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1.
Metal encapsulation in zeolitic materials through one-pot hydrothermal synthesis (HTS) is an attractive technique to prepare zeolites with a high metal dispersion. Due to its simplicity and the excellent catalytic performance observed for several catalytic systems, this method has gained a great deal of attention over the last few years. While most studies apply synthetic methods involving different organic ligands to stabilize the metal under synthesis conditions, here we report the use of metallosiloxanes as an alternative metal precursor. Metallosiloxanes can be synthesized from simple and cost-affordable chemicals and, when used in combination with zeolite building blocks under standard synthesis conditions, lead to quantitative metal loading and high dispersion. Thanks to the structural analogy of siloxane with TEOS, the synthesis gel stabilizes by forming siloxane bridges that prevent metal precipitation and clustering. When focusing on Fe-encapsulation, we demonstrate that Fe-MFI zeolites obtained by this method exhibit high catalytic activity in the NH 3-mediated selective catalytic reduction (SCR) of NO x along with a good H 2O/SO 2 tolerance. This synthetic approach opens a new synthetic route for the encapsulation of transition metals within zeolite structures. 相似文献
2.
We report a simple synthesis protocol for making phthalocyanines (Pcs) starting from phthalonitriles. This method is general and requires no specialised equipment. The complexes are isolated and characterised using X‐ray diffraction, NMR, FTIR and Raman spectroscopy and high‐resolution mass spectrometry. First, we study and present a one‐step synthesis route to a metal‐free Pc (H 2PcH 16), as well as to the corresponding MPcH 16 complexes of Mn, Fe, Co, Ni, Cu and Zn. Then, we show that this route can also be used to make the fluorinated Pc analogues (MPcF 16). Finally, we present a new and useful procedure for inserting a metal ion into a metal‐free H 2PcH 16 ring, by direct metalation, yielding the corresponding MPcH 16 complex. This last method is especially useful if you want to make different MPcH 16 complexes. 相似文献
3.
Syntheses for the new photosensitizers HOSiPc-OSi(CH 3) 2(CH 2) 3N(CH 2) 1 or 3(CH 3) 2, Pc 34 and Pc 25, have been developed and the order of activity of these photosensitizers and the previously reported photosensi-tizer Pc 4, HOSiPcOSi(CH 3) 2(CH 2) 3N(CH 3) 2, in the dark and with broad-band red light toward Plasmodium falciparum in red blood cell (RBC) suspensions has been studied. The order of activity has been found to be Pc 4 Pc 34 Pc 25. Thus, the activity of the photosensitizers under both sets of conditions is inversely proportional to the length of their terminal amino alkyl chains. The 50% inhibition dye concentration (IC 50) in the dark for the parasites in RBC suspension with Pc 4 is 24 nM and the dye concentration and light fluence that yield:3 log 10 of parasite inactivation with Pc 4 are 2 mM and 3 J/cm 2, respectively. The synthesis of DNA and proteins by the parasites in culture was strongly inhibited by Pc 4 in the dark while parasite lactate dehydrogenase (pLDH) activity was unaffected. With Pc 4 and light, DNA and protein synthesis of the parasites in culture was strongly inhibited, pLDH activity of the parasites was moderately inhibited and ribosome density of the parasite cells was reduced. Gel electrophoresis studies showed that synthesis of all parasite proteins was inhibited to a similar extent. These results suggest that Pc 4 both in the dark and with light inactivates the cells by disturbing their machinery for the synthesis of not just one but a whole series of proteins. It is concluded that Pc 4 and light may be able to serve as a practical sterilization combination not only for HIV and other viruses but also for malaria parasites in RBC concentrates, and that Pc 4 by itself may have potential as a chemotherapeutic agent toward malaria. 相似文献
4.
A major difficulty in photodynamic therapy is the poor solubility of the photosensitizer (PS) under physiological conditions which correlates with low bioavailability. PS aggregation leads to a decrease in the photodynamic efficiency and a more limited activity in vitro and in vivo. To improve the aqueous solubility and reduce the aggregation of 2,9(10),16(17),23(24)‐tetrakis[(2‐dimethylamino)ethylsulfanyl]phthal‐ocyaninatozinc(II) (Pc9), the encapsulation into four poloxamine polymeric micelles (T304, T904, T1107 and T1307) displaying a broad spectrum of molecular weight and hydrophilic–lipophilic balance was investigated. The aqueous solubility of Pc9 was increased up to 30 times. Morphological evaluation showed the formation of Pc9‐loaded spherical micelles in the nanosize range. UV/Vis and fluorescence studies indicated that Pc9 is less aggregated upon encapsulation in comparison with Pc9 in water–DMSO 2% and remained photostable. Pc9‐loaded micelles generated singlet molecular oxygen in high yields. Photocytotoxicity assays using human nasopharynx KB carcinoma cells confirmed that the encapsulation of Pc9 in T1107 and T1307 increases its photocytotoxicity by 10 times in comparison with the free form in water–DMSO. In addition, Pc9 incorporated into cells was mainly localized in lysosomes. 相似文献
5.
The title complex salt, (C 16H 36N)[MnBr(C 32H 16N 8)] or (TBA)[Mn IIBr(Pc)] (TBA is tetrabutylammonium and Pc is phthalocyaninate), has been obtained as single crystals by the diffusion technique and its crystal structure was determined using X‐ray diffraction. The high‐spin ( S = ) [Mn IIBr(Pc)] − macrocycle has a concave conformation, with an average equatorial Mn—N(Pc) bond length of 2.1187 (19) Å, an axial Mn—Br bond length of 2.5493 (7) Å and with the Mn II cation displaced out of the 24‐atom Pc plane by 0.894 (2) Å. The geometry of the Mn IIN 4 fragment in [Mn IIBr(Pc)] − is similar to that of the high‐spin ( S = ) manganese(II) tetraphenylporphyrin (TPP) in [Mn II(1‐MeIm)(TPP)] (1‐MeIm is 1‐methylimidazole). 相似文献
6.
A novel approach to heteroleptic heteronuclear rare earth metal(III) trisphthalocyaninates was proposed with the complexes [(15C5) 4Pc]M*[(15C5) 4Pc]M(Pc) as examples (15C5 is 15-crown-5, Pc 2? is the phthalocyaninate dianion, and M* ?? M = Yb and Y). Unsubstituted lanthanum bisphthalocyaninate, La(Pc) 2, was used for the first time as a Pc 2? donor in the synthesis of such complexes. This substantially increased the yields of the target heteronuclear complexes over the previous literature data. 相似文献
7.
The synthesis of a new azafullerene C 59N–phthalocyanine (Pc) dyad is described. The key step for the synthesis of the C 59N–Pc dyad was the formation of the C 59N‐based carboxylic acid, which was smoothly condensed with hydroxy‐modified Pc. The structure of the C 59N–Pc dyad was verified by 1H and 13C NMR spectroscopy, IR spectroscopy, UV/Vis spectroscopy and MS measurements. The photophysical and electrochemical properties of the C 59N–Pc dyad were investigated in both polar and non‐polar solvents by steady state and time‐resolved photoluminescence and absorption spectroscopy, as well as by cyclic voltammetry. Different relaxation pathways for the photoexcited C 59N–Pc dyad, as a result of changing the solvent polarity, were found, thus giving rise to energy‐transfer phenomena in non‐polar toluene and charge‐transfer processes in polar benzonitrile. Finally, the detailed quenching mechanisms were evaluated and compared with that of a C 60–Pc dyad, which revealed that the different excited‐state energies and reduction potentials of the two fullerene spheres (i.e. C 59N vs. C 60) strongly diverged in the deactivation pathways of the excited states of the corresponding phthalocyanine dyads. 相似文献
8.
Different ammonium fluoroferrates (NH 4) xFeF 2x (2≤ x≤3) have been investigated. The thermal decomposition of the compounds obtained can be interpreted by their identical crystal structures (cryolite type). The decomposition products of all ammonium fluoroferrates formed in initial stage are isostructural of NH 4FeF 4. The decomposition is accompanied by the partial reduction of Fe(III) to Fe(II) by ammonium isolated. The end product of the thermal decomposition is FeF 2 and FeF 3 mixture. 相似文献
9.
(H 2O) 0.33FeF 3, grown by hydrothermal synthesis, crystallizes in the orthorhombic system with cell dimensions a = 7.423(3) Å, b = 12.730(4) Å, c = 7.526(3)Å, and space group Cmcm, Z = 12. The structure, derived from single crystal X-ray diffraction data (605 independent reflections) is refined to R = 0.019 ( Rω = 0.021). The framework of the Fe IIIF 6 octahedra is related to that of hexagonal tungsten bronze (HTB) Rb 0.29WO 3. At 122°C, zeolithic water is evolved from hexagonal tunnels without any noticeable change of the fluorine skeleton. The related anhydrous compound represents a new form of iron trifluoride which is denoted HTBFeF 3; at 525°C, it transforms into the cubic form of ReO 3-type. (H 2O) 0.33FeF 3 and HTBFeF 3 are antiferromagnetic, with Néel temperatures of TN = 128°7 ± 0.5 K and TN = 97 ± 2 K, respectively. 相似文献
10.
Synthetic zeolites X & Y have been examined for their abilities to take in Co, Ni and Zn radioisotopes. Distribution coefficients ( K
d
) have been determined, with and without competing cations, and at various pH values. Elution studies on zeolites containing Co, Ni and Zn radioisotopes considered the effect of acid and alkaline conditions, calcination and cement encapsulation. Leach rates arising from these experiments have been calculated. The general conclusions can be drawn are that zeolites X & Y are suitable for decontamination of aqueous wastes containing Co, Ni and Zn. Cement encapsulation is appropriate but no advantage accrues from pre-calcination. Some comments on the likely mechanism of leaching losses have been made. 相似文献
11.
A new metal–organic compound FeF 6(HAmTAZ) 3 which (HAmTAZ = 3-amino-1,2,4-triazole) was hydrothermally synthesized from an equimolar mixture of FeF 2 and FeF 3 with HAmTAZ, aqueous HF and ethanol solvent at 410 K yielded a new hybrid class I fluoroferrate. The structure was characterized by single-crystal X-ray diffraction data. The crystal structure of FeF 6(HAmTAZ) 3 crystallizes in the trigonal system space group R3c with a = b = 12.5230 (6) Å, c = 18.5950 (16) Å, γ = 120° and Z = 6. The structure was built up from isolated octahedral FeF 6 separated by [HAmTAZ] + cations. The thermal analysis has shown that the decomposition undergoes two steps between 475 and 775 K. IR and mass spectrometry have been used to confirm the presence of the organic molecule in the crystal lattice and determine the evacuated vapours during the decomposition, respectively. The magnetization of the title compound has no revealed any ferromagnetic component in the range of magnetic field from ?20 to 20 KOe at room temperature. 相似文献
12.
Iron fluoride (FeF 3) is considered as a promising cathode material for Li-ion batteries (LIBs) due to its high theoretical capacity (712 mAh/g) with a 3e ? transfer. Herein, we have designed a strategy of hierarchical and mesoporous FeF 3/rGO hybrids for LIBs, where the hollow FeF 3 nanospheres are the main contributor to the specific capacity and the 2D rGO nanosheets are the matrix elevating the electronic conductivity and buffering the volume expansion. The unique FeF 3/rGO hybrid can be rationally synthesized by a non-aqueous in-situ precipitation method, offering the merits of large specific surface area with rich active sites, fast transport channels for lithium ions, effective alleviation of volume expansion during cycles, and accelerating the electrochemical reaction kinetics. The FeF 3/rGO hybrid electrode possesses a high initial discharge capacity of 553.9 mAh/g at a rate of 0.5 C with 378 mAh/g after 100 cycles, acceptable rate capability with 168 mAh/g at 2 C, and feasible high-temperature operation (320 mAh/g at 70 °C). The superior electrochemical behaviors presented here demonstrates that the FeF 3/rGO hybrid is a potential electrode for LIBs, which may open up a new vision to design high-efficiency energy-storage devices such as LIBs based on transition metal fluorides. 相似文献
13.
The hydrogenation properties of magnesium hydride mechanically milled with iron fluorides (FeF 2 and FeF 3), were investigated by Temperature Programmed Desorption (TPD) and volumetric methods using a Sieverts-type apparatus, as
prepared upon dehydrogenation and finally upon subsequent hydrogenation. The activation energy of hydrogen desorption (E a), calculated from the Kissinger formula using TPD measurements obtained with different heating rates, showed significant
decreases of Ea in comparison to that of milled MgH 2 without any dopants. Moreover, the influence of these metal fluorides on the thermodynamics of the decomposition process
was also examined. In the case of the FeF 2 dopant, rehydrogenation following desorption caused the complete decomposition of the iron fluoride to BCC iron and the formation
of a predominant MgH 2 phase. In contrast to FeF 2, the addition of FeF 3 led to the formation of β-MgH 2 as a major phase coexisting with Mg 2FeH 6 and MgF 2 compounds. The presence of pure Fe in the MgH 2+FeF 2 composite, as opposed to MgH 2+FeF 3 containing Mg 2FeH 6 and MgF 2, did not cause any significant influence on the sorption properties of MgH 2. Moreover, the original material doped with FeF 3 predominantly showed iron in the Mg 2FeH 6 compound, while the FeF 2 dopant iron mostly showed the nearly pure BCC metallic phase
相似文献
14.
Kinetic analysis of the thermal destruction of complexes of zinc(II)tetra- tert-butylphthalocyanine Zn(t-Bu) 4Pc with organic solvent molecules has been carried out. For ligands having high ionization potentials, long refluxing of solution is required for preparing biligand complexes. For molecular ligands whose ionization potentials do not exceed 9.2 eV, the composition of complexes with Zn(t-Bu) 4Pc is independent of the preparation parameters. The destruction of the Zn(t-Bu) 4Pc complexes with n-propylamine, diethylaniline, piperidine (1: 1, cold synthesis), diethylamine, morpholine, quinoline, or cyclopentanone (1: 2, hot synthesis; 1: 2, cold synthesis) obeys fist-order equations; for complexes with pyridine, 1,4-dioxane, DMF, cyclopentanone (1: 1, hot synthesis), 3-dimethylaminopropionitrile, or piperidine (1: 2, hot synthesis), destruction obeys second-order equations. The activation energies of thermal destruction for the first group of molecular complexes fall in the range from 89 to 370 kJ/mol; the rate-controlling stage is nucleation and growth. For the second group, the activation energies fall in the range from 160 to 640 kJ/mol; the rate-controlling stage is a chemical reaction. 相似文献
15.
On the Thermal Decomposition of (NH 4) 2[FeF 5(H 2O)] on Quasi-Isobaric Conditions The thermal decomposition of (NH 4) 2[FeF 5(H 2O)] was investigated by thermal and X-ray analysis. Quasi-isobaric conditions are realized by using a special crucible which guaranteed a pressure of the gaseous products of 70 kPa. In dependence on the partial pressure α- or β-(NH 4) 2FeF 5 were formed during dehydration. Further intermediate products are NH 4FeF 4, (NH 4) 1?xFeF 4?x, and (NH 4) yFeF 3 with x = 0.15–0.20 and y = 0.12–0.15. Structural relations between these phases are discussed and comparable considerations to the Al system were made. 相似文献
16.
Relative enthalpies for low-and high-temperature modifications of Na 3FeF 6 and for the Na 3FeF 6 melt have been measured by drop calorimetry in the temperature range 723–1318 K. Enthalpy of modification transition at 920
K, δ trans
H(Na 3FeF 6, 920 K) = (19 ± 3) kJ mol −1 and enthalpy of fusion at the temperature of fusion 1255 K, δ fusH(Na 3FeF 6, 1255 K) = (89 ± 3) kJ mol −1 have been determined from the experimental data. Following heat capacities were obtained for the crystalline phases and for
the melt, respectively: C
p(Na 3FeF 6, cr, α) = (294 ± 14) J (mol K) −1, for 723 = T/K ≤ 920, C
p(Na 3FeF 6, cr, β) = (300 ± 11) J (mol K) −1 for 920 ≤ T/K = 1233 and C
p(Na 3FeF 6, melt) = (275 ± 22) J (mol K) −1 for 1258 ≤ T/K ≤ 1318. The obtained enthalpies indicate that melting of Na 3FeF 6 proceeds through a continuous series of temperature dependent equilibrium states, likely associated with the production of
a solid solution.
相似文献
17.
We proposed a new approach to the synthesis of heteroleptic crown-substituted terbium(III) bisphthalocyaninate, [(15C5)4Pc]Tb(Pc) (1) based on the reaction of unsubstituted lanthanum bisphthalocyaninate (La(Pc)2) with tetra-15-crown-5-phthalocyanine (H2[(15C5)4Pc]) and terbium(III) acetate in a mixture of octanol and chloronaphthalene in the presence of 1,8-diazabicyclo[ 5.4.0]undec-7-ene as an organic base. For the first time, we carried out a comparative spectrophotometric titration of compound 1 with MBPh4 solutions (M = K, Rb, Cs) and demonstrated the formation of isostructural cofacial supramolecular dimers. Spectral-structural correlations were developed for evaluation of the distances between phthalocyanine ligands in new supramolecular assemblies, which can be used for the development of polynuclear suprasingle-molecule magnetic materials. 相似文献
18.
The hydrothermal synthesis, using tris-(2-ethylamino)amine ( tren) as a template, and the crystal structures of three new hybrid iron fluorides, (H 3O) 2·[H 3tren] 2·(FeF 6) 2·(FeF 5(H 2O))·2H 2O ( I), [H 3tren] 2·(FeF 6) 2·(FeF 2(H 2O) 4)·8H 2O ( II) and [H 3tren] 2·(FeF 6)·(F) 3·H 2O ( III), are reported. I, II, and III are triclinic ( P-1), monoclinic ( P2 1/ c) and orthorhombic ( I222), respectively. The structure of I is built up from isolated FeF 6 and FeF 5(H 2O) distorted octahedra separated by triprotonated [H 3tren] 3+ cations, disordered H 3O + cations and H 2O molecules. In II, Fe IIIF 6 and neutral [Fe IIF 2(H 2O) 4] octahedra form, together with [H 3tren] 3+ cations, infinite (100) layers separated by extra water molecules. The structure of III consists of isolated and disordered FeF 6 octahedra, fluoride anions F − connected to [H 3tren] 3+ cations and extra fluoride anions F − disordered with H 2O molecules. All [H 3tren] 3+ cations have a “spider” type conformation. 57Fe Mössbauer characterization shows that +III valence state can only be considered for iron cations in I and III and preliminary Mössbauer results are consistent with the presence of both +II and +III valences for iron cations in II, in agreement with the crystallographic results. 相似文献
19.
An original synthesis method for the synthesis of hydrated iron trifluoride is presented. This method, based on solvothermal process starting from iron salt and HF in alcool, is economic and simple. The electrochemical performances of the composite phase FeF 3·0.33H 2O/Graphitic oxide is showing enhanced capacity of 250 mAh/g at 0.05 °C. 相似文献
20.
Triclinic crystals of bismuth(III) triple-decker phthalocyanine, Bi 2Pc 3, Pc=C 32H 16N 82−, were grown directly by the reaction of Bi 2Se 3 with 1,2-dicyanobenzene at 220°C. The Bi 2Pc 3 molecule is centrosymmetric with the bismuth atoms located closer to the peripheral phthalocyaninato(2−) rings than to the central ring. Each bismuth(III) ion is connected by four N-isoindole atoms to the peripheral and by four N-isoindole to the central Pc ring with average distances of 2.333 and 2.747 Å, respectively. This indicates a stronger connection of Bi(III) to the peripheral saucer-shaped macrocyclic rings than to the central rings. The neighbouring phthalocyaninato(2−) moieties in the Bi 2Pc 3 molecule are separated by a distance of 3.101(5) Å. The central Pc ring is rotated by 36.4° with respect to the peripheral ones. Differences in Bi–N bond lengths are a result of interaction of the bismuth ion with peripheral and central rings as well as the repulsion forces between two bismuth ions in the same Bi 2Pc 3 molecule, which are separated by a distance of 3.839(2) Å. The crystal packing is characterized by a distance of 3.56 Å between Pc rings of neighbouring Bi 2Pc 3 molecules. 相似文献
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