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1、1,08级二班 徐林娜,爱拼才会赢,2,一、引言,之一 三个孩子和父亲 之二 行走的背囊,3,自我分析 专业介绍 专业的就业方向及前景,探求中前进,4,梦幻职业,环境评价师,研究人员,一名老师,5,目 标 分 析,一、首选职业一名老师 （1）优势 （2）劣势 （3）存在机会 （4）潜在威胁,6,备 选 目 标 之一环境评价师,一 优势 二 劣势 三 存在机会 四 潜在威胁,7,之二科研工作,优势 劣势 存在机会 潜在威胁,8,大 二 大 三 大 四,.未来三学年的计划,9,结束语 付出总有收获,没有兢兢业业的付出，哪来甘甜欢畅的成功喜悦 。 未来掌握在自己手中。 成功，不相信眼泪；成功，不相信
2、颓废;成功不相信幻影,未来,要靠自己打拼。,10,多谢，再见,11,Synthesis, Structure, and Magnetism of a Polyoxometalate with CoordinativelyUnsaturated d-Electron-Transition Metal Centers Zhen Luo, Paul Kogerler, Rui Cao, and Craig L. Hill*, Department of Chemistry, Emory University, Atlanta, Georgia 30322, and Institut fur Anor
3、ganische Chemie,RWTH Aachen University, 52074 Aachen, GermanyReceived April 21, 2009 A series of tetrabutylammonium salts of transition-metal substituted Wells-Dawson polyoxometalates has beensynthesized by phase-transfer techniques and characterized by infrared spectroscopy elemental analysis, andv
4、ariable-temperature magnetic measurements. X-ray-quality crystals were obtained with diffusionmethodusingdifferent organic solvents. The X-ray crystal structure of (n-C4H9)4N11H5Cu4(P2W15O56)2 (1) (monoclinic, P2(1)/n, Z = 2, a = 19.7269(6) A , b = 17.6602(5) A , c = 44.2525(11) A , = 91.182(2); R1
5、= 8.35% based on 31 282 independent reflections) reveals the presence of two unusual coordinatively unsaturated Cu(II) centers. In the absence of cocatalysts, 1 does not catalyze the aerobic oxidation of organic substrates in organic solvents.,12,Introduction The development of new materials to cata
6、lyze the selectiveaerobic oxidation of sulfur-based compounds under ambientconditions (1 atm air/O2 and 25 C) is of both intellectual and practical interest.1-6 In recent years, several different catalyticsystems based on polyoxometalates (POMs) have beeninvestigated. Okun et al.7-12 reported severa
7、l bulk and cationic-silica-supported POMs that catalyze the selective aerobic oxidation of 2-chloroethyl ethyl sulfide (CEES, a mustard gas simulant) to 2-chloroethyl ethyl sulfoxide under ambient conditions. The most recent work11,12 showed that tetrabutylammonium (TBA) salts of an iron(III)-substi
8、tuted POM, TBA3H2FeH(ONO2)2PW11O39 3(HNO3), and related Cu(II)-substituted derivatives are extremely fast and selective catalysts for aerobic (air-based) sulfoxidation. These studies indicate that the catalytic turnover frequency reflects a significant synergy between the d-electron-metal-substitute
9、d POMunit and nitrate. Unfortunately, the exact nature of this nitrate-POM interaction, despite considerable effort to clarify this issue experimentally, remains unclear for two reasons: (1) the X-ray structural determinations of these monosubstituted R-Keggin polyanions reveal that the substituted
10、position (most frequently copper and iron in these highly active catalysts) is always 12-fold disordered, precluding identification of the terminal ligand, and (2) the paramagnetismof these highly active catalystsmakes observation of the terminal ligands on the d-electron-metal centers impossible,13
11、,In the context of ongoing studies of metal-substitutedPOMsas catalysts for ambient-temperature, air-based oxidation of sulfides, trivacant Na12R-P2W15O56 3 18H2O was chosen as the precursor to prevent disorder in the X-ray structures of the Cu- and Fe-substituted derivatives. We report here the syn
12、thesis of Cu4-, Co4-, Mn4-, and Fe4- substituted derivatives of P2W15O5612- as their tetra-nbutylammonium(TBA) or tetra-n-heptylammonium (THpA) salts using a phase-transfer method that simulates the environment of the organic-solvent-soluble POM component of the highly active Cu- and Fe-substituted
13、POM aerobic oxidation catalysts. The organic-soluble POMs were characterized by a range of techniques including magnetochemical analysis of the Cu(II)-based polyanion. We further report the provocative finding that the Cu(II) centers in the polyanion of 1, namely, 1a, are coordinatively unsaturated.
14、 The coexistence of unsaturated and saturatedCu(II) centers is reminiscent of the polyanion, Cu4(Ge- W9O34)2, recently reported by Yamase and co-workers.,14,Experimental Section,General Methods and Materials. Na12R-P2W15O56 3 18H2O and Na14CuCu4(H2O)2(R-P2W15O56)2 3 53H2O were prepared according to
15、literature methods,14,15 and their purities were checked by FT-IR. All of the starting reagents, Cr- (NO3)3 3 9H2O, Mn(NO3)2, Fe(NO3)3 3 9H2O, Co(NO3)2, Cu- (NO3)2 3 2.5H2O, AgNO3, CuBr2, (n-C4H9)4NBr (TBABr), (n-C4H9)4NNO3 (TBANO3), (n-C7H15)4NBr, acetonitrile, dichloromethane, chloroform, carbon t
16、etrachloride, 1,2-dichloroethane, tetrahydrofuran, toluene, hexane, decane, octadecene, 1,3-dichlorobenzene, and CEES were purchased from Aldrich and used without further purification. Gas chromatography was performed on a Hewlett-Packard 5890 gas chromatograph equipped with a 5% phenyl methyl silicone capillary column, a flame ionization detector, and a Hewlett-Packard 3390A series integrator using N2 as the carrier gas. Elemental analyses for K, Na, Cu, Si
