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1.
Ruthenium(II) Phthalocyaninates(2–): Synthesis and Properties of (Acido)(carbonyl)phthalocyaninato(2–)ruthenate(II), [Ru(X)(CO)Pc2?]? (X = Cl, Br, I, NCO, NCS, N3) (nBu4N)[Ru(OH)2Pc2?] is reduced in acetone with carbonmonoxid to blue-violet [Ru(H2O)(CO)Pc2?], which yields in tetrahydrofurane with excess (nBu4N)X acido(carbonyl)phthalocyaninato(2–)ruthenate(II), [Ru(X)(CO)Pc2?]? (X = Cl, Br, I, NCO, NCS, N3) isolated as red-violet, diamagnetic (nBu4N) complex salt. The UV-Vis spectra are dominated by the typical π-π* transitions of the Pc2? ligand at approximately 15100 (B), 28300 (Q1) und 33500 cm?1 (Q2), only fairly dependent of the axial ligands. v(C? O) is observed at 1927 (X = I), 1930 (Cl, Br), 1936 (N3, NCO) 1948 cm?1 (NCS), v(C? N) at 2208 cm?1 (NCO), 2093 cm?1 (NCS) and v(N? N) at 2030 cm?1 only in the MIR spectrum. v(Ru? C) coincides in the FIR spectrum with a deformation vibration of the Pc ligand, but is detected in the resonance Raman(RR) spectrum at 516 (X = Cl), 512 (Br), 510 (N3), 504 (I), 499 (NCO), 498 cm?1 (NCS). v(Ru? X) is observed in the FIR spectrum at 257 (X = Cl), 191 (Br), 166 (I), 349 (N3), 336 (NCO) and 224 cm?1 (NCS). Only v(Ru? I) is RR-enhanced.  相似文献   

2.
Ruthenium(II)-Phthalocyaninates(1–): Synthesis and Properties of (Halo)(carbonyl)phthalocyaninato(1–)ruthenium(II) Brown-violet (halo)(carbonyl)phthalocyaninato(1–)ruthenium(II), [Ru(X)(CO)Pc?] (X = Cl, Br) is prepared by oxidation of [Ru(X)(CO)Pc2?]? with the corresponding halogen or dibenzoylperoxide. The eff. magnetic moment μeff = 1.74 (X = Cl), 1.68 μB (Br) confirms the presence of a low-spin RuII complex of the Pc? radical. Accordingly, only the first ring oxidation at ~0.64 V and the first ring reduction at ~ ?1.19 V is observed in the cyclovoltammogram of [Ru(X)(CO)Pc2?]?. The UV-VIS-NIR spectra characterizing a monomeric Pc? radical with intense π-π* transitions at 14500, 19800, 25100 and 33900 cm?1 are compared with those of [Ru(Cl)2Pc?] and of monomeric as well as dimeric [Zn(Cl)Pc?]. The IR and resonance Raman(RR) spectra are characteristic for a Pc? radical, too. Diagnostic in-plane vibrations of the Pc? ligand are in the IR spectrum at 1071, 1359, 1445 cm?1 and in the RR spectrum (λ0 = 488.0 nm) at 567, 1597 cm?1. v(C? O) at 1950 cm?1 and v(Ru? X) at 260 (X = Cl) resp. 184 cm?1 (X = Br) are observed only in the IR spectrum.  相似文献   

3.
A new chromophore has been identified in copper‐doped apatite pigments having the general composition [Sr10(PO4)6(CuxOH1?x?y)2], in which x=0.1, 0.3 and y=0.01–0.42. By using X‐ray absorption spectroscopy, low‐temperature magnetization measurements, and synchrotron X‐ray powder structure refinement, it has been shown that the oxygenated compounds contain simultaneously diamagnetic Cu1+ and paramagnetic Cu3+ with S=1. Cu3+ is located at the same crystallographic position as Cu1+, being linearly coordinated by two oxygen atoms and forming the OCuO? anion. The Raman spectroscopy study of [A10(PO4)6(CuxOH1?x?y)2,], in which A=Ca, Sr, Ba, reveals resonance bands at 651–656 cm?1 assigned to the symmetric stretching vibration (ν1) of OCuO?. The strontium apatite pigment exhibits a strong paramagnetic anisotropy with an unprecedentedly large negative zero‐field splitting parameter (D) of ≈?400 cm?1. The extreme magnetic anisotropy causes slow magnetization relaxation with relaxation times (τ) up to 0.3 s at T=2 K, which relates the compounds to single‐ion magnets. At low temperature, τ is limited by a spin quantum‐tunneling, whereas at high temperature a thermally activated relaxation prevails with Ueff≈48 cm?1. Strong dependence of τ on the paramagnetic center concentration at low temperature suggests that the spin‐spin relaxation dominates in the spin quantum‐tunneling process. The compound is the first example of a d‐metal‐based single‐ion magnet with S=1, the smallest spin at which an energy barrier arises for the spin flipping.  相似文献   

4.
CrIII Phthalocyaninates: Synthesis, Properties, and Crystal Structure of l-Bis(triphenylphosphine)iminium trans-Di(nitrito(O))phthalocyaninato(2–)chromate(III) [Cr(H2O)2Pc2?]Ix reacts with excess (PNP)NO2 in dimethylformamide to yield less soluble greenblack l-bis(triphenylphosphine)iminium trans-di(nitrito(O))phthalocyaninato(2–)chromate(III), l(PNP)trans[Cr(ONO)2Pc2?], which crystallizes in the triclinic space group P1 (No. 2) with Z = 2. The Cr atom is in the center of the Pc2? ligand and the two nitrite ions are monodentate O-coordinated in a mutually trans arrangement to the Cr atom. The Cr? O and Cr? Niso bond distances are 1.9898(14) und 1.981(2) Å, respectively. The geometric data of the coordinated nitrite ion are: d(N? O) = 1.307(2) Å; d(N? O) = 1.205(2) Å; ?(O? N? O) = 113.7(2)°; ?(Cr? O? N) = 116.85(12)°. The non-bonding O atoms are trans to the Cr atom. The Pc2? ligand is slightly saddled. Three weak spin-allowed trip-quartet(TQ) transitions (in 103 cm?1): TQ1 (8.20) < TQ2 (11.3) < TQ3 (20.33) and the characteristic π-π* transitions of the Pc2? ligand: B (14.68) < Q1 (27.1) < Q2 (29.0) < N (35.4) are observed in the UV-VIS-NIR spectrum. Prominent luminescence spectra are obtained by excitation within the TQ1 region, in which the spin-forbidden trip-sextet transition at 7376 cm?1 dominates at low temperatures (T < 50 K). The vibrational spectra are discussed. In coincidence of the excitation lines with TQ3, vs(Cr? O) at 378 cm?1 is selectively resonance Raman (RR) enhanced. vas(Cr? O) is observed in the FIR spectrum at 391 cm?1. The following internal vibrations (in cm?1) of the nitrito ligand are in the MIR spectrum: vas(N? O)/1447 > vas(N? O)/1018/1029 > δ(O? N? O)/828 and in the RR-spectrum: vs(N? O)/1410 > vs(N? O)/952, the last followed by three overtones.  相似文献   

5.
Lattice Vibration Spectra. LXIII. Be(IO3)2 · 4 H2O, a Hydrate with Unusual Bonding and Lattice Dynamics The IR and Raman spectra (4000–50 cm?1) of Be(IO3)2 · 4 H2O and of deuterated specimens are recorded at 90 and 300 K and discussed in terms of the unusual relations of the masses of the atoms involved and the large polarization power of the beryllium ions. Thus, the translatory modes of the Be2+ ions (BeO4 skeleton vibrations), the librations of the H2O molecules, and the internal vibrations of the IO3? ions in the spectral regions of 300–400 and 600–1000 cm?1 couple and coincide producing unusual vH/vD isotopic ratios of partly < 1. The H-bond donor strengths of the water molecules is so much increased (due to the very large ionic potential of Be2+ ions, viz. 49 e nm?1) (synergetic effect) that the H-bonds formed are similar in strength as those in hydrates of hydroxides with the very strong H-bond acceptor group OH? (vOD of matrix isolated HDO molecules 2 074 and 2 244 (H2O I) and 2 206 and 2 349 cm?1 (H2O II))  相似文献   

6.
The infrared absorption spectra of some dialkyldimethoxystannanes have been investigated in the 400–1500 cm?1 region. The bands associated with vs(SnC2) and vs(SnO2) vibrations have been found at 510–521 cm?1 and 466–475 cm?1. The group of bands between 560 and 620 cm?1 is assigned jointly to va(SnC2) and va(SnO2) vibrations. v(C? O) of the methoxy groups linked to tin appears at 1064–1068 cm?1.  相似文献   

7.
OsII Phthalocyaninates(2?): Synthesis and Properties of (Halo)(carbonyl)phthalocyaninato-(2?)osmate(II) Soluble, blue tetra(n-butyl)ammonium (halo)(carbonyl)phthalocyaninato(2?)osmate(II), (nBu4N)[Os(X)(CO)Pc2?] (X = Cl, Br, I) is obtained by the reaction of [Os(THF)(CO)Pc2?] (THF: tetrahydrofurane) with (nBu4N)X in THF. In the cyclovoltammograms there are three reversible electrode processes at ?1.21 ± 0.01, 0.18 ± 0.04 and 0.65 ± 0.01 V assigned to the three redox pairs Pc2?/Pc3?, OsII/OsIII and Pc2?/Pc3?. In the electronic absorption spectra only the intense B and Q regions are observed at ~ 15800 resp. 27500, 33000 cm?1. The infrared and resonance Raman spectra closely resemble those of other phthalocyaninates(2?) of low valent osmium. In the infrared spectrum v(C? O) is detected at 1896 ± 4 cm?1 and v(Os? X) at 260 (X = Cl), 175 (X = Br) or 143 cm?1 (X = I).  相似文献   

8.
Ruthenium(III) Phthalocyanines: Synthesis and Properties of Di(halo)phthalocyaninato(1?)ruthenium(III) Di(halo)phthalocyaninato(1?)ruthenium(III), [Ru(X)2Pc?] (X = Cl, Br, I) is prepared by oxidation of [Ru(X)2Pc2?]? (Cl, Br, OH) with halogene in dichloromethane. The magnetic moment of [Ru(X)2Pc?] is 2,48 μB (X = Cl) resp. 2,56 μB (X = Br) in accordance with a systeme of two independent spins (low spin RuIII and Pc?: S = 1/2). The optical spectra of the red violet solution of [Ru(X)2Pc?] (Cl, Br) are typical for the Pc? ligand with the “B” at 13.5 kK, “Q1” at 19.3 kK and “Q2 region” at 31.9 kK. Sytematic spectral changes within the iron group are discussed. The presence of the Pc? ligand is confirmed by the vibrational spectra, too. Characteristic are the metal dependent bands in the m.i.r. spectra at 1 352 and 1 458 cm?1 and the strong Raman line at 1 600 cm?1. The antisymmetric Ru? X stretch (vas(Ru? X)) is observed at 189 cm?1 (X = I) resp. 234 cm?1 (X = Br). There are two interdependent bands at 295 and 327 cm?1 in the region expected for vas(Ru? Cl) attributed to strong interaction of vas(Ru? Cl) with an out-of-plane Pc? tilting mode of the same irreducible representation. Only the symmetric Ru? Br stretch at 183 cm?1 is selectively enhanced in the resonance-Raman(RR) spectra. The Raman line at 168 cm?1 of the diiodo complex is assigned to loosely bound iodine. The broad band at 978 cm?1 in the RR spectra of the dichloro complex is due to an intraconfigurational transition within the electronic ground state of low spin RuIII split by spin orbit coupling.  相似文献   

9.
Lattice Vibration Spectra. LXXVI. On Basic Copper Salts — Crystal Structure, IR and Raman Spectra of Cu2(OH)3NO2 Single-crystal X-ray as well as IR and Raman data of Cu2(OH)3NO2 are presented and discussed with respect to an order-disorder (OD) phase transition and the strength of hydrogen bonds. Cu2(OH)3NO2 crystallizes pseudosymmetrically in the monoclinic space group P21/m (Z = 2, a = 562.22(4), b = 605.94(5), c = 663.55(4) pm and β = 95.415(5)°) forming a layered structure of edge-connected, elongated CuO6 octahedra (final R value 2.5% for 1047 symmetry averaged reflections with I ≥ 2.5 μ1). The NO2? ions are on a split position with dynamic disordering at ambient temperature. On temperature lowering the disorder is frozen out with a symmetry decrease to space group P21. The disorder of the NO2? ions causes four different arrangements of OH(2)? with different strengths of the H…O hydrogen bonds present OD stretching modes in the spectra of isotopically dilute samples 2628, 2535, 2435, and 2343 cm?1 at 90 K. The OH(1)? ions form weak H…N H-bonds to the lone-pair of the nitrogen atoms of the NO2? ions (vOD 2563 cm?1).  相似文献   

10.
Vibrational and Electronic Spectra of Decahalogenodiosmates(IV), [Os2X10]2?, X ? Cl, Br The IR and Raman spectra of the edge-sharing bioctahedral anions [Os2X10]2?, X ? Cl, Br, are assigned according to point group D2h. The bands are found in three characteristic regions; at high wavenumbers stretching vibrations with terminal ligands v(OsClt): 365–280, v(OsBrt): 235–195; in a middle region with bridging ligands v(OsClb): 270–240, v(OsBrb): 175–165 cm?1; the deformation bands are observed at distinct lower frequencies. The electronic spectra of the dimers show intraconfigurational transitions near 2000, 1000, and 600 nm which by position and intensity correspond to those of the monomeric complexes. They are therefore discussed separately for both metal centers according to C2v symmetry. Two additional band systems are presumable pair transitions arising from interactions of the central ions within the dimeric complexes. Due to the different bonding strength of terminal or bridging ligands the intensive charge transfer bands are shifted by 3000–4000 cm?1 bathochromicly or by 2000–3000 cm?1 hypsochromicly compared with the hexahaloosmates(IV).  相似文献   

11.
The hardness of oxo ions (O2?) means that coinage‐metal (Cu, Ag, Au) clusters supported by oxo ions (O2?) are rare. Herein, a novel μ4‐oxo supported all‐alkynyl‐protected silver(I)–copper(I) nanocluster [Ag74?xCuxO12(PhC≡C)50] ( NC‐1 , avg. x=37.9) is characterized. NC‐1 is the highest nuclearity silver–copper heterometallic cluster and contains an unprecedented twelve interstitial μ4‐oxo ions. The oxo ions originate from the reduction of nitrate ions by NaBH4. The oxo ions induce the hierarchical aggregation of CuI and AgI ions in the cluster, forming the unique regioselective distribution of two different metal ions. The anisotropic ligand coverage on the surface is caused by the jigsaw‐puzzle‐like cluster packing incorporating rare intermolecular C?H???metal agostic interactions and solvent molecules. This work not only reveals a new category of high‐nuclearity coinage‐metal clusters but shows the special clustering effect of oxo ions in the assembly of coinage‐metal clusters.  相似文献   

12.
Synthesis and Spectroscopical Characterization of Di(halo)phthalocyaninato(1–)rhodium(III), [RhX2Pc1?] (X = Cl, Br, I) Bronze-coloured di(halo)phthalocyaninato(1–)-rhodium(III), [RhX2Pc1?] (X = Cl, Br) and [RhI2Pc1?] · I2 is prepared by oxidation of (nBu4N)[RhX2Pc2?] with the corresponding halogene. Irrespective of the halo ligands, two irreversible electrode reactions due to the first ringreduction (ER = ?0,90 V) and ringoxidation (EO = 0,82 V) are present in the cyclovoltammogram of (nBu4N)[RhX2Pc2?]. The optical spectra show typical absorptions of the Pc1?-ligand at 14.0 kK and 19.1 kK. Characteristic vibrational bands are at 1 366/1 449 cm?1 (i. r.) and 569/1 132/1 180/1 600 cm?1 (resonance Raman (r. r.)). The antisym. (Rh? X)-stretching vibration is observed at 294 cm?1 (X = Cl), 240 cm?4 (Br) and 200 cm?1 (I). Only the sym. (Rh? I)-stretching vibration at 133 cm?1 is r. r. enhanced together with a strong line at 170 cm?1, which is assigned to the (I? I)-stretching vibration of the incorporated iodine molecule. Both modes show overtones and combinationbands.  相似文献   

13.
The preparation, structures, and magnetic properties of a series of metal formate perovskites [CH3NH3][MnxZn1?x(HCOO)3] were investigated. The isostructural solid solution can be prepared in the complete range of x=0–1. The metal–organic perovskite structures consist of an anionic NaCl type [MnxZn1?x(HCOO)3?] framework with CH3NH3+ templates located in the nearly cubic cavities and forming hydrogen bonds to the framework. When the proportion of Mn increased (i.e., x changed from 0 to 1), the lattice dimensions and metal–oxygen and metal–metal distances show a slight, nonlinear increase because of the increased averaged metal ionic radius and the local structure distortion. Through the series, the magnetism changes from the long‐range ordering of spin‐canted antiferromagnetism for x≥0.40 to paramagnetism when x≤0.30, and the percolation limit was estimated to be xP=0.31(2) for this simple cubic lattice. In the low‐temperature region, enhancement of magnetization and the gradual decrease and final disappearance of coercive field, remnant magnetization, and spin‐flop field upon dilution were observed through this isotropic Heisenberg magnetic series. IR spectroscopic and thermal properties were also investigated.  相似文献   

14.
We have succeeded in constructing a metal–organic framework (MOF), [Cu(bpdc)(H2O)2]n (H2bpdc=2,2′‐bipyridyl‐3,3′‐dicarboxylic acid, 1 ), and two poly‐POM–MOFs (POM=polyoxometalate), {H[Cu(Hbpdc)(H2O)2]2[PM12O40] ? n H2O}n (M=Mo for 2 , W for 3 ), by the controllable self‐assembly of H2bpdc, Keggin‐anions, and Cu2+ ions based on electrostatic and coordination interactions. Notably, these three compounds all crystallized in the monoclinic space group P21/n, and the Hbpdc? and bpdc2? ions have the same coordination mode. Interestingly, in compounds 2 and 3 , Hbpdc? and the Keggin‐anion are covalently linked to the transition metal copper at the same time as polydentate organic ligand and as polydentate inorganic ligand, respectively. Complexes 2 and 3 represent new and rare examples of introducing the metal N‐heterocyclic multi‐carboxylic acid frameworks into POMs, thereby, opening a pathway for the design and the synthesis of multifunctional hybrid materials based on two building units. The Keggin‐anions being immobilized as part of the metal N‐heterocyclic multi‐carboxylic acid frameworks not only enhance the thermal stability of compounds 2 and 3 , but also introduce functionality inside their structures, thereby, realizing four approaches in the 1D hydrophilic channel used to engender proton conductivity in MOFs for the first time. Complexes 2 and 3 exhibit good proton conductivity (10?4 to ca. 10?3 S cm?1) at 100 °C in the relative humidity range 35 to about 98 %.  相似文献   

15.
Monomeric and Dimeric Chromium(III) Phthalocyanines: Synthesis and Properties of Hydroxopyridinophthalocyaninatochromium(III) and μ-Oxodi(pyridinophthalocyaninatochromium(III)) Heating of ?[Cr(OH)Pc2?]”? in pyridine (Py) gives the paramagnetic (T = 273 K) complexes [Cr(OH)(Py)Pc2?] (μCr = 3.84 μB) and [(Cr(Py)Pc2?)2O] (μCr = 1.24 μB) by consecutive substitution and condensation reactions. The UV-VIS spectra are characterized by the typical B, Q, and N regions of the Pc2? ligand being shifted hypsochromically for the dimer with respect to the monomer due to excitonic coupling (1.5 kK). Regions of weak absorbance between 8 and 13 resp. 19 kK are assigned to trip-quartet transitions for both complexes. A weak band at 870 cm?1 in the FIR/MIR spectra is assigned to vas(Cr? O? Cr). In the resonance Raman(RR) spectra v(Cr? O) at 514 cm?1 resp. vs(Cr? O? Cr) at 426 cm?1 is selectively enhanced. Further strong RR-lines of the μ-Oxo dimer at 110 and 631 cm?1 are assigned to a (Py? Cr? O)- resp. internal pyridine deformation of a1g symmetry. An assignment as 2vas(Cr? O? Cr) is proposed for the remarkable RR line at 1740 cm?1.  相似文献   

16.
Synthesis, Crystal Structure, and Properties of Copper(II) Ultraphosphate CuP4O11 CuP4O11 was synthesised from Cu2P4O12 and P4O10 (500°C, sealed silica ampoules) using iodine and a few mg of CuP2 or phosphorus as mineraliser. Chemical transport reactions in a temperature gradient 600 → 500°C led to the formation of well developed, colourless, transparent crystals with edge-lengths up to 5 mm (deposition rate m ≈? 2 mg/h). The crystal structure of copper(II) ultraphosphate (C1 ; Z = 8; a = 13.084(3) Å, b = 13.024(2) Å, c = 10.533(2) Å, α = 89.28(2)°, β = 118.42(2)°, γ = 90.30(2)°) has been determined and refined from X-ray data obtained from a pseudo-merohedrally twinned crystal (twin element two-fold rotation axis // b; volume ratio: 17/3; 3063 independent reflections with 2θ ? 53.4°; 291 variables; conventional residual (based on F) R1 = 0.038, wR2 = 0.101 (based on F2), GooF = 1.10). The crystal structure of CuP4O11 is built from four crystallographically independent ten-membered polyphosphate rings of very similar conformation. These rings are linked to form two-dimensional nets parallel (?2 0 1) planes. There is a close topological relationship between these nets and those formed in polyphosphides CdP4 and CuP2. Copper on two crystallographic sites (Cu2P8O22) is coordinated by oxygen thus forming elongated [CuO6] octahedra (deq(Cu? O) ≈? 1.96 Å; dax(Cu? O) ≈? 2.34 Å). The crystal g-tensor of CuP4O11 has been determined from powder samples to g1 = 2.09, g2 = 2.24, g3 = 2.36. These values are in good agreement with molecular g-values from calculations within the framework of the angular overlap model on the two independent CuO6 octahedra (Cu2+(1): gx = 2.09, gy = 2.10, gz = 2.52; Cu2+(2): gx = 2.08, gy = 2.11, gz = 2.52) assuming exchange coupling. The observed broad absorption band (7000 cm?1 to 13000 cm?1) from powder reflectance measurements (4000–28000 cm?1) and the bulk magnetic susceptibility of μexp = 1.99 μB is also reproduced nicely by this calculations.  相似文献   

17.
Composition‐tailored Mn1?xRuxO2 2 D nanosheets and their reassembled nanocomposites with mesoporous stacking structure are synthesized by a soft‐chemical exfoliation reaction and the subsequent reassembling of the exfoliated nanosheets with Li+ cations, respectively. The tailoring of the chemical compositions of the exfoliated Mn1?xRuxO2 2 D nanosheets and their lithiated nanocomposites can be achieved by adopting the Ru‐substituted layered manganese oxides as host materials for exfoliation reaction. Upon the exfoliation–reassembling process, the substituted ruthenium ions remain stabilized in the layered Mn1?xRuxO2 lattice with mixed Ru3+/Ru4+ oxidation state. The reassembled Li–Mn1?xRuxO2 nanocomposites show promising pseudocapacitance performance with large specific capacitances of approximately 330 F g?1 for the second cycle and approximately 360 F g?1 for the 500th cycle and excellent cyclability, which are superior to those of the unsubstituted Li–MnO2 homologue and many other MnO2‐based materials. Electrochemical impedance spectroscopy analysis provides strong evidence for the enhancement of the electrical conductivity of 2 D nanostructured manganese oxide upon Ru substitution, which is mainly responsible for the excellent electrode performance of Li–Mn1?xRuxO2 nanocomposites. The results underscore the powerful role of the composition‐controllable metal oxide 2 D nanosheets as building blocks for exploring efficient electrode materials.  相似文献   

18.
One μ‐alkoxo‐μ‐carboxylato bridged dinuclear copper(II) complex, [Cu2(L1)(μ‐C6H5CO2)] ( 1 )(H3L1 = 1,3‐bis(salicylideneamino)‐2‐propanol)), and two μ‐alkoxo‐μ‐dicarboxylato doubly‐bridged tetranuclear copper(II) complexes, [Cu4(L1)2(μ‐C8H10O4)(DMF)2]·H2O ( 2 ) and [Cu4(L2)2(μ‐C5H6O4]·2H2O·2CH3CN ( 3 ) (H3L2 = 1,3‐bis(5‐bromo‐salicylideneamino)‐2‐propanol)) have been prepared and characterized. The single crystal X‐ray analysis shows that the structure of complex 1 is dimeric with two adjacent copper(II) atoms bridged by μ‐alkoxo‐μ‐carboxylato ligands where the Cu···Cu distances and Cu‐O(alkoxo)‐Cu angles are 3.5 11 Å and 132.8°, respectively. Complexes 2 and 3 consist of a μ‐alkoxo‐μ‐dicarboxylato doubly‐bridged tetranuclear Cu(II) complex with mean Cu‐Cu distances and Cu‐O‐Cu angles of 3.092 Å and 104.2° for 2 and 3.486 Å and 129.9° for 3 , respectively. Magnetic measurements reveal that 1 is strong antiferromagnetically coupled with 2J =‐210 cm?1 while 2 and 3 exhibit ferromagnetic coupling with 2J = 126 cm?1 and 82 cm?1 (averaged), respectively. The 2J values of 1–3 are correlated to dihedral angles and the Cu‐O‐Cu angles. Dependence of the pH at 25 °C on the reaction rate of oxidation of 3,5‐di‐tert‐butylcatechol (3,5‐DTBC) to the corresponding quinone (3,5‐DTBQ) catalyzed by 1–3 was studied. Complexes 1–3 exhibit catecholase‐like active at above pH 8 and 25 °C for oxidation of 3,5‐di‐tert‐butylcatechol.  相似文献   

19.
This paper continues an investigation into the ethylene–vinyl chloride copolymers prepared by partial reduction of poly(vinyl chloride). The infrared spectra of the copolymers have been obtained and the individual resonances assigned. Each infrared band has been quantitatively analyzed in terms of peak position (cm?1) and intensity, and correlations with the sequence microstructure (dyad, triads, etc.) have been determined. The infrared resonances have been found to be sensitive to long sequences; i.e., (V)x or (E)x where x ≥ 10. Sequences of up to 10–15 monomer units were seen to affect the position (cm?1) and intensity of C? H stretching and bending frequencies. Methylene rocking bands between 850 and 700 cm?1 were observed to be sequence dependent with ? V(E)xV? resonanting at 860, 750, or 730 cm?1 for x = 0, 1 and 2, or ≥3, respectively. The C? Cl stretching resonances, which are well known for their conformational complexity in pure PVC, were found to be dominated by sequence length effects reducing to two bands at 665 and 610 cm?1 characteristic of and isolated ? CH? Cl unit in a long methylene chain.  相似文献   

20.
A five-coordinate copper complex with the tripod ligand tris(1H-benzimidazol-2-ylmethyl)amine (ntb), of composition [Cu(ntb)(H2O)] (C1O4)2?·?C5H4N2O3?·?H2O (C5H4N2O3?=?4-nitropyridine-N-oxide), was synthesized and characterized by means of elemental analyses, electrical conductivities, thermal analyses, IR, and U.V. The crystal structure of the copper complex has been determined by single-crystal X-ray diffraction, and shows that the CuII is bonded to a tris(1H-benzimidazol-2-ylmethyl)amine (ntb) ligand and a water molecule through four N atoms and one O atom, giving a distorted trigonal–bipyramidal coordination geometry with approximate C 3 molecular symmetry. Cyclic voltammograms of the copper complex indicate a quasi-reversible Cu+2/Cu+ couple. Electron spin resonance data confirm a trigonal-bipyramidal structure and with g 2?<?g ζ and a very small value of A 2 (20?×?10?4?cm?1).  相似文献   

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