Complex Formation and Flower Colors

The pigment of the blue cornflower, protocyanin, is a complex of high molecular weight. Iron(III) and aluminum ions combine with the anhydro base of the cyanin to form deep-blue complexes, which are stable in the physiological pH range. Complexes of this type also have been synthesized. Alkali metal salts play no part in blue flower pigments. Formation of blue complexes can be prevented by sequestration of the metal ions with stronger complexing agents, e.g. flavonols. The variation of flower colors can be explained to a large extent on the basis of the complex formation of anthocyanins. In delphinidin glycosides, the color base or anhydro base is stable even in slightly acidic media.     

The Chemistry of Rose Pigments

In this article we present a survey of the pigments found in the flowers and fruits of old and modern varieties of roses. The yellow colors are produced by carotenoids, the reds by anthocyanins, and the modern oranges by a mixture of the two. The great structural diversity of the carotenoids contrasts with a surprisingly small number of anthocyanins. For the carotenoids found in roses, a clear correspondence exists between the structure and the breeding partners used; the old yellow roses, which arose from crosses with Chinese varieties, mainly contain carotenoids from early stages in the biosynthesis, while in the modern yellow roses, which are descended from Central Asian foetida types, hydroxylations, epoxidations, and epoxide transformations readily occur. A recently elucidated carotenoid degradation sequence follows the scheme C₄₀ → C₁₃ + C₂₇ → C₁₃ + C₁₄. The C₁₃ compounds are odoriferous substances that contribute to the scent of roses. In the physiological pH region, copigmentation with flavonol glycosides is crucial for stabilization of the anthocyanin chromophores. Many roses, including the “apothecary's rose”, which was once used medicinally, contain large amounts of strongly astringent ellagitannins, monosaccharide esters of gallic acid.     

硬质聚氯乙烯自然老化的变色行为与分子结构变化

以硬质聚氯乙烯(PVC)为研究对象,通过色差实验、FTIR、UV等方法探究了PVC在湿热、辐射低的琼海和暖温、干旱且辐射高的若羌地区自然老化的变色行为与分子结构变化.结果表明,太阳辐射是影响PVC自然老化过程中变色行为和分子结构变化的主要环境因素,PVC在干旱、辐射高的若羌地区比在湿热、辐射低的琼海地区更易变黄和变红,而在两地变暗的程度相近;这是因为随着自然老化时间的延长,PVC逐渐发生脱除氯化氢反应和氧化反应,在干旱且辐射高的若羌,更易发生脱除氯化氢反应,而在湿热且辐射低的琼海,脱除氯化氢反应和氧化反应的速度相近,在若羌老化的PVC样品生成了更多的共轭长度(n)≥8的C=C长共轭序列所致.     

Structure and Bonding in Cyclic Sulfur-Nitrogen Compounds—Molecular Orbital Considerations

The molecular structures of monocyclic sulfur-nitrogen ring systems, such as S₂N₂, S₃N, S₄N and S₅N, can be considered as examples of electron rich (4n + 2)π systems. The structures of S₄N₄, S₄N, P₄S₄, As₄S₄ and the bicyclic structures S₄N, S₄N as well as S₅N₆ can be rationalized on the basis of a planar tetrasulfur tetranitride with 12π electrons.     

Molecular and Crystal Structure of Magnolol—C18H18O2

Magnolol, 2, 2′-dihydroxy-5, 5′-diallylbiphenyl (C₁₈H₁₈O₂) was isolated from the heartwood of Taiwan sassafras, Sassafras randaiense (Hay.) Rehd. (Lauraceae) and characterized by single crystal X-ray diffraction. It crystallized in monoclinic P 2₁/C. The cell parameters are a=10.905(3), b=8.834(4), c=16.103(9) Å, β=106.76°(3), z=4. The structure was solved by direct method. The dihedral angle between two benzene rings is about 45′ which seems to be the best arrangement for intra- and inter-molecular H-bondings. O … O distances are ～2.6 Å which indicate very strong H-bonding. The solid structure can be discribed as a helix chain of molecules connected through H-bonds parallel to b-axis.     

切花泥主成分的色谱—质谱联用分析

本文通过切花泥的高温裂解，利用色谱－质谱联用方法对其成分进行了结构分析。     

Cyanidosilicates—Synthesis and Structure

Starting from fluoridosilicate precursors in neat cyanotrimethylsilane, Me₃Si?CN, a series of different ammonium salts [R₃NMe]⁺ (R=Et, ⁿPr, ⁿBu) with the novel [SiF(CN)₅]^2? and [Si(CN)₆]^2? dianions was synthesized in facile, temperature controlled F^?/CN^? exchange reactions. Utilizing decomposable, non‐innocent cations, such as [R₃NH]⁺, it was possible to generate metal salts of the type M₂[Si(CN)₆] (M⁺=Li⁺, K⁺) via neutralization reactions with the corresponding metal hydroxides. The ionic liquid [BMIm]₂[Si(CN)₆] (m.p.=72 °C, BMIm=1‐butyl‐3‐methylimidazolium) was obtained by a salt metathesis reaction. All the synthesized salts could be isolated in good yields and were fully characterized.     

Structure determination and colour properties of a new directly linked flavanol-anthocyanin dimer

The structure of catechin-(4α→8)-malvidin 3-O-glucoside obtained by reaction of taxifolin and malvidin 3-O-glucoside following a protocol adapted from proanthocyanidin dimer synthesis was determined by NMR spectrometry. Incorporation of the anthocyanin moiety into a covalent linked flavanol-anthocyanin dimer did not modify its colour properties (i.e., hydration equilibrium constant and copigmentation).     

金花茶花朵中微量元素的研究

对金花茶花朵不同部位微量元素的含量进行了分析研究.采用微波消解样品,电感耦合等离子体原子发射光谱法同时测定钾、钠、钙、镁、磷、铜、铁、锌、锰、钼、镍、铅、镉、铬的含量.结果表明,花朵中富含微量元素,且而各元素含量在花瓣、花蕊、花粉之中差异较大,为进一步开发金花茶的花朵提供依据.     

Bioactive Glasses—Structure and Properties

Bioactive glasses were the first synthetic materials to show bonding to bone, and they are successfully used for bone regeneration. They can degrade in the body at a rate matching that of bone formation, and through a combination of apatite crystallization on their surface and ion release they stimulate bone cell proliferation, which results in the formation of new bone. Despite their excellent properties and although they have been in clinical use for nearly thirty years, their current range of clinical applications is still small. Latest research focuses on developing new compositions to address clinical needs, including glasses for treating osteoporosis, with antibacterial properties, or for the sintering of scaffolds with improved mechanical stability. This Review discusses how the glass structure controls the properties, and shows how a structure‐based design may pave the way towards new bioactive glass implants for bone regeneration.     

My Research History on the Chemical Standpoint—From Molecular Structure to Surface Science

The structure of molecules using gas electron diffraction (GED) was my graduate study. However, I was making a new apparatus for precise measurements by GED and formulated a scheme for the least‐squares analysis for a smooth continuous curve of scattering intensity. My research was completely shifted to the solid surface after moving to Gakushuin University, where I briefly studied the liquid structure of CCl₄ molecules, and I then moved to the Institute for Solid State Physics, the University of Tokyo. My studies of surface science were focused on the electronic properties and related phenomena, and various experimental methods were developed. The plasmon dispersions elucidated the initial oxidation of aluminum and one‐dimensional metal on Si(001)2 × 1–K. Irreversible phase transition was discovered on MgO(001) using the LEED Kikuchi pattern. The electronic structure of the dislocation was observed on MgO(001) by the electron time‐of‐flight method. The phase transition on Si(001) and the rotational epitaxy in a K monoatomic layer on Cu(001) were found. Next, I changed to studies of the dynamical phenomena on the surface, where very low energy reactive ion scattering on metal surfaces and laser‐induced desorption caused by electronic transition of NO and CO molecules from metal surfaces were observed, and the hydrogen atom location at the surface and interface was measured with a high depth resolution using a resonance nuclear reaction of ¹H + ¹⁵N²⁺ at 6.385 MeV. Finally, I moved to the University of Electro‐Communications and studied thin single‐crystal oxide layers on transition metals, in which the band‐gap narrowing was found, and then a Pt monoatomic layer was prepared on the α‐Al₂O₃ film.