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Five novel chiral 2D materials with general formula λ-ZrPO4(OH)1-x(RCOO)x(dmso) have been prepared by covalent anchoring of five different chiral carboxylic acids to the sheets of λ-zirconium phosphate (λ-ZrP), namely (S)-(+)-Mandelic acid (MAN), (R)-(−)-α-Methoxyphenylacetic acid (MPA), (S)-(+)-Ibuprofen (IBU), (S)-(+)-6-Methoxy-α-methyl-2-naphthaleneacetic acid (MMN) and (−)-Menthyloxyacetic acid (MEN). The synthesized materials were characterized by X-ray diffractometry, FT-IR spectrophotometry, elemental and thermogravimetric analyses and polarimetry. The X-ray diffraction patterns revealed that the interlayer separations increase from 1.02 nm (pure λ-ZrP) to 1.31–2.31 nm as a result of the incorporation of the mentioned acids within the interlayer gallery. The polarimetry measurements showed that the synthesized materials have appreciable optical activities suggesting they could have protentional applications in the field of chiral separation techniques.

Condensation of 4-hydrazino-1,3-diphenylpyrazolo[3,4-d]-pyrimidine with the aldohexoses, namely, D-glucose, D-galactose, D-mannose and the aldopentoses, D-arabinose, D-xylose and D-ribose, by heating in an aqueous ethanol in the presence of a catalytic amount of HCl, gave the respective aldehydo-sugar hydrazones. Oxidative cyclisation of such hydrazones by stirring with iron(III) chloride in ethanol at room temperature afforded the expected acyclo C-nucleosides 3-substituted-7,9-diphenylpyrazolo[4,3-e][1,2,4]triazolo[4,3-c]-pyrimidines. The structures of the cyclised sugar hydrazones were confirmed by their elemental analyses and spectral data.

The intercalation of primary alkylamine into Zirconium phosphate (ZrP) is very powerful synthetic tool to facilitate the diffusion and incorporation of huge organic and inorganic molecules inside the interlayer gallery of ZrP. The intercalation of primary alkylamine into α- and γ-type ZrP is well studied. However, the intercalation chemistry of λ-ZrP has never been investigated until now. It has been found that λ-type materials with extended interlayer separation can be obtained by intercalation of primary alkylamines (CnH2n+1NH2; n = 1, 2, 4 and 6) into the interlayer gallery of λ-ZrP.

A new layered pillared material [ZrPO4(OH)0.60(C14H8O4)0.20(CH3)2SO] based on λ-zirconium phosphate (λ-ZrP) and 1,4-biphenyldicarboxylic acid (bpdc) has been prepared. The synthesized material is characterized by X-ray diffractometry, FT-IR spectrophotometry, elemental, thermogravimetric and N2 adsorption/desorption analyses. The used analysis techniques reveal that the bpdc is successfully incorporated inside the interlayer region of λ-ZrP. Regarding the N2 adsorption/desorption analysis of λ-ZrP-bpdc, it gives a moderate specific area of 98 m2 g−1 and an average pore diameter of 0.88 nm. Therefore, a new λ-type rigid microporous framework is obtained. From the practical perspective, there would be a good potential for implementing applications of ZrPO4(OH)0.60(C14H8O4)0.20(CH3)2SO in the fields of inclusion chemistry, molecular shape recognition and heterogeneous catalysis. A new layered pillared material [ZrPO4(OH)0.60(C14H8O4)0.20(CH3)2SO] based on λ-zirconium phosphate (λ-ZrP) and 1,4-biphenyldicarboxylic acid (bpdc) has been prepared. The synthesized material is characterized by X-ray diffractometry, FT-IR spectrophotometry, elemental, thermogravimetric and N2 adsorption/desorption analyses. The used analysis techniques reveal that the bpdc is successfully incorporated inside the interlayer region of λ-ZrP. Regarding the N2 adsorption/desorption analysis of λ-ZrP-bpdc, it gives a moderate specific area of 98 m2 g−1 and an average pore diameter of 0.88 nm. Therefore, a new λ-type rigid microporous framework is obtained. From the practical perspective, there would be a good potential for implementing applications of ZrPO4(OH)0.60(C14H8O4)0.20(CH3)2SO in the fields of inclusion chemistry, molecular shape recognition and heterogeneous catalysis.

New dicarboxylate-functionalized pillared materials with a general formula of λ-ZrPO4(OH)1-x(OOC(CH2)nCOO)x/2(dmso) (n=6, 8 and 10) have been prepared by post-synthesis modification of the inorganic layers of λ-zirconium phosphate (λ-ZrP), where the superficial Chloride monovalent anionic ligands of λ-layer are partially exchanged with the divalent anionic ligands of a series of long-chain aliphatic dicarboxylic acids, namely octanedioic acid, decanedioic acid and dodecanedioic acid. The synthesized materials are characterized by X-ray diffractometry, FT-IR spectrophotometry, elemental and thermogravimetric analyses. The X-ray diffraction patterns show that the obtained solid phases are pure. Furthermore, the interlayer distance of λ-ZrP systematically increases from 1.02 to 1.59 nm as a result of the incorporation of the mentioned acids inside the interlayer gallery.

λ−Zirconium phosphate adipate dimethyl sulphoxide, λ-ZrPO4(OOC-(CH2)4-COOH)(CH3)2SO, is prepared by means of topotactic anion exchange of the chloride ligand of λ-Zirconium phosphate, λ-ZrPO4Cl(CH3)2SO, with adipate. The samples are characterized by thermal analyses, X-ray diffractometry and FT-IR spectrophotometry. The used analysis approaches provide strong evidence that the chloride monovalent anions of λ-Zirconium phosphate are completely exchanged with the carboxylate groups of the adipate monoanionic ligands. Moreover, the adipate ligands replace the chloride anions in a 1:1 stoichiometry. In this case the formula of the derivative should contain the monoanionic adipate fragment: (OOC-(CH2)4-COOH). This formula is in agreement with TGA and elemental analysis. With respect to intercalation properties, the synthesized adipate-solid phase has a higher acidic character and a larger gallery height in comparison to the pristine λ-Zirconium phosphate (1.47, 1.02 nm, respectively). Therefore, this material is expected to be a suitable host for intercalation of huge basic guests.

A new hybrid organic–inorganic material denoted by ZrPMP·1.7H2O, where PMP = N,N′-piperazinebis(methylenephosphonic acid), is prepared through the decomposition of zirconium fluoro-complex in the presence of PMP. This material is characterized by X-ray diffractometry, solid 31P NMR and FT-IR spectrophotometries and thermal analyses. All of the above mentioned analyses provide strong evidence that this material is structurally related to α-type layered zirconium phosphate.

Batch intercalation experiments have carried out using γ-zirconium phosphate (γ-ZrP) and one of its cationic surfactant forms (γ-ZrP/SUR+) for removing crystal violet from aqueous solutions. The intercalation reactions have conducted along two different intervals of time (24 and 48 h). The intercalation process has followed up by X-ray diffractometry (XRD), UV–Visible and FT-IR spectrophotometries. Regarding γ-ZrP, XRD patterns show that obtained phases are impure, even after 48 h of the reaction time at a maximum dye loading of 18%. On the other side, γ-ZrP/SUR+ gives an impure phase after 24 h while a pure one (2.47 nm) is obtained after 48 h at a maximum dye loading of 19%. In both cases, the observed dye loading values are approximately equal to the one calculated by molecular modeling (ca. 20%). The used analysis approaches prove that dye uptake capacity is a function of the reaction time and inclination angle of the dye molecules inside the solid matrices, where the highest dye uptakes are observed with γ-ZrP and γ-ZrP/SUR+ after 48 h of the reaction time. This time (48 h) is long enough for the dye molecules to be sufficiently accumulated inside the interlayer regions, in such situation dye molecules are forced to stand up perpendicular to the inorganic layers. With respect to intercalation properties, the difference between γ-ZrP and γ-ZrP/SUR+ could be referred to the difference between their gallery heights (1.22 and 3.00 nm, respectively). The pre-intercalation of γ-ZrP with the surfactant molecules assists the inclusion and intercalation of the huge dye molecules into the interlayer region.

The synthesis of polyphenylethynyl diphosphonic acids was accomplished as well as their incorporation to γ-ZrP by topotactic phosphate/phosphonate partial exchange. The materials, characterized by solid-state NMR, XRD, elemental analysis and molecular modelling, bore truly pillared structures with a high degree of ultramicroporosity. The remaining surface phosphates from the partial phosphate/phosphonate replacement were further exchanged with methylphosphonate, phosphite or hypophosphate leading to a library of new materials that retained the pillared ultramicroporous structure. The porous solids displayed reasonable capacities to store hydrogen by physisorption.

The preparation of organic–inorganic materials based on the topotactic exchange reactions of the γ phase of zirconium phosphate and polyphenyl bisphosphonates is reported. The treatment of these materials with hypophosphoric, phosphorous and methylphosphonic acids easily led to an isomerization of the γ phases to their α allotropes. These reactions rendered finely engineered supramolecular structures by means of mild, simple processes performed in the solid–liquid interface. This kind of clean γ-to-α transformations described in our work has few precedents in the literature and allows for the effortless preparation of libraries of similar materials in which the testing of a given set of properties versus subtle structural changes may be easily performed. Using this rationale we have produced materials able to store up to 1.7% (w/w) of H 2 at 77 K and 1 atm with such high ultramicroporosity that the DOE-goal H 2 densities established for 2010 could be complied at pressures well below 5 atm.

The pillaring of γ-zirconium phosphate with either dissymmetric or non-dissymmetric polyethylenoxa diphosphonates leads to organic–inorganic nanostructures, in which the coiling of organic columns is the source of supramolecular chirality and chiral memory.

The construction of organic−inorganic scaffolds based on γ-zirconium phosphate and polyethylenoxa diphosphonates is described. Microcrystalline materials with a controlled, low degree of pillaring are synthesized and characterized by elemental analysis, X-ray powder diffraction, solid-state NMR, and thermogravimetric analysis. The mechanism for the topotactic polyethylenoxa-pillaring reaction is proposed and confronted with previous ones suggested for the reaction of nonpolar organic diphosphonates. The affinity among the polyethylenoxa chains and the superficial acidic phosphates of the layered salt is thus clearly evidenced. The work shows how the inner structure of the pillared microcrystals may be easily modified by a second exchange of the remaining superficial phosphates by other phosphorus species as the low-polar hypophosphite. The rigidity of the layers and the wedge-like effect of intercalated amines at the edges of the microcrystals cause them to increase the interlayer distance, and hence poro...

The intercalation of malachite green (MG) in γ-zirconium phosphate (γ-ZrP) and one of its cationic surfactant forms (γ-ZrP/SUR+) has been investigated by the batch method and followed by X-ray diffractometry. X-Ray diffraction patterns showed that an impure phase (1.18 and 1.96 nm) was obtained with γ-ZrP while a pure one (2.47 nm) with γ-ZrP/SUR+ at a dye loading of 14% and 18%, respectively. In both cases, computer models and calculations based on the dye dimensions and the structure of the host showed that the maximum ion-exchange capacity is ca. 12–16%, which reflects the very high capacity by which γ-ZrP and γ-ZrP/SUR+ are characterized in the uptake of MG. The difference in the dye loading between the corresponding derivatives of pristine γ-ZrP and γ-ZrP/SUR+ is attributed to the difference in interlayer distances and the variable cross-section of the dye depending on its orientation and/or conformation within the interlayer region.

The design of porous solids of controlled molecular geometry for umpteen applications is a challenge of enormous technological and scientific importance. The placing of organic molecules between the layers of certain inorganic salts leads to enduring solid materials where the confinement makes the organic molecules change their properties or even display new ones at the supramolecular level. Past and ongoing results of our research group concerning the chemistry of metal phosphates/phosphonates are reviewed in relation with recognition, chemically-driven porosity changes, chiral memory and supramolecular chirality, luminescence signaling, photoinduced electron-transfer, gas storage and drug confinement.

The luminescence of certain lanthanides can be obtained in full if the metals are chelated to a suitable chromophor (antenna effect). This phenomenon may be achieved within the body of a porous solid. There are many examples in the literature regarding this approach. The present paper accounts for our recent findings concerning lanthanide luminescence within zirconium phosphate, a quite versatile laminar inorganic salt. The strategy of building 3D scaffolds from the 2D inorganic salt and 1D organic pillars is detailed. The covalent attachment of conveniently functionalized chromophores to the lanthanide-containing inorganic lamellae renders solid materials that can be used as organic–inorganic phosphors. The creation of supramolecular chirality within these layered solids, something that have been easily achieved by us in previous work, may lead to a new kind of phosphor producing circularly polarized luminescence with high efficiency.