- A permanently porous van der Waals solid by using phosphonate monoester linkers in a metal organic framework
-
A bis(phosphonatemonoester) is employed as a linker in a Zn(ii) metal organic framework. The complex is a layered structure pillared only by vdW interactions between alkyl groups. Nonetheless, permanent pores are formed as confirmed by PXRD and gas sorption analysis.
- Iremonger, Simon S.,Liang, Junmei,Vaidhyanathan, Ramanathan,Shimizu, George K. H.
-
-
Read Online
- Organic-inorganic hybrids assembled from lanthanide and 1,4-phenylenebis(phosphonate)
-
A series of novel organic-inorganic hybrids based on trivalent lanthanide (Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho) and 1,4-phenylbis(phosphonate) formulated as Ln[O3P(C6H4)PO3H] has been obtained as single phases under hydrothermal conditions. In the praseodymium compound (Za1), single crystals have been obtained and the crystal structure has been determined. Za1 crystallizes in the monoclinic space group, C2/c, with a = 5.6060(4) A, b = 20.251(7) A, c = 8.2740(6) A, β = 108.52(1)°. All other compounds are isostructural to Za1 as confirmed by Rietveld refinement using X-ray powder diffraction data. Compounds are characterized by thermal analyses (TG-MS and SDTA), elemental analysis, IR spectra, and X-ray thermodiffraction analysis. Their visible photoluminescence properties are also discussed.
- Amghouz, Zakariae,Garcia-Granda, Santiago,Garcia, Jose R.,Clearfield, Abraham,Valiente, Rafael
-
-
Read Online
- Fe-MIL-101 modified by isatin-Schiff-base-Co: a heterogeneous catalyst for C-C, C-O, C-N, and C-P cross coupling reactions
-
A metal-organic framework functionalized with a cobalt-complex is preparedviapost-synthetic modification of Fe-MIL-101-NH2. Initially, Fe-MIL-101-NH2reacted with isatin to produce Fe-MIL-101-isatin-Schiff-base, which can anchor the cobalt by the addition of cobalt acetate. The resulting MOF-Co catalyst is characterized by employing multiple techniques. This new modified MOF acts as a heterogeneous and recyclable catalyst for efficient Ullmann, Buchwald-Hartwig, Hirao, Hiyama and Mizoroki-Heck cross-coupling reactions of several aryl halides/phenylboronic acid/phenyltosylate with phenols, anilines/heterocyclic amines, triethyl phosphite, triethoxyphenylsilane and alkenes and generates the expected coupling products in good to high yields.
- Farrokhi, Alireza,Rouzifar, Majid,Sansano, José Miguel,Sobhani, Sara
-
p. 19963 - 19976
(2021/11/12)
-
- A hydrophilic heterogeneous cobalt catalyst for fluoride-free Hiyama, Suzuki, Heck and Hirao cross-coupling reactions in water
-
A hydrophilic heterogeneous cobalt catalyst of chitosan, denoted as mTEG-CS-Co-Schiff-base, has been successfully prepared. This newly synthesized catalyst was characterized by different methods such as XRD, FE-SEM, TEM, TGA, FT-IR, 13C{1H} CP/MAS NMR, XPS and ICP analyses. The catalyst displayed excellent activity for the palladium and fluoride-free Hiyama, Suzuki, Heck and Hirao reactions of various aryl iodides, bromides and chlorides (i.e., the most challenging aryl halides which are cheaper and more widely available than aryl iodides and bromides) in water. The presence of triethylene glycol tags with hydrophilic character on the Co-complex supported on chitosan provides dispersion of the catalyst particles in water, which leads to higher catalytic performance and also facile catalyst recovery by successive extraction. It was reused for at least six successive runs without any discernible decrease in its catalytic activity or any remarkable changes in catalyst structure. The use of water as a green solvent, without requiring any additive or organic solvent, as well as use of a low cost and abundant cobalt catalyst instead of expensive Pd catalysts along with the catalyst recovery and scalability, make this method favorable from environmental and economic points of view for the C-C and C(sp2)-P coupling reactions. Notably, this is the first report on the application of a cobalt catalyst in Hiyama reactions.
- Sobhani, Sara,Hosseini Moghadam, Hadis,Skibsted, J?rgen,Sansano, José Miguel
-
p. 1353 - 1365
(2020/03/11)
-
- Synthesis of Arsenopyrite-Type Rhodium Pernitride RhN2 from a Single-Source Azide Precursor
-
Nitrogen-rich noble metal nitrides possess unique mechanical and catalytic properties, therefore their synthesis and characterization is of interest for fundamental solid state chemistry and materials science. In this study we have synthesized a novel sin
- Bykov, Maxim,Yusenko, Kirill V.,Bykova, Elena,Pakhomova, Anna,Kraus, Werner,Dubrovinskaia, Natalia,Dubrovinsky, Leonid
-
p. 3667 - 3671
(2019/07/31)
-
- Synthesis of arylphosphonates catalyzed by Pd-imino-Py-γ-Fe2O3 as a new magnetically recyclable heterogeneous catalyst in pure water without requiring any additive
-
A palladium-Schiff base complex immobilized covalently on γ-Fe2O3 (Pd-imino-Py-γ-Fe2O3) was synthesized and characterized by different methods such as XRD (X-ray diffraction), SEM (scanning electron microscopy), TEM (transmission electron microscopy), FT-IR (Fourier transform infrared spectroscopy), TGA (thermogravimetric analysis), ICP (inductively coupled plasma), XPS (X-ray photoelectron spectroscopy), VSM (vibrating sample magnetometer) and elemental analysis. It was used as a new magnetically recyclable heterogeneous Pd catalyst for the synthesis of arylphosphinates via Csp2-P coupling reactions. A wide range of electrophilic benzenes were coupled successfully with triethylphosphite to generate the corresponding products in good to high yields in pure water without using any additive. The true heterogeneous Pd-imino-Py-γ-Fe2O3 could be reused simply with the aid of a magnetic bar for eight consecutive cycles without any drastic loss of its reactivity.
- Sobhani, Sara,Ramezani, Zohreh
-
p. 29237 - 29244
(2018/06/06)
-
- Visible-Light photo-Arbuzov reaction of aryl bromides and trialkyl phosphites yielding aryl phosphonates
-
Aryl phosphonates are functional groups frequently found in pharmaceutical and crop protection agents. For their synthesis via C?P bond formation typically transition-metal-catalyzed reactions are used. We report a visible-light photo-Arbuzov reaction as an efficient, mild, and metal-free alternative. Rhodamine 6G (Rh.6G) is used as the photocatalyst, generating aryl radicals under blue light. Coupling of the radicals with a wide range of trivalent phosphites gives aryl phosphonates in good to very good isolated yields. The mild reaction conditions allow the introduction of a phosphonate group into complex and sensitive pharmaceutically active molecules such as benzodiazepams and nicergoline by the activation of a carbon?halogen bond.
- Shaikh, Rizwan S.,Düsel, Simon J.S.,K?nig, Burkhard
-
p. 8410 - 8414
(2018/05/23)
-
- A Pd complex of a NNN pincer ligand supported on γ-Fe2O3@SiO2 as the first magnetically recoverable heterogeneous catalyst for C-P bond forming reactions
-
A Pd complex of a NNN pincer ligand supported on γ-Fe2O3@SiO2 as a new phosphine-free Pd catalyst was synthesized and characterized by different methods such as SEM, TEM, FT-IR, TGA, ICP, XRD, XPS and elemental analysis. The synthesized catalyst was successfully used as the first magnetically recoverable heterogeneous catalyst for the synthesis of arylphosphonates via C-P bond formation by a cross-coupling reaction of different electrophilic benzenes with phosphite esters under solvent-free conditions.
- Sobhani, Sara,Vahidi, Zahra,Zeraatkar, Zohre,Khodadadi, Samaneh
-
p. 36552 - 36559
(2015/05/05)
-
- Phosphonate monoesters as carboxylate-like linkers for metal organic frameworks
-
Bidentate phosphonate monoesters are analogues of popular dicarboxylate linkers in MOFs, but with an alkoxy tether close to the coordinating site. Herein, we report 3-D MOF materials based upon phosphonate monoester linkers. Cu(1,4-benzenediphosphonate bis(monoalkyl ester), CuBDPR, with an ethyl tether is nonporous; however, the methyl tether generates an isomorphous framework that is porous and captures CO2 with a high isosteric heat of adsorption of 45 kJ mol-1. Computational modeling reveals that the CO 2 uptake is extremely sensitive both to the flexing of the structure and to the orientation of the alkyl tether.
- Iremonger, Simon S.,Liang, Junmei,Vaidhyanathan, Ramanathan,Martens, Isaac,Shimizu, George K. H.,Daff, Thomas D.,Aghaji, Mohammad Zein,Yeganegi, Saeid,Woo, Tom K.
-
body text
p. 20048 - 20051
(2012/01/19)
-
- Efficient energy and electron transfer between donor and acceptor chromophores in aluminophosphate hybrid materials
-
The first organic-inorganic hybrid materials (OIHMs) having one or a combination of two chromophores in different ratios are obtained from the aryl phosphonic acid and aluminum lactate via sol gel process. The structures of these OIHMs are analyzed by the 27Al and 31P NMR. The fluorescence resonance energy transfer (FRET) as well as photoinduced electron transfer (PET) between donor and acceptor chromophores in these hybrid materials have been investigated and the efficiencies can be up to 97 and 93%, respectively.
- Lo, Chih-Yuan,Chen, Chih-Hsien,Tsai, Tim W. T.,Zhang, Long,Lim, Tsong-Shin,Fann, Wunshain,Chan, Jerry C. C.,Luh, Tien-Yau
-
scheme or table
p. 539 - 546
(2011/04/22)
-
- Mesoporous crystalline solid compound of a diphosphonate/phosphite of a tetravalent metal, with a narrow distribution of mesopores
-
The present invention discloses a compound comprising a diphosphonate/phosphite of a tetravalent metal: (where M, R, x and y have the meaning given in the description), in the form of a crystalline solid with an alpha-type lamellar structure with a distance between layers of 7.4 to 20? (depending on the dimensions of radical R), a BET surface area of 250 to 400m2 /g, and porosity within the mesopore range, with at least 50% of the pores measuring 20 to 30?. The compound, depending on the radical R used, may or may not have microporosity in the region between layers. Such a diphosphonate/phosphite of a tetravalent metal is obtained by reaction between diphosphonic acid, phosphorous acid and an oxyhalide of a tetravalent metal, in a solvent comprising dimethyl-sulphoxide/water containing hydrofluoric acid.
- -
-
-
- Mesoporous crystalline compound of a tetravalent metal
-
The present invention discloses a compound comprising a diphosphonate/phosphite of a tetravalent metal:, , M[(O3P-R-PO3)1-(x+y)(HPO3)2X(O3P-R-PO3H2)2y], , (where M, R, x and y have the meaning given in the description), in the form of a crystalline solid with an alpha-type lamellar structure with a distance between layers of 7.4 to 20? (depending on the dimensions of radical R), a BET surface area of 250 to 400m2/g, and porosity within the mesopore range, with at least 50% of the pores measuring 20 to 30?. The compound, depending on the radical R used, may or may not have microporosity in the region between layers. Such a diphosphonate/phosphite of a tetravalent metal is obtained by reaction between diphosphonic acid, phosphorous acid and an oxyhalide of a tetravalent metal, in a solvent comprising dimethyl-sulphoxide/water containing hydrofluoric acid.
- -
-
-
- THE EFFECT OF ORTHO SUBSTITUENTS IN SRN1 REACTIONS. SOME SYNTHETIC APPLICATIONS.
-
Several ortho-substituted iodobenzenes were allowed to react, via the SRNl mechanism, with mixtures of diethyl phosphite ion and pinacolone enolate ion.From product composition data, the relative reactivities of the two nucleophiles were reckoned.They represent relative reactivities in attachment to aryl radical intermediates.Most of the ortho effects are slight, but there is evidence that large ortho substituents hinder attachment of the phosphite more than the enolate nucleophile.The methoxy and diethoxyphosphoryl substituents, when para to the site of substitution, respectively favour and disfavour the phosphite with respect to the enolate ion.SRNl reactions of ortho-substituted halobenzenes are, for some substituents, followed by other reactions which afford products of synthetic interest.
- Bunnett, Joseph F.,Mitchel, Eric,Galli, Carlo
-
p. 4119 - 4132
(2007/10/02)
-
- PALLADIUM-CATALYZED NEW CARBON-PHOSPHORUS BOND FORMATION
-
Dialkyl arylphosphonates are prepared by the palladium-catalyzed reaction of aryl bromides with dialkyl phosphite in the presence of triethylamine.The similar treatment of vinyl bromides gives dialkyl vinylphosphonates stereoselectively.
- Hirao, Toshikazu,Masunaga, Toshio,Yamada, Naoto,Ohshiro, Yoshiki,Agawa, Toshio
-
p. 909 - 913
(2007/10/02)
-