Amine Template Research Articles

Effects of organoamine template and transition metal coordination mode on the self-assembly of reduced polyoxomolybdenum phosphate

Four new compounds of reduced polyoxomolybdenum phosphate (V) with the formula (H2enMe)4(MnH2O)2{Mn[Mo6O12(OH)3(HPO4)2(PO4)2]2}·5H2O (1) (enMe = 1,2-diaminopropane), (H3N(CH2)4NH3)4(MnH2O)2{Mn[Mo6O12(OH)3(HPO4)2 (PO4)2]2}·2H2O (2), (H3dien)4{Mn[Mo6O12(OH)3(HPO4)2(PO4)2]2}·8H2O (3) (dien = diethylenetriamine) and (H2en)5{Cu2[Mo6O12(OH)3(HPO4)3(PO4)]2}·3H2O (4) (en = ethylenediamine) have been successfully synthesized under similar reactive condition and characterized by single-crystal X-ray diffraction. For compounds 1–3, despite slight distinction of amine, the organic amine template effect lead them to have different topological structures. The transition metal ion Mn2+ was replaced by Cu+, resulting in compound 4 with infinite chains since Cu+ exhibits a two-coordination mode. To the best of our knowledge, compound 4 is the first zigzag chain-like structure reduced polyoxomolybdenum phosphates containing Cu+. Other characterizations of these compounds by elemental, IR, thermal analysis and catalytic properties are also performed. The formation of these four compounds reveals that the organoamine and transition metal play important roles during the synthesis.

Designer Template Initiator for Sequence Regulated Polymerization: Systems Design for Substrate‐Selective Metal‐Catalyzed Radical Addition and Living Radical Polymerization

"Template initiator"' platforms (1) have been designed for expressing the sequence information in a template in radical polymerization. Thus, we demonstrated the structural adequacy of 1 consisting of two initiating sites placed ortho to each other in benzene: one for living cationic polymerization to introduce a template carrying substrate-recognition tags, and the other for metal-catalyzed living radical polymerization to achieve sequence regulation. For example, for two positional isomers with an amine template for an acid monomer, only the ortho initiator induced selective radical addition of MAA (recognizable) over MMA (non-recognizable). Another version was an oligo(vinyl ether) with a multiple amine template, which demonstrated template effects for MAA recognition over BzMA in copolymerization.

Synthesis, characterization, and catalytic behavior of two open-framework zinc phosphites with 2D and 3D structures

Abstract Two new zincophosphites are obtained via a hydrothermal process. Single crystal data indicate that 1 has a two dimensional motif with the organic amine template embedded between the layers, while 2 has a three-dimensional structure with the organic amine template enclosed into the cavities. Knoevenagel condensation of benzaldehyde and ethyl cyanoacetate is carried out with these two complexes as support in ethanol at 333 K respectively. Experimental results indicate that only 1 is efficient for the catalysis. The catalytic ability depends on their structural characters.

Amine templated two- and three-dimensional uranyl sulfates

Structural variability in amine template uranyl sulfate frameworks is observed with two- and three-dimensional structures containing channels of dimensions 7.4 A x 5.1 A, 36 A x 5.8 A, and 10 A x 10 A.

Computational prediction of the formation of microporous aluminophosphates with desired structural features

A better understanding of the relationship between the synthetic factors and the resulting structures is of great importance to rationalizing the synthesis of the target zeolitic materials. We present a computational study for predicting the formation of (6,12)-ring-containing microporous aluminophosphates (AlPOs), using a data classification approach. Through analyses of a database of AlPO synthesis with ca. 1600 reaction data, we identified a number of synthetic parameters such as three gel molar ratios of Al 2O 3, P 2O 5 and the organic amine template, as well as eleven parameters associated with the geometric and electronic characteristics of the templates deemed to be useful in distinguishing (6,12)-ring-containing AlPOs from the other AlPOs. Using these parameters, we have trained a support vector machine (SVM)-based classifier on a training dataset containing 360 (6,12)-ring-containing AlPOs and 1069 AlPOs without such rings. Analysis results revealed that the geometric size of the organic template, particularly the second longest distance of the template along with the gel molar ratios, has good predictive power for microporous aluminophosphates containing (6,12)-rings. This work demonstrates the general feasibility in establishing a relationship between the synthetic parameters and the structural features of the synthesized microporous materials, providing a useful guidance to the rational design and synthesis of such materials as well as other inorganic crystalline materials.

Cover Picture: Phys. Status Solidi C 6/10

AbstractOn p. 2190 of this issue, Jesús A. Blanco et al. report having succeeded in the synthesis and characterization of γ‐titanium phosphate nanotubes incorporating trioctylamine. The cover picture contains transmission electron microscopy images showing several nanotubes. These nanostructured materials present two or more phases, the interlayer distance being controlled by the alkyl chain length and the amount of amine template as is schematized in the upper part of the picture.The first author, Jesús A. Blanco is an assistant professor at the University of Oviedo, Spain, where he teaches solid state physics and has worked for more than 20 years in materials cience using synchrotron radiation and neutron beam techniques. Current scientific interests are in nanostructured materials and their physical‐chemical properties. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Selective Radical Addition with a Designed Heterobifunctional Halide: A Primary Study toward Sequence-Controlled Polymerization upon Template Effect

A ruthenium(II)-catalyzed, highly selective, quantitative radical addition of an alkene, methacrylic acid (MAA), has been achieved by using a template halide (2) containing a built-in amine group as a recognition site for the carboxyl group of the substrate. The specific ionic binding of MAA by the amine template (1:1 molar ratio) led to preferential formation of the 1:1 MAA-2 adduct, whereas a similar halide without a template induced MAA oligomerization even in the presence of an externally added amine. A competitive radical addition of MAA versus its ester form [methyl methacrylate (MMA)] on the halide further demonstrated that the substrate selectivity [k'(MAA)/k'(MMA)] for 2 is enhanced more than 10 times by the intramolecular introduction of the template relative to the result for the nontemplate halide. These specificities are most likely triggered by the specific interaction (recognition) of the carboxyl group in MAA via the acid-selective template amine, which is implanted in the close vicinity of the radical addition site in 2. These results intimate possibility of control over the repeat-unit sequence in precision polymerization.

M 3 muscarinic acetylcholine receptor antagonists: SAR and optimization of bi-aryl amines

Exploration of multiple regions of a bi-aryl amine template led to the identification of highly potent M 3 muscarinic acetylcholine receptor antagonists such as 14 (pA 2 = 11.0) possessing good sub-type selectivity for M 3 over M 2. The structure–activity relationships (SAR) and optimization of the bi-aryl amine series are described.

Synthesis and characterization of layered and scrolled amine-templated vanadium oxides

In order to fully understand the formation mechanism, structure, and role of structural curvature of vanadium oxide nanotubes (VONTs), two isostructural materials (one planar and the other curved)—ethylenediammonium (enH2) intercalated V7O16 and vanadium oxide nanourchins (VONUs)—were synthesized and characterized via X-ray diffraction (XRD), electron microscopy, thermal gravimetric analysis (TGA), Fourier transform infrared spectroscopy, and magnetic measurements. The synthesis route to (enH2)V7O16 is developed using vanadium pentoxide as a starting material and employing pH control. VONUs are synthesized using n-dodecylamine as an amine template for the first time. We demonstrate that the structure of the vanadium oxide layer in these compounds is similar to that of VONTs and their magnetic properties all fit to the same model including the temperature-independent, Curie–Weiss, and spin ½ antiferromagnetic dimer contributions. The vanadium oxidation state in tubular structures appears to be higher than in planar compounds such as (eH2)V7O16 and BaV7O16. The role of the template and vanadium reduction in the formation of nanotubes is discussed.

Highly photoactive ZnO by amine capping-assisted hydrothermal treatment

ZnO nanoparticles have been prepared by amine template assisted sol–gel precipitation and further hydrothermal treatment. We have investigated the effect of different pH values achieved by means of triethylamine (TEA) addition in the final surface and structural properties. Two sets of samples were obtained after thermal treatment, one with no hydrothermal pre-treatment and a second hydrothermally pre-treated. Surprisingly the precipitate obtained after the amine addition also exhibits good photocatalytic properties. It has been stated that calcination treatment leads in both sets of samples to a significant improvement in the photocatalytic properties of the studied systems. Therefore, interesting comparison has been performed between hydrothermal pre-treated and direct thermal treated samples. Surface and morphological features notably differ from ZnO prepared using different synthetic route. Wide surface and structural characterization of the samples have been carried out, and correlations with precipitation pH are pointed out from this characterization. In all cases, the amine templated ZnO obtained exhibit high conversion values for phenol photo-oxidation reaction. Further calcination treatment in all of the studied samples clearly leads to photocatalytic conversions higher than that exhibited by TiO2 Degussa P25. This fact is even more significant if we consider that hydrothermally and calcined ZnO exhibit almost null surface area values, leading to a startling intrinsic photoactivity. The structural excellence (crystallinity, lack of defects, crystallite size, etc.) of such systems is clearly responsible for their high photoactivity values.

Synthesis of ZnS hollow nanospheres with holes using different amine templates

ZnS hollow nanospheres with holes were prepared by reacting ZnSO4 with H2S, the sulfide source formed in the reaction of CS2 with ethylenediamine, 1,3-propylenediamine, butylamine or 2-(2-aminoethylamino) ethanol, which also acted as a template agent, at 50°C under agitation. The shape, particle size of about 100–850 nm and hole size of about 150–600 nm of ZnS hollow nanospheres with holes were shown by SEM and TEM images. These ZnS nanospheres with β cubic ZnS phase and composed of 2–5 nm nanocrystals were characterized by XRD and HRTEM. The blue shift of maximum absorption in UV-vis displayed the effect of quantum size. The two amino groups of amine templates reacted favorably with Zn2+ to form uniform and relatively smooth ZnS nanospheres with holes, while hydroxyethyl played a disadvantageous role. A reasonable mechanism of hole formation by H2S rushing out is suggested.

Influence of amine template on the photoactivity of TiO2 nanoparticles obtained by hydrothermal treatment

TiO2 nanoparticles have been prepared by amine template-assisted sol–gel precipitation and further hydrothermal treatment. We have investigated the effect of different amines (hydrazine and triethylamine) in the final surface and structural properties. It has been stated that the different amounts of amine could act as an interesting template upon hydrothermal treatment. Further thermal treatment also leads to a significant improvement in the photocatalytic properties of the studied systems. Surface and morphological features notably differ from TiO2 prepared using different synthetic routes. Wide surface and structural characterization of the samples have been carried out, and correlations with precipitation pH are pointed out from this characterization. In all cases, amine template TiO2 obtained exhibit high conversion values for phenol photo-oxidation reaction. Further calcination treatment of all the studied systems clearly leads to photocatalytic conversions higher than that exhibited by TiO2 Degussa P25.

Synthesis of ZSM-5 on kaolin microspheres in the absence of an organic amine template

AbstractZeolite ZSM-5 was synthesized successfully, in situ, on pyrokaolin microspheres (PKM) under hydrothermal conditions, without the use of an organic amine template. The utility of alkali-modified pyrokaolin microspheres (AMKM) was also evaluated. The resulting products were characterized using X-ray diffraction, scanning electron microscopy (SEM) and N2-adsorption isotherm data. The material containing ZSM-5 synthesized from the system PKM-additional silica-water had a large surface area and pore volume with significant enhancements in the micropore surface area and micropore volume. The SEM images show that the synthesis of zeolite ZSM-5 from pyrokaolin microspheres (PKM) led to the formation of polycrystalline aggregates <2 μm in size. The purity of the zeolite ZSM-5 produced was affected by both the pH value of the reactant system and the reaction temperature. In the system containing AMKM-additional silica-water, very little of the synthesized zeolite resided on the kaolin microspheres.

Synthesis of Nanolayers of Lead Titanate Ceramics Using Organic Lipid Templates

In this work, an attempt to probe the feasibility of formation of nanolayers of piezoelectric material viz lead titanate by lipid matrix using stearic acid (CH3(CH2)17COOH) and octadectyl amine (CH3(CH2)19NH3) templates deposited by thermal evaporation technique was attempted in two successive stages. This paper also discusses the kinetic study of nanolevel thin films during the entrapment of Pb2+ in a fatty acid template of about 50 nm thickness and TiF6 2− ions in the fatty amine template of about 50 nm thickness, followed by in situ hydrolysis of the metal ions using quartz crystal microgravimetry (QCM). Glass substrate containing lead and titanium incorporated organic lipid matrix were heated at 300°C for various durations to probe the physical change in the lipid matrix entrapped with metal ions. The X‐ray diffraction patterns were analyzed at each step of entrapment of metal ions and in situ hydrolysis. Silicon wafers of N‐type, having orientation hkl=111 was used as substrate material for FTIR analysis to confirm the formation of lipid templates without any disintegration in the functional groups present in the lipid. This paper presents the process development of nanomaterials using organic lipid templates on various substrates such as silicon wafers, quartz substrate, glass substrate etc., and also highlights its potential applications.

Supermicroporous alumina–silica zinc oxides

A new family of porous mixed oxides with pores largely in the 8–20 Å range have been prepared. TEOS acts as a solvent and as a source of silica to which aluminum butoxide and transition metal acetates are added. Neutral amines are added as templates and to effect hydrolysis. This paper describes the ZnO–Al 2O 5–SiO 2 system but similar results have been obtained with other transition metal oxides. An interesting feature of the technique is that the larger the amine template the greater is the surface area of the mixed oxide with only a slight increase in the average pore diameter. Both NMR and atomic pair distribution functional methods have been used to prove the homogeneity of the mixed oxide products. This preparative method complements our earlier report in Chemical Communications on mixed oxides prepared with ZrO 2 and TiO 2 incorporating transition metal oxides.

New Series of Layered Vanadyl Phosphates with Varied Polyamine Templates

Four two-dimensional vanadyl phosphates, (H3dien)[(VOPO4)2(OH)]·H2O (dien = diethylenetriamine) (1), (H2dach)1.5[(VOPO4)2(OH)]·2H2O (dach = 1,4-diaminocyclohexane) (2), (H2tmdpp)[V3O4(OH)(PO4)2]·3H2O (tmdpp = 4,4‘-trimethylenedipiperidine) (3), and (H2tmdpp)(H1.5tmdpp)K0.5[V5O7(H2O)2(PO4)4]·H2O (4), with clearly distinct but orderly increasing layer separations from 7.75 to 18.07 Å, have been prepared via hydrothermal routes and characterized by single-crystal X-ray diffraction, thermogravimetric analysis, and magnetic susceptibility or ion-exchange studies. The series possesses three unique layer topologies, but all contain VIVO5 square pyramid, PO4 tetrahedron, discrete dimers of V−O polyhedra, and 3-, 4-, 5-, and 8-membered rings. Structures 1 and 2 are VIV species, having the same layer topology but different amine cations. Compounds 3 and 4 are VIV/VV mixed valent, holding the same amine templates in varied inclined angles. Being similar to 1 and 2, the layer of 3 contains extra vanadate groups. In contrast, the layers in 4 are distinct and contain VVO6 and VIVO6 octahedra besides VIVO5 square pyramid. It exhibits an interlayer d-spacing of 18.07 Å, the largest propped up by noncovalent intermediates between VPO layers. With an extremely low density of 1.71 g·cm-3, compound 4 also demonstrates the lightest layered material ever prepared in the V/P/O system. Structural relationship, template effect, factors controlling layer gaps, ion exchange, thermal stability, and magnetic properties are discussed.

Two- and three-dimensional mesoporous iron oxides with microporous walls.

Age concern: Alkyl amine templates act as bifunctional surfactants which can template mesostructures with microporous walls. Ordered two-dimensional hexagonal mesoporous iron oxide with P6mm symmetry and three-dimensional cubic mesoporous iron oxide with Fm3m symmetry (see TEM image) have been prepared by using decylamine as the template, iron(III) ethoxide as the precursor, and different aging conditions.

Design of a Novel Molecular-Imprinted Rh−Amine Complex on SiO2and Its Shape-Selective Catalysis for α-Methylstyrene Hydrogenation

A new molecular-imprinted Rh−amine complex with a template-shaped cavity acting as a shape-selective reaction space was prepared by metal-complex attaching and molecular imprinting techniques on a SiO2 surface. Rh(η3-C3H5)3 reacted with SiO2, and the precursor was attached on the surface to form a bidentate structure Rh(C3H5)(OSi)2. α-Methylbenzylamine with a shape similar to that of a half-hydrogenated alkyl intermediate of α-methylstyrene coordinated to the attached Rh as a template ligand. Then SiO2−matrix overlayers were stacked on the surface by the hydrolysis−polymerization of Si(OCH3)4 surrounding the attached Rh complexes with the amine template. Final evacuation at 373 K promoted the removal of the template ligand from the Rh complex embedded in the surface pore of the SiO2−matrix overlayers. All the structures of the attached Rh complexes were characterized by the means of ICP, XPS, ESR, FT-IR, solid-state MAS NMR, EXAFS, DFT, GC, and H2 adsorption. The imprinted Rh complex has an unsaturated structure Rh(amine)(OSi)(HOSi) and exhibits high catalytic activity for α-methylstyrene hydrogenation. On the contrary, the other supported Rh complexes before imprinting are inactive for the hydrogenation. Furthermore, the active Rh complex is durable under the reaction condition despite the unsaturated conformation which usually tends to gather each other. The imprinted cavity locating on the active Rh center acts as a shape-selective reaction space for α-methylstyrene. The inhibition of the hydrogenation by the use of seven amines with different shapes demonstrates the shape-selective behavior of the imprinted Rh complex discriminating one methyl group and the position of the phenyl ring.

Structural diversity in organically templated uranium sulfatesElectronic supplementary information (ESI) available: three-dimensional packing diagrams for USO-6–USO-10. See http://www.rsc.org/suppdata/dt/b2/b209208e/

The potential of organic amine templates to direct the synthesis of metal sulfate frameworks has been investigated. Eight novel uranyl sulfates have been prepared using a templated uranyl sulfate precursor under hydrothermal conditions. The topologis of the isolated phases vary from the molecular (0-D), to chains (1-D) to layered (2-D) frameworks. [N4C6H22]2[(UO2)2(SO4)6] (USO-10) is molecular or zero-dimensional. Two different types of one-dimensional uranyl-containing chains have been observed. [N2C4H12][UO2(H2O)(SO4)2] (USO-3), [N2C5H14][UO2(H2O)(SO4)2] (USO-4) and [N2C3H12][UO2(H2O)(SO4)2] (USO-9) contain chains based upon a [UO2(SO4)4/2] backbone. [N2C10H10][UO2(SO4)2]·H2O (USO-6) and [N2C6H18][(UO2)2(H2O)3(SO4)3] (USO-7) contain chains based upon a [UO2(SO4)3/3] backbone. Two layered or two-dimensional compounds, [N2C6H14][UO2(H2O)(SO4)2] (USO-5) and [N2C3H5]2[(UO2)2(SO4)3] (USO-8) have also been isolated. All the new phases have been characterised using a range of physical techniques including single crystal X-ray structure analysis.

XAFS study on the local structure of Ti in amorphous mesoporous titania

We applied XAFS spectroscopies to investigate the local structure of Ti in mesoporous titania synthesized with a primary amine template, which has an extremely large surface area (>1200 m2 g−1) and an amorphous nature, because the atomic structure was expected to differ in many points from that in all the other known titanium oxides. The coexistence of 5- and 6-fold coordinations of Ti is demonstrated by deconvoluting the pre-edge peaks of the Ti K edge XANES. Their populations are evaluated as 39% and 61%, respectively. The number of 5-fold Ti is decreased by a calcination at 673 K, accompanied by a considerable decrease of the BET surface area. The anharmonic pair distribution function is used for the analysis of EXAFS from the Ti–O bond in order to calculate reliable structural parameters. Template extraction considerably increases the Debye–Waller factor, suggesting that the micelles filling the pores suppress large vibrations of the Ti–O bond in mesoporous titania.