7), IrCl2(Cp)(1-Cl) (8), IrCl2(Cp)(1′-Cl) (8′), IrCl2(Cp)(1-Br) (9), cis-/trans-PdCl2(1-Cl)2 (10), cis-/trans-PdCl2(1-Br)2 (11), cis-PtCl2(1-Cl)2 (12) and cis-PtCl2(1-Br)2 (13). Reaction of Pd(Me)Cl(cod) (cod = cycloocta-1,5-diene) with either 1 equiv. of 1-Br or the known pyridylphosphines 1′-Cl, 1-OH or 1-H gave the P/N-chelate complexes Pd(Me)Cl(1-Br-1-H) (14)-(17). All new compounds have been fully characterised by spectroscopic and analytical methods. Furthermore the structures of 4, 5, 10 and 16 · (CH3)2SO have been elucidated by single crystal X-ray crystallography. A crystal structure of the dinuclear metallocycle trans,trans-[PdCl2{μ-P/N-{Ph2PCH2N(H)}C5H4N}]2 · CHCl3, 18 · CHCl3, has also been determined. Here 1-H bridges, using both P and pyridyl N donors, two dichloropalladium centres affording a 12-membered ring with the PdCl2 units adopting a head-to-tail arrangement.  相似文献   

4.
Reactions of ligands 1-ethyl-5-methyl-3-phenyl-1H-pyrazole (L1) and 5-methyl-1-octyl-3-phenyl-1H-pyrazole (L2) with [PdCl2(CH3CN)2 and K2PtCl4 gave complexes trans-[MCl2(L)2] (L = L1, L2). The new complexes were characterised by elemental analyses, conductivity measurements, infrared, 1H and 13C{1H} NMR spectroscopies and X-ray diffraction. The NMR study of the complex [PdCl2(L1)2], in CDCl3 solution, is consistent with a very slow rotation of ligands around the Pd-N bond, so that two conformational isomers can be observed in solution (syn and anti). Different behaviour is observed for complexes [PdCl2(L2)2] and [PtCl2(L)2] (L = L1, L2), which present an isomer in solution at room temperature (anti). The crystal structure of [PdCl2(L1)2] complex is described, where the Pd(II) presents a square planar geometry with the ligands coordinated in a trans disposition.  相似文献   

5.
The ligands 1-hydroxymethylpyrazole (hl1), 1-(2-hydroxyethyl)pyrazole (hl2) and 1-(3-hydroxypropyl)pyrazole (hl3) react with [PdCl2(CH3CN)2] to give trans-[PdCl2(hl)2] compounds. Due to a hindered rotation around the Pd-bond, these compounds present two different conformations in solution: anti and syn. The conformation presented depends on the relative disposition of the hydroxyalkylic chains of the two pyrazolic ligands. The present study was carried out on the basis of NMR experiments. The present paper reports the crystal structure of trans-[PdCl2(hl2)2]. The synthesis and characterisation of compounds [Pd(hl)4](BF4)2 (hl = hl1, hl2 and hl3) starting from [Pd(CH3CN)4](BF4)2 and the corresponding chlorocomplexes trans-[PdCl2(hl)2] are also described.  相似文献   

6.
The coordination chemistry and reactivity of zinc(II) complexes supported by monoanionic hydrotris(pyrazolyl)borate ligands substituted by 3,3,3-mesityl groups (TpMs) and 3,3,5-mesityl groups (TpMs∗) have been investigated. Salt metathesis of ZnCl2, ZnEt2, and Zn(OAc)2 with Tl[TpMs] or Tl[TpMs∗] cleanly afforded the corresponding compounds TpMsZnCl (1), TpMsZnEt (2), TpMs∗ZnEt (3), and TpMsZnOAc (5). Compound 3 slowly disproportionates in benzene solution to afford the bis(ligand) complex (κ2-TpMs∗)2Zn (4). Acetate complex 5 as well as TpMsZnOCOPh (6) and [TpMs∗ZnOAc]2 (7) were alternatively prepared by acidolysis of the parent ethyl complexes (2, 3) with the corresponding carboxylic acid. No reaction was observed between 2 and 3 and alcohols (ROH; R = Et, iPr, Bn), while salt metathesis reactions of ZnEt(OR) with Tl[TpMs] led to 2 instead of the desired zinc-alkoxide complex. Compounds 1-7 were characterized by elemental analysis, 1H and 13C NMR spectroscopy, as well as by X-ray diffraction studies for 1, 2, 4, 5 and 7. The former compounds adopt a monomeric structure in the solid state while [TpMs∗ZnOAc]2 (7) exists as an anti-syn bridged acetate dimer. Complex 4 is four-coordinated, featuring a rare bidentate coordination mode of the TpMs∗ ligands. The results are rationalized in terms of the variable steric constraint around the zinc atom provided by the TpMs and TpMs∗ ligands.  相似文献   

7.
Hydrothermal reactions of rare earth ions(III) with a flexible building unit (1,3,4-thiadiazole-2,5-diyldithio)diacetic acid (H2tzda) lead to five novel coordination polymers with 1D chain and 3D network structures, namely, {[Y2(tzda)3(H2O)10] · 5H2O}n (1) and [Ln2(tzda)3(H2O)5]n [Ln = Er (2), Pr (3), Nd (4), Eu (5)]. Compound 1 has one-dimensional ribbon-like chain structure constructed by [Y2(tzda)3] units through the syn-anti bidentate bridging mode of carboxylate groups. Compounds 2-5 possess compact three-dimensional network structures which are made up of [Ln2(tzda)3] (Ln = Er, Pr, Nd and Eu) units bridged by carboxylate groups. In these compounds, the flexible tzda2− ligand is versatile and displays six different coordination fashions to meet the requirement of the coordination preference of the metal center. Furthermore, the magnetic behaviors for 2-5 in the temperature range of 5.0-300 K and photoluminescent property of 5 are significantly investigated in this paper.  相似文献   

8.
Reactions of FeII, CoII, NiII, and ZnII salts with 6-quinolinecarboxylic acid (HL) under the hydrothermal conditions afford three monomeric complexes [M(L)2(H2O)4] (M = FeII for 1, CoII for 2, and NiII for 3) and a 1-D polymeric species {[Zn(L)2(H2O)] · H2O}n (4). The crystal structures of the ligand HL and these four complexes have been determined by using the X-ray single-crystal diffraction technique. The results suggest that complexes 1-3 are isostructural, displaying novel 3-D pillar-layered networks through multiple intermolecular hydrogen bonds, whereas in coordination polymer 4, the 1-D comb-like coordination chains are extended to generate a hydrogen-bonded layer, which is further reinforced via aromatic stacking interactions. Solid-state properties such as thermal stability and fluorescence emission of the polymeric ZnII complex 4 have also been investigated.  相似文献   

9.
Photolysis of the molybdaborane [(η5-C5H5)(η51-C5H4)-arachno-2-MoB4H7] (1) in benzene-d6 gives ca. 60% conversion to the compound [(η5-C5H5)(η51-C5H4)-nido-2-MoB4H5] (2). Compound 2 could not be isolated as a solid and is thermally unstable at 20 °C in solution with a half-life of 3-4 h. Repeated photolysis and thermolysis of 1 in the presence of BH3 · thf gives a low yield of the known metallacarbaborane [(η5-C5H5)(η23-C3H3)-closo-1-MoC2B9H9] (3) suggesting that 3 is formed from 1 via 2. Reaction of 1 with PEt3 gives initially [(η5-C5H5)(η51-C5H4)-arachno-2-MoHB4H4PEt3] (4). Longer reaction times (>10 min, 20 °C) give in addition [(η5-C5H5)(η51-C5H4)-arachno-1-MoHB3H3PEt3] (5). Both 4 and 5 are unstable in solution or the solid state decomposing to the molybdacarbaborane [(η5-C5H5)(η32- C3H3)-nido-1-MoC2B3H5] (6), [Mo(η-C5H5)2H2] and BH3 · PEt3. Compound 1 is deprotonated cleanly by KH in thf at the Mo-H-B bridging proton to give (7).  相似文献   

10.
Electrospray (ESI) mass spectra analysis of acetonitrile solutions of a series of neutral chloro dimers, pincer type, and monomeric palladacycles has enabled the detection of several of their derived ionic species. The monometallic cationic complexes Pd[κ1-C1-N1-S-C(CH3S-2-C6H4)C(Cl)CH2N(CH3)2]+ (1a) and [Pd[κ1-C1-N1-S-C(CH3S-2-C6H4)C(Cl)CH2N(CH3)2](CH3CN)]+ (1b) and the bimetallic cationic complex [κ1-C1-N1-S-C(CH3S-2-C6H4)C(Cl)CH2N(CH3)2]Pd-Cl-Pd[κ1-C1-N1-S-C(CH3S-2-C6H4)C(Cl)CH2N(CH3)2]+ (1c) were detected from an acetonitrile solution of the pincer palladacycles Pd[κ1-C1-N1-S-C(CH3S-2-C6H4)C(Cl)CH2N(CH3)2](Cl) 1. For the dimeric compounds {Pd[κ1-C1-N-C(Y-2-C6H4)C(Cl)CH2N(CH3)2](μ-Cl)}2 (2, Y=H and 3, CF3), highly electronically unsaturated palladacycles [Pd[κ1-C1-N-C(Y-2-C6H4)C(Cl)CH2N(CH3)2]+ (2d, 3d) and their mono and di-acetonitrile adducts, namely, [Pd[κ1-C1-N-C(Y-2-C6H4)C(Cl)CH2N(CH3)2](CH3CN)]+ (2e, 3e) and [Pd[κ1-C1-N-C(Y-2-C6H4)C(Cl)CH2N(CH3)2](CH3CN)2]+ (2f and 3f) were detected together with the bimetallic complex [Pd[κ1-C1-N-C(Y-2-C6H4)C(Cl)CH2N(CH3)2]-Cl-Pd[κ1-C1-N-C(Y-2-C6H4)C(Cl)CH2N](CH3)2]+ (2a, 3a) and its acetonitrile adducts [κ1-C1-N-C(Y-2-C6H4)C(Cl)CH2N(CH3)2](CH3CN)Pd-Cl-Pd[ κ1-C1-N-C(Y-2-C6H4)C(Cl)CH2N(CH3)2]+ (2b, 3b) and [κ1-C1-N-C(Y-2-C6H4)C(Cl)CH2N(CH3)2](CH3CN)Pd-Cl-Pd[κ1-C, κ1-N-C(Y-2-C6H4)C(Cl)CH2N(CH3)2(CH3CN)]+ (2c, 3c). The dimeric palladacycle {Pd[κ1-C1-N-C(CH3O-2-C6H4)C(Cl)CH2N(CH3)2](μ-Cl)}2 (4) is unique as it behaves as a pincer type compound with the OCH3 substituent acting as an intramolecular coordinating group which prevents acetonitrile full coordination, thus forming the cationic complexes [(C6H4(o-CH3O)CC(Cl)CH2N(CH3)2OCN)Pd]+ (4b), [(C6H4(o-CH3O)CC(Cl)CH2N(CH3)2- κOCN)Pd(CH3CN)]+ (4c) and [(C6H4 (o-MeO)CC(Cl)CH2N(CH3)2O, κCN)Pd-Cl-Pd(C6H4(o-CH3O)CC(Cl)CH2N(CH3)2OCN)]+ (4a). ESI-MS spectra analysis of acetonitrile solutions of the monomeric palladacycles Pd[κ1-C1-N-C(Y-2-C6H4)C(Cl)CH2N(CH3)2](Cl)(Py) (5, Y=H and 6, Y=CF3) allows the detection of some of the same species observed in the spectra of the dimeric palladacycles, i.e., monometallic cationic 2d-3d, 2e-3e and {Pd[κ1-C1-N-C(Y-2-C6H4)C(Cl)CH2N(CH3)2](Py)}+ (5a, 6a) and {Pd[κ1-C1-N-C(Y-2-C6H4)C(Cl)CH2N(CH3)2](CH3CN)(Py)}+ (5b, 6b) and the bimetallic 2a, 3a, 2b, 3b, 2c and 3c. In all cationic complexes detected by ESI-MS, the cyclometallated moiety was intact indicating the high stability of the four or six electron anionic chelate ligands. The anionic (chloride) or neutral (pyridine) ligands are, however, easily replaced by the acetonitrile solvent.  相似文献   

11.
Reaction of PPN[W(CO)3(R2PC2H4PR2)(SH)] (PPN=Ph3PNPPh3; R=Me, 1; R=Ph, 2) with aromatic aldehydes in the presence of trifluoroacetic acid gave tungsten complexes of thiobenzaldehydes mer-[W(CO)3(R2PC2H4PR2)(η2-SCHR)] (R=Me, 3a-3f; R=Ph, 4a-4e) in high yields. Analogous complexes of aliphatic thioaldehydes mer-[W(CO)3(Me2PC2H4PMe2)(η2-SCHR)] (3g-3l) could only be obtained from the highly electron-rich thiolate complex 1. The structure of 3i (R=i-Bu) was determined by X-ray crystallography. In solution the complexes 3 and 4 are in equilibrium with small quantities of their isomers fac-[W(CO)3(R2PC2H4PR2)(η2-SCHR)]. Reaction of complexes 3 with dimethylsulfate followed by salt metathesis with NH4PF6 gave the alkylation products mer-[W(CO)3(Me2PC2H4PMe2)(η2-MeSCHR)]PF6 (5a-5l) as mixtures of E and Z isomers. The methylated thioformaldehyde complex mer-[W(CO)3(Me2PC2H4PMe2)(η2-MeSCH2)]PF6 (5m) was prepared similarly. Nucleophilic addition of hydride (from LiAlH4) to 5 initially gave thioether complexes mer-[W(CO)3(Me2PC2H4PMe2)(MeSCH2R)] (mer-6) which rapidly isomerized to fac-[W(CO)3(Me2PC2H4PMe2)(MeSCH2R)] (fac-6).  相似文献   

12.
4-aryl-2-amino-6-(4-hydroxy-2-oxo-2H-chromen-3-yl)-pyridin-3-carbonitrile (1), 4-aryl-2-oxo-6-(4-hydroxy-2-oxo-2H-chromen-3-yl)-pyridin-3-carbonitriles (2a-2c), 3-(6-aryl-1,2,5,6- tetrahydro-2-thioxopyrimidin-4-yl)-4-hydroxy-2H-chromen-2-one (3a, 3b) and pyrazol-3-yl-4-hydroxycoumarin derivatives (4a-4c, 5, 6a, 6b, 7a, 7b, and 8a-8c) were prepared in order to measure their % change dopamine release in comparison to amphetamine as reference, using PC-12 cells in different concentrations. In addition, the molecular modeling study of the compounds into 3BHH receptor was also demonstrated. The calculated inhibition constant (ki) implemented in the AutoDock program revealed identical correlation with the experimental results to that obtained binding free energy (ΔGb) as both parameters revealed reasonable correlation coefficients (R2) being 0.51 involving 10 compounds; (1, 2b, 2c, 3a, 3b, 4a, 4b, 6a, and 8c).  相似文献   

13.
Syntheses of three new N-arylanilido-arylimine bidentate Schiff base type ligand precursors, ortho-C6H4[NH(2,6-iPr2C6H3)](CHNAr1) [Ar1 = p-FC6H4 (2a); C6H5 (2b); p-OMeC6H4 (2c)], and their four-coordinated boron complexes, ortho-C6H4[N(2,6-iPr2C6H3)](CHNAr1)BF2 [Ar1 = p-FC6H4 (3a); C6H5 (3b); p-OMeC6H4 (3c)] are described. The boron complexes 3a-3c were synthesized from the reaction of BF3(OEt2) with the lithium salt of their corresponding ligand. All complexes were characterized by 1H and 13C NMR spectroscopy and molecular structures of complexes 3a and 3c were determined by X-ray crystallography. The photophysical properties of complexes 3a-3c were briefly examined. All three complexes display bright green fluorescence in solution and in the solid state. Electroluminescent devices with complex 3c as the emitter were fabricated. These devices were found to give green emission with maximum current efficiency of 2.92 cd/A and maximum luminance of 670 cd/m2.  相似文献   

14.
A novel polymerizable organosilyl-modified Dawson-type polyoxometalate (POM) [α2-P2W17O61{CH2C(CH3)COO(CH2)3Si}2O]6− (1) was synthesized as both salt (Me2NH2-1) and H+ form (H-1). They were characterized with complete elemental analysis, thermogravimetric and differential thermal analysis (TG/DTA), FTIR, (1H, 13C, 29Si, 31P and 183W) NMR and n-butylamine titration method. H-1 was immobilized to a polymer network through free radical copolymerization with methyl methacrylate (MMA). The acidities of H-1 and hybrid copolymer (H-1-co-MMA) were evaluated using the Hammett indicators (dicinnamalacetone and benzalacetophenone; pKa values of the protonated indicators are −3.0 and −5.6, respectively). The pKa value of H-1 was estimated as that between −3.0 and −5.6 in CH3CN solution and H-1 was immobilized in H-1-co-MMA with the original acidity being retained. Glass transition point (Tg) and molecular weight distribution of H-1-co-MMA were affected by the used amount of H-1 because of the cross-linking effect of H-1.  相似文献   

15.
Herein, we report the synthesis and structural characterization of alkaline-earth complexes with the bibracchial lariat ethers N,N′-bis(2-aminobenzyl)-4,13-diaza-18-crown-6 (L2) and N,N′-bis(benzimidazol-2ylmethyl)-4,13-diaza-18-crown-6 (L4). The X-ray crystal structures of the Ca(II) and Sr(II) complexes of L2 show the pendant arms of the ligand disposed on opposite sides of the macrocyclic mean plane, which results in an anti conformation in the solid state. A similar anti conformation is also observed for the Mg(II) complex of L4, whereas the Ca(II), Sr(II) and Ba(II) complexes of L4 adopt a syn conformation in the solid state, with the two pendant arms pointing at the same side of the crown moiety. However, a different behavior is observed in solution. Indeed, 1H and 13C NMR spectroscopy, in combination with density functional theory (DFT) calculations performed at the B3LYP level, suggests that the [M(L2)]2+ and [M(L4)]2+ (M = Ca, Sr or Ba) complexes exist in solution as a mixture of syn and anti isomers involved in a dynamic equilibrium. Our results also show that the relative abundance of the syn conformation increases as the ionic radius of the metal ion increases and, furthermore, for a given metal ion the proportion of syn isomer is always higher for L4 complexes than for L2 ones.  相似文献   

16.
Interaction of [NbCl5] with the diphenol 2,2′-CH3CH[4,6-(But)2C6H2OH]2 (LH2) affords, after work-up, the red crystalline complex [NbCl(NCMe)L2] (1). Under similar conditions, [NbOCl3] and the sulfur-bridged diphenol 2,2′-S[4,6-(But)2C6H2OH]2 (LSH2) afford the orange complex [NbCl(LS)2] (2). Crystal structure determinations of 1 · 2MeCN and 2 reveal monomeric 6- and 7-coordinate complexes, respectively. The polymerization behaviour of 1 and 2 towards ethylene, in the presence of alkylaluminium co-catalysts has been examined and has been compared with that of the known niobium aryloxides [Nb(Me-L2)Cl2]2 (3), {Nb[(But-L2)H]2Cl(NCMe)} (4) and [Nb(But-L2)Cl2] (5), derived from the linear-linked aryloxide trimers 2,6-bis(4,6-dimethylsalicyl)-4-tert-butylphenol [(Me-L2)H3] and 2,6-bis(4-methyl-6-tert-butylsalicyl)-4-tert-butylphenol [(But-L2)H3]. The crystal structure of the acetonitrile solvate of 3 · 4MeCN, is also reported.  相似文献   

17.
Four coordination polymers based on AgI/3-sulfobenzoate/N-donor ligands, [Ag2Na2(3-sb)2(H2O)7]n (1), {[Ag2(3-sb)(apy)]·(H2O)}n (2), {[Ag2(4,4′-bipy)2(H2O)3]·[Ag2(4,4′-bipy)2(H2O)2]·2(3-sb)·4(H2O)}n (3) and {[Ag(3-sb)(bpe)(H2O)][Ag(bpe)(H2O)]·3(H2O)}n (4) where 3-sb is 3-sulfobenzoate, apy is 2-aminopyridine, bipy is 4,4′-bipyridine and bpe is 1,2-bis(4-pyridyl)ethylene, were prepared and characterized, and their fluorescence and electric conductivity properties were studied. Complex 1 is a 3D architecture in which 3-sb ligands exhibit μ41(O1,O2-Ag): κ1(O3,O5-Na) trans-trans coordination mode. The molecular structure of 2 is a 2D layer. Complexes 3 and 4 are cation-anion species and 1D polymers. In these complexes hydrogen bonds provide additional assembly forces, giving 3D hydrogen bonding networks for 1 and 3, and 2D layers for 2 and 4. Abundant weak interactions, such as Ag-Ag interactions in 1-3, Ag-π interactions in 1-4, π-π interactions in 1, 3-4, and C-H···π interactions in 3-4, also can be found. The weak interactions are strongly related to the fluorescence and electric conductivity properties, providing the way for understanding the relationship between structures and properties.  相似文献   

18.
Synthesis, spectroscopic and magnetic properties, and X-ray crystal structures of two copper(II) polymers Cu(2-qic)Br (2-qic = quinoline-2-carboxylate) (1) and Cu(2-pic)Br (2-pic = pyridine-2-carboxylate) (2) are described. These compounds are isostructural with Cu(2-qic)Cl and Cu(2-pic)Cl, respectively, the X-ray crystal structures of which were reported recently. Both complexes are polynuclear copper(II) compounds (1D and 2D, respectively) based on syn-anti carboxylate bridges and additionally on linear monobromo- (in 1) and dibromo-bridging (in 2) motifs. The magnetic properties were investigated in the temperature range 1.8-300 K. They reveal the occurrence of strong antiferromagnetic coupling (J1 = −102.5 cm−1) through the single bromo-bridge in 1, which is much stronger than that transmitted by the single chloro-bridge (J = −57.0 cm−1). Very weak ferromagnetic interaction through the syn-anti carboxylate bridge J2 is expected as it was observed in isomorphous Cu(2-qic)Cl (J = 0.37 cm−1). For 2 a weak ferromagnetic couplings through the syn-anti carboxylate (zJ′ = 1.35 cm−1) and dibromo-bridges (J = 8.31 cm−1) were found. The experimental results indicate that the observed ferromagnetic exchange through dibromo-bridge is weaker than that in the chloride analog (J = 15.0 cm−1). The magnitude of magnetic interactions is discussed on the basis of structural data of compounds 1 and 2 and their halide analogues.  相似文献   

19.
A series of pyrazole-bridged heterometallic 3d-4f complexes, [CuDy(ipdc)2(H2O)4] · (2H2O)(H3O+) (1) and [CuLn(pdc)(ipdc)(H2O)4] · H3O+ (Ln = Ho (2), Er (3), Yb (4); H3ipdc = 4-iodo-3,5-pyrazoledicarboxylic acid; H3pdc = 3,5-pyrazoledicarboxylic acid), {[Cu3Ln4(ipdc)6(H2O)16] · xH2O}n (Ln = Sm (5), x = 8.5; Ln = Eu (6), x = 7; Ln = Gd (7), Tb (8), x = 9), have been synthesized and structurally characterized. Ligand H3ipdc was in situ obtained by iodination of ligand H3pdc. Complexes 1-4 are pyrazole-bridged heterometallic dinuclear complexes, and 2-4 are isostructural. Complexes 5-8 are isostructural and comprised of an unusual infinite one-dimensional tape-like chain based on pyrazole-bridged heterometallic dinuclear units. The magnetic properties of compounds 1-4, 7 and 8 have been investigated through the magnetic measurement over the temperature range of 1.8-300 K.  相似文献   

20.
The malonato-bridged copper(II) complex [Cu(mal)(H2O)(azpy)1/2] · H2O (1) (mal = malonate, azpy = 4,4′-azobispyridine) has been synthesized and characterized by X-ray diffraction. The structure of 1 consists of malonato-bridged uniform copper(II) chains which are covalent connected through azpy to form two-dimensional wavelike network. The magnetic pathway of complex 1 is through a single syn-anti carboxylate bridge connecting equatorial and equatorial positions of adjacent copper(II) atoms, and have the value of the intrachain ferromagnetic coupling (J = 8.73(3) cm−1) and interchain antiferromagnetic coupling (zJ′ = − 1.31(1) cm−1) through a numerical expression for a ferromagnetic uniform chain.  相似文献   

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