共查询到20条相似文献,搜索用时 15 毫秒
1.
The anions binding properties of the pyrrole-based tripodal anion receptor 1 were studied by X-ray crystallography, 1H NMR, and ESI-MS. It revealed that this new tripodal receptor has a preference for binding H2PO4− and F− ions. 相似文献
2.
Ryo Kato 《Tetrahedron letters》2004,45(22):4273-4276
Potential use of a surfactant-like receptor is demonstrated at the 1,2-dichloroethane-water interface for strong and selective binding of H2PO4− over Br− and Cl−. The analysis by interfacial tensiometry reveals that the interfacial adsorption of a thiourea-isothiouronium conjugate, BT-C1, is significantly stabilized by the binding of H2PO4− with the adsorption constant of 1.7 × 105 M−1 while the interfacial adsorptivity of this receptor is relatively moderate for Br− (0.81 × 105 M−1) and Cl− (0.63 × 105 M−1). Such complexation-induced interfacial adsorption behaviors of BT-C1 are discussed as a basis for the development of receptor-based chemical sensors for phosphate anions. 相似文献
3.
A new series of acyclic anion receptors (1-4) based on methyl 5-(aminomethyl)-1H-pyrrole-2-carboxylate were designed and synthesized. The anion recognition properties of these receptors were examined by 1H NMR spectroscopy and rationalized by density functional theoretical calculation. Receptor 1 displays the highest affinity and selectivity for anionic guests mainly due to the intramolecular hydrogen bonds and rigid molecular geometry. 相似文献
4.
Bibiana Moreno-Valle Milagros Aguilar-Martínez Marisela Martínez-Quiroz Valentín Miranda-Soto José García-Elías 《Supramolecular chemistry》2018,30(1):9-19
A new group of ureylbenzamide-based receptors (1–4) has been synthesized; its binding affinity and capacity to form supramolecular complexes in solution with different anions have been investigated. For designing these receptors, it was considered a combination of the positions of the urea and amide groups (ortho and meta), and the chromophore groups naphthyl and nitrophenyl, yielding four receptors. The position and chromophore structure affected the acidity of the urea and amide hydrogens in the order 4>3>2>1. All the spectroscopic studies showed a significant change of 1 and 2 compared with 3 and 4 in the presence of different TBAX salts in acetonitrile. The 1H-NMR spectra show a preferential interaction of the anions with the urea group in receptors 1 and 2 due to the less steric hindrance, while there is a cooperative interaction of amide group in receptors 3 and 4 due to the closeness of both groups. 相似文献
5.
Both the structure and intramolecular flexibility of a series of aza crown ethers were studied by experimental NMR and theoretical molecular modeling. The stoichiometries of complexation to the anions H2PO4− and HSO4− and resulting complex stabilities were determined by experimental NMR (1H, 31P) titration and, in addition, the structure and mobility changes of the aza crown ethers upon complexation were also examined. 相似文献
6.
The high-temperature phase behaviour of RbH2PO4 and CsH2PO4 have been studied. RbH2PO4 undergoes a single quasi-irreversible phase transition with an enthalpy of 4.665 kJ mol?1. The transition is found to occur over the temperature range 86–111°C. CsH2PO4 undergoes two transitions at 149 and 230°C. The lower one is quasi-irreversible and has an enthalpy of 4.284 kJ mol?1. The one at 230°C is reversible and has an enthalpy of 1.071 kJ mol?1. 相似文献
7.
Frederick M. Pfeffer Alisha M. Buschgens Thorfinnur Gunnlaugsson 《Tetrahedron letters》2005,46(38):6579-6584
The 4-amino-1,8-naphthalimide-based anion receptor 3 binds dihydrogenphosphate with 1:1 stoichiometry through cooperative hydrogen bonding to a naphthalimide N-H and thiourea N-H groups. This was clearly established from 1H NMR titration experiments in DMSO-d6 where a substantial shift in the resonance for the naphthalimide N-H was observed concomitant with the expected thiourea N-H chemical shift migration upon successive additions of H2PO4−. However, whilst 1H NMR titration experiments indicate that 3 was capable of binding other anions such as acetate, the naphthalimide N-H does not participate and the N-H resonance was essentially invariant during the titration. The lack of cooperative binding in this instance was justifiable on steric grounds. 相似文献
8.
Two zinc phosphates (ZnPO), [H2(N2C9H20)]·[Zn(H2PO4)4] (I) and [H2(N2C9H20)]2·[Zn2(HPO4)3(H2PO4)2]·H2O (II), are synthesized under hydrothermal conditions using 4-amino-2.2.6.6-tetramethylpiperidine as organic template. I crystallizes in space group with , , , α=92.57(1)°, β=89.76(1)°, γ=102.16(2)°, and Z=2. Its structure, refined to R=0.029 and Rw=0.076 for 4279 independent reflections, consists of [Zn(H2PO4)4]2− clusters held together through strong hydrogen bonds to form pseudo-layers between which the doubly protonated amine molecules are inserted. II is monoclinic, C2, with , , , β=103.72(5)°, and Z=4 (R=0.079, Rw=0.268, 2477 independent reflections). The structure of II consists of ∞[Zn2(HPO4)3(H2PO4)2]4− inorganic (2D) layers built up from vertex-sharing [ZnO4] and [(H2/H)PO4] tetrahedra. Organic cations and water molecules ensure the connection between these layers via hydrogen bonds. It is shown that numerous (1D), (2D), e.g., [H2(N2C9H20)]2·[Zn2(HPO4)3(H2PO4)2]·H2O, and (3D) (ZnPO) result from the condensation of the [Zn(H2PO4)4]2− clusters. 相似文献
9.
A. V. Shtemenko V. G. Stolyarenko K. V. Domasevich 《Russian Journal of Coordination Chemistry》2007,33(2):79-84
The complex [Re2(HPO4)2(H2PO4)2(H2O)2] · 4H2O (I) was synthesized and investigated by conductometric, potentiometric, electronic and vibration spectroscopic methods.
Thermal behavior of the title compound was studied and its molecular structure was determined from X-ray diffraction data.
In the dimeric neutral complex, the bridging pairs of the hydrophosphate and dihydrophosphate groups close four five-membered
Re-O-P-O-Re chelate rings. The O atom of water molecule occupies the axial position in the metal coordination polyhedron.
The Re-Re distance 2.2168(8) ? corresponds to quadruple bond.
Original Russian Text ? A.V. Shtemenko, V.G. Stolyarenko, K.V. Domasevich, 2007, published in Koordinatsionnaya Khimiya, 2007,
Vol. 33, No. 2, pp. 83–88. 相似文献
10.
Research on the underpotential deposition of H (upd H) and anion adsorption on Pt( 100) in 0.5 M aqueous H2SO4 solution by cyclic voltammetry (CV) indicates that the overall adsorption/desorption charge density is affected strongly by variation of the temperature T, and that it decreases by about 1/3 when T is raised from 293 to 328 K. The sharp peak at 0.375 V vs. RHE assigned to the anion adsorption decreases its potential, current density and charge density. The CV feature assigned to the upd H, a wide shoulder overlapping the sharp peak, also decreases with T augmentation, but the decline of its charge density is less pronounced. The results indicate that the Hupd and anion surface coverages, θHAN and θAN respectively are strongly temperature-dependent. This behavior may be assigned to lateral repulsive interactions. 相似文献
11.
12.
José Pérez Eduardo Pérez Beatriz del Vas Luis García Jose Luis Serrano 《Thermochimica Acta》2006,443(2):231-234
(NH4)2SO4 and (NH4)H2PO4 are the principal components in the powder material used in fire extinguishers. In this paper the mutual influence in their thermal decomposition is investigated by thermogravimetry. Two methods for the quantification of both salts in mixtures (NH4)2SO4/(NH4)H2PO4 are proposed. The first employs thermogravimetry and is based on the measurement of the mass fraction in the 500-550 °C interval, once (NH4)2SO4 has totally decomposed to yield gaseous products. The second uses some selected peaks in the X-ray diffractogram. 相似文献
13.
Electrical conduction (dc) studies are made with pure and cobalt(II)-doped single crystals of NH4H2PO4 and KH2PO4. The effect of the dopant concentration on the enthalpy for the migration of protons and the enthalpy for the rotation of the H2PO4 group have been studied. It is suggested that proton migration occurs through a synchronous phosphate rotation mechanism. Tritium diffusion studies in KDP and 32PO4 diffusion in ADP crystals have been made. The mechanisms for the conduction and diffusion processes are found to be different in nature. The distribution coefficients of Co(II) dopant in ADP (2.92 × 10?3) and KDP (1.14 × 10?3) are calculated. The following enthalpy values are obtained.
KDP (eV) | ADP (eV) | |
Enthalpy for the migration of protons | 0.01 ± 0.01 | 0.15 ± 0.02 |
Enthalpy for the rotation of phosphate group | 0.71 ± 0.01 | 0.66 ± 0.01 |
Enthalpy for T-diffusion | 0.14 ± 0.01 | — |
Enthalpy for 32PO4 diffusion | — | 0.24 ± 0.01 |