On the algebraic construction of chemistry from quantum mechanics. A fundamental valency vector field defined on the euclidean 3-space and its relation to the Hilbert space

To obtain from quantum mechanics directly the qualitative deductions of chemistry, a mathematical machinery is set up. A single vector space, and a dyad space relate different molecules or spatial configurations of an isomeric set of atoms to each other. Different electronic Hamiltonians belong to the dyad space and are treated so as to be used directly without the intermediary of orbitals, parameter choices, or variational calculations.     

Template tailoring: Accurate determination of heterozygous alleles using peptide nucleic acid and dideoxyNTP

Measurement of the length of DNA fragments plays a pivotal role in genetic mapping, disease diagnostics, human identification and forensic applications. PCR followed by electrophoresis is used for DNA length measurement of STRs, a process that requires labeled primers and allelic ladders as standards to avoid machine error. Sequencing‐based approaches can be used for STR analysis to eliminate the requirement of labeled primers and allelic ladder. However, the limiting factor with this approach is unsynchronized polymerization in heterozygous sample analysis, in which alleles with different lengths can lead to imbalanced heterozygote peak height ratios. We have developed a rapid DNA length measurement method using peptide nucleic acid and dideoxy dNTPs to “tailor” DNA templates for accurate sequencing to overcome this hurdle. We also devised an accelerated “dyad” pyrosequencing strategy, such that the combined approach can be used as a faster, more accurate alternative to de novo sequencing. Dyad sequencing interrogates two bases at a time by allowing the polymerase to incorporate two nucleotides to DNA template, cutting the analysis time in half. In addition, for the first time, we show the effect of peptide nucleic acid as a blocking probe to stop polymerization, which is essential to analyze the heterozygous samples by sequencing. This approach provides a new platform for rapid and cost‐effective DNA length measurement for STRs and resequencing of small DNA fragments.     

新型可聚合双发色团电致发光材料的合成

自１９８７年Ｔａｎｇ［１］报道了高效、高亮度的双层有机薄膜电致发光器件以来,电致发光材料的研究受到了广泛的关注．接着在１９９０年,英国剑桥大学Ｂｕｒｏｕｇｈｅｓ等［２］首次利用聚亚苯基乙烯（Ｐｏｌｙ（ｐ ｐｈｅｎｙｌｅｎｅｖｉｎｙｌｅｎｅ）,ＰＰＶ）...     

Anionic Polymerization Characteristics of the 1:1 Complex of n-Butylsodium and n-,s-Dibutylmagnesium (Sodium Tributylmagnesiate)

The behavior of isoprene and styrene polymerizations initiated by the complex of n-butylsodium and n-,s-dibutylmagnesium (sodium tributylmagnesiate) has been examined. The styrene-benzene system was found to yield stable active centers and polymers of predictable molecular weight and narrow molecular weight distributions. Isoprene, however, did not follow this behavior and yielded polydisperse material having molecular weights lower than those predicted on the basis that only n-butylsodium is capable of initiating chain growth. The polyisprene microstructure was found to consist of ～60% 3,4 and ～40% 1,4 units.     

卟啉-酞菁分子内能量传递和电子转移的溶剂效应

用稳态荧光光谱研究了以氧原子和哌嗪作为连接基的卟啉酞菁二元分子在不同溶剂中的分子内能量传递和电子转移过程结果表明;分子内的能量传递和电子转移是两个相互竞争的过程，在非极性溶剂中，激发单重态的能量传递是主要过程，而在极性溶剂中则以电子转移为主运用Rehm-Weller公式计算了两种二元化合物在不同溶剂中的电子转移反应的自由能变化△G0ET，表明溶剂的极性对电子转移反应的自由能变化△G0ET影响很大极性越大;体系中的电子转移反应的△G0ET、越负，电子转移反应越易进行由于电子转移过程较能量传递过程进行得快，所以表现为体系中能量传递效率降低而电子转移效率增大。两种二元化合物的能量传递效率（φEnT）利和电子转移效率（φET）随溶剂的极性的变化具有相同的变化趋势     

Absolute line intensities in methyl bromide: The 7-μm region

This work deals, for the first time, with the modeling of absolute line intensities in the fundamental ν₂ and ν₅ bands of CH₃⁷⁹Br and CH₃⁸¹Br at 7 μm. For that, four unapodized absorption spectra of CH₃Br (natural abundance, 99% purity, P × L = 0.082 − 0.165 atm × cm, room temperature) were measured in the range 1260-1560 cm⁻¹, at a resolution of 0.002 cm⁻¹ using a Fourier transform spectrometer Bruker IFS 120 HR. For both isotopomers, 313 line intensities were analyzed within the dyad system required to account properly for the strong Coriolis coupling between ν₂ and ν₅. The intensity fit of experimental data led to the determination of the dipole moment derivatives d₂ = ∂μ/∂q₂ and d₅ = ∂μ/∂q₅ relative to the ν₂ and ν₅ bands, as well as the first-order Herman-Wallis correction in K to d₅. The observed line intensities are fitted to 3.0% (3.3%) for ν₂ at 1309.9 cm⁻¹ and 2.6% (3.0%) for ν₅ at 1442.9 cm⁻¹, respectively for CH₃⁷⁹Br and CH₃⁸¹Br. The values derived for the vibrational band strengths of ν₂ and ν₅ are 55.7(0.6) and 39.2(0.3) cm⁻² atm⁻¹ at 296 K, respectively. The corresponding assignments and line positions of the dyad from previous work [F. Kwabia Tchana, I. Kleiner, J. Orphal, N. Lacome, O. Bouba, J. Mol. Spectrosc. 228 (2004) 441] are combined with the present intensity study to provide an improved CH₃Br database for atmospheric applications.     

CONFORMATIONAL CHARACTERISTICS OF POLY(ACRYLIC ACID) AND POLY(METHACRYLIC ACID)

A full-relaxation optimization of molecule and the Dreiding force field are employed toobtain the geometry parameters and the conformational energy surfaces of meso or racemicdyad of poly(acrylic acid) (PAA) and poly(methacrylic acid) (PMAA). Three differentcarbonyl-bond orientations of side-groups resulted in the differences in depth of potentialwells in their energetic contours for a meso or a racemic dyad. These discrepancies areinterpreted as a result of various fine structures corresponding to grid search conformationsas well as thereby different interactions. The analysis on the most stable conformationsof PMAA confirmed that the ester groups are nearly perpendicular to the plane definedby the two adjacent skeletal bonds but may possibly change their relative orientations tomeet the requirement of lower energy during the conformational state transition. For eachpolyme, two global energy maps of a meso and a racemic dyad were finally constructedfrom the superposition of energy data for the three kinds of side-group orientations by theBoltzmann factors. From an ensemble average, the proposed scheme with three rotationalisomeric states (RIS) allowed us to access the experimentally unperturbed dimensions ofPAA chain via the configurational statistical mechanics. Although the calculation wasbased on the short-range, local interactions, it was interested to note that the experimentalcharacteristic ratios just fell within the range calculated for atactic chains.     

用能量转移探测萘-蒽二元分子体系的构象变化

合成了一个带有末端取代的能量给体-萘和能量受体-蒽的开链冠醚（DSA）.吸收光谱表明两个发色团之间在基态时没有相互作用.选择性激发萘观察到萘的荧光强度下降, 同时伴随着蒽的发射增强, 表明发生了从萘至蒽的单重态-单重态能量转移.能量转移效率受溶剂极性的影响.可以认为在极性小的溶剂如苯中－OCH2CH2O－单元中的中心C－C键主要以反式存在,而在极性大的溶剂如乙腈中则以邻交叉式为主.因此,开链冠醚末端取代的萘和蒽之间的距离随着溶剂极性的增大,能量转移效率却随之降低.表明能量转移可以用于探测以柔性配体键连接的给体-受体体系在不同极性溶剂中的构象变化特性.