A new multi analytical approach for the identification of synthetic and natural dyes mixtures. The case of orcein-mauveine mixture in a historical dress of a Sicilian noblewoman of nineteenth century

Abstract

In this paper, the application of a multi-analytical approach for the characterisation of synthetic and natural dyes in a historical textile is presented. The work is focused on a historical dress of a Sicilian noblewoman, dating from about 1865–1870. Firstly, SERS on fibre was performed, in order to individuate the classes of dyes employed. The SERS spectra suggested the presence of two main dyes: mauveine and orcein. In order to confirm these preliminary results, two different extraction protocols were applied. The extracts obtained were analysed by ESI-MS, MALDI-ToF and UHPCL-MS analyses, confirming the SERS results. In particular, the application of the ammonia mild extraction technique allowed to selectively extract the phenoxazonic dyes, separating them already in the extraction step from the synthetic ones. Thanks to this multi-analytical approach, this dress could be considered as one of the first examples of employment of synthetic dyes in association with natural ones.     

Addition of diazocyclopropane generatedin situ to acrylic acid derivatives and transformations of resulting functionally substituted spiro(pyrazolinecyclopropanes)

The reaction of diazocyclopropane generatedin situ with acrylonitrile or methyl acrylate to give 1∶1, 1∶2, and 2∶1 cycloadducts was carried out. The products resulting from 1,3-dipolar cycloaddition and subsequent isomeriation,viz., 3-cyano- and 3-methoxycarbonylspiro(2-pyrazoline-5,1′-cyclopropanes), isolated in the first step in ∼70% yield, react in an alkaline solution with the above acrylates or diazocyclopropane as C(3)-nucleophiles to give the corresponding 3-(2′-cyanoethyl)-, 3-(2′-methoxycarbonylethyl)-, or 3-(cyclopropylazo)-1-pyrazolines. The thermal deazotization of these pyrazolines to spiropentane derivatives was investigated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 532–539, March, 1997.     

半化学法制备Pb(Fe2/3W1/3)O3陶瓷粉体的反应机理

铅系弛豫铁电陶瓷钨铁酸铅Pb(Fe2/3W1/3)O3(PFW)是一种重要的介电材料,具有较大的介电常数(8000)和较低的烧结温度(小于900℃),适用于制备低烧高介的多层陶瓷电容器犤1～4犦。在传统氧化物法合成PFW的过程中,易生成恶化介电性能的钨酸铅(PbWO4或Pb2WO5)或焦绿石相(Pb2FeWO6)等其他相犤3,4犦。尽管通过加入过量5%的Fe2O3可以消除这些其他相,但因含较多的变价铁离子(Fe3+和Fe2+)而产生介电老化的缺点犤5犦。虽然二次合成法被广泛用于制备铅系弛豫铁电陶瓷犤6犦,但对制备PFW陶瓷的效果并不明显,仍有少量的钨酸铅PbWO4存在,并且预烧…     

STUDY ON THE NANOSECOND TRANSIENT ABSORPTION SPECTRA OF HYPOCRELLIN A

In this paper, the nanosecond transient absorption spectra and the fluorescence spectraof Hypocrellin A(HA) are examined in solvents of varying polarity. There are three absorp-tion bands in dilute HA solutions: Ⅰa, Ⅱa are defined as the triplet-triplet absorption ofHA, the band Ⅲa is supposed to be the absorption of the solvent--sepatated ion pair (SSIP).In more concentrated solutions, only the absorption of SSIP was observed. The effects ofsolvent polarity on transient absorption spectra and fluorescence spectra of HA and the effectof oxygen on the intensities of the fluorescence of HA are discussed. Then a reasonablemechanism for the photolysis of HA is proposed.     

Bimetallic Alkoxides of Barium and Zirconium: Preparation of BaZrO3 Powder

Complex formation in solutions of barium and zirconium alkoxides in ROH (R=i-Pr, Et) was studied. A number of bimetallic complexes were isolated, and their structure and properties were studied. The sol-gel method yields a single-phase BaZrO₃ powder only wheni-PrOH solutions of the alkoxides are used. In this case, the oxocomplex, BaZrO(OPr-i)₄.(1–2)i-PrOH, is the precursor of the mixed oxide.     

双核铁原子簇体系的CI计算

用ＩＮＤＯ／ＣＩ方法研究了含有Ｆｅ－Ｆｅ键的原子簇体系［Ｆｅ２Ｓ２Ｘ４］＾２－（Ｘ＝Ｃｌ，Ｂｒ，Ｉ）的电子光谱及电子结构，对于这些多谱带体系，谱带波数计算值与实验值符合，在谱带的指认分析中，发现了πｄ＾１→πｄ等新的跃迁方式，对跃迁方式作了解释和分类，并讨论了谱带的电荷转移性质，此外，还对体系的化学键等性质进行了分析。     

Study on the Phase Diagram of CsCl-CeCl3-HCl(11%)-H2O System and the Properties of the Compounds

The equilibrium solubility of CsCl-CeCl3-HCl(11%)-H2O qua-ternary system at 25℃ has been determined by the physicchemical analysis method ,and the phase diagram was plotted, Two new double salts 3CsCl.CeCl3.3H2O and CsCl.CeCl3.4H2O obtained from the complicated system were identified and characterized by XRD,TG-DTA ,DSC,UV and fluorescence spectroscopy, Studies on the fluorescence excitation and emission show that 3CsCl.CeCl3.3H2O and CsCl.CeCl3.4H2O have upconversion luminescence of infrared-visible range,and the upconversion emission intensity increases with the increase of ratio of CeCl3 in CsCl.     

瓜环与哌嗪衍生物主客体配合物的研究(英)

本文采用核磁共振技术研究瓜环与哌嗪衍生物主客体配合物的结构特征。¹H核磁共振谱证实八元瓜环能与一些哌嗪衍生物形成稳定的双客体主客体配合物,六元瓜环与一些哌嗪衍生物形成稳定的1∶1主客体配合物。而五、七元瓜环和哌嗪衍生物则未表现出明显地相互作用。形成的自组装主客体配合物得到质谱的进一步证实。     

GIAO/DFT evaluation of 13C NMR chemical shifts of selected acetals based on DFT optimized geometries

DFT/B3LYP calculations of the ground-state conformation of eight cyclic and acyclic acetals are presented and compared with experimental data. Results of single-point GIAO/DFT calculations at five different levels of theory show that isotropic shieldings need to be empirically scaled to achieve agreement with experimental chemical shifts. Statistical evaluation of data indicates that the most accurate prediction of 13C chemical shifts is achieved at the MPW1PW91/6-311G** level of theory. An empirical equation describing the relationship between delta values and shielding constants is postulated. This equation has been applied to the non-chair ground-state conformation of the six-membered acetonide and to the conformationally flexible benzodioxonine derivative. The agreement observed between the experimental and predicted chemical shifts shows that calculations at the MPW1PW91/6-311G** level of theory are adequate for addressing questions of conformation.     

Structure of the blue forms of bisphthalocyanines of rare-earth elements

Using electron spectroscopy, X-ray photoelectron spectroscopy, and ESR spectroscopy, the blue forms of bisphthalocyanines of rare-earth elements were found to have structures of sandwich-type complexes with isoelectronic phthalocyanine ligands linked with tetravalent metal ions, [Pc^2–Ln⁴⁺Pc^2–]⁰. A comparative spectral and electrochemical study of the blue and green forms oftert-butyl-substituted bisphthalocyanines was carried out for almost the whole series of rare-earth metals. Lutetium octa(perfluoro-tert-butyl)- and perchlorobisphthalocyanines were synthesized for the first time.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 425–430, March, 1995.This study was financially supported by the Russian Foundation for Basic Research (grant No. 94-03-08903).