About
37
Publications
3,517
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
2,879
Citations
Publications
Publications (37)
The spontaneous self-assembly of a neutral circular trinuclear Ti(IV) -based helicate is described through the reaction of titanium(IV) isopropoxide with a rationally designed tetraphenolic ligand. The trimeric ring helicate was obtained after diffusion of n-pentane into a solution with dichloromethane. The circular helicate has been characterized...
We report the synthesis and structural characterisation of two titanium(IV) complexes. A new titanium(IV) complex bearing four picolinato ligands, denoted as Ti(pic)4, has been prepared under solvothermal conditions. This complex identified by single‐crystal diffraction is a new example of an octacoordinated environment for titanium(IV) and is clos...
The work presented here concerns the evaluation of the reactivity of the [Ti8O8(OOCCH2But)(16)] cluster towards phenol, resorcinol and catechol using NMR techniques. Whereas the reactions conducted in the presence of phenol and resorcinol showed to be particularly slow, it appeared that catechol allowed the quantitative displacement of the carboxyl...
A new class of organic crystalline 2,2'-biphenol-based H-bonded material displaying 1D-channels encapsulating solvent molecules is described. A reversible guest-induced crystal-to-crystal conversion between the solvated H-bonded phase and a compact H-bonded non-solvated phase was observed. The energy competition between intramolecular H-bonds forma...
A binuclear Ti(IV)-based helicate synthesized from a symmetric tetrahydroxyheptaphenylene strand was self-assembled in solution and shown to undergo a spontaneous head-to-tail differentiation according to single-crystal X-ray diffraction.
The orange-colored and hydrolytically stable compound {[Ti2O(Hbhmpc)(H(2)bhmpc)(H(2)bhmpc)] C4H8O2 HX}(2) (with H(3)bhmpc = 2,6-bis(hydroxymethyl)-p-cresol and X = OEt or CCl3) has been studied by a combination of single crystal Xray diffraction data, U V-vis. spectroscopy, IR and Raman spectroscopes, H-1, C-13 and O-17 solution NMR spectroscopes,...
The 3,3'-diphenyl-2,2'-biphenol (dpbpolH(2)) ligand is shown to react with Ti(OPr(i))(4) in a 2:1 ratio to yield a novel C(2)-symmetric mononuclear octahedral Ti(IV) bis-biphenolate complex, cis-Ti(dpbpol)(2)(HOPr(i))(2).
Incorporation of lithium and sodium in MIL-74 aluminum and gallium phosphates has been successfully achieved by hydrothermal synthesis resulting in A(2)Al(7)(PO4)(12).4tren.A(H2O)(16) (A = Li, Na) and Li2Ga7(PO4)(12).4tren.Li(H2O)(16). The structure-directing agent is the tris(2-aminoethyl)amine (tren), and the synthesis was carried during 36 h at...
Incorporation of lithium and sodium in MIL-74 aluminum and gallium phosphates has been successfully achieved by hydrothermal synthesis resulting in A2Al7(PO4)12·4tren·A(H2O)16 (A = Li, Na) and Li2Ga7(PO4)12·4tren·Li(H2O)16. The structure-directing agent is the tris(2-aminoethyl)amine (tren), and the synthesis was carried during 36 h at a temperatur...
Crystalline materials obtained by reacting titanium(IV) isopropoxide (1) with widely different ligands such as 1,3-propanediol, 2,2′-biphenol or triphenylacetic acid using acetone as a solvent have been characterised using single-crystal X-ray diffraction, 1H, 13C and 17O NMR spectroscopies and theoretical modelling. In the case of the previously d...
Chiolite has been selected as a test case for developing a general approach to solve inorganic structures from powders by combining NMR, modeling, and X-ray diffraction. The different steps of the strategy are successfully performed, building the candidate integrant units using NMR, simulating candidate crystal structures using the computational AA...
Aluminum 1,4-benzenedicarboxylate Al(OH)[O(2)C-C(6)H(4)-CO(2)]. [HO(2)C-C(6)H(4)-CO(2)H](0.70) or MIL-53 as (Al) has been hydrothermally synthesized by heating a mixture of aluminum nitrate, 1,4-benzenedicarboxylic acid, and water, for three days at 220 degrees C. Its 3 D framework is built up of infinite trans chains of corner-sharing AlO(4)(OH)(2...
An iron−aluminum phosphate Fe3Al6(PO4)12·4tren·17H2O (MIL-74) has been hydrothermally synthesized with the tris(2-aminoethyl)amine (tren) as a structure-directing agent (453 K, 36 h, autogenous pressure). Single-crystal X-ray diffraction, magnetic measurements, and Mössbauer and solid-state NMR spectroscopies were carried out to characterize the co...
A new mixed zinc-aluminum phosphate Zn(3)Al(6)(PO(4))(12), 4tren, 17H(2)O (MIL-74) has been hydrothermally synthesized with the tris(2-aminoethyl)amine (tren) as a structure-directing agent (453 K, 36 h, autogenous pressure). The solid was characterized by a nonclassical method combining single-crystal X-ray diffraction and several solid-state NMR...
For Abstract see ChemInform Abstract in Full Text.
A new fluorinated gallium phosphate, MIL-50, has been synthesized under mild hydrothermal conditions using 1,6-diaminohexane. The chemical formula of MIL-50 is Rb(2)Ga(9)(PO(4))(8)(HPO(4))(OH)F(6).2N(2)C(6)H(18).7H(2)O. The structure is a network of hexameric units of Ga(3)(PO(4))(3)F(2) and Ga(3)(PO(4))(2)(HPO(4))F(3) via corner sharing. It create...
A new gallium phosphatooxalate hybrid material, (C10H28N4)[Ga6(OH)2(PO4)2(HPO4)4(C2O4)3]·3.5H2O (1), has been synthesized under mild hydrothermal conditions (150 °C) in the presence of the amine 1,4-bis(3-aminopropyl)piperazine (APPIP) as a structure-directing agent. The compound was structurally characterized by single-crystal X-ray diffraction, t...
The 2D satellite transition magic angle spinning (STMAS) experiment generates efficiently high-resolution isotropic NMR spectra of half-integer quadrupolar nuclei. The experiment involves excitation and coherence transfer of satellite transitions into the central transition. It requires efficient refocusing of satellite transitions and sample spinn...
High resolution solid state NMR has been achieved for nuclei that exhibit quadrupolar interaction to the second order by MQMAS and more recently by STMAS. Both methods extend to several variants, 3QMAS, 5QMAS, … for MQMAS as well as ST1MAS, ST2MAS,… for STMAS. These experiments contain the same information content i.e. anisotropic second-order powd...
This chapter discusses the nuclear magnetic resonance (NMR) crystallography of AlPO4-CJ2. It also describes the main steps of NMR crystallography—namely, topological analysis, space group, and metric determination. AlPO4-CJ2 is an aluminophosphate with an open framework structure. This compound has been studied by in-situ NMR to follow its crystall...
A new aluminophosphate, MIL-34, is investigated from its as-synthesized structure to its calcined microporous form. Single-crystal X-ray diffraction measurements on the as-synthesized MIL-34 (Al(4)(PO(4))(4)OH x C(4)H(10)N, space group P-1, a = 8.701(3) A, b = 9.210(3) A, c = 12.385(3) A, alpha = 111.11(2) degrees, beta = 101.42(2) degrees, gamma =...
A new aluminophosphate, MIL-34, is investigated from its as-synthesized structure to its calcined microporous form. Single-crystal X-ray diffraction measurements on the as-synthesized MIL-34 (Al-4(PO4)(4)OH .C4H10N, space group P-1, a = 8.701(3) Angstrom, b = 9.210(3) Angstrom, c = 12.385(3) Angstrom, alpha = 111. 11(2)degrees, beta = 101.42(2)degr...
Three aluminum polycations, Al13ϵ-Keggin Johansson-type, Al13 Mögel-type and Al30 δ-Taulelle-type have been measured by 27Al solid state NMR, using MAS and 3QMAS spectroscopies. The number of inequivalent aluminum obtained by these high resolution NMR experiments leads to a comparison with their respective XRD results obtained on single crystal. In...
Recently, the need for more accurate structure description that will allow to analyze possible retrosynthesis of microporous compounds has led us to use and develop new structural strategies to access structure determination by solid state NMR techniques. At first, an example, AlPO4-CJ2, between crystallogenesis and crystal structure is explored. A...
The structure of AlPO4-CJ2 aluminophosphate has been reinvestigated by MAS, MQMAS (multiple quantum magic angle spinning), CP-MQMAS (cross polarization-MQMAS), and HETCOR (heteronuclear correlation) NMR spectroscopy. The CP-MQMAS method showed that the sample, when not allowed adequate time for crystallization, included a substantial concentration...
Polyacrylamide (PAM) and its hydrolysis products are widely used flocculants in water treatment. These relatively flexible polymers may also serve as models for certain natural organic matter rich in carboxyl groups in aquatic systems. We studied the aggregation kinetics of hematite in the presence of neutral and hydrolyzed polyacrylamide (HPAM) at...
Borocryptates of caesium and ammonium ions dissolved in a nematic liquid crystal were studied by NMR of quadrupolar nuclei $^{11}$B, $^{10}$B and $^{133}$Cs or $^{14}$N. Borocryptates are chiral molecules. We studied the racemic mixtures of enantiomers obtained by synthesis. In the particular solvent we used, the signal of a quadrupolar nucleus app...
Enantiomeric differentiation of chiral borocryptates using NMR
spectroscopy in a chiral liquid crystalline medium is achieved using
different NMR probes localised both on the receptor and on the substrate;
the observed chirality at the substrate is described as being induced by
the spiroborate junction and mediated by the peristatic chirality of th...
Using the mobile adsorption model which was previously developed to describe the kinetics of polyelectrolyte adsorption on charged sorbents, we have determined the polyelectrolyte concentration profiles from the amount of polyelectrolyte adsorbed on the successive plates of a chromatographic column resulting from the progressive coverage of the suc...
Surface exclusion chromatography is particularly suitable to determine the structure of highly dilute solutions, where more common methods such as light scattering are inefficient and other chromatographic techniques cannot be employed due to strong adsorption of the solutes on the stationary phases. This process was simulated using two kinetic mod...
We present results relative to the kinetics of adsorption of the diblock copolymer poly(vinylpyridine)-polystyrene on silica from toluene solution using a radiolabeled polymer. The investigations are carried out by controlling the rate of the polymer supply to the adsorbent to determine the kinetic coefficient K(N(s)) as a function of the number of...
We present results of a study of chromatographic separation based on surface area exclusion induced by the irreversible adsorption of the diblock copolymer poly(vinylpyridine)-polystyrene on silica from toluene solutions using a radiolabeled polymer. This characteristic of the copolymer enabled the number of adsorbed copolymers to be determined as...
The progress of surface coverage during block copolymer adsorption was investigated by determining the temporal variation of the polymer concentration in the liquid phase surrounding the non-porous adsorbent. Two kinetically different processes were observed. A fast adsorption process stopped after a short period while a slow superadsorption progre...
The progress of surface coverage during polymer adsorption is investigated by determining the temporal variation of the polymer concentration in the liquid phase surrounding nonporous adsorbents. Three adsorption experiments are interpreted using results of computer simulations. Adsorption of a neutral polymer onto a nonionogenic adsorbent may be i...
The kinetics of adsorption of diblock copolymers of poly(2-vinylpyridine) and polystyrene from toluene solutions on silica was investigated by using radiolabeled polymers. To study the relaxation of the anchoring block, only copolymers with a large pyridine block was selected. Adsorption was performed from solutions at concentrations below the cmc....
