Wyniki wyszukiwania - BazTech

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Krótka historia niektórych wzorów

Kroszczyński W.

Wiadomości Chemiczne

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2013

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[Z] 67, 7-8

733--749

EN

This article is an attempt to present how the classical detective work has been performed in order to determine chemical structures. In the past, discussion on these examples was the way of learning of the organic chemistry. Thermal degradation was the main method of analysis currently replaced with the spectroscopy. Perhaps the history of chemistry may help to understand mentalities of creators of new branches of science. On the other hand, it gives arguments for a cultivation of „impractical” sciences. The article describes the earliest attempts to present simple organic formulas undertaken by Couper and Kekulé. Examples of a transformation of aromatic compounds present how results of derivatization led to conclusions concerning structures. Experiments and logic line of thought was supported by a great intuition. More complicated molecules were investigated by degradation reactions. For example, A. Baeyer at the beginning of his investigations concerning indigo, subjected isatin (obtained from indigo by oxidation) to different reducing reagents. He obtained indoldiol, oxindole, indole etc. Then these relatively simple compounds were synthesized and served as by-products for indigo. Some methods of the industrial production of indigo were elaborated on the base of works of Baeyer [16–20]. Similarly, the structures of chrysin, brazilin and haematoxilin have been resolved mainly by their degradation. The final structures were confirmed by synthesis.

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Investigations of selected properties of pharmacologically active compounds by chromatographic and potentiometric methods on the chrysin example

Pusz J., Zapała W., Papciak B.

Polish Journal of Chemical Technology

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2008

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Vol. 10, nr 1

41-44

EN

The RP-TLC method was used to determine the dissociation constant of chrysin (5,7-dihydroxyflavone) in methanol-aqueous (1:1 v/v) solutions. In this method the pK value was quantified on the basis of retention data and a retention model. The accuracy of determining the model parameters was analysed using the following statistical criteria: the sum of the squared differences between the experimental and theoretical data, approximation of standard deviation, and the Fisher test. Besides, in this work the potentiometric method was used. Investigations were carried out at ionic strength I=0.1 at T= 298 K. The dissociation constant were determined using the Rossotti method as well as the numerical method based on the procedures of non-linear curve fitting using Microsoft Excel Solver and the user-defined function. It has been found that the differences in the evaluated pK values were relatively small and did not exceed 1.2%.

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Badania nad otrzymaniem krystalicznych form niektórych flawonoidów, ich sulfonowych pochodnych oraz kompleksów z jonami metali

Pusz J., Nitka B., Kopacz S.

Zeszyty Naukowe Politechniki Rzeszowskiej. Chemia

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2004

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z. 19 [216]

147--161

PL

Zbadano 276 układów do krystalizacji moryny, chryzyny, kwercetyny, ich sulfonowych pochodnych oraz kompleksów z jonami metali. Uzyskano formy krystaliczne dla moryny i soli sodowej kwasu moryno-5'-sulfonowego (NaMSA), sulfonowych pochodnych kwercetyny - kwasu kwercetyno-5'-sulfonowego (QSA-5') i soli sodowej kwasu kwercetyno-8,5'-disulfonowego (Na2QDSA) oraz kompleksów In(III) i Fe(IlI) z chryzyną, które zbadano metodą rentgenografii strukturalnej. Uzyskane wyniki wskazują, że QSA-5' może mieć układ regularny, tetragonalny lub heksagonalny, natomiast pozostałe związki - układ jednoskośny lub trójskośny. Wykonano zdjęcia uzyskanych form krystalicznych metodą elektronowej mikroskopii skaningowej.

EN

The 276 systems to receipt crystalline forms of morin, chrysin, quercetin, their sulphonic derivatives and complexes of metal ions were examined. The crystalline forms of morin, sodium salt of morin-5'-sulphonic acid (NaMSA), quercetin-5'-sulphonic acid (QSA-5'), sodium salt of quercetin-8,5'-disulphonic acid (Na2QDSA) and complexes of In(III) and Fe(III) ions with chrysin were obtained. The method of structural X-rays radiography and electron scanning microscopy were used.

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Fizykochemiczne właściwości kompleksów wybranych jonów metali d-elektronowych z chryzyną w stanie stałym

Pusz J., Nitka B., Kopacz S.

Zeszyty Naukowe Politechniki Rzeszowskiej. Chemia

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2002

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z. 18 [194]

77-85

PL

Otrzymano w stanie stałym nowe związki jonów tytanu(IV), cyrkonu(IV) i cynku(II) z chryzyną. Zbadano ich skład oraz określono niektóre właściwości fizyko-chemiczne na podstawie badań termograwimetrycznych w atmosferze powietrza, widma w nadfiolecie i zakresie widzialnym, spektroskopii IR i NMR.

EN

New solid compounds of Ti(IV), Zr(IV) and Zn(II) with chrysin were obtained. Their composition and some physicochemical properties were studied (thermogravimetric analysis, ultraviolet, visible, infrared and 13C NMR spectroscopy). The composition M:L of compounds were: 1:4 for Ti(IV) and Zr(IV); 1:2 for Zn(II). A structure for compounds was proposed.