50446-44-1Relevant academic research and scientific papers
Selective Implantation of Diamines for Cooperative Catalysis in Isoreticular Heterometallic Titanium–Organic Frameworks
López-Maya, Elena,Padial, Natalia M.,Castells-Gil, Javier,Ganivet, Carolina R.,Rubio-Gaspar, Ana,Cirujano, Francisco G.,Almora-Barrios, Neyvis,Tatay, Sergio,Navalón, Sergio,Martí-Gastaldo, Carlos
, p. 11868 - 11873 (2021)
We introduce the first example of isoreticular titanium–organic frameworks, MUV-10 and MUV-12, to show how the different affinity of hard Ti(IV) and soft Ca(II) metal sites can be used to direct selective grafting of amines. This enables the combination of Lewis acid titanium centers and available -NH2 sites in two sizeable pores for cooperative cycloaddition of CO2 to epoxides at room temperature and atmospheric pressure. The selective grafting of molecules to heterometallic clusters adds up to the pool of methodologies available for controlling the positioning and distribution of chemical functions in precise positions of the framework required for definitive control of pore chemistry.
The epoxidation of olefins catalyzed by a new heterogeneous polyoxometalate-based catalyst with hydrogen peroxide
Zhang, Zhenxin,Zhao, Wei,Ma, Baochun,Ding, Yong
, p. 318 - 322 (2010)
Inorganic-organic hybrid material was formed by [PW11O 39]7- and benzene-1,3,5-[tris(phenyl-4-carboxylic acid)] tris (2-trimethyl-ammonium ethyl) ester. This hybrid material behaved as a very effective and selective heterogeneous catalyst for the epoxidation of olefins with hydrogen peroxide as an oxidant. This heterogeneous catalyst could be easily recovered and reused after reaction without loss of activity.
Independent verification of the saturation hydrogen uptake in MOF-177 and establishment of a benchmark for hydrogen adsorption in metal-organic frameworks
Furukawa, Hiroyasu,Miller, Michael A.,Yaghi, Omar M.
, p. 3197 - 3204 (2007)
Hydrogen isotherms for MOF-177, Zn4O(1,3,5-benzenetribenzoate) 2, crystals were independently measured by volumetric and gravimetric methods at 77 K to confirm its hydrogen uptake capacity and to establish the importance of calibrating gas adsorption instrumentation prior to evaluating H2 storage capacities. Reproducibility of hydrogen adsorption experiments is important because non-systematic errors in measurements can easily occur leading to erroneous reports of capacities. The surface excess weight percentage of hydrogen uptake in MOF-177 samples is 7.5 wt% at 70 bar, which corresponds to an absolute adsorbed amount of 11 wt%. These values are in agreement with our previous report and with those found independently by Southwest Research Institute. Considering its well-known structure and its significant H2 uptake properties, we believe MOF-177 is an excellent material to serve as a benchmark adsorber. The Royal Society of Chemistry.
Removal of toxic dyes from aqueous medium using adenine based bicomponent hydrogel
Sukul, Pradip K.,Malik, Sudip
, p. 1902 - 1915 (2013)
By utilizing hydrogen bonding and π-π stacking interactions, we have demonstrated the construction of three dimensional adenine based gel networks due to the self assembly with complementary tricarboxylic acid derivatives which were designed and unambiguously characterized with the help of NMR, HRMS, and FTIR. Upon cooling the homogeneous aqueous solution of adenine and tricarboxylic acid, it formed hydrogels which were thermoreversible in nature and characterized by various instrumental techniques such as OM, FESEM, TEM, AFM, FL, XRD, FT-IR, rheology etc. Networks of belts in the hydrogel were clearly observed and the dimension of belt depended on the tricarboxylic acid used. The intermolecular hydrogen bonds which were considered to be the driving force for the formation of stable gel were confirmed by FT-IR studies. In spite of the absence of symmetry either in bpca or adenine, these two moieties surprisingly produced gels and it was due to the symmetrical position of complementary interaction sites between adenine and tricarboxylic acids. The mechanical strength of the hydrogel network as revealed by rheological study depended on the tricarboxylic acid used in the two-component systems and also on the composition of fixed pair. These kind of hydrogels have potential to be utilized as inexpensive materials for the treatment of waste water containing organic dyes (methylene blue, rhodamine 6G and crystal violet) that are widely used in textile as well as dye industries.
Structures and H2 adsorption properties of porous scandium metal-organic frameworks
Ibarra, Ilich A.,Lin, Xiang,Yang, Sihai,Blake, Alexander J.,Walker, Gavin S.,Barnett, Sarah A.,Allan, David R.,Champness, Neil R.,Hubberstey, Peter,Schroeder, Martin
, p. 13671 - 13679 (2010)
Two new three-dimensional ScIII metal-organic frameworks {[Sc3O(L1)3(H2O)3] ·Cl0.5(OH)0.5(DMF)4(H2O) 3}∞ (1) (H2L1=1,4-benzene- dicarboxylic acid) and {[Sc3O(L2)2(H 2O)3](OH)(H2O)5(DMF)} ∞ (2) (H3L2=1,3,5-tris(4-carboxyphenyl) benzene) have been synthesised and characterised. The structures of both 1 and 2 incorporate the trinuclear trigonal planar [Sc3(O)(O 2CR)6] building block featuring three ScIII centres joined by a central μ3-O2- donor. Each Sc III centre is further bound by four oxygen donors from four different bridging carboxylate anions, and a molecule of water located trans to the μ3-O2- donor completes the six coordination at the metal centre. Frameworks 1 and 2 show high thermal stability with retention of crystallinity up to 350 °C. The desolvated materials 1 a and 2 a, in which the solvent has been removed from the pores but with water or hydroxide remaining coordinated to ScIII, show BET surface areas based upon N2 uptake of 634 and 1233 M2 g-1, respectively, and pore volumes calculated from the maximum N2 adsorption of 0.25 Cm3 g-1 and 0.62 Cm3 g-1, respectively. At 20 Bar and 78 K, the H2 isotherms for desolvated 1 a and 2 a confirm 2.48 and 1.99 Wt % total H2 uptake, respectively. The isosteric heats of adsorption were estimated to be 5.25 and 2.59 KJ mol -1 at zero surface coverage for 1 a and 2 a, respectively. Treatment of 2 with acetone followed by thermal desolvation in vacuo generated free metal coordination sites in a new material 2 b. Framework 2 b shows an enhanced BET surface area of 1511 M2 g-1 and a pore volume of 0.76 Cm3 g-1, with improved H2 uptake capacity and a higher heat of H2 adsorption. At 20 Bar, H2 capacity increases from 1.99 Wt % in 2 a to 2.64 Wt % for 2 b, and the H2 adsorption enthalpy rises markedly from 2.59 to 6.90 KJ mol-1. It's ScIIIandalous: {[Sc3O(L1)3(H 2O)3]·Cl0.5OH0.5(DMF) 4(H2O)3}∞ (1) (H 2L1=1,4-benzenedicarboxylic acid) and {[Sc 3O(L2)2(H2O)3]OH(H 2O)5(DMF)}∞ (2) (H3L 2=1,3,5-tris(4-carboxyphenyl)benzene) incorporate the trinuclear trigonal planar [Sc3(O)(O2CR)6] building block. After appropriate thermal treatment on the acetone-exchanged sample 2, the generation of free metal coordination sites has been achieved to give an increase in the BET surface area in 2 b. Copyright
Synthesis of 3,5-Disubstituted Isoxazoles through a 1,3-Dipolar Cycloaddition Reaction between Alkynes and Nitrile Oxides Generated from O-Silylated Hydroxamic Acids
Carloni, Laure-Elie,Mohnani, Stefan,Bonifazi, Davide
supporting information, p. 7322 - 7334 (2019/11/05)
In this paper, we report the regioselective synthesis of 3,5-disubstituted isoxazoles by 1,3-dipolar cycloaddition between alkynyl dipolarophiles and nitrile oxide dipoles generated in-situ from O-silylated hydroxamic acids in the presence of trifluoromethanesulfonic anhydride and NEt3. Thanks to the mild, metal-free and oxidant-free conditions that this strategy offers, the reaction was successfully applied to a wide variety of alkynyl dipolarophiles, demonstrating the tolerance of this approach to diverse functional groups. In particular, we have shown that the method was compatible with biological molecules such as peptides and peptide nucleic acids (PNA). This protocol constitutes another example of metal-free 1,3-dipolar cycloaddition leading to the regioselective formation of isoxazoles.
A metal oxide catalytic oxidation three 1, 3, 5 - (4 - carboxyl phenyl) benzene method (by machine translation)
-
Paragraph 0028; 0030; 0031; 0032, (2018/07/30)
The invention discloses a metal oxide catalytic oxidation process for preparing 1, 3, 5 - three (4 - carboxyl phenyl) benzene method. The method comprises the following steps: 1) the 1, 3, 5 - three (4 - methyl phenyl) benzene, organic metal catalyst, a ligand and an additive in a solvent after mixing, under the action of the oxidizing agent, in the 80 - 130 °C temperature, 0.5 - 5.5 mpa gauge pressure under the conditions of the reaction 5 - 22 the H; 2) after the end of the oxidation reaction, filtering to remove the organic metal catalyst, then adding the extraction reagent and water, by extraction to obtain the organic phase and aqueous phase; 3) organic phase sequentially through the drying, filtering, concentrating and purifying processing, to obtain 1, 3, 5 - three (4 - carboxyl phenyl) benzene. The invention adopts the metal oxide as the catalyst, hydrogen peroxide, air or oxygen as the oxidizing agent, can effectively reduce the cost, reduce the production of three wastes, environmental protection, mild reaction conditions, high product yield, is suitable for industrial production. (by machine translation)
Method for preparing polyphenyl polyacid monomers
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Paragraph 0071-0093, (2018/03/24)
The invention relates to a preparation method for preparing polyphenyl polyacid monomers. The method comprises the steps that polymethyl polyphenyl is reacted with an oxidizing agent in an inert solvent under the catalysis of metal salt in the presence or absence of a ligand or in the presence or absence of an additive A as a co-catalyst or in the presence or absence of an additive B as a co-catalyst, and then the polyphenyl polyacid monomers are obtained. The method is relatively mild in condition, simple in operation, small in pollution and low in economic cost. The polyphenyl polyacid monomers can be used for synthesizing metal-organic frameworks (MOF) or self-assembled materials. (The chemical formulas are shown in the description.).
Method for preparation of 1, 3, 5-tris(4-carboxyphenyl)benzene by catalytic oxidation of Anderson polyacid
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Paragraph 0031; 0033; 0035; 0037; 0038; 0039, (2018/09/20)
The inventon discloses a method for preparation of 1, 3, 5-tris(4-carboxyphenyl)benzene by catalytic oxidation of Anderson polyacid. The specific steps include: 1) subjecting 1, 3, 5-tris(4-methylphenyl)benzene, a catalyst, an oxidant and an additive to oxidation reaction in a solvent, wherein the oxidant is air, oxygen or hydrogen peroxide, and the catalyst is an Anderson type polyacid catalyst;and 2) at the end of the oxidation reaction, filtering out the catalyst, then adding an extracting solvent and water for extraction so as to obtain an organic phase and an aqueous phase, and carryingout drying, filtering, concentration and purification on the organic phase in order to obtain the1, 3, 5-tris(4-carboxyphenyl)benzene. The method adopts Anderson polyacid as the catalyst, which has the characteristics of high reaction activity, mild reaction conditions and environmental friendliness, high specific selectivity, and recyclability, and adopts hydrogen peroxide, air or oxygen as the oxidant, can low the cost and reduce the production of three wastes, and is suitable for industrial production.
High surface area and Z′ in a thermally stable 8-fold polycatenated hydrogen-bonded framework
Zentner, Cassandra A.,Lai, Holden W. H.,Greenfield, Joshua T.,Wiscons, Ren A.,Zeller, Matthias,Campana, Charles F.,Talu, Orhan,Fitzgerald, Stephen A.,Rowsell, Jesse L. C.
supporting information, p. 11642 - 11645 (2015/07/15)
1,3,5-Tris(4-carboxyphenyl)benzene assembles into an intricate 8-fold polycatenated assembly of (6,3) hexagonal nets formed through hydrogen bonds and π-stacking. One polymorph features 56 independent molecules in the asymmetric unit, the largest Z′ reported to date. The framework is permanently porous, with a BET surface area of 1095 m2 g-1 and readily adsorbs N2, H2 and CO2.
