火焰结构的平面激光诱导荧光技术观测

用平面激光诱导荧光（PLIF）技术测量了烧煤油的酒精喷灯单脉冲激光诱导荧光，由平面荧光图可清晰地看到氢氧基与C2、C3在火焰中的位置，同时，也看到了煤油火焰由发生、发展到熄灭过程中火焰结构的变化；PLIF技术是研究火焰结构的有力工具。     

The splitting of low-lying states for hydroxyl molecule under spin--orbit coupling

The splitting of potential energy curves for the states $X^{2}\Pi _{3/2}$, $^{2}\Pi _{1/2}$ and $A^{2}\Sigma ^{ +}$ of hydroxyl OH under spin--orbit coupling (SOC) has been calculated by using the SO multi-configuration quasi-degenerate perturbation theory (SO-MCQDPT). Their Murrell--Sorbie (M--S) potential functions have been derived, then, the spectroscopic constants for $X^{2}\Pi _{3/2}$,$^{ 2}\Pi _{1/2}$ and $A^{2}\Sigma ^{ + }$ have been derived from the M--S function. The calculated dissociation energies for the three states are $D_{0}$[OH($X^{2}\Pi _{3/2})$]=34966.632cm$^{-1}$, $D_{0}$[OH($^{2}\Pi _{1/2})$]=34922.802cm$^{-1}$, and $D_{0}$[OH($A^{2}\Sigma ^{ + })$]=17469.794cm$^{-1}$, respectively. The vertical excitation energy $\nu [ {{ }^2\Pi _{1/2} ( {\nu = 0} ) \to {X}{ }^2\Pi _{3/2} ( {\nu = 0} )} ] = 139.6{\rm cm}^{-{\rm 1}}$. All the spectroscopic data for the $X^{2}\Pi _{3/2}$ and $^{2}\Pi _{1/2 }$ are given for the first time except the dissociation energy of $X^{2}\Pi _{3/2}$.     

Two New Compounds from Rhododendron Przewalskii Maxim

Two new ionone derivatives, rhododendrone A and rhododendronside, have been isolated from the alco-holic extract of the aerial parts of Rhododendron Przewalskii Maxim. The structures of the two compounds, (3R, 6S)-3-hydroxy-a-ionone 1 and 1,1,5-trimethyl-6-(3-hydroxyl)cyclohexene-5-yl-1-β-D-pyranoglucoside 2, have been elucidated on the basis of the spectroscopic analyses.     

Studies on the Scavenger Activities of Salicylaldehyde and Methyl Salicylate Against Hydroxyl Radical

Active oxygen species have a carcinogenesis effect, and can cause mutation, cardiovascular diseases, inflammation and aging, etc. Hydroxyl radicals generated either from a radiolysis of water contained in biological tissues or from a redox cycling implicated in a wide range chemical toxicants, have been recognized as the extremely reactive oxidative species which can attack DNA bases and sugar moiety of nucleotides and lead to radiation or chemical injury of DNA and other biological targets.     

OH在火焰中浓度分布图像及与温度关系的PLIF和CARS研究

用平面激光诱光（ＰＬＩＦ）技术了平面火焰炉、狭缝缝火焰的单脉冲激光诱导ＯＨ荧炙。由平面荧光图可得到氢氧基相对浓度分布和它的宽度。对扩散火焰,高温区在ＯＨ带内侧;ＯＨ带的外侧则是火焰的边界,相干反斯托克斯拉斯拉曼光谱（ＣＡＲＳ）的测量结果对比提出了有力的佐证。湍流火焰的ＰＬＩＦ图则清晰地显示出火焰面的不规则性,氢氧基的ＰＬＩＦ图像是研究火焰结构和流场的有力工具。     

Synthesis and Crystal Structure of a Three-dimensional Mn（Ⅱ） Coordination Polymer with 3-（Pyrazin-2-yloxy）-pyridine and Azide Anion as Mixed Bridge Ligand

A three-dimensional coordination polymer [Mn2（μ1.3-N3）4（μ-PP）2]n （PP = 3-（pyrazin-2-yloxy）-pyridine） has been synthesized with 3-（pyrazin-2-yloxy）-pyridine and azide anion as mixed bridge ligand, and its crystal structure was determined by X-ray crystallography. The crystal data： triclinic system, space group P1, with a = 6.794（4）, b = 9.885（6）, c = 9.947（6） A, α = 64.170（6）, β= 84.190（8）, γ= 85.319（8）°, V = 597.7（6）A^3, Z = 1, C18H14Mn2N18O2, Mr = 624.35, Dc = 1.735 g/cm^3, F（000） = 314 and μ = 1.117 mm^-1. In the crystal, the azide anion acts as a bridge ligand and makes adjacent Mn（Ⅱ） ions connect into a two-dimensional sheet on the ab plane, then 3-（pyrazin-2-yloxy）-pyridine serves as a bidentate bridge ligand to connect neighboring sheets along     

Regioselective ring opening of epoxides using NH4SCN/silica sulfuric acid： An efficient approach for the synthesis of β-hydroxy thiocyanate under solvent-free conditions

Silica sulfuric acid was developed as a stable and efficient heterogeneous catalyst in organic synthesis. This solid acid catalyzed the regioselective ring opening of epoxides by thiocyanate anion to give thiocyanohydrins as key intermediates in agricultural and pharmaceutical chemistry in high yields under solvent-free conditions.     

显示OH浓度分布图像的平面激光诱导荧光技术

用平面激光诱导荧光 (PLIF)技术测量平面火焰炉、狭缝火焰炉的单脉冲激光诱导OH荧光。由平面荧光图可得到氢氧基相对浓度分布和它的宽度。对于扩散火焰 ,高温区在OH带内侧 ;而对于预混火焰 ,二者基本一致。湍流火焰的PLIF图则清晰地显示出火焰面的不规则性。氢氧基的PLIF图像是研究火焰结构和流场的有力工具。     

A Convenient Method for Synthesis of Novel Cyclic Ethers （IR, 2R,3R, 5S, 7S, 9R, 12R）-3-（t-Butyldimethylsilyl）oxy-7-methoxymethyl- oxy-2, 10-dimethyl-12-oxatricyclo [7.2.1.0^5,12] dodecane

Novel cyclic esters (1R, 2R, 3R, 5S, 7S, 9R, 12R)-3-(t-butyldimethylsilyl)oxy-7-methoxymethyloxy-2, 10-dimethyl-12-oxatricyclo [7.2.1.0^5,12] dodecane were prepared when their precursor 1 was treated with SOC12/pyridine. A plausible mechanism was hypothesized.     

An Efficient Cationic Cyclization Approach for the Construction of Labdane Diterpenoid Decalin Ring Skeleton

An effective approach for the construction of the decalin ring skeleton of labdane diterpenoids was developed based on a key biomimetic cationic polyene cyclization of an epoxy allylsilane precursor. The synthetic approach demonstrated here would be useful in the enantioselective and diastereoselective total synthesis of natural labdane diterpenoids in general.