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O spektrofotometrii inaczej

Biniaś Włodzimierz

Polish Journal of Materials and Environmental Engineering

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2024

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Vol. 7 (27)

1--31

EN

The article is written in a popular science convention. It concerns issues related to generally understood issues that are involved in explaining the principles of the impact of the measure-ment beam in spectrophotometric research. To explain this, we need to answer basic ques-tions about what a photon is? What is wave-particle dualism? What do chemical bonds look like? What conditions must be met for a photon to be adsorbed by a chemical moiety? There are many inaccuracies in the current theories that do not explain the observed phenomena. The phenomenological models of the photon and chemical bonds that I have created are in-tended to explain photoelectric and optical phenomena that are not explained by either the wave or particle nature of photons. There is also no clear model of chemical bonds that would explain the phenomena observed in spectrophotometry. Phenomenological considerations are accompanied by several physical considerations and calculations in order to illustrate certain phenomena and proportions prevailing on the atomic scale. The above considerations are of a debatable nature and are an attempt to break away from stereotypical concepts operating in the world of science. Spectrophotometry is an analytical method that combines theories about photons, the structure of matter and phenomena that concern their mutual interactions. The phenomena visible in it can be interpreted more easily using my phenomenological image of matter.

2

Ag+/S2O8 2– system for the degradation of aqueous flutriafol

Yang H., Zhou W., Yang L., Deng J., Hu Q., Wei H., Au C., Yi B.

Environment Protection Engineering

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2018

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Vol. 44, nr 2

57--72

EN

The degradation of flutriafol in aqueous persulfate (S2O82–) system in the presence of selected transition metal ions was investigated. In the presence of Ag+ or Fe2+, flutriafol degradation occurs, whereas in the presence of Mn2+, Co2+, Ni2+, Cu2+, Zn2+ and Bi3+ ions, the degradation is less than 15%. The Ag+/ S2O82– aqueous system being the most effective was adopted for experimental and theoretical investigations. It was confirmed that pH of 3.0 is the most suitable, and that both · SO4–and ·OH– radicals are the main active species to afford flutriafol degradation, with the former contributes more than the latter. To elucidate degradation mechanism, molecular orbital calculations were performed and reaction intermediates identified by GC/MS and HPLC/MS/MS analyses. Three degradation pathways are proposed that involve the cleavage of C–N and C–C bonds as a result of ·SO4– attack, as well as the formation of hydroxylated products due to · OH radicals.

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Molecular orbital study of hydrated clusters of LiOH

Miyazaki S., Osamura Y.

Bulletin of the Polish Academy of Sciences. Chemistry

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2002

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Vol. 50, No. 4

463-489

EN

The molecular structures of the hydrated species of LiOH, LiOH(H2O)n for n = 1 ~ 5, were studied in terms of density functional B3LYP molecular orbital method. Since the water molecules act as both acid and base toward LiOH, all stable structures located at energy minima are found to be cyclic geometries. The distance between Li+ and OH(-) increases as the number of water molecules increase. Due to the covalent nature of LiOH, the dissociation of LiOH toward Li and OH(-) requires sufficient number of water molecules. Only non-dissociated structures were obtained in the case of a small number of water molecules (n < 3). Even in the case of LiOH(H(2)O)(5), the non-dissociated structures are calculated to be more stable than the dissociated structures. The number of isomers increases substantially with the increase of the number of water molecules. The ionic structures can be classified into contact ion-pair and solvent separated ion-pair structures. The four water molecules can coordinate to Li+ ion and the OH(-) ion can accept three water molecules in most cases. The stabilization energies of hydration for LiOH are calculated to be much larger than those of strong acids such as HCl and H(2)SO(4). The predicted vibrational spectra of each size of clusters indicate an irregular tendency of the stretching frequency of Li-O depending on the number of water molecules.

4

Zjawisko homokoniugacji

Krawczyk H.

Wiadomości Chemiczne

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1998

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[Z] 52, 9-10

673--697

PL

Homokoniugacja to nakładanie się orbitali dwóch układów p rozdzielonych grupą niesprzęgającą się, taką jak CH2 [1]. Ta prosta definicja w pełni oddaje istotę tego zjawiska, które od klasycznego sprzężenia różni się jedynie tym, że przyczyną jest tutaj nakładanie się orbitali p atomów nie sąsiadujących bezpośrednio ze sobą. Zjawisko homokoniugacji zostało po raz pierwszy zaobserwowane przez Winsteina przy okazji badania wspomagania anchimerycznego, tj. wpływu grup sąsiadujących na reakcje substytucji nukleofilowej [2, 3]. W 1954 r. autor ten podjął próbę teoretycznego opisu zjawiska i wprowadził termin 'homokoniugacja' do literatury chemicznej [4]. Następnie w 1959 r., została opisana szczególna forma homokoniugacji, jaką jest homoaromatyczność [5, 6]. Istotny postęp dokonał się dzięki wprowadzeniu przez Hoffmanna [7] podziału oddziaływań orbitalnych dalekiego zasięgu na oddziaływania przez przestrzeń (TS) i przez wiązania (TB). Późniejsze prace eksperymentalne i obliczenia teoretyczne pozwoliły na określenie wpływu na homokoniugację różnych czynników strukturalnych, z których najważniejszym jest geometria układu zawierającego oddziaływujące orbitale p [8]. Omawiane zjawisko odgrywa ważną rolę w wypadku wielu molekuł o bardzo zróżnicowanej budowie. W norbornadienie zostało ono zaobserwowane po raz pierwszy przez Wilcoxa i Winsteina w 1960 r. [9]. Układ ten był następnie wszechstronnie badany. Najważniejsze wyniki tych prac posłużą w dalszych częściach tego artykułu do ilustracji omawianych zagadnień.

EN

The presented paper concerns the homoconjugation effect in different molecules, particularly in the norbornadiene system. Information on the discovery and nature of the homoconjugation phenomenon [6, 7], classification of structures in which its presence has been found [32-56] as well as some of the most important methods, like UV [9, 65, 66], ETS [26], 13C NMR [82-96], ab initio [8, 17, 98, 99], used for examining this phenomenon are discussed in this work.