Templating Effect of Amion Monolayers on the Formation of Anionic Clay Sheets at an Air-Water Interface

Monolayers have been reported to play a template role in the formation of minerals at interfaces. For example, the oriemted nucleation of calcite is controlled by self-assembled monolayers (SAMs) of to-terminated alkanethiols ((CH₂)_nX)^[1].This presentation shows the templating effect of a Langnuir monolayer of stearic acid (SA) during the preparation a thin film of anionic clay, The work is an extension of our previous works on the formation of a hybrid film of a clay and a metal complex by the Langmuir-Blodgett (LB) method^[2].     

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.     

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。     

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.     

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.     

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.     

巯基乙胺自组装膜表面润湿性的变化

报道了巯基乙胺自组装膜在不同的时间尺度内表面润湿性的特征变化.利用接触角滴定方法对其表面状态进行实时监控表明,自组装膜由固/液界面转移至固/气界面后,接触角在短时间内经历了一个快速升高过程和一个相对较慢的变化过程.从表面自由能的角度,讨论了该现象的机理.采用不同pH值的缓冲溶液进行接触角滴定,得到了巯基乙胺自组装膜的滴定曲线,从而确定表面pKb值为1.7±0.2.从接触角滴定曲线在长时间内的变化趋势中发现,pK_b值无显著变化,但曲线整体向上平移,并且滴定曲线中上下平台的差值随时间增长而减小.     

Selective desulfurization of 1,3-dithianes, -oxathiolanes and -thiazolidines by tributyltin hydride

Selective desulfurization of 2-alkyl-1,3-dithianes, -oxathiolanes, or -thiazolidines 1 with one equivalent of tri-n-butyltin hydride yields acyclic compounds R¹R²CHX(CH₂)_nSSnBu₃ (X = S,O,NH; N= 2,3), (2) which can be destannylated to the corresponding mercaptans 3.     

Kinetics of the formation of butanethiol monolayers on gold substrates, as studied by infrared spectroscopy

We have studied the formation of butanethiol self-assembled monolayers (C₄SAMs) and sub-monolayers chemisorbed on Au(111) surfaces using infrared reflection-absorption spectroscopy. Our IR study follows the evolution of the adsorbates from a disordered phase of sub-monolayer C₄ at short deposition times, to the more ordered arrangement of butanethiol films following extended exposure to the thiol solution. From the variation of the absorbances of CH₃ vibrations with the deposition time, we find that the initial deposition of the imperfect monolayer from solution is rapid at high concentrations, and can last many hours in very dilute solutions; this rapid absorption is followed by a much slower process of additional absorption and self-organisation. From the evolution of the frequency and intensity of the CH₂ related absorption bands, we observed that the angle of butanethiol molecular axis with respect to the surface normal is significantly greater in the initial state than for the final well-formed film; the intensities of CH₂ modes for fully equilibrated monolayers and sub-monolayers are extremely weak due to the nearly orthogonal orientation of the transition dipole moment with respect to the surface normal and to the polarisation of the incident radiation. Our data suggests that the initial deposition sites for individual butanethiol adsorbates are randomly distributed on the gold substrate.     

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.     

顺二氨二水合铂(Ⅱ)与生物膜磷脂反应的核磁共振研究

用NMR法研究了顺二氨二水合铂(Ⅱ)(AAP)与α-二棕搁酸磷脂酰胆碱(DPPC)的相互作用方式,以阐明在顺铂-细胞相互作用中膜磷脂的贡献。¹H及¹³C谱表明,DPPC与AAP在CDCl₃中作用时,铂结合在DPPC的头部并引起DPPC分子中gauche向trans的构象转变。65℃测定DPPC脂质体与AAP在D₂O溶液中反应不同时间后的-N(CH₃)₃、-(CH₂)_n及-CH₃基团¹H的T₁值表明,铂在磷脂上的结合引起的磷脂构象变化会导致膜分子重新装配。     

Intramolecular hydrogen bonding in some acyclic alcohols

The extent of intramolecular hydrogen bonding, occurring in dilute CCl₄ solutions, of members of the series (n = 2–5) HO.(CH₂)_n.OH and MeO.(CH₂)_n.OH has been determined. The results permit the interpretation of the patterns of hydrogen bonding in the three monomethyl ethers of butane-1,2,4-triol and in 1,4-dimethoxybutan-2-ol. In these compounds, where hydrogen bonding allows the formation of rings of different sizes the sequence of preference 5> 6> 7 was observed.     

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.     

氧和碳酸根桥联的双核铁(Ⅲ)配合物的合成、结构和光谱研究

氧桥联的双核铁配合物一直是无机化学工作者十分感兴趣的研究课题 .近年来 ,由于在生物体内发现多种金属蛋白和金属酶的活性中心存在氧和羧酸根桥联的双核铁结构单元 ,如蚯蚓血红蛋白 [1]、甲烷单加氧酶 [2 ]、核糖核酸还原酶 [3]、饱和脂肪酸还原酶 [4 ]和紫色酸性磷酸酶 [5]等 ,使得对氧桥联的双核铁配合物的研究成为当前生物无机化学研究中的热点之一[6] .为进一步了解氧桥联的双核铁配合物的物理化学性质 ,我们在系统研究的基础上 ,合成了一个新的氧和碳酸根桥联的双核铁配合物 ,测定了其晶体结构 ,研究了其电子吸收光谱 .1　实验部分1 …     

Collisions of slow polyatomic ions with surfaces: The scattering method and results

Surface-induced dissociation (SID) and reactions following impact of well-defined ion beams of polyatomic cations C₂H₅OH⁺, CH₄⁺, and CH₅⁺ (and its deuterated variants) at several incident angles and energies with self-assembled monolayers (SAM), carbon surfaces, and hydrocarbon covered stainless steel were investigated by the scattering method. Energy transfer and partitioning of the incident projectile energy into internal excitation of the projectile, translational energy of products, and energy transferred into the surface were deduced from the mass spectra and the translational energy and angular distributions of the product ions. Conversion of ion impact energy into internal energy of the recoiling ions peaked at about 17% of the incident energy for the perfluoro-hydrocarbon SAM, and at about 6% for the other surfaces investigated. Ion survival probability is about 30–50 times higher for closed-shell ions than for open-shell radical cations (e.g., 12% for CD₅⁺ versus 0.3% for CD₄⁺, at the incident angle of 60° with respect to the surface normal). Contour velocity plots for inelastic scattering of CD₅⁺ from hydrocarbon-coated and hydrocarbon-free highly oriented pyrolytic graphite (HOPG) surfaces gave effective masses of the surface involved in the scattering event, approximately matching that of an ethyl group (or two methyl groups) and four to five carbon atoms, respectively. Internal energy effects in impacting ions on SID were investigated by comparing collision energy resolved mass spectra (CERMS) of methane ions generated in a low pressure Nier-type electron impact source versus those generated in a Colutron source in which ions undergo many collisions prior to extraction and are essentially vibrationally relaxed. This comparison supports the hypothesis that internal energy of incident projectile ions is fully available to drive their dissociation following surface impact.     

Two Coordination Compounds Bearing Bis(2-dimethylaminoethyl) Ether: Syntheses,Crystal Structures and Catalytic Application to the Henry Reaction

Two novel coordination compounds, namely [Cu₂(BDMAEE)(CH₃COO)₄]_n(1) and[Ni(BDMAEE)Cl₂](2)[BDMAEE=bis(2-dimethylaminoethyl) ether], have been synthesized and characterized by IR, elemental analysis, PXRD and X-ray single crystal diffraction. In compound 1, the central Cu(Ⅱ) ion is coordinated with four oxygen atoms and one nitrogen atom, forming a distorted square pyramidal geometry. The asymmetric units composed of one Cu(Ⅱ) ion, two acetates and a half of BDMAEE are connected to form an infinite 1D chain structure by the bridging acetate and the BDMAEE. In compound 2, the central Ni(Ⅱ) ion is coordinated with one oxygen atom, two chlorine anions and two nitrogen atoms, forming a distorted square pyramidal geometry. The compounds exhibited excellent catalytic properties in the Henry reaction of nitromethane with some aromatic aldehydes, and the optimized reaction conditions were obtained.     

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。     

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.     

Density functional and multiphoton ionization studies of N,N-dimethylformamide–(methanol)n clusters

The multiphoton ionization of the hydrogen-bonded clusters N,N-dimethylformamide–(methanol)_n (DMF–(CH₃OH)_n) was studied using a time-of-flight mass spectrometer at the wavelengths of 355 and 532 nm. At both wavelengths, a series of protonated DMF–(CH₃OH)_nH⁺ ions was obtained. The clusters were also investigated by density functional theory B3LYP method in conjunction with basis sets 6-31+G(d,p) and 6-311+G(2d,p). Equilibrium geometries of both neutral and ionic DMF–CH₃OH clusters, and dissociation channels and dissociation energies of the ionic clusters are presented. The results show that when DMF–CH₃OH is vertically ionized and dissociated, DMFH⁺ and CH₃O are the dominant products via proton transfer reaction. A high energy barrier makes another channel corresponding to the production of DMFH⁺ and CH₂OH disfavored. In the DMF–(CH₃OH)H⁺ ion, the proton prefers to link with the O atom of DMF molecule. Variation of atomic charges during proton transfer in hydrogen bond of the protonated cluster DMF–(CH₃OH)H⁺ ion is also discussed.     

红外光谱法研究乙烯在Pd/SiO2上的化学吸附

本文报导了15℃时乙烯在Pd/SiO₂上化学吸附的红外光谱。表面吸附物加氢后的气相产物是乙烷和少量的丁烷。实验表明乙烯在Pd/SiO₂上化学吸附产生了三种表面种:即σ键型的表面种PdCH₂CH₂Pd、由自加氢和二聚作用形成的正丁基表面种CH₃CH₂CH₂CH₂Pd和由解离吸附产生的表面碳化物。