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1.
A series of four isostructural dodecanuclear complexes [MnIII9MnII2LnIII(O)8(OH)(piv)16(NO3)(CH3CN)]·xCH3CN·yC7H16 (piv = pivalate; x = ½, y = ¾, Ln = Tb (1); x = 2, y = ½, Ln = Dy (2), Ho (3), and Y (4)) has been prepared for which the structural motif described as ‘a lanthanide ion nested in a large manganese shell’ is observed. All compounds show out-of-phase signals in their ac susceptibilities, and their single-molecule magnet behaviour was confirmed by single-crystal micro-SQUID studies of 1-3 which show hysteresis loops of molecular origin at T < 1.0 K. The SMM behaviour observed in compounds 1-3 is more pronounced than that for 4, which contains the diamagnetic YIII ion. This is principally the result of ferromagnetic coupling between the paramagnetic anisotropic LnIII ions (TbIII, DyIII and HoIII) and the manganese shell, which enhances the total spin ground state of the complexes.  相似文献   

2.
《Polyhedron》2007,26(9-11):1876-1880
The crystalline one-dimensional compounds, [M2(bza)4(pyz)]n (bza = benzoate; pyz = pyrazine; M = CuII (1)) and [M2(bza)4(2-mpyz)]n (2-mpyz = 2-methylpyrazine; M = RhII (2), CuII (3)), demonstrate gas absorbency of NO. The amounts of adsorbed NO gas are 0.61 for 1, 0.30 for 2, and 0.23 for 3 per M2 unit at 195 K (800 Torr). The crystals of 1 adsorbed more NO molecules than did those of 2 and 3. The magnetic susceptibilities of the NO-inclusion crystals indicate that included NO molecules interact antiferromagnetically with neighboring guests without dimerization to N2O2. Magnetic behaviors indicated NO aggregation in the narrow 1D channels of 13 under unsaturated adsorption conditions.  相似文献   

3.
《Polyhedron》2007,26(9-11):2252-2258
A 2-D cyanide- and triamine-bridged MnIICrIII ferrimagnet, [Mn3(dien)2(H2O)2][Cr(CN)6]2 · 4H2O (1), has been prepared by the combination of Mn2+, diethylenetriamine (dien) co-ligand and [Cr(CN)6]3−. This compound forms a unique 2-D hollow sheet structure constructed by 1-D ribbon networks on the basis of triamine (dien)-bridged trinuclear MnII units. Compound 1 readily looses all lattice water molecules and irreversibly changes to a dehydrated form, [Mn3(dien)2(H2O)2][Cr(CN)6]2 (1a), in the air. Cryomagnetic studies of 1 and 1a reveal an antiferromagnetic interaction between CrIII and MnII ions, and an unusual long-range ferrimagnetic ordering below 30 K (1) and 40 K (1a) with multiple magnetic phase changes below TC. MCD spectra of 1a show a strong Faraday ellipticity associated with the LMCT band of the Cr–CN below 300 nm. Faraday ellipticity is remarkably enhanced below TC in line with the characteristics long-range ferrimagnetic ordering.  相似文献   

4.
Several multinuclear ferrocenyl–ethynyl complexes of formula [(η5-C5H5)(dppe)MII?CC–(fc)n–CC–MII(dppe)(η5-C5H5)] (fc = ferrocenyl; dppe = Ph2PCH2CH2PPh2; 1: MII = Ru2+, n = 1; 2: MII = Ru2+, n = 2; 3: MII = Ru2+, n = 3; 4: MII = Fe2+, n = 2; 5: MII = Fe2+, n = 3) were studied. Structural determinations of 2 and 4 confirm the ferrocenyl group directly linked to the ethynyl linkage which is linked to the pseudo-octahedral [(η5-C5H5)(dppe)M] metal center. Complexes of 15 undergo sequential reversible oxidation events from 0.0 V to 1.0 V referred to the Ag/AgCl electrode in anhydrous CH2Cl2 solution and the low-potential waves have been assigned to the end-capped metallic centers. The solid-state and solution-state electronic configurations in the resulting oxidation products of [1]+ and [2]2+ were characterized by IR, X-band EPR spectroscopy, and UV–Vis at room temperature and 77 K. In [1]+ and [2]2+, broad intervalence transition band near 1600 nm is assigned to the intervalence transition involving photo-induced electron transfer between the Ru3+ and Fe2+ metal centers, indicating the existence of strong metal-to-metal interaction. Application of Hush’s theoretical analysis of intervalence transition band to determine the nature and magnitude of the electronic coupling between the metal sites in complexes [1]+ and [2]2+ is also reported. Computational calculations reveal that the ferrocenyl–ethynyl-based orbitals do mix significantly with the (η5-C5H5)(dppe)Ru metallic orbitals. It clearly appears from this work that the ferrocenyl–ethynyl spacers strongly contribute in propagating electron delocalization.  相似文献   

5.
《Polyhedron》1999,18(26):3391-3399
Two polymorphs (I: mp 49.0–50.0°C; II: mp 80.0–82.0°C) of N,N-dimethyl-selenobenzamide, (CH3)2NC(Se)Ph, have been observed. Both I and II can be prepared separately using the same reaction under different conditions. The phase change from phase I to phase II occurs at low temperatures and this has been confirmed by solid state NMR (13C), powder X-ray, and single-crystal structural studies. The single-crystal X-ray diffraction study reveals that the lower melting point form (phase I) crystallizes in the triclinic space group P-1 with two conformations in the unit cell, while the higher melting point form (phase II) crystallizes in the monoclinic space group P21/c with one conformation in the unit cell. Theoretical calculations on model clusters using the Universal Forcefield (UFF) show that the total energy of phase I (triclinic form) is 5.9 kcal per mol molecule higher than that of phase II (monoclinic form). Also, the immersion energy which is due to non-bonding interactions, namely Van der Waals and Coulombic (electrostatic) terms, has been calculated using UFF. The Van der Waals terms were very similar in the two crystalline forms (triclinic: −43.1 kcal mol−1; monoclinic: −44.8 kcal mol−1), but the Coulombic terms were significantly different (triclinic: −14.0 kcal mol−1; monoclinic: −31.5 kcal mol−1) and favor the monoclinic form. The triclinic form (phase I) is a kinetically favored metastable phase and upon cooling it changes to the monoclinic form (phase II), a thermodynamically stable phase.  相似文献   

6.
Iron mixed-valence complex, (n-C3H7)4N[FeIIFeIII(dto)3] (dto = C2O2S2) shows a new-type of phase transition coupled with spin and charge around 120 K, where the charge transfer between the FeII and FeIII sites occurs reversibly, and shows the ferromagnetic transition at 7 K. To investigate the magnetic structure and its dimensionality of (n-C3H7)4N[FeIIFeIII(dto)3], we have synthesized a mixed crystal system, (n-C3H7)4N[FeII1?xZnIIxFeIII(dto)3], and measured its magnetic properties. In this system, the magnetic moment is reduced with increasing of Zn ratio. Moreover, the ferromagnetic interaction changes to the antiferromagnetic one and the remnant magnetization disappears between x = 0.48 and 0.96, while the charge transfer between the FeII and FeIII sites disappears above x = 0.26. In this paper, we present the magnetic dilution effect on the charge transfer phase transition and the ferromagnetic transition by means of magnetic susceptibility measurement and 57Fe Mössbauer spectroscopy.  相似文献   

7.
《Polyhedron》2007,26(9-11):2291-2298
The reaction of [NEt4]3[Cr(CN)6] with titanium(III) p-toluenesulfonate at a pH of 2 affords a gray solid whose metal content and spectroscopic and magnetic properties are fully consistent with it being a Prussian blue material of stoichiometry “TiIII[CrIII(CN)6] · H2O”. The carbon, nitrogen, and hydrogen content, however, are not consistent with this stoichiometry, and further investigation showed that the gray material has a powder X-ray diffraction profile, infrared spectrum, and magnetic properties very similar to those of the “all-chromium” Prussian blue CrII[CrIII(CN)6]0.67 · 6H2O. All data, including the C, H, and N weight percentages, are consistent with the conclusion that the material isolated is a nanocomposite of CrII[CrIII(CN)6]0.67 · xH2O and TiO2 in the ratio of 1–1.6. These results suggest that TiIII reduces some of the [CrIII(CN)6]3− ions to generate TiIV and CrII; the former hydrolyzes to amorphous TiO2 · 2H2O, the latter loses its bound CN ligands and reacts with unreacted [CrIII(CN)6]3− ions to generate the crystalline all-chromium PB species. The electrochemical potentials suggest that the [CrIII(CN)6]3− ion should not be reduced by TiIII; evidently, this unfavorable reaction is driven by the insolubility of the reaction products. The results constitute a cautionary tale in two respects: first, that the characterization of Prussian blue materials must be conducted with care and, second, that the insolubility of Prussian blue analogues can sometimes drive reactions that in solution are thermodynamically unfavorable.  相似文献   

8.
The reaction of organoaluminum compounds containing O,C,O or N,C,N chelating (so called pincer) ligands [2,6-(YCH2)2C6H3]AliBu2 (Y = MeO 1, tBuO 2, Me2N 3) with R3SnOH (R = Ph or Me) gives tetraorganotin complexes [2,6-(YCH2)2C6H3]SnR3 (Y = MeO, R = Ph 4, Y = MeO, R = Me 5; Y = tBuO, R = Ph 6, Y = tBuO, R = Me 7; Y = Me2N, R = Ph 8, Y = Me2N, R = Me 9) as the result of migration of O,C,O or N,C,N pincer ligands from aluminum to tin atom. Reaction of 1 and 2 with (nBu3Sn)2O proceeded in similar fashion resulting in 10 and 11 ([2,6-(YCH2)2C6H3]SnnBu3, Y = MeO 10; Y = tBuO 11) in mixture with nBu3SniBu. The reaction 1 and 3 with 2 equiv. of Ph3SiOH followed another reaction path and ([2,6-(YCH2)2C6H3]Al(OSiPh3)2, Y = MeO 12, Me2N 13) were observed as the products of alkane elimination. The organotin derivatives 411 were characterized by the help of elemental analysis, ESI-MS technique, 1H, 13C, 119Sn NMR spectroscopy and in the case 6 and 8 by single crystal X-ray diffraction (XRD). Compounds 12 and 13 were identified using elemental analysis,1H, 13C, 29Si NMR and IR spectroscopy.  相似文献   

9.
The use of a convenient source of MnIII ions, namely the [Mn(OR)(O2CR′)2]n (R = H, Me, and R′ = Me, But) family of 1-D coordination polymers, afforded two new enneanuclear and decanuclear molecular clusters, homometallic [Mn9O7(O2CBut)13(MeCN)2] (3) and heterometallic [Mn10?xFex(OMe)20(O2CMe)10] (x < 10) (4), respectively. Compound 3 was synthesized by a solvent-induced structural transformation, whereas complex 4 resulted from the reaction of [Mn(OH)(O2CMe)2]n with an FeIII source. The core of 3 comprises two [Mn4O2]8+ butterfly units and a [Mn3O]7+ triangular unit fused together by sharing one Mn atom. Magnetic susceptibility measurements of 3 revealed dominant antiferromagnetic interactions within the molecule, and a ground state of S = 1 with many low-lying excited states. Complex 4 is a mixed FeIII/MnIII single-strand molecular wheel, which forms 3D nanotubular stacks arranged in a zig–zag fashion. The described work suggests that the [Mn(OR)(O2CR′)2]n compounds represent excellent starting materials for MnIII carboxylate cluster chemistry.  相似文献   

10.
In the case of iron mixed-valence complexes whose spin states are situated in the spin-crossover region, conjugated phenomena coupled with spin and charge are expected. In general, the Fe site coordinated by six S atoms is in the low-spin state, while the Fe site coordinated by six O atoms is in the high-spin state. From this viewpoint, we have synthesized and investigated physical properties for an monothiooxalato-bridged (mto = C2O3S) iron mixed-valence complex, (n-C4H9)4N[FeIIFeIII(mto)3], consisting of FeIIIO3S3 and FeIIO6 octahedra, which behaves as a ferrimagnet with its magnetic transition temperature of TN = 38 K and Weiss temperature of θ = ?93 K. From the analysis of 57Fe Mössbauer spectra of 57Fe enriched complexes, (n-C4H9)4N[57FeIIFeIII(mto)3] and (n-C4H9)4N[FeII57FeIII(mto)3], the charge transfer between FeII and FeIII exists in the paramagnetic phase. Considering the time window of 57Fe Mössbauer spectroscopy, the time scale of the valence fluctuation is at least slower than 10?7 s. In order to confirm the valence fluctuation between FeII and FeIII, we investigated the dielectric constant and found an anomalous enhancement attributed to the Fe valence fluctuation between 170 and 250 K.  相似文献   

11.
Two new hybrid materials, (C4H14N2)[MII(H2O)6](SO4)2·4H2O (MII: Co (I), Ni (II)), have been synthesised by slow evaporation method at room temperature and crystallographically characterized. They crystallise isotypically in the monoclinic system, space group P21/n, with the following unit-cell parameters a = 9.2285(3), b = 11.3333(4), c = 10.6693(4) Å, β = 109.004(2)°, Z = 2 and V = 1055.07(6) Å3 for I and a = 9.2127(2), b = 11.3182(2), c = 10.6434(2) Å, β = 109.094(1)°, Z = 2 and V = 1048.74(4) Å3 for II. The structure of the two supramolecular compounds consists of metallic cation octahedrally coordinated to six water molecules, sulfate anions, 1,4-butanediammonium cation and water molecules linked together via two types of hydrogen bonds, O–H?O and N–H?O. The two compounds are not stable at room temperature and their partial dehydration depends on the humidity of the environment. The thermal decomposition of precursors, studied by thermogravimetric analysis (TG) and temperature-dependent X-ray diffraction (TDXD), shows successive intermediate hydrates and crystalline anhydrous compounds upon dehydration.  相似文献   

12.
《Polyhedron》2003,22(14-17):1857-1863
The syntheses and magnetic properties are reported for three Mn4 single-molecule magnets (SMMs): [Mn4(hmp)6(NO3)2(MeCN)2](ClO4)2·2MeCN (3), [Mn4(hmp)6(NO3)4]·(MeCN) (4), and [Mn4(hmp)4(acac)2(MeO)2](ClO4)2·2MeOH (5). In each complex there is a planar diamond core of MnIII 2MnII 2 ions. An analysis of the variable-temperature and variable-field magnetization data indicate that all three molecules have intramolecular ferromagnetic coupling and a S=9 ground state. The presence of a frequency-dependent alternating current susceptibility signal indicates a significant energy barrier between the spin-up and spin-down states for each of these three MnIII 2MnII 2 complexes. The fact that these complexes are SMMs has been confirmed by the observation of hysteresis in the plot of magnetization versus magnetic field measured for single crystals of complexes 3 and 4. The hysteresis loops for both of these complexes exhibit steps characteristic of quantum tunneling of magnetization. Complex 4 shows its first step at zero field, whereas the first step for complex 3 is shifted to −0.10 T. This shift is attributable to weak intermolecular antiferromagnetic exchange interactions present for complex 3.  相似文献   

13.
Two new complexes [MnIII(HL)2(acac)] and [MnII(HL)2]n have been obtained by reacting manganese(III) acetylacetonate monohydrate or manganese(II) chloride monohydrate with 2-salicylichydrazono-1,3-dithiolane ligand (H2L). Both compounds have been fully characterized by spectroscopic methods and single crystal X-ray diffraction. In the solid state, the molecular packing are described and discussed in term of weak H-bonds and short contacts. The unprecedented bridging coordination mode of this ligand lead to the first 2-salicylichydrazono-1,3-dithiolane-bridged coordination polymer [MnII(HL)2]n. The EPR spectrum of this compound was obtained with g  2.07, corresponding to a manganese ion (+II) in octahedral high-spin coordination sphere. The MnII complex exhibit paramagnetic behavior corresponding to quasi-isolated metal centers.  相似文献   

14.
By reaction of dichloroheptasilane [(SiMe3)2MeSi]2SiCl2 with lithiumphosphanides LiPHR, the silylphosphanes [(SiMe3)2MeSi]2SiClPHR with R = 2, 4, 6-tri-tert-butylphenyl ( = supermesityl, Mes1) (1) and Si(SiMe3)3 ( = hypersilyl, Hyp) (2) were prepared. Both compounds were characterized with X-ray diffraction, multinuclear NMR spectroscopy and elemental analysis. Compound 1 did not react with n-BuLi, but only with a large excess of tert-BuLi. Phosphasilene [(SiMe3)2MeSi]2SiPMes1 could be identified by a 31P NMR signal at +346 ppm. All attempts to separate it from the reaction mixture failed due to many by-products which had formed through SiSi and SiP bond cleavage. Lithiation of 2 was possible with 4.2 equiv. of tert-BuLi, and crystals of the lithiumphosphanide [(SiMe3)2MeSi]2SiClPLiHyp (3) could be obtained from THF, albeit in a quality not sufficient for X-ray diffraction. All attempts to achieve LiCl elimination and formation of the phosphasilene [(SiMe3)2MeSi]2SiPSi(SiMe3)3 failed due to the unusual stability of the lithiumphosphanide. Prolongued refluxing in toluene (110 °C) only led to complete loss of coordinated THF, and 31P7Li spin spin coupling could be observed in the 31P NMR spectrum (1JPLi = 84 Hz).Reaction of potassium phosphanide [(SiMe3)3Si]SiMe3PK with SiCl4 led to the formation of [(SiMe3)3Si](SiMe3)P(SiCl3) (4), which could be successfully characterized with X-ray diffraction and multinuclear NMR spectroscopy. SiP bond lengths vary between 218 pm (SiCl3) and 230 pm (hypersilyl). Despite these differences, 31P29Si coupling constants are nearly identical (92.4 Hz and 85.5 Hz, respectively).  相似文献   

15.
[FeIII4(acac)6(Br-mp)2] (1) and [FeIII4(acac)6(tmp)2] (2) were obtained from the reaction of Fe(acac)2 with the appropriate tripodal alcohol. Both magnetic clusters show clear signatures for ferrimagnetic super exchange coupling. A fit of the DC susceptibility of 1 with the Kambe model gives J = ?8.2 ± 0.2 cm?1, with g = 1.96 ± 0.02. Powder AC susceptibility data display significant frequency dependence for both compounds. The observation of an out-of-phase component demonstrates that these molecules may be single-molecule magnets (SMMs). AC susceptibility data for frozen solutions of 1 and 2 in toluene also show an out-of-phase signal proving these molecules are SMMs in solution. Going from powder to solution, the χ″ signals shift to higher temperatures which points towards an increase in energy barrier for the magnetization relaxation.  相似文献   

16.
17.
The oxidation of 3-O-methyl-d-glucopyranose (Glc3Me) by CrVI in acid medium yields CrIII, formic acid and 2-O-methyl-d-arabinose as final products when a 50-times or higher excess of Glc3Me over CrVI is used. The redox reaction takes place through the combination of CrVI  CrIV  CrII and CrVI  CrIV  CrIII pathways. Intermediacy of free radicals and CrII in the reaction was demonstrated by the observation of induced polymerization of acrylamide and detection of CrO22+ formed by reaction of CrII with O2. Intermediate oxo-CrV–Glc3Me species were detected by EPR spectroscopy. In 0.3–0.5 mol/L HClO4, intermediate CrV rapidly decompose to the reaction products, while, at pH 5.5–7.5, where the redox processes are very slow, five-coordinate CrV bis-chelates of the pyranose and furanose forms of Glc3Me remain more than 15 h in solution. The C1–C2 bond cleavage of Glc3Me upon reaction with CrVI distinguishes this derivative from glucose, which is oxidized to gluconic acid.  相似文献   

18.
A systematic investigation of the reactions of Cu(ClO4)2 · 6H2O with maleamic acid (H2L) in the presence of 2,2′-bipyridine (bpy) has been carried out. The chemical and structural identity of the products depends on the solvent, the absence or presence of external hydroxides in the reaction mixture and the molar ratio of the reactants. Various reaction schemes have led to the isolation of the complexes [Cu2(HL)2(bpy)2(H2O)2](ClO4)2 (1), [Cu2(HL)2(bpy)2(H2O)2](ClO4)2 · 2H2O (1 · 2H2O), [Cu(L′′)(bpy)]n · 2nH2O (2 · 2nH2O), [Cu2(L′′)(bpy)2(H2O)2]n(ClO4)2n · 0.5nH2O (3 · 0.5nH2O), [Cu2(L′′)2(bpy)2] · 2MeOH (5 · 2MeOH), [Cu2(L′)2(bpy)2(ClO4)2] (6) and [Cu(ClO4)2(bpy)(MeCN)2] (7b), where L′′2? and L′? are the maleate(?2) and monomethyl maleate(?1) ligands, respectively. The HL? ion has been transformed to L′′2? and L′? in the known compounds 2 · 2nH2O and 6, respectively, via metal ion-assisted processes involving hydrolysis (2 · 2nH2O) and methanolysis (6) of the primary amide group. The reaction that leads to 6 takes place through the formation of the mononuclear complex [Cu(ClO4)2(bpy)(MeOH)2] (7a), whose structure was assigned on the basis of its spectral similarity with the structurally characterized complex 7b. The structures of the cations in 1 and 1 · 2H2O consists of two CuII atoms bridged by the carboxylate groups of the two HL? ligands, each exhibiting the less common η2 coordination mode; a chelating bpy molecule and a H2O ligand complete square pyramidal coordination at each metal centre. The structure of the dinuclear repeating unit in the 1D coordination polymer 3 · 0.5nH2O consists of two CuII atoms bridged by two syn,syn η1:η1:μ2 carboxylate groups belonging to two L′′2? ions; each ligand bridged two neighboring [CuII,II2] units thus promoting the formation of a helical chain. The structure of the dinuclear molecule of complex 5 · 2MeOH consists of two CuII atoms bridged by two η2 carboxylate groups from two L′′2? ligands; the second carboxylate group of each maleate(?2) ligand is monodentately coordinated to CuII, creating a remarkable seven-membered chelating ring. The L′? ion behaves as a carboxylate-type ligand in 6, with the carboxylate group being in the familiar syn,syn η1:η1:μ2 coordination mode; a chelating bpy molecule and a coordinated ClO4? complete five-coordination at each CuII centre. The crystal structures of the complexes are stabilized by various H-bonding patterns. Characteristic IR bands of the complexes are discussed in terms of the known structures and the coordination modes of the ligands.  相似文献   

19.
《Polyhedron》2005,24(16-17):2250-2256
A mixed-valence Mn6 cluster, [Mn6O2(t-BuCO2)10(H2O)(NNPy)2] (2), has been synthesized by the assembly of [Mn6O2(t-BuCO2)10(THF)4] · THF (1) with a nitronyl nitroxide radical molecule, 2-(p-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (NNPy). Complex 2 consists of [Mn6O2]10+ core and two NNPy radical attachments, where the [Mn6O2]10+ core is composed of two MnIII ions (i.e., the inner Mn ions) bridged by two μ4-O2− and four MnII ions (i.e., the outer Mn ions) surrounding the inner MnIII ions via the two μ4-O2−, forming an edge-shared double-tetrahedral polygon (vertices: Mn ions, centers: μ4-O2−). Bridges by pivalate groups in μ2- and μ3-modes assist the coordination spheres around these Mn ions. Two of the outer MnII ions in trans position are, to the sixth coordination site, occupied by NNPy molecule (pyridine-N coordination). One of the outer MnII ions is occupied by a water molecule to complete octahedral geometry, but the rest of them is vacancy taking a square-pyramidal geometry. The variable-temperature direct current (DC) magnetic susceptibility was collected in the temperature range of 1.81 to 300 K at a 1 kOe appled field. The molar magnetic susceptibility (χM) steadily increases from 0.053 emu mol−1 at 300 K to 0.29 emu mol−1 at 20 K, showing a kink (peak), and then increases rapidly to 0.70 emu mol−1 at 1.81 K. The profile of this magnetic behavior indicates that the intracluster spin cancellation takes place bellow 20 K to derive an SMn6 = 0 by strong antiferromagnetic interaction between Mn ions. This is consequently leading to paramagnetic isolation of only the two nitronyl nitroxide units as if remaining as exchange-uncorrelated spin carriers. The variable-temperature ESR spectra show a sharp signal below 30 K with g = 2.00, proving the presence of free nitronyl nitroxide radical, in which double integral of such signal obeys the Curie–Weiss law that follows the susceptibility result in the low-temperature region.  相似文献   

20.
The hydrothermal syntheses and structures of two new open-framework iron phosphates, [C5N2H14]2[FeIII2F2(HPO4)4]·2H2O, I, and [C5N2H14][FeIII4(H2O)4F2(PO4)4], II, are presented. While the structure of I consist of FeO4F2 octahedra and HPO4 terahedra linked to form one-dimensional structure, that of II consist of FeO4(H2O)2, FeO4(H2O)F, FeO4F2 and PO4 units connected to give rise to a three-dimensional structure. The structure of I resembles the naturally occurring mineral tancoite while II resembles the iron phosphate, ULM-12, [C6N2H14][Fe4(PO4)2F2(H2O)3]. Magnetic susceptibility studies indicate anti-ferromagnetic behavior in both the compounds with TN=200 and 175 K for I and II, respectively. Crystal data: I, monoclinic, space group=P21/n (no. 14). a=7.2261(6), b=16.5731(14), c=11.0847(10) Å, β=97.265(2)°, V=1316.8(2) Å3, Z=4, ρcalc=1.952 g cm−1, μ(MoKα)=1.446 mm−1, R1=0.0448 and wR2=0.1141 for 1882 data [I>2σ(I)]; for II, monoclinic, space group=P21/n (no. 14). a=9.9691(3), b=12.4013(3), c=17.3410(3) Å, β=103.762(1)°, V=2082.32(9) Å3, Z=4, ρcalc=2.576 g cm−1, μ(MoKα)=3.162 mm−1, R1=0.0510 and wR2=0.1064 for 2979 data [I>2σ(I)].  相似文献   

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