Sock-Sung Yun

Catalytic behavior of BiPO4 in the multicomponent bismuth phosphate system on the propylene ammoxidation

We found that the multicomponent bismuth phosphate (MBP) with multiphase activates catalytically the ammoxidation reaction of propylene and consists of mainly BiPO4 and metal molybdates, etc. The MBP has been characterized by several techniques such as DTA, XRD, and BET surface area and total pore volume measurements. The DTA curve clearly shows that there are phase transitions with sharp breaks of the curve. The specific surface area and total pore volume decrease with increasing of the BiPO4 phase content, showing that the BiPO4 phase remains essentially on the catalyst surface and blocks the active sites and catalyst pores. It would mean that the catalytic behavior in the MBP depends on the catalyst surface covered with the BiPO4 phase adequately. The pathway of the selective oxidation due to the controlled amounts of the BiPO4 phase favors the formation of acrylonitrile. The improvement of catalytic performances of the mixture of phases is explained by the synergy effect.

A novel, wave-like, two-dimensional anionic host with Cationic and neutral guests: crystal structure of [C6H11NH3][Cu2(CN)3] · 2C6H5NH2

A novel inclusion compound, [C6H11NH3][Cu2(CN)3] · 2C6H5NH2, has been synthesized and structurally characterized by X-ray crystallographic methods. It crystallizes in the monoclinic space group P21/n with a = 8.839(1), b = 18.894(2), c = 14.080(3) Å, β = 93.76(1)°, V = 2346.5(7) Å3, Z = 4. The structure is composed of the anionic layered two-dimensional host [Cu2(CN)3]− and the cationic onium guest [C6H11NH3]+ and neutral guests, C6H5NH2. Each Cu(I) atom is bonded to three cyanide ligands and exhibits trigonal coordination. Cu(I)–CN–Cu(I) bridges from puckered hexagons with all edges shared. The cyclohexylammonium and aniline guests are situated between host layer sheets. The cyclohexylammonium ion has a chair conformation and lies perpendicular to the host layer. The aniline molecules are arranged perpendicular and inclined at approximately 45° to the host layer, respectively. Both guest molecules are held together by a network of hydrogen bonds.

Synthesis and crystal structure of bis(dicyclohexylammonium) Tetracyanonickel(II)

A novel, one-dimensional nickel(II) complex, [(C6H11)2NH2]2[Ni(CN)4], has been synthesized and structurally characterized by X-ray single crystallographic methods. The complex crystallizes in the triclinic, space group P1 with a = 9.237(1), b = 9.576(2), c = 9.689(3) Å, α = 61.51(2), β = 85.69(3), γ = 74.27(2)°, V = 723.6(3) Å3, Z = 1. The square-planar Ni(II) centre of the cyanonickellate anion is four coordinated by cyanide ligands. The dicyclohexylammonium cation occupies a bridging position by hydrogen bonding to the cyanide ligand nitrogen atoms of adjacent anions.

Ignition delay times of nitromethaneoxygenargon mixtures behind reflected shock

The substituted NO 2 reduced the role of oxygen as the promotor of the detonation and decreased the activation energy, compared with the case of methane. It could be due to one of two factors: the C-N bond energy or the reactivity of the NO 2 radical deriving additional branching chain processes for the detonation reaction

Synthesis of molybdenum-triosmium cluster complexes: Reaction of (μ-H)2Os3(CO)10 with (η-C5H5)(CO) 2MOCC6H4Me

Abstract The reaction of Cp(CO) 2 MoCTol (Cp = η 5 -C 5 H 5 , Tol = p -C 6 H 4 Me) and (μ-H) 2 Os 3 (CO) 10 under mild conditions (5–20°C) produces three molybdenum-triosmium mixed-metal cluster compounds, CpMoOs 3 (CO) 11 [μ 3 -η 2 C(O)CH 2 Tol] ( 4 , 65%) as a major product together with two minor products CpMoOs 3 (CO) 10 (μ 3 -CTol) 2 (μ-H) ( 5 , 10%) and CpMoOs 3 (CO) 10 )(μ 3 -(η 2 -C 2 Tol 2 ))(μ-H) ( 6 , 6%). Compounds 4 , 5 and 6 have been isolated as crystalline solids and characterized by spectroscopic methods. Fluxionality of compound 4 has been examined by variable temperature 13 C NMR spectroscopy. Compound 5 in solution undergoes a degenerate metal framework rearrangement. 1 H NMR analysis of the tolyl methyl resonances of 5 for the rearrangement process gives Δ G c ≠ = 15.2 ± 0.2 kcal/mol at the temperature of coalescence.

Crystal structure, and thermal and magnetic properties of 2,4-dinitrobenzoatoterbium(III) complex

The Tb(III) complex containing 2,4-dinitrobenzoate (2,4-DNB), Tb(2,4-DNB)3(H2O)2] · C2H5OH has been synthesized and its crystal structure analyzed by X-ray diffraction methods. The complex crystallizes in the triclinic space group P 1, as a linear polymeric chain in which terbium ions are bridged by carboxylate groups. The eight-coordinate Tb ion with six carboxylate groups and two water molecules forms a slightly distorted square antiprism. Thermal and magnetic properties of the terbium complex were also studied.

Crystal structure and thermal properties of a dimeric (2,6-dinitrophenolato)lithium(I) complex

The crystal structure of a (2,6-dinitrophenolato)lithium complex has been determined by single-crystal X-ray diffraction methods. It is triclinic, space group , with a = 5.205(2), b = 8.972(3), c = 10.608(4) Å, β = 77.99(6)°, V = 474.2(3) Å3, Z = 1. The dimeric complex is centrosymmetric, excluding outer-sphere water molecules. The Li(I) ion is coordinated to five oxygen atoms to form square pyramidal geometry. There is a water molecule in the apical position, and four oxygen atoms from two 2,6-dinitrophenol (2,6-DNP) ligands form the basal plane. TG-DTG curves show that there are two steps for the mass loss during the thermal decomposition of the complex [Li(2,6-DNP)(H2O)]2·2H2O. The first, between 57 and 80°C, corresponds to dehydration, and the second, between 330 and 370°C, corresponds to decomposition of the complex with explosion.

Syntheses and Crystal Structures of Three-Dimensional Cyanocadmate Clathrates with Imidazole

The crystal structures of two clathrates with imidazole (=imH), [Cd3(CN)6(imH)2]·C6H12, I, and [Cd3(CN)6(imH)2]·C6H5Cl, II, have been analyzed by single-crystal X-ray diffraction methods. Clathrate I crystallizes in the monoclinic system, space group P21/n with a=13.416(2), b=14.140(2), c=14.151(1)Å, β=105.08(9)°, V=2592.1(5)&Aringsup3;, Z=4, R 1=0.0360, wR 2=0.0850 for 5931 independent reflections; II: monoclinic P21/n, a=12.369(2), b=14.313(2), c=14.416(4)Å, β=106.04(2)°, V=2452.7(9)&Aringsup3;, Z=4, R 1=0.0398, wR 2=0.1105 for 5642 independent reflections. The three-dimensional host structures of clathrates I and II are isostructural with each other. The host framework is built through cyanide bridges among two kinds of Cd ions, tetrahedral and octahedral, in a ratio of 2 : 1. The tetrahedral Cd(1) centre is linked to three octahedral Cd(3) atoms and one tetrahedral Cd(2) atom; the tetrahedral Cd(2) centre is ligated by one unidentate imidazole ligand and linked to one tetrahedral Cd(1) atom and two octahedral Cd(3) atoms; the octahedral Cd(3) centre is ligated by one unidentate imidazole ligand and linked to three tetrahedral Cd(1) atoms and two tetrahedral Cd(2) atoms. The novel host structure provides two types of channels, a large, elongated, rectangular channel and a small rectangular channel. The larger channel is occupied by imidazole ligands coordinated to tetrahedral Cd(2) and octahedral Cd(3). The smaller channel accommodates the guest molecules cyclohexane and chlorobenzene.

Synthesis and crystal structure of oxo-bridged binuclear titanium complex [{Ti(acac)2Cl}{TiCp2(Cl)}(μ-O)] and its catalytic reactions toward silation of aldehyde

Abstract Reaction of [Cp2TiCl2] with two equivalents of 2,4-pentanedione in the presence of one equivalent of NEt3 in CH3CN at room temperature yielded oxo-bridged binuclear titanium complex [{Ti(acac)2Cl}{TiCp2(Cl)}(μ-O)], which was characterized crystallographically and spectroscopically. Reaction mixture of oxo-bridged binuclear titanium complex and 2nBuLi catalytically activate the mixture of phenylsilane and aldehyde to yield O-silation products at room temperature.

Dehydrocoupling Synthesis and Optoelectronic Properties of Polysilole

Abstract Dehydrocoupling of 2,3,4,5-tetraphenylsilole dihydride 1 with various inorganic hydrides (such as Red-Al, N-Selectride, and super-hydride) produces polysiloles 2 in high yields. The polysiloles emit green light at 520 nm and are electroluminescent at 520 nm.