Formation of Highly Dispersed Rhodium Particles by Chemical and Photochemical Reduction

1992 ◽  
Vol 272 ◽  
Author(s):  
Zhibang Duan ◽  
M.J. Hampden-Smith ◽  
A. Datye ◽  
P.J. Nigrey ◽  
C. Quintana ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Room Temperature ◽  
Metal Particles ◽  
X Ray Diffraction ◽  
Photochemical Reduction ◽  
X Ray ◽  
Homogeneous Solutions ◽  
Highly Dispersed ◽  
Metal Organic

ABSTRACTNanometer-sized metal particles have been prepared by chemical and photochemical reduction of homogeneous solutions of metal-organic rhodium(I) compounds. Reduction of [(COD)RhCl]2 with LiBEt3H in THF resulted in the formation of solutions containing crystalline, mono-dispersed Rh particles with average sizes of 2–4nm as determined by TEM and SAXS. The species [(COD)RhH]4 was isolated during the formation of the Rh colloids but was found not to be an intermediate in the reduction of Rh(I) to Rh(0). The catalytic activity of these highly dispersed metals towards pyrene hydrogenation has been investigated. Photochemical reduction of [(ethylene)2Rh(OEt)]2 at room temperature also resulted in formation of Rh as shown by TEM, EDS, ED and X-ray diffraction.

scholarly journals Aluminium incorporation in polar, semi- and non-polar AlGaN layers: a comparative study of x-ray diffraction and optical properties

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Duc V. Dinh ◽  
Nan Hu ◽  
Yoshio Honda ◽  
Hiroshi Amano ◽  
Markus Pristovsek
Keyword(s):  
Room Temperature ◽  
Optical Emission ◽  
Vapour Phase ◽  
Optical Data ◽  
Bandgap Energy ◽  
X Ray Diffraction ◽  
Vapour Phase Epitaxy ◽  
X Ray ◽  
Metal Organic ◽  
Organic Vapour

Abstract Growth of AlxGa1−xN layers (0 ≤ x ≤ 1) simultaneously on polar (0001), semipolar ($$10\bar{{\rm{1}}}$$ 10 1 ¯ 3) and ($$11\bar{{\rm{2}}}2$$ 11 2 ¯ 2 ), as well as nonpolar ($$10\bar{{\rm{1}}}0$$ 10 1 ¯ 0 ) and ($$11\bar{{\rm{2}}}0$$ 11 2 ¯ 0 ) AlN templates, which were grown on planar sapphire substrates, has been investigated by metal-organic vapour phase epitaxy. By taking into account anisotropic in-plane strain of semi- and non-polar layers, their aluminium incorporation has been determined by x-ray diffraction analysis. Optical emission energy of the layers was obtained from room-temperature photoluminescence spectra, and their effective bandgap energy was estimated from room-temperature pseudo-dielectric functions. Both x-ray diffraction and optical data consistently show that aluminium incorporation is comparable on the polar, semi- and non-polar planes.

Synthesis and Crystal Structure of a Cadmium(II) Complex with 2-(4΄-Chlorine-Benzoyl)-Benzoic Acid and 1,10-Phenanthroline

2011 ◽  
Vol 339 ◽  
pp. 313-316
Author(s):  
Xiu Mei Li ◽  
Zhi Tao Wang ◽  
Qing Wei Wang
Keyword(s):  
Benzoic Acid ◽  
Room Temperature ◽  
Supramolecular Network ◽  
X Ray Diffraction ◽  
Organic Complex ◽  
Orthorhombic Space Group ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
Metal Organic Complex ◽  
Metal Organic

A new metal-organic complex Cd2(cbba)4(phen)2 (Hcbba = 2-(4΄-chlorine-benzoyl)- benzoic acid, phen = 1,10-phenanthroline) 1 has been hydrothermally synthesized and structurally characterized by elemental analysis, IR, fluorescence spectrum and single-crystal X-ray diffraction. The compound crystallizes in orthorhombic, space group Pbcn with a = 12.0976(4), b = 18.0925(6), c = 31.6829(10) Å, V = 6934.6(4) Å3, C80H48Cd2Cl4N4O12, Mr = 1623.82, Dc = 1.555 g/cm3, μ(MoKα) = 0.8365 mm1, F(000) = 3264, Z = 4, the final R = 0.0396 and wR = 0.0960 for 5372 observed reflections (I > 2(I)). It exhibits a 3D supramolecular network through π-π interactions and shows green luminescent property at room temperature.

Synthesis, crystal structures, and thermal and spectroscopic properties of two Cd(II) metal-organic frameworks with a versatile ligand

2016 ◽  
Vol 71 (8) ◽  
pp. 909-917 ◽  
Author(s):  
Jia-Ming Li ◽  
Kun-Huan He ◽  
Zhong-Feng Shi ◽  
Hui-Yuan Gao ◽  
Yi-Min Jiang
Keyword(s):  
Room Temperature ◽  
Metal Organic Frameworks ◽  
Spectroscopic Properties ◽  
Supramolecular Architecture ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bridging Ligand ◽  
Hydrogen Bond Interactions ◽  
Distorted Octahedral ◽  
Metal Organic

AbstractTwo new metal-organic frameworks, namely, [Cd(L)(H2O)]n (1) and {[Cd0.5(L)(4,4′-bipy)0.5][Cd0.5(H2O)(4,4′-bipy)0.5]·H2O}n (2), where H2L = N-pyrazinesulfonyl-glycine and 4,4′-bipy = 4,4′-bipyridine, have been synthesized and characterized by single-crystal X-ray diffraction, IR spectroscopy, elemental, thermogravimetric, and photoluminescent analysis. X-ray diffraction crystallographic analyses indicate that 1 displays a distorted octahedral metal coordination in a 3-connected (4, 82) topology, while the molecular structure of 2 has a 4-connected (4, 4) topology with two perfectly octahedrally coordinated Cd centers. The L2– ligand serves as a N,N,O-tridentate, μ2-pyrazine-bridging, and μ2-carboxylate-bridging ligand in 1, and as a N,O-bidentate and μ2-carboxylate-bridging ligand in 2. In the crystal, a 3D supramolecular architecture is formed by O–H···O hydrogen bond interactions in 1, but through O–H···O as well as π···π stacking in 2. The two compounds show intense fluorescence in the solid state at room temperature.

scholarly journals High CO2 Adsorption Enthalpy Enabled by Uncoordinated N-Heteroatom Sites of a 3D Metal-Organic Framework

2019 ◽  
Vol 2019 ◽  
pp. 1-5 ◽  
Author(s):  
Yongting Zhao ◽  
Yiming Xie
Keyword(s):  
Room Temperature ◽  
Co2 Adsorption ◽  
Metal Organic Framework ◽  
Adsorption Properties ◽  
X Ray Diffraction ◽  
High Adsorption ◽  
Adsorption Enthalpy ◽  
X Ray ◽  
Metal Organic ◽  
Organic Framework

A 3D metal-organic framework (MOF), Mn2L2(H2O)2 · (DMF) {H2L = 5- (Pyridin-2-yl)-3, 3′-bi (1H-1,2,4-triazole)} (1) with uncoordinated N-heteroatom sites, has been obtained through hydrothermal method and structurally characterized by X-ray structural analysis, powder X-ray diffraction (PXRD), and thermal analysis (TGA). The framework of compound 1 exhibits fascinating adsorption properties and shows high adsorption enthalpy of CO2. The experimental results prove which uncoordinated nitrogen heteroatom sites can markedly increase the reciprocity between host frame and CO2 at room temperature.

scholarly journals STUDY ON CATALYTIC ACTIVITY OF TIO2/SIO2, IN THE OXIDATION OF STYRENE

2009 ◽  
Vol 12 (3) ◽  
pp. 77-84
Author(s):  
Thao Tien Nguyen ◽  
Ngoan Thi Nguyen ◽  
Long Van Dang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Catalytic Activity ◽  
Ir Spectroscopy ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mild Conditions ◽  
Scanning Electron

All TiO2/SiO2 samples were prepared by the impregnation of Ti(i-PrO)4 in isopropanol at room temperature followed drying and calcination. The solids were characterized by several techniques including X- ray diffraction (XRD), IR spectroscopy, Scanning Electron Microscopy (SEM). No reflection lines of TiO2 are detected at a low content of TiO2 (< 7%), but are more visible at a higher concentration. The catalysts are tested in the liquid oxidation of styrene under mild conditions, producing mainly benzaldehyde. The effects of variables on the catalytic activity are also investigated.

scholarly journals Lead Based Metal Organic Frameworks(Pb-MOFs): Anion Influence, Luminescence and Gas Adsorption Study

2019 ◽  
Vol 70 (10) ◽  
pp. 3545-3548
Author(s):  
Shamaila Iram ◽  
Muhammad Imran ◽  
Farah Kanwal ◽  
Shoomaila Latif ◽  
Zafar Iqbal
Keyword(s):  
Surface Area ◽  
Room Temperature ◽  
Gas Adsorption ◽  
Lead Nitrate ◽  
X Ray Diffraction ◽  
N2 Adsorption ◽  
X Ray ◽  
Adsorption Capacities ◽  
Metal Organic ◽  
Organic Linker

Two Lead based organic frameworks (1&2) have been synthesized using 4,6-dihydroxy-2-mercaptopyrimidine (H2DMP) as organic linker. Lead nitrate (1) and Lead acetate (2) salts were used to investigate their influence on morphology of resulting MOFs, adsorption capacities and luminescence behaviour. Structure and morphology of these MOFs was established on the basis of UV/Vis, Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), 1H NMR, energy dispersive spectroscopy (EDS), thermogravimetric analysis (TGA) and X-ray diffraction technique. Brunauer-Emmett-Teller (BET) studies revealed better N2 adsorption capacity for 1 (surface area 814 m2/g) when compared with 2 (surface area 196 m2/g). Photoluminescence behaviour of (1&2) was investigated in solid state at room temperature and has been attributed to metal-centred s�p transition.

scholarly journals Natural vs. Synthetic Phosphate as Efficient Heterogeneous Compounds for Synthesis of Quinoxalines

2021 ◽  
Vol 22 (24) ◽  
pp. 13665
Author(s):  
Abbas Amini ◽  
Azadeh Fallah ◽  
Ahmad Sedaghat ◽  
Ahmad Gholami ◽  
Chun Cheng ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Room Temperature ◽  
Reaction Times ◽  
Atomic Ratio ◽  
Energy Dispersive ◽  
Chemical Analyses ◽  
X Ray Diffraction ◽  
X Ray ◽  
Recyclable Catalysts ◽  
Scanning Electron

Natural phosphate (NP) and synthetic fluorapatite phosphate (SFAP) were proposed as stable, inexpensive, readily available and recyclable catalysts for the condensation of 1,2-diamines with 1,2-dicarbonyls in methanol to afford quinoxaline at room temperature. NP provided as high as 92–99% yield for quinoxalines in short reaction times (i.e., 1–45 min), while SFAP created quinoxalines with 87–97% yield in 60–120 min. From the chemical analyses, X-ray fluoresecency, X-ray diffraction, energy dispersive X-ray and Fourier-transform infrared spectroscopy methods, two main phases (CaO, P2O5) appeared in NP together with other low content phases (SiO2, Fe2O3). Compared to other phases, apatite (CaO and P2O5 as Ca10(PO4)6) played a major role in the catalytic activity of NP. SFAP with similar Ca/P atomic ratio showed a relatively lower catalytic activity than NP for the condensation of 1,2-diamine with 1,2-dicarbonyl in methanol at ambient temperature. To investigate the recyclability of catalysts, the surface properties of NP and 6-recycled NP were investigated using scanning electron microscopy, energy dispersive X-ray and Brunauer–Emmett–Teller and Barrett–Joyner–Halenda methods. Some differences were observed in NP and 6-recycled NP’s particle size, surface area, the volume and size of pores, and the content of elements; nevertheless, the use–reuse process did not noticeably change the catalytic property of NP.

Preparation and Photocatalytic Properties of Bi2WO6 with Different Morphologies

2013 ◽  
Vol 779-780 ◽  
pp. 390-393
Author(s):  
Ying Chen ◽  
Xu Wang ◽  
Hua Song ◽  
Hua Lin Song
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Photocatalytic Activity ◽  
Catalytic Activity ◽  
Room Temperature ◽  
Great Influence ◽  
X Ray Diffraction ◽  
X Ray ◽  
Morphology And Structure ◽  
Scanning Electron

Bismuth tungstate (Bi2WO6) microcrystalline with different surfactant were successfully prepared by a facile hydrothermal route.The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and BrunauerEmmettTeller surface area (BTE) in detail. The photocatalytic activity of the samples was also evaluated using the degradation of Rh B at room temperature under visible light irradiation. It was found that the surfactant played important roles in the formation process of controlling the morphology and structure of the catalyst and also had a great influence on the catalytic activity. SDS and CTAB effectively improved the catalytic activity and PVP was good at controlling morphologies.

Response of a Zn(II)-based Metal-Organic Coordination Polymer towards Trivalent Metal Ions (Al3+, Fe3+, Cr3+) Probed by Spectroscopic Approaches

2021 ◽  
Author(s):  
Sudip Kumar Mondal ◽  
Partha Mahata ◽  
Pooja Daga ◽  
Priyanka Manna ◽  
Prakash Majee ◽  
...  
Keyword(s):  
Coordination Polymer ◽  
Diffraction Analysis ◽  
Room Temperature ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Trivalent Metal ◽  
X Ray ◽  
Diffusion Technique ◽  
Metal Organic ◽  
Trivalent Metal Ions

A new zinc-based two-dimensional coordination polymer, [Zn(5-AIP)(Ald-4)]·H2O (5-AIP = 5-amino isophthalate, Ald-4 = aldrithiol-4), 1, has been synthesized at room temperature by layer diffusion technique. Single-crystal X-ray diffraction analysis of...

Ionothermal Synthesis and Crystal Structure of a Neutral 2D Metal- Organic Framework Based on Cobalt(II) 1,2,3-Benzenetricarboxylate

2014 ◽  
Vol 69 (8) ◽  
pp. 864-870 ◽  
Author(s):  
Shun Shun Liu ◽  
Rui Min Zhou ◽  
Shuai Chen ◽  
Yan Bai ◽  
Dong Bin Dang
Keyword(s):  
Room Temperature ◽  
Metal Organic Framework ◽  
X Ray Diffraction ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
Distorted Trigonal Bipyramid ◽  
Metal Organic ◽  
Benzenetricarboxylic Acid ◽  
Neutral Metal ◽  
Organic Framework

A neutral metal-organic framework [CoNa3(1,2,3-Hbtb)(1,2,3-btb)] (1) has been synthesized through an ionothermal method using 1-ethyl-3-methylimidazolium bromide as solvent (1,2,3- H3btb=1,2,3-benzenetricarboxylic acid). The complex has been characterized by IR spectroscopy, elemental analysis, PXRD and single-crystal X-ray diffraction. The structure of 1 exhibits a layer network structure in which Co(II) is five-coordinated forming a distorted trigonal bipyramid. Na1 and Na3 are surrounded by seven oxygen atoms, and Na2 is six-coordinated. In the structure, the anions of 1,2,3-H3btb are embedded in two bridging μ8 coordination modes. The luminescence properties of 1 have been investigated in the solid state at room temperature.

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