Search

C9H6Br6, hexagonal, P63/m (no. 176), a = 8.8911(3) Å, c = 10.6847(5) Å, V = 731.48(6) Å3, Z = 2, Rgt(F) = 0.0441, wRref(F2) = 0.1094, T = 293 K. [ABSTRACT FROM AUTHOR]

Two novel CoII metal–organic frameworks {[Co(BIMB)2(H2O)2](SO4)·EG·3 H2O}n (I) and {[Co(TIMB)2](SiF6)}n (II) were hydrothermally synthesized by corresponding metal salt with organic ligands 1,3,5-tris[(1H-imidazol-1-yl)methyl]benzene (TIMB) or 1,4-bis((1H-imidazol-1-yl)methyl)benzene (BIMB). Crystal structural analysis reveals that they exhibit varied structures. Compound I contains two crystallographically unique CoII centers, each lying on an inversion center and having a slightly distorted octahedral environment. The BIMB ligands link the CoII cations to generate a three-dimensional porous framework with a 4-connected uninodal (65.8) topology. Compound II exhibits a two-dimensional sheeted metal-organic structure running parallel to the (0 0 1) plane, in which TIMB ligands join Co2+ centers having a six-coordinated octahedral structure. In the solid state, adjacent sheets are further bridged by guest SiF6- anions via C–H...F hydrogen-bonding interactions, giving rise to a three-dimensional supramolecular network structure with a 2-nodal (3-c)2(6-c) net. The topological analysis suggests that the point Schläfli symbol of compound II is (43)2(46.66.83). In addition, their thermal stabilities have also been investigated. [ABSTRACT FROM AUTHOR]

The one-dimensional (1D) spatial distributions of OH absolute concentration in methane/air laminar premixed flat flame under different equivalence ratios at atmospheric pressure are investigated by using bi-directional laser-induced fluorescence (LIF) detection scheme combined with the direct absorption spectroscopy. The effective peak absorption cross section and the average temperature at a height of 2 mm above the burner are obtained by exciting absorption on the Q1(8) rotational line in the A2Σ+ (ʋ′ = 0) ← X2Π (ʋ″ = 0) at 309.240 nm. The measured values are 1.86×10−15 cm2 and 1719 K, respectively. Spatial filtering and frequency filtering methods of reducing noise are used to deal with the experimental data, and the smoothing effects are also compared using the two methods. The spatial distribution regularities of OH concentration are obtained with the equivalence ratios ranging from 0.8 to 1.3. The spatial resolution of the measured result is 84 μm. Finally, a comparison is made between the experimental result of this paper and other relevant study results. [ABSTRACT FROM AUTHOR]