醇-二苯甲酮光化夺氢反应活泼自由基的ESR研究

本文用自由基捕捉剂2,3,4,6-四甲基亚硝基苯(ND)及苯亚甲基叔丁基氮氧化合物(PBN)与ESR相结合的方法研究了CnH_2n+1OH(n=1,2,…8)、(CH₃)₂CH(CH₂)_nOH(n=0,1,2)、CH₂=CHCH₂OH及C₆H₅CH₂OH等十三种醇与二苯甲酮的光化夺氢反应中的活泼自由基,结果表明: 1.用ND时,二苯酮分别夺取CnH_2n+1OH、(CH₃)₂CH(CH₂)_nOH及RCH₂OH(R=CH₂=CH、C₆H₅)中α-C、叔-C及α-C上的氢,而捕捉到C_n-1H_2n-1CHOH、(CH₃)₂CH(CH₂)_nOH及RCHOH自由基。 2.用PBN时,捕捉的自由基与ND捕获的相同。     

Synthesis and properties of alkyldicyclopentadienyl-vanadium(III) compounds

The compounds Cp₂VR (R = CH₃, C₂H₅, n-C₃H₇, n-C₄H₉, n-C₅H₁₁, CH₂C(CH₃)₃ or CH₂Si(CH₃)₃) have been prepared from Cp₂ VCl and RMgX in n-pentane. The air-sensitive compounds are stable at room temperature, but decompose between 65 and 138°C. The thermal stability decreases in the order R = CH₃ CH₂Si(CH₃)₃ > C₂H₅ > CH₂C(CH₃)₃ > n-C₅H₁₁ > n-C₄H₉ > n-C₃H₇. Compounds with R = i-C₃H₇ or t-C₄H₉ could not be obtained.     

Structural tuning of coordination polymers by 4-connecting metal node and secondary building process

Due to variation in ligand's conformation, metal node's connecting geometry, and secondary building process by anions, bat-like, dumbell-like, diamondoid, or pillar-layer topologies are achieved.     

Laser desorption ion trap mass spectrometry of self-assembled monolayers

It is demonstrated that laser desorption ion trap mass spectrometry (LD-ITMS) can be successfully applied to the chemical analysis of a monolayer of adsorbates on a solid surface. Negative ion spectra obtained from LD-ITMS of self-assembled monolayers adsorbed from solutions of alkanethiols (CH₃(CH₂)_nSH with N = 5, 9, and 15) onto polycrystalline gold surfaces displayed clear ion peaks corresponding to the sulfonate adsorbate species. Sulfonate ions with the general formula CH₃(CH₂)_nSO⁻₃ were detected at m/z 165, 221, and 305, respectively, and were derived from the partial oxidation of the corresponding alkanethiol self-assembled monolayers. Little fragmentation and no clustering was observed in these mass spectra. These results indicate that the sensitivity of LD-ITMS is sufficient to allow its application to a wide array of problems in surface science.     

Structural Investigation of Langmuir-Blodgett Films on Self-Assembly Modified Au Substrates

To improve the homogeneity and stability of single-layer azobenzene LB films on gold, self-assembled monolayers (SAMs) of terminally substituted alkyl thiol, HS(CH₂)₂-X(X=NH2,OH, COOH and CH₂SO₃Na, respectively), were used to modify the substrates before LB film deposition. It was found that single-layer C₈C₃ LB films on these modified substrates were more uniform and stable. Reflecion-Absorption(RA) FTIR measurements on these films indicated that at the LB/SAMs interface, ionic bonds. have formed for the modification with -NH₂ while hydrogen bonding occurred for modifications with -OH. -COOH and -SO₃Na,respectively. It can be concluded that the ionic or hydrogen bonding at the LB/SAM interface is responsible for the improvement in homogeneity and stability. It was believed that the less defected films after the time aging were most probably due to the ionic bond and hydrogen bonding mentioned above.     

醇添加对钴基催化剂费托合成反应的影响

在固定床微反应器上利用全产物在线分析方法, 研究了钴基催化剂上伯醇C_nH_2n+1OH (n=2, 3, 5, 6)在惰性气氛(Ar)和氢气气氛下的反应行为以及添加C_nH_2n+1OH对费托(FT)合成反应的影响, 并结合原位漫反射傅里叶变换红外光谱(DRIFTS)表征. 结果表明: 碳数为n的醇在Ar 气氛和H₂气氛下反应主要有脱羰和脱水两条反应路径, 分别生成碳数为n-1的烃和相同碳数的烃. 低碳数醇(乙醇和正丙醇)的添加对费托合成产物分布无明显影响; 而较高碳数的醇(正戊醇, 正己醇)的加入使碳数为n-1以上烃的选择性显著增加, 这是由于C_nH_2n+1OH加入后生成的碳数为n-1和n的中间体可进一步发生链引发反应, 生成更多的长链烃.     

Synthesis and Characterization of Solid Supports Containing silicon

Combinatorial chemistry has been a new field of chemistry since 1990's.^[1][2] More than 90% of researchers play their emphases on the studies of the solid supports such as P-(CH₂)_n-N and P-(CH₂)_n-O(n=1,2,3), but only a couple researchers play their emphases on the studies of the P-(CH₂)_n-Si(n=1,2,3). Because of the characteristic of the Si-Ar bond, we devise a series of the solid supports containing Si-Ar bond.These solid supports containing silicon were synthesized in two methods. At the same time,we also synthesized the monomer of the solid supports containing silicon or tin. The structures of these compounds were characterized by IR, elemental analysis.The synthetic routes of the solid supports containing silicon are shown in scheme 1 and the synthetic routes of the monomer of the solid supports containing silicon or tin are shown in scheme 2.     

添加剂对TiO2/水分散体流变性的影响

研究了TiO₂生产中有关助剂对其流变性能的影响,得到了TiO₂/水分散体的流变性能与三乙醇胺用量之间的关系,并找到了最佳用量.实验发现,六偏磷酸钠为分散剂时,其使用效果有时间依赖性;碳酸铵作絮凝剂时则对分散体的流变性能和形成的絮凝体有影响.     

Synthesis,Structures and Properties of Three New Compounds Based on Multidentate Ligand Containing Triazole and Pyrimidine

Three new compounds, namely, [Zn(mtpo)₂(H₂O)4](1), [Cd(mtpo)₂·CH₃CH₂OH]_n(2) and [Mn(mtpo)₂·CH₃CH₂OH]_n(3)(Hmtpo=4,7-dihydro-5-methyl-7-oxo-[1,2,4]triazolo[1,5-a]pyrimidine), have been synthesized via hydrothermal or solvothermal methods and characterized by means of elemental analyses, Fourier transform infrared(FTIR) spectroscopy, powder X-ray diffraction(PXRD), thermogravimetric analysis(TGA) and single-crystal X-ray diffraction. The results obtained from the single-crystal X-ray diffraction indicate that compound 1 has a mononuclear structure, and crystallizes in a monoclinic crystal system with P2₁/c space group, which exhibits a 2D supramolecular network constructed by hydrogen bonds and π-π interactions. Compounds 2 and 3 are isomorphous and crystallize in a tetragonal system with space group of I4₁/a. The M²⁺(M=Cd, Mn) ions in compounds 2 and 3 have the octahedral coordination geometry. Hmtpo acts as a bridging ligand linking the metal ions to form an infinite 3D framework with 4-connected {4²·8⁴} topology. There are hydrogen bonds between the guest ethanol molecules and the mtpoligands, which make the ethanol molecules exist in a 3D framework. In addition, luminescent properties of compounds 1 and 2 as well as magnetic property of compound 3 were investigated and water vapor adsorption and nitrogen sorption for compounds 2 and 3 were researched at 298 and 77 K, respectively.     

Synthesis and Crystal Structure of 1D Cd-amine Coordination Polymer and Its Luminescent Properties

A novel one dimension（1D） cadmium coordination polymer {[Cd（mpda）3]·2（NO3）}n（1） was synthesized via refluxing a mixture of tetradentate Schiff base ligand N,N＇-bis（2-pyridinylethylidene）phenylene-1,3-diamine（L） and Cd（NO3）2 in acetonitrile, whose structure was characterized by means of single crystal X-ray diffraction, FTIR spectroscopy, elemental analysis and proton nuclear magnetic resonance（1H NMR）. Center metal Cd（II） ion is six-coordinated by six nitrogen atoms from six different m-phenylenediamine（mpda）, giving rise to a [CdN6] octahe- dral coordination environment. The two adjacent cadmium centers are linked by three mpda molecules leading to the construction of 1D chain structure. The crystal structure is stabilized by N-H…O hydrogen bonds to form three-dimension supramolecule. Compound 1 exhibits intense yellow luminescence in solid state at 298 K（λem=554 nm）, which shows a blue shift at 77 K（ca. 147 nm）. Additionally, fluorescence characteristics of compound 1 were investigated in different solvents（polarity： DMSO〉CH3CN〉CH3OH〉CHC13〉toluene） at 298 and 77 K. The results show that the emission peak of compound 1 in solvent exhibits a slight bathochromic shift. However, the emission peaks of compound 1 in CH3OH and CHC13 are red shift compared with that in CH3CN. It is revealed that the lumi- nescence behavior of compound 1 depends on not only the polarity of solvent but also the hydrogen bonding proper- ties between solvent and solute. In addition, the emission peak of compound 1 in solution shows a red shift obviously at 77 K than that at 298 K（ca. 144-159 nm）, with the fluorescence lifetime increased at 77 K. The lifetime in DMSO at 77 K（r=12.470μs） was the longest one. The quantum yield of compoud 1 increases with increasing the polarity of solvent within a range of 1.8%-8.3 %.     

Ab initio and DFT computer studies of complexes of trimethylphosphine and products of substituted phosphonium cations with hydroxide, chloride and fluoride anions: Phosphorus analogues of choline and acetylcholine

Theoretical calculations (DFT, MP2) are reported for up to four sets of reaction products of trimethylphosphine, (CH₃)₃P, each with H₂O, HCl and HF together with DFT calculations on up to three sets of reaction products of substituted phosphonium cations, (CH₃)₃P–R⁺. These products comprise (a) P(III) normal complexes (CH₃)₃PHY, (b) P(IV) ‘reverse’ complexes Y(H–CH₂)₃P–R, (c) P(IV) ylidic complexes YHCH₂(CH₃)₂P–R and (d) P(V) covalent compounds Y–P(CH₃)₃–R for Y=HO, Cl and F and R=H, CH₃, C₂H₅, C₂H₄OH and C₂H₄OC:OCH₃. Calculations are carried out at the B3LYP/6-31+G(d,p) level in all cases and also at the MP2/6-31+G(d,p) level for systems in which R=H. Minimum energy structures are determined for predicted complexes or structures and geometrical properties, harmonic vibrations and BSSE corrected binding energies are reported and compared with the limited experimental information available. Potential energy scans predict equilibria between covalent trigonal bipyramidal P(V) forms and reverse complexes comprising hydrogen bonded or ion pair, tetrahedral P(IV) forms separated by low potential energy barriers. Similar scans are also reported for equilibria between reverse complexes and ylidic complexes for Y=OH and R=CH₃, C₂H₅, C₂H₄OH and C₂H₄OC:OCH₃. Corrected binding energies, structures and values of harmonic modes are discussed in relation to bonding The names ‘pholine’ and ‘acetylpholine’ are suggested for phosphorus analogues to choline and acetylcholine.     

硫代多联吡啶铂(Ⅱ)配合物的合成、性质及在光催化制氢中的应用

合成了2个新配体4-(4-硫代乙酸)甲苯基-6-苯基-2,2'-联吡啶HC^N^N(PhCH₂SCOCH₃)(L3)和6-(4-硫代乙酸)甲苯基-2,2'-联吡啶 HC^N^N (CH₂SCOCH₃)(L5)及其发光的铂(Ⅱ)配合物ClPtC^N^N(PhCH₂SCOCH₃)(C3)和ClPtC^N^N(CH₂SCOCH₃)(C5). 通过¹H NMR谱和质谱对它们的结构进行了表征, 采用X射线单晶衍射分析确定了C3的晶体结构. 利用紫外-可见吸收光谱、 发射光谱及激发态寿命测定研究了它们的光物理性质和电化学性质, 以及配合物作为光敏剂在光催化制氢中的应用. 通过系列配合物产氢效率的比较, 揭示了它们的产氢效率和激发态寿命的关系.     

·OH自由基引发CH3SSCH3•+自由基裂解反应机理的理论研究

采用UωB97X-D/6-311+G^**方法, 研究了气相、 甲苯和水中OH自由基(·OH)引发CH₃SSCH₃自由基阳离子(CH₃SSC{\mathrm{H}}_{\mathrm{3}}^{?}⁺, DMDS^?+)裂解的反应机理, 并讨论了溶剂效应对反应的影响. 结果表明, ·OH和DMDS^·+首先形成自由基耦合产物CH₃S(OH)SCH₃⁺(R1)和氢提取产物复合物[CH₂=SSCH₃+H₂O]⁺(R2); 随后R1裂解直接发生 S—S键断裂协同质子转移, 而R2裂解依次发生构象变化、 C=S键亲碳加成和S—S键断裂协同质子转移. 去质子化的裂解产物为CH₃SOH, CH₂=S和HSCH₂OH. 甲苯略微降低了裂解反应速控步骤的自由能垒. 水溶剂有利于R1裂解, 但不利于R2裂解, 尤其是单个水分子参与反应. 在气相、 甲苯和水中, 以·OH和DMDS^·+为初始反应物, 虽然速控步骤的自由能垒为167.6~202.8 kJ/mol, 但裂解反应均是放热反应(?154.3~?31.4 kJ/mol).     

CH3CF2O2与HO2自由基反应机理的理论研究

用密度泛函理论(DFT)的B3LYP方法，在6-311G、6-311+G(d)、6-311++G(d, p) 基组水平上研究了CH₃CF₂O₂与HO₂自由基反应机理. 结果表明, CH3CF₂O₂与HO₂自由基反应存在两条可行的通道. 通道CH3CF₂O₂＋HO₂→IM1→TS1→CH₃CF₂OOH＋O₂的活化能为77.21 kJ•mol^－1，活化能较低，为主要反应通道，其产物是O₂和CH₃CF₂OOH. 这与实验结果是一致的；而通道CH₃CF₂O₂＋HO₂→IM2→TS2→IM3→TS3→IM4＋IM5→IM4＋TS4→IM4＋OH＋O₂→TS5＋OH＋O₂→CH₃＋CF₂O＋OH＋O₂→CH₃OH＋CF₂O＋O₂的控制步骤活化能为93.42 kJ•mol^－1，其产物是CH₃OH、CF₂O和O₂. 结果表明这条通道也能发生，这与前人的实验结果一致.     

Studies on the E7 liquid crystal orientations confined to perfluorinated carboxylic acid-treated cylindrical cavities of Anodisc membranes by FTIR spectroscopy

The orientation of E7 liquid crystal (LC) confined within 200 nm diameter cylindrical cavities of Anodisc membranes are investigated by FTIR dichroism techniques. The cavity walls of the confining pores were chemically modified with different length perfluorinated carboxylic acids (PCAs, C _n F_2n+1COOH, n = 3, 4, 5, 6) at 1, 3 and 5 mM concentrations. From the FTIR spectra of PCA-treated alumina Anodsic membranes, we found salt formation between the -COOH group of the PCAs and the Anodisc membranes. From the FTIR spectra of LC-filled Anodisc membranes, we found an abrupt alignment direction change, from parallel to perpendicular, of the LC molecules along the long axis of the cavities between n = 4 and n = 5 for the 1 mM concentration of PCA. However, for the 5 mM concentration of PCA, the parallel-to-perpendicular alignment direction of LC molecules changed between n = 3 and n = 4. These LC orientation changes for PCA-treated Anodisc membranes occurred at shorter length than for hydrocarbon carboxylic acid (HCA, C _n H_2n+1COOH)-treated Anodisc membranes. This change may be caused by the lower surface energy of the -(CF₂) _n CF₃ chain of PCA than that of the -(CH₂) _n CH₃ chain of HCA.     

Polymer swelling. Part 17: Systematization of steric effects on adsorption parameters as exemplified by swelling of poly(styrene-co-divinylbenzene) to saturation using linear and non-linear acyclic aliphatic ether liquids

The adsorption parameters () for five branched aliphatic ethers were established experimentally in the usual way [17]. It was shown that when this set of -values is combined with the set already established for the unbranched ethers [17], the union set enables one to estimate with reasonable confidence the -values for all the possible structural permutations derivable from the general molecular structure [GMS] H(CH₂)_m+1[(CH₃)_q′CH_2−q′ OCH_2−q(CH₃)_q](CH₂)_n+1H, and for a portion of those that are derivable from the GMS (CH₃)_q′+1CH_2−q′[(CH₂)_mO(CH₂)_n]CH_2−q(CH₃)_q+1, using the corresponding Log vs N linear relationship deduced in these and earlier sorption studies, in which N = m+n+q+q′+4. It was shown that the data for the -values derived thereby comprise a self-consistent rigidly interconnected multidimensional universe of linear Log vs N relationships that represent series of subsets of the above GMSs resulting from varying one integer (m+n+q or ′) while the other three are held constant.     

几种硅烷及其氟取代衍生物的质子核磁共振

属于H_mF_2-mSi(CH₂CH₅)_n(CHCH₂)_2-n型的九个化合物可以系统地合成出来。本文报导它们的质子核磁共振谱。     

电子转移溶剂重组能计算的自洽反应场新方法

基于非平衡溶剂化理论, 推导了用于非平衡溶剂化能数值计算的类导体屏蔽模型(COSMO)的相关公式. 在此基础上, 修改了HONDO99中COSMO模块, 并用以估算了[(CH₂)₂C]+—(CH₂)_n—C(CH₂)₂(n＝1～13)体系中的电子转移溶剂重组能. 结果表明, 溶剂重组能值与电子转移距离的倒数有很好的线性关系. 根据溶剂重组能数值解结果, 用新的双球模型给出了合理的给受体球半径.     

系列Cu(Ⅱ/Ⅰ)配聚物的合成、结构及光电性能

采用水热方法合成了3种Cu(Ⅱ/Ⅰ)配聚物及超分子, (1) [K₂Cu₂(ox)(btec)(MeOH)₂]_n, (2) {[Cu(pdc)(H₂O)₂]?H₂O}_n, (3) [Cu(cyan)(phen)]?H₂O (H₂ox: 草酸, H₄btec: 均苯四甲酸, MeOH: 甲醇, H₂pdc: 2, 5-吡啶二羧酸, phen: 邻菲啰啉, Hcyan: 氰尿酸). 通过X射线单晶衍射、表面光电压光谱(SPS)、固体紫外-可见(UV-Vis)、傅里叶变换红外(FTIR)光谱、元素分析等方法对配合物进行了表征. 结构解析结果表明, 配合物(1)是具有三维(3D)无限结构的配聚物; (2)是具有二维(2D)无限结构的配聚物, 但又通过氢键进一步连成了三维(3D)网络, (1)与(2)的中心金属均为Cu(II)离子; (3)为含Cu(I)的单核配合物, 但又通过氢键和π-π堆积作用, 使它成为2D超分子化合物. 配合物SPS结果显示, 配合物(1)-(3)在300-800 nm范围内都呈现光伏响应, 表明三者均具有一定的光电转换能力. 讨论了配合物的组成、结构、维数、配体种类、中心金属离子价态及配位微环境对SPS的影响,并将SPS与UV-Vis 光谱进行了关联.     

Interaction of antitumor drug Sn(CH3)2Cl2 with DNA and RNA

Sn(CH₃)₂Cl₂ exerts its antitumor activity in a specific way. Unlike anticancer cis-Pt(NH₃)₂Cl₂ drug which binds strongly to the nitrogen atoms of DNA bases, Sn(CH₃)₂Cl₂ shows no major affinity towards base binding. Thus, the mechanism of action by which tinorganometallic compounds exert antitumor activity would be different from that of the cisplatin drug. The aim of this study was to examine the binding of Sn(CH₃)₂Cl₂ with calf thymus DNA and yeast RNA in aqueous solutions at pH 7.1–6.6 with constant concentrations of DNA and RNA and various molar ratios of Sn(CH₃)₂Cl₂/DNA (phosphate) and Sn(CH₃)₂Cl₂/RNA of 1/40, 1/20, 1/10, 1/5. Fourier transform infrared (FTIR) and UV–visible difference spectroscopic methods were used to determine the Sn(CH₃)₂Cl₂ binding mode, binding constant, sequence selectivity and structural variations of Sn(CH₃)₂Cl₂/DNA and Sn(CH₃)₂Cl₂/RNA complexes in aqueous solution. Sn(CH₃)₂Cl₂ hydrolyzes in water to give Sn(CH₃)₂(OH)₂ and [Sn(CH₃)₂(OH)(H₂O)_n]⁺ species. Spectroscopic evidence showed that interaction occurred mainly through (CH₃)₂Sn(IV) hydroxide and polynucleotide backbone phosphate group with overall binding constant of K(Sn(CH₃)₂Cl₂–DNA)=1.47×10⁵ M⁻¹ and K(Sn(CH₃)₂Cl₂–RNA)=7.33×10⁵ M⁻¹. Sn(CH₃)₂Cl₂ induced no biopolymer conformational changes with DNA remaining in the B-family structure and RNA in A-conformation upon drug complexation.