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31.
Synthesis,Physical Properties and Application of a Series of New Polyoxometalate-Based Ionic Liquids
Yohan Martinetto Salom Basset Bruce Pgot Catherine Roch-Marchal Franck Camerel Jelena Jeftic Betty Cottyn-Boitte Emmanuel Magnier Sbastien Floquet 《Molecules (Basel, Switzerland)》2021,26(2)
This paper deals with the preparation and the characterization of four new ionic liquids resulting from the pairing of various polyoxotungstates or polyoxomolybdates with the cation trihexyltetradecylphosphonium. The physical properties measured by different techniques evidence that the viscosity and the rheological behaviors of such POM-based ionic liquids, POM-ILs, strongly depend on the nature of the POM, especially its charge. Playing on the nature of the POM, we can indeed obtain Newtonian liquids or some much more viscous materials exhibiting characteristics of resins or pseudo-plastics. In a second part of this study, the potentialities of using such materials both as solvent and catalyst for the oxidation of a series of alcohols are presented as proof of concept. This part highlights great differences in strength and selectivity as a function of the POM-IL used. Furthermore, a very simple way to recycle the catalyst is also presented. 相似文献
32.
Large Mo18O52 crystals are obtained by an appropriate crystallization method. The examination of their well developed surfaces by the use of reflection high energy electron diffraction (RHEED) proves that these are (100) surfaces stepped along [010] directions. It is concluded that this oxide surface conformation can be connected to the particular Mo18O52 structure which is built up of MoO3 slabs of finite width mutually joined by crystallographic shear planes (CS planes). Transmission electron microscopy (TEM) analysis from Mo18O52 crystal flakes confirms that these are single crystals without disorder in the periodicity of the CS planes. 相似文献
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34.
El Moll H Kemmegne-Mbouguen JC Haouas M Taulelle F Marrot J Cadot E Mialane P Floquet S Dolbecq A 《Dalton transactions (Cambridge, England : 2003)》2012,41(33):9955-9963
We report the syntheses and characterizations of the first polyoxothiometalate complexes isolated from the reaction of the oxothiocationic [Mo(V)(2)O(2)S(2)](2+) precursor and bisphosphonate ligands H(2)O(3)PCR(OH)PO(3)H(2) (R = C(4)H(5)N(2), zoledronic acid; R = C(3)H(6)NH(2), alendronic acid). [(Mo(2)O(2)S(2)(H(2)O))(4)(O(3)PC(O)(C(4)H(6)N(2))PO(3))(4)](8-) (Mo(8)S(8)(Zol)(4)) and [(Mo(2)O(2)S(2)(H(2)O))(4)(O(3)PC(O)(C(3)H(6)NH(3))PO(3))(4)](8-) (Mo(8)S(8)(Ale)(4)) contain four Mo(V) dimers connected via bisphosphonate ligands. These compounds offer a unique opportunity to compare the structures and properties of cyclic compounds obtained with [Mo(2)O(2)S(2)](2+) and with [Mo(2)O(4)](2+). The oxothio compounds appear less stable in solution than the oxo analogue, confirming the higher lability and versatility of [Mo(2)O(2)S(2)]-based compounds compared to [Mo(2)O(4)]-based POMs. Multinuclear and multidimensional solid-state NMR studies were carried out to complement X-ray diffraction analysis. Information on short-range interactions, dynamic behaviors, and local disorder within the crystalline materials are therefore reported. Furthermore, the electrocatalytic properties of Mo(8)S(8)(Ale)(4) and of the analogous [(Mo(2)O(4)(H(2)O))(4)(O(3)PC(O)(C(3)H(6)NH(3))PO(3))(4)](8-) (Mo(8)O(8)(Ale)(4)) immobilized onto the surface of a glassy carbon electrode were studied, thus evidencing the ability of [Mo(2)O(2)S(2)]-based cycles to promote the reduction of protons into hydrogen, whereas the oxo analogue appeared inactive. 相似文献
35.
Sébastien Floquet Vladimir S. Korenev Akram Hijazi Laure Guénée Emmanuel Cadot 《Liquid crystals》2013,40(7):1000-1007
Two dimethyldioctadecylammonium (DODA+) salts of a new keplerate with the general formula [Mo132O312S60(SO4)x(H2O)132–2x](12 + 2x)? and abbreviated DODAn?Mo132S60 (n = 44, 56) were synthesised and characterised. Both clusters were fully characterised by the combination of Polarised Optical Microscopy, Differential Scanning Calorimetry and Small-angle X-Ray Diffraction showing self-organisation in lamellar (L) liquid crystalline phases. We demonstrated that the lamellar periodicity h of the mesophases can be controlled with the number of DODA+ associated to the clusters. Finally, these new results were compared to those gained from a previously published analogue, the fully oxo keplerate noted DODA36?Mo132 that also self-organise with temperature, but in a slightly more structured lamellar liquid crystalline phase. 相似文献
36.
Thanh‐Loan Lai Dr. Mouhamad Awada Dr. Sébastien Floquet Dr. Catherine Roch‐Marchal Nancy Watfa Dr. Jérôme Marrot Dr. Mohamed Haouas Dr. Francis Taulelle Prof. Dr. Emmanuel Cadot 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(38):13311-13320
The internal functionalization of the Keplerate‐type capsule Mo132 has been carried out by ligand exchange leading to the formation of glutarate and succinate containing species isolated as ammonium or dimethylammonium salts. Solution NMR analysis is consistent with asymmetric inner dicarboxylate ions containing one carboxylato group grafted onto the inner side of the spheroidal inorganic shell while the second hangs toward the center of the cavity. Such a disposition has been confirmed by the single‐crystal X‐ray diffraction analysis of the glutarate containing {Mo132} species. A detailed NMR solution study of the ligand‐exchange process allowed determining the binding constant KL of acetate (AcO?), succinate (HSucc?) or glutarate (HGlu?) ligands at the 30 inner coordinating sites, which vary such as K<K<K‐supported by the associated thermodynamic parameters ΔrS* and ΔrH*. Such a variation is mainly explained by a positive entropic gain attenuated by unfavorable steric effect. Furthermore, these results are completed by 1H DOSY and 1H EXSY NMR experiments which are in agreement with bulky guests firmly trapped within the cavity. At last, variable temperature 1H NMR study below 290 K revealed a striking line broadening occurring abruptly within a 5 K range. Such an effect appears closely related to the presence of the ammonium cations suspected to be present within the cavity and then has been interpreted as an inner‐phase transition leading to a frozen state. 相似文献
37.
Tracking “Apolar” NMe4+ Ions within Two Polyoxothiomolybdates that Have the Same Pores: Smaller Clathrate and Larger Highly Porous Clusters in Action 下载免费PDF全文
Dr. Vladimir S. Korenev Antoine G. Boulay Dr. Mohamed Haouas Dr. Fatma Bannani Prof. Dr. Vladimir P. Fedin Prof. Dr. Maxim N. Sokolov Emmanuel Terazzi Somenath Garai Prof. Dr. Achim Müller Dr. Francis Taulelle Dr. Jérôme Marrot Dr. Nathalie Leclerc Dr. Sébastien Floquet Prof. Dr. Emmanuel Cadot 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(11):3097-3105
38.
Jean-François Lemonnier Sébastien Floquet Jérôme Marrot Emmanuel Cadot 《Journal of Cluster Science》2006,17(2):267-282
The novel polyoxothioanion [Mo4S4O4(OH)2(OH2)3pba]2? where pba4? ligand is the 1,3-propylenebis(oxamate), was prepared by reacting Mo12S12O12(OH)12(OH2)6 ring with [Cu-pba]2? in aqueous medium. NaK[Mo4O4(μ-S)4(μ-OH)2(μ-H2O)(H2O)2(pba)] ·7H2O was isolated in the solid state and fully characterized by X-ray diffraction study (tetragonal, P4(2)/m [a=20.4962(4) Å; b=20.4962(4) Å; c=14.7013(5) Å). The molecular structure consists of an arc cycle shape tetranuclear enchainment {Mo4S4O4(OH)2 (OH2)3} closed by a pba4? ligand. The 3-D packing, resulting from the connection between K+ and Na+ and the coordination complex {Mo4-pba]2? is described. The 1H-NMR characterization of the complex in aqueous solution is given. The 1H-NMR spectrum exhibits four signals assigned to four enantiotopic protons of the alkyl chain of the pba4? ligand and is in agreement with crystal structure of the complex [Mo4-pba]2?. The compound was also characterized by infrared spectroscopy. 相似文献
39.
Korenev VS Floquet S Marrot J Haouas M Mbomekallé IM Taulelle F Sokolov MN Fedin VP Cadot E 《Inorganic chemistry》2012,51(4):2349-2358
Reaction of the cyclic lacunary [H(7)P(8)W(48)O(184)](33-) anion (noted P(8)W(48)) with the [Mo(2)S(2)O(2)(H(2)O)(6)](2+) oxothiocation led to two compounds, namely, [K(4){Mo(4)O(4)S(4)(H(2)O)(3)(OH)(2)}(2)(WO(2))(P(8)W(48)O(184))](30-) (denoted 1) and [{Mo(4)O(4)S(4)(H(2)O)(3)(OH)(2)}(2)(P(8)W(48)O(184))](36-) (denoted 2), which were characterized in the solid state and solution. In the solid state, the structure of [K(4){Mo(4)O(4)S(4)(H(2)O)(3)(OH)(2)}(2)(WO(2))(P(8)W(48)O(184))](30-) reveals the presence of two disordered {Mo(4)O(4)S(4)(H(2)O)(3)(OH)(2)}(2+) "handles" connected on both sides of the P(8)W(48) ring. Such a disorder is consistent with the presence of two geometrical isomers where the relative disposition of the two {Mo(4)O(4)S(4)(H(2)O)(3)(OH)(2)}(2+) handles are arranged in a perpendicular or parallel mode. Such an interpretation is fully supported by (31)P and (183)W NMR solution studies. The relative stability of both geometrical isomers appears to be dependent upon the nature of the internal alkali cations, i.e., Na(+) vs K(+), and increased lability of the two {Mo(4)O(4)S(4)(H(2)O)(3)(OH)(2)}(2+) handles, compared to the oxo analogous, was clearly identified by significant broadening of the (31)P and (183)W NMR lines. Solution studies carried out by UV-vis spectroscopy showed that formation of the adduct [{Mo(4)O(4)S(4)(H(2)O)(3)(OH)(2)}(2)(P(8)W(48)O(184))](36-) occurs in the 1.5-4.7 pH range and corresponds to a fast and quantitative condensation process. Furthermore, (31)P NMR titrations in solution reveal formation of the "monohandle" derivative [{Mo(4)O(4)S(4)(H(2)O)(3)(OH)(2)}(P(8)W(48)O(184))](38-) as an intermediate prior to formation of the "bishandle" derivatives. Furthermore, the electrochemical behavior of [{Mo(4)O(4)S(4)(H(2)O)(3)(OH)(2)}(2)(P(8)W(48)O(184))](36-) was studied in aqueous medium and compared with the parent anion P(8)W(48). 相似文献
40.
Thevenard J Floquet N Ramont L Prost E Nuzillard JM Dauchez M Yezid H Alix AJ Maquart FX Monboisse JC Brassart-Pasco S 《Chemistry & biology》2006,13(12):1307-1315
We previously demonstrated that the NC1[alpha3(IV)185-191] CNYYSNS peptide inhibited in vivo tumor progression. The YSNS motif formed a beta turn crucial for biological activity. The aim of the present study was to design a YSNSG cyclopeptide with a constrained beta turn on the YSNS residues more stable than CNYYSNS. By nuclear magnetic resonance and molecular modeling, we demonstrated that the YSNSG cyclopeptide actually adopted the expected beta-turn conformation. It promoted melanoma cell adhesion and prevented their adhesion to the native peptide. It inhibited in vitro cell proliferation and migration through Matrigel by downregulating proteolytic cascades. Moreover, intraperitoneal administration of the YSNSG cyclopeptide inhibited melanoma progression far more efficiently than the native peptide. The increased solubility and stability at low pH of the YSNSG cyclopeptide suggest this peptide as a potent antitumor therapeutic agent. 相似文献