Half-sandwich β-diketonato complexes of zirconium and their application as catalysts to ethylene polymerization

The bis(β-diketonato) Zr complexes CpZr(acac)2Cl (acac = acetylacetonato) (1) and Cp*Zr(acac)2Cl (2) can be synthesized by the reac-tion of Cp′ZrCl3(Cp′ = Cp or Cp*) with 2 equiv of lith-ium acetylacetonate. CpZr(acac)2Cl (1) can be quan-titatively prepared by treatment of Cp2ZrCl2 with ex-cess acetylacetone. The tris(β-diketonato) Zr com-plex CpZr(tfac)3 (tfac = trisfluoroacetylacetonato) (3) has been prepared by treatment of CpZrCl3 with so-dium trisfluoroacetylacetonate. The replacement of both chlorine atoms and one Cp group from zir-conocene dichloride by nonfluorinated diketone,acetylacetone,readily occurs at room temperature in triethylamine medium,offering the tris(β-diketonato) Zr complex CpZr(acac)3 (4). The complexes were characterized by 1H NMR spectroscopic methods. In addition,the molecular structures of complexes 3 and 4 have been determined by X-ray diffraction methods. When activated by excess methylaluminoxane (MAO),these complexes were active for ethylene polymerization,offering polyethylenes with high mo-lecular weights and narrow molecular weight distribu-tions. Complex 4 showed a very high ethylene po-lymerization activity of up to 7100 kg PE/mol Zr·h at 5 atm. Complexes 1 and 2 were also active for ethyl-ene/1-hexene copolymerization.     

Green Light-Emitting Region-Regular Poly（9,9-Dihexylfluorene-co-Fluorenone） Prepared from Solvent-Free Oxidative Coupling Polymerization

Soluble green light-emitting poly（9,9-dihexylfluorene- co-fluorenone） was synthesized by solvent-free oxidative coupling polymerization of 9,9-dihexylfluorene in a facile one-step reaction. The polymers were characterized by FT-IR, ^1H NMR, ^13C NMR, UV-Vis and fluorescence spectroscopy. The region-regular structure of the polymer linking at 2, 7＇-position on the fluorene moieties was obtained. The FT-IR spectra of the polymers showed fluorenone vibration. The fluorescence spectra of the solid thin film of the polymers displayed green light-emitting, which was emitted from fluorenone moieties produced in the polymerization process.     

氰根桥联的Cu_2~ⅡFe~Ⅱ和Ni_6~ⅡFe~Ⅱ化合物的合成、表征和磁性

Two cyano\|bridged complexes {\\-2\[Fe(CN)\-6\]}\-∞(L=NH\-2CH\-2CH\-2CH\-2OH(ampt)(1),NH\-2CH\-2CH(CH\-3)OH(amtt)(2)) and cyanobridged Ni\+Ⅱ\-6Fe\+Ⅱ cluster \[Fe(CN—Ni(tetren))\-6\](ClO\-4)\-8(tetren)(3) were synthesized,and have been characterized by elemental analysis and IR spectrum.The experimental results show that the oxide state of Fe is changed from Fe\+Ⅲ to Fe\+Ⅱ after the synthesis reaction.The magnetization versus T and magnetic susceptibility of (2) were measured and showed that the interaction between Cu\+Ⅱ ions separated by diamagnetic low spin Fe\+Ⅱ is weak antiferromagnetic.     

Formation of the Inclusion Complex of Orange II with β-Cyclodextrin and Its Photostability

Inclusion complex of Orange II with β-Cyclodextrin (β-CD) and the anti-photolysis effect under UV-light were investigated. The molar ratio of inclusion complex of β-Cyclodextrin and Orange Ⅱ is 1∶1. The formation constant K=1.236×103 L/mol was determined by the UV and Fluorescence spectra respectively, which was quite in accordance with the calculation with a modified Benesi-Hildbrand equation. The inclusion complex was characterized by the IR spectra and the molar ratio of inclusion complex is 1∶1 too. The formation constant K=1.266×103 L/mol was determined by 1 H NMR analysis and was nearly the same by UV and fluorescence spectra. The photocatalytic decolorization rate of Orange Ⅱ solutions containing β-CD and TiO2 was smaller by 51.9% than that of the Orange Ⅱ solutions only containing TiO2, while in the case of direct photolysis of Orange Ⅱ solutions, β-CD can lower the photolysis rate by 48.1% under UV-light. This result indicates β-CD can inhibit the photolysis and photocatalytic decolorization of Orange Ⅱ under UV-light. The β-CD inclusion complex was found to be persistent to UV-light photolysis.     

密度泛函理论方法研究稀土-过渡金属化合物的磁性和自旋密度图

Magnetic coupling constants J for the complete structures of rare earth\|transition metal compounds:LGdCu(NO\-3)\-3·Me\-2CO(1,Gd(Ⅲ)Cu(Ⅱ)) and [Ce(C\-4H\-7ON)\-4(H\-2O)\-3][Cr(CN)\-6]·2H\-2O(2, Ce(Ⅲ)Cr(Ⅲ)) have been calculated by the combination of the broken\|symmetry approach with the spin project method under the DFT framework.The J value for 1 is a small number in absolute value -2 4cm -1 for calculation,3 5cm -1 for experimental measurement.The spin density distributions are in detail discussed on the basis of Mulliken population analysis,taking into account the coexistence of spin delocalization and spin polarization mechanisms.For 1,the spin distribution in the ground state may be understood as a result of the competition between two mechanisms:a spin delocalization from Cu(Ⅱ) and a spin polarization of Gd(Ⅲ),and the former is dominant.In the case of 2,both transition metal Cr(Ⅲ) and rare earth Ce(Ⅲ) display a spin polarization effect on the surrounding atoms,where a counteraction of the opposite polarization effects leads a low spin density on the bridging ligand C1N1.In the ground state of 2,the stronger polarization effect of Cr(Ⅲ) even causes the positive spin density on the adjacent bridging atom N1.     

DIRECT ELECTROCHEMICAL SYNTHESIS AND CHARACTERIZATION OF NEODIMIUM( Ⅱ ) COMPLEX WITH 2-HYDROXY-2,4,6- CYCLOHEPTATRIENONE(TROPOLONE)

Tris(tropolonato)neodimium( Ⅲ )has been prepared by the electrochemical oxidation of neodimium meral anode in acetonitrile solution of 2-hydroxy - 2,4,6 - cycloheptatrienone(tropolone). The unusual divalent neodimium complex was formed at the first step of electrosyn - thesis. The final product ,Nd (C7H6O2)3, has been characterized by microanalysis and the studies of IR and H, C3 NMR spectra.     

DIRECT ELECTROCHEMICAL SYNTHESIS AND CHARACTERIZATION OF NEODIMIUM （Ⅲ） COMPLEX WITH 2-HYDROXY-2,4,6-CYCLOHEPTATRIENONE（TROPOLONE）

Tris(tropolonato)neodimium(Ⅲ）has been prepared by the electrochemical oxidation of neodimium metal anode in acetonitrile solution of 2-hydroxy-2,4,6-cycloheptatrienone(tropolone).The unusual divalent neodimium complex was formed at the first step of electrosyn-thesis.The final product,Nd(C7H6O2)3,has been characterized by microanalysis and the studies of IR and ^1H,C3 NMR spectra.     

Synthesis and Characterization of Quaternary Complexes Ln(CH_2ClCOO)_2 (NO_3) (phen)

Many binary lanthanide complexes have been studied. However, few mixed anion complexes with bidentate heterocyclic amines were synthesized. We synthesized mixed anion complexes Ln ( CH2 ClCOO )2 (NO3 ) ( phen) which was determined by elemental analyses . The IR spectra analyses indicate that NO3- , CH2 ClCOO- and phen are coordinated with Ln . The molar conductances of the complexes at 10-3 mol · L-1 were founded to be between 32.4 and 35.8 S·cm2· mol-1 , suggesting the nonelectrolytes in N-Dimethylformamide. And we determined the fluorescent spectra Eu(CH2ClCOO)2(NO3) ( phen ) and ESR spectra of Gd ( CH2 ClCOO )2 ( NO3) ( phen) .     

Optical properties of NdxGd1−xAl3(BO3)4 crystal

The optical properties of Nd x Gd 1-x Al\-3(BO\-3)\-4 (NGAB) crystal are reported. The refractive index of it were mesured by V_prism method. The absorption spectra and the flourescence specra of NGAB were also obtained. The optical parameters of NGAB were calculated following J_O theory, the three optical parameters are Ω 2 =1 805×10 -20 , Ω 4=1 85×10 -20 , Ω 6=3 793×10 -20 (RMS=1 4×10 -7 ) and β c( 4F 3/2 → 4I 11/2 ) is about 0 53.     

Synthesis and Characterization of Quaternary Complexes [Ln(CH_2=C(CH_3)-COO)_2(NO_3)(phen)]_2

Many trinary lanthanide complexes have been studied. However, few mixed anion complexes with bidentate heterocyclic amines were synthesized. Mixed anion complexes [Ln (CH2=C(CH3)-COO)2(NO3)(phen)]2 was synthesized and its properties were determined by elemental analyses, IR and TGA. The IR spectra analysis indicate that NO3- , CH2=C(CH3)-COO- and Phen are coordinated with Ln. And the fluorescent spectra of [Eu(CH2=C(CH3)-COO)2(NO3)(phen)]2 and 1H NMR spectra of [La(CH2=C(CH3)-COO)2 (NO3)(phen)]2 was determined respectively.     

NiSO4/γ-Al2O3 催化H2还原反应动力学研究

针对矿物燃料燃烧所产生的二氧化硫气体的污染问题,进行了负载于氧化铝上的硫酸镍催化H₂还原SO₂反应的动力学研究。在固定床流动积分反应器中考察了反应温度、空速及反应物中H₂与SO₂配比对反应速度的影响。动力学的实验条件：温度范围为370～450℃,反应混合气的流速为8000mL/h,反应物中H₂与SO₂的比例为0.5～2.0。通过数值积分方法进行拟合,发现反应的积分动力学方程较好的符合r_SO2= Kp_H2b_SO2p_SO2/[ 1+b_SO2p_SO2+b_H2Op_H2O+(b_S2p_S2)^1/2]. 即典型的存在产物吸附阻碍的R-E方程。这一结果与本实验室对该催化剂表征所发现的H₂在催化剂上无明显吸附,而H₂O,S₂,SO₂明显吸附相一致。     

Mo2C膜表面粗糙度随温度和时间变化规律的研究

对以羰基金属气相沉积制备的Mo2 C膜表面粗糙度进行了测量 ;在测量基础上进行统计 ,找出了表面高度分布并确定表面粗糙度随时间和温度的变化规律 .结果表明 :Mo2 C膜表面粗糙化属快速粗糙化 ,粗糙度随时间的变化具有标度函数的特征 ;粗糙度随基底温度升高而增大     

CH2(X3B1)和C2H(X2∑+g)分子的结构与解析势能函数

运用密度泛函理论(DFT)的B3LYP方法在6-311 G**水平上,对基态CH2、C2H分子的结构进行了优化计算,得到CH2分子的稳定结构为C2υ构型,电子态为X3B1,平衡核间距RCH＝0.1079 nm、离解能De＝8.037 eV;C2H分子的稳定结构为C∞υ构型,电子态为X2∑g ,平衡核间距RCH＝0.1059 nm、R∞＝0.1211 nm、离解能De＝12.05 eV,用多体项展式理论推导了基态CH2和C2分子的解析势能函数,其等值势能图准确再现了基态CH2和C2H分子的结构特征及其势阱深度与位置.     

Mo原子表面扩散激活能的计算及Mo2C膜成膜机理

应用Ｃｏｌｌｉｎｓ模型,计算了Ｍｏ原子表面扩散激活能。根据实验结果,论证了如下结论：在制备Ｍｏ２Ｃ膜的过程中,Ｍｏ（ＣＯ）６的变化遵从先被基底吸附,发生相变再进行级联式分解的两步机制;其成膜过程是Ｍｏ（ＣＯ）６先分解,再由Ｍｏ碳化为Ｍｏ２Ｃ成膜。用Ｇｉｂｂｓ函数最小的原理,探讨了成膜的适宜温度。     

两个1,4-二酮衍生物的顺反异构体的确定及其1H,13C核磁共振信号归属

应用一系列一维和二维核磁共振实验包括梯度选择性1H-1H同核相关谱(gCOSY)、1H-13C 异核单量子相干谱(gHSQC)、1H-13C异核多量子相干谱(gHMBC)以及核Overhauser效应谱(NOESY),对两个新型吡咯和呋喃衍生物的前体--1,4-二羰基衍生物(E)-1,4-di(benzo)[1,3]dioxol-5-y1)-2-(methylthio)but-2-ene-1,4-dione(A)和(Z)-1,4-di(benzo)[1,3]dioxol-5-y1)-2-(methylthio)but-2-ene-1,4-dione(B)的顺反异构体进行了确定,并对其1H,13℃核磁共振信号进行了完全归属.     

2,2’-二取代联萘化合物的NMR研究

根据~1H NMR,同核自旋去偶和二维COSY(400MHZ)的实验结果,对四种2,2′-二取代-1,1~1-联萘化合物的萘环质了作了归属指定,指出联萘酚的H_8(H’_8)共振峰应在高场,不宜接 Sadtler标准谱图指定在低场。讨论了萘环环电流各向异性和二萘环平面二面角对萘环质子的影响。当萘环二面角变化时,H_8(H’_8)受到的影响最大,随着二面角减小,H_8(H’_8)的共振明显地移向低场。     

偶氮苯类人工受体中间体的合成及~1H NMR谱

在一种仿G蛋白耦合型信号转导的人工超分子系统中引入一类偶氮苯结构的化合物,用来模拟跨膜受体。以苯胺为原料,合成几种人工受体中间体-偶氮苯化合物,选取其中4,4’-二羧基偶氮苯与谷氨酸甲酯(GluOMe)进行连接,得到一种氨基酸甲酯偶氮苯衍生物(Azo-AAOMe),并对其1H NMR谱进行了研究。核磁谱图显示,所合成的化合物正是预期产物。     

Angulatin E和Angulatin H的NMR数据解析

从苦皮藤根皮中分离得到2个β-二氢沉香呋喃类多元醇酯类化合物:1β,2β-二乙酰氧基-4α,6α-二羟基-8α-异丁酰氧基-9β-苯甲酰氧基-15-异戊酰氧基-β-二氢沉香呋喃(1,Angulatin E),1β,2β,15-三乙酰氧基-4α,6α-二羟基-8α -异丁酰氧基-9β-苯甲酰氧基-β-二氢沉香呋喃(2,A...     

计算(2~(k_1),2~(k_2))型二重(r_1,r_2)-循环矩阵全部特征值的快速算法

利用矩阵分块逐次降阶的方法 ,给出了计算 (2 k1 ,2 k2 )型二重 (r1 ,r2 ) -循环矩阵全部特征值的快速算法 ,证明了其乘除的计算量为 (k1 +k2 ) 2 k1 + k2 - 1 ,加减的计算量为 (k1 +k2 ) 2 k1 + k2 .     

4—氯苯酮的NMR研究

利用１Ｈ１Ｈ二维相关谱详细地解析了４氯苯酮的核磁共振氢谱．利用苯环上１３Ｃ化学位移的取代基效应规律对碳谱作了完整的归属