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Monatshefte Für Chemie

Sara Norrehed, Christoffer Karlsson, Mark E Light, Anders Thapper, Ping Huang, Adolf Gogoll
N , N' -Diphenyl-3,7-diazacyclooctane and structurally related N , N' -diphenylbispidine derivatives react with silver(I) ions in a high-yielding C-C coupling reaction to produce dication-diradical species, with the silver ions serving a double function both as template and as an oxidant. The resulting bis(benzidino)phane derivatives are persistent organic radicals, stable for several months in solution as well as in the solid state, at room temperature and above, as well as being exposed to the atmosphere...
2019: Monatshefte Für Chemie
Martin Anschuber, Robert Pollice, Michael Schnürch
No abstract text is available yet for this article.
2019: Monatshefte Für Chemie
Nikolaus Gorgas, Aleksandra Ilic, Karl Kirchner
An iron(II) hydride PNP pincer complex is applied as catalyst for the chemoselective transfer hydrogenation of aldehydes using an aqueous solution of sodium formate as hydrogen source. A variety of aromatic, heteroaromatic, and aliphatic aldehydes could be reduced to the corresponding alcohols in good to excellent yields with a catalyst loading of 1.0 mol% at 80 °C and 1 h reaction time. If present, C-C double bonds remained unaffected in course of the reaction, even when they are conjugated to the carbonyl group of the aldehyde...
2019: Monatshefte Für Chemie
Mathias Glatz, Jan Pecak, Lena Haager, Berthold Stoeger, Karl Kirchner
A series of neutral bis- and cationic tris-carbonyl complexes of the types cis -[M(κ3 P,N,P -PNP)(CO)2 Y] and [M(κ3 P,N,P -PNP)(CO)3 ]+ was prepared by reacting [M(CO)5 Y] (M = Mn, Re; Y = Cl or Br) with PNP pincer ligands derived from the 2,6-diaminopyridine, 2,6-dihydroxypyridine, and 2,6-lutidine scaffolds. With the most bulky ligand PNPNH - t Bu, the cationic square-pyramidal 16e bis-carbonyl complex [Mn(PNPNH - t Bu)(CO)2 ]+ was obtained. In contrast, in the case of rhenium, the 18e complex [Re(PNPNH - t Bu)(CO)3 ]+ was formed...
2019: Monatshefte Für Chemie
Sara R M M de Aguiar, Christian Schröder-Holzhacker, Jan Pecak, Berthold Stöger, Karl Kirchner
The new chiral PNP pincer ligand N 2 , N 6 -bis((3a R , 8a R )-2,2-dimethyl-4,4,8,8-tetraphenyltetrahydro[1,3]dioxolo[4,5- e ][1,3,2]dioxaphosphepin-6-yl)pyridine-2,6-diamine (PNP-TADDOL) was synthesized in 80% isolated yield. Complexes of the type [M(PNP-TADDOL)(CO)3 ] (M = Cr, Mo, and W) were prepared via a solvothermal approach. This methodology constitutes a fast, simple, and practical synthetic method to obtain complexes of that type in high isolated yields. The X-ray structure of the molybdenum complex is presented...
2019: Monatshefte Für Chemie
Jonas Aronow, Christian Stanetty, Ian R Baxendale, Marko D Mihovilovic
A continuous flow procedure for the synthesis of methyl glycosides (Fischer glycosylation) of various monosaccharides using a heterogenous catalyst has been developed. In-depth analysis of the isomeric composition was undertaken and high consistency with corresponding results observed under microwave heating was obtained. Even in cases where addition of water was needed to achieve homogeneity-a prerequisite for the flow experiments-no detrimental effect on the conversion was found. The scalability was demonstrated on a model case (mannose) and as part of the target-oriented synthesis of d- glycero -d- manno heptose, both performed on multigram scale...
2019: Monatshefte Für Chemie
Bogdan R Brutiu, Wilhelm Andrei Bubeneck, Olivera Cvetkovic, Jing Li, Nuno Maulide
A Brønsted acid-catalyzed selective arene-ynamide cyclization is described. This reaction proceeds via a keteniminium intermediate and enables the preparation of seven-membered ring enamide products. Mechanistic studies uncover an unusual product inhibition behavior.
2019: Monatshefte Für Chemie
Aneta Pogorzelska, Beata Żołnowska, Jarosław Sławiński, Anna Kawiak, Krzysztof Szafrański, Mariusz Belka, Tomasz Bączek
A new series of 2-alkylthio- N -(quinazolin-2-yl)benzenesulfonamide derivatives have been synthesized and evaluated in vitro for their antiproliferative activity by MTT assay against cancer cell lines HCT-116, MCF-7, and HeLa as well as the NCI-60 human tumor cell lines screen. In NCI screen, three compounds inhibited approximately 50% growth of RPMI-8226 and A549/ATCC cell lines. The mean of IC50 calculated in MTT assays for three tested cell lines was about 45 μM for four compounds. The QSAR allowed finding statistically significant OPLS models for HeLa cell line...
2018: Monatshefte Für Chemie
Barbara Mirosław, Dmytro Babyuk, Agnieszka Łapczuk-Krygier, Agnieszka Kącka-Zych, Oleg M Demchuk, Radomir Jasiński
5-(Nitromethyl)-3-phenyl-4,5-dihydroisoxazole was obtained as a product of a high-yielding [3 + 2] cycloaddition reaction of in situ-generated benzonitrile N -oxide and 3-nitroprop-1-ene. For the first time, the regiochemistry of this reaction was unambiguously proven by X-ray structural analysis. The quantum-chemical calculation performed at the M06-2X/6-31G(d) (PCM) theoretical level affords a basis for explaining the course of reaction as well as the nature of transition states. Next, further DFT calculations together with spectral data shed light on structural aspects of the product...
2018: Monatshefte Für Chemie
Matthias H M Klose, Anna Schöberl, Petra Heffeter, Walter Berger, Christian G Hartinger, Gunda Koellensperger, Samuel M Meier-Menches, Bernhard K Keppler
Size-exclusion chromatography-inductively coupled plasma-mass spectrometry (SEC-ICP-MS) was used to study the serum-binding preferences of two metallodrugs with anticancer activities in vivo, namely the organoruthenium compound plecstatin-1 and its isosteric osmium analog. The complexes were administered intraperitoneally into mice bearing a CT-26 tumor. Comparing the total metal content of mouse whole blood and serum underlined that the metallodrugs are mainly located in serum and not in the cellular fraction of the blood samples...
2018: Monatshefte Für Chemie
Bartosz Szulczyński, Piotr Rybarczyk, Jacek Gębicki
Malodorous odors, by definition, are unpleasant, irritating smells being a mixture of volatile chemical compounds that can be sensed at low concentrations. Due to the increasing problem of odor nuisance associated with odor sensations, and thus the need to remove them from the air, deodorization techniques are commonly used. Biofiltration is one of the methods of reducing odorants in the air stream. In the paper, the possibility of using an electronic nose as an alternative method to gas chromatography for the online monitoring and evaluation of efficiency of the n -butanol vapors biofiltration process in a transient state was investigated...
2018: Monatshefte Für Chemie
Bartłomiej Michał Cieślik, Lesław Świerczek, Piotr Konieczka
This article presents the most popular methods of sewage sludge management and analytical techniques which could be a powerful tool in designing new sewage sludge management methods. Chemical analysis is also described as a vital point at the subsequent stages of technological processes control and sewage sludge quality assessment. It is also an instrument essential to maintaining control of processed sewage sludge introduced to the environment as ready-to-use materials. The sludge management method is conditioned by the compliance with legal acts concerning sludge management...
2018: Monatshefte Für Chemie
Anna Różańska, Dorota Sieńska, Tomasz Dymerski, Jacek Namieśnik
The quality of the fruit is affected by several main ingredients and the aroma plays a fundamental role during the selection of fruit by consumers. In the case where several fruit have similar aromas and only one of them has specific health properties, it is very important to find the differences in the volatile organic compounds (VOCs) composition to distinguish these samples. Such situations are often found for hybrid fruit. Sweetie is a hybrid of grapefruit and pummelo. Sweetie fruit is characterized by high antioxidant potential and a positive effect on human health...
2018: Monatshefte Für Chemie
Anna Różańska, Tomasz Dymerski, Jacek Namieśnik
The food authenticity assessment is an increasingly important issue in food quality and safety. The application of an electronic nose based on ultra-fast gas chromatography technique enables rapid analysis of the volatile compounds from food samples. Due to the fact that this technique provides chemical profiling of natural products, it can be a powerful tool for authentication in combination with chemometrics. In this article, a methodology for classification of Not From Concentrate (NFC) juices was presented...
2018: Monatshefte Für Chemie
Martyna Lubinska-Szczygeł, Dominika Pudlak, Tomasz Dymerski, Jacek Namieśnik
Citrus fruits are very popular food products. There are many species and varieties of them. There are also documented cases of some citrus fruits causing a severe allergic reaction. Some species of the citrus fruits, especially hybrid ones show a reduced allergenic effect due to the lack of seeds. There is a need for rapid methods for evaluation of citrus' botanical origin. During research, the headspace of three citrus fruits Citrus Aurantifolia, Citrus japonica , and Citrus  ×  floridana was analysed using electronic nose based on ultrafast gas chromatography and gas chromatography with mass spectrometry...
2018: Monatshefte Für Chemie
Dagmara Kempińska, Agata Kot-Wasik
Limited drinking water resources and water pollution are one of the main worldwide problems. To reduce the consumption of fresh water resources, the use of treated wastewater has been proposed. The farmlands have been irrigated with wastewater for centuries, but the composition of used sewage has changed over the years. Recent research has revealed the presence of hundreds of new organic contaminants in many environmental waters, including wastewaters and their receivers. For this reason, wastewater profiling and monitoring are of high importance and urgent need...
2018: Monatshefte Für Chemie
Hubert Byliński, Tomasz Dymerski, Jacek Gębicki, Jacek Namieśnik
No abstract text is available yet for this article.
2018: Monatshefte Für Chemie
Marcin Wieczorek, Marek Dębosz, Paweł Świt, Aleksandra Piech, Joanna Kasperek, Paweł Kościelniak
The possibility of adapting the Standard Addition Method (SAM) to calibration in very difficult analytical conditions, namely when there is a need to determine an analyte with the use of nonlinear calibration graph and in the presence of matrix components causing additive interference effect, is investigated. To this aim the SAM in the common version and the Chemical H-point Standard Addition Method (C-HPSAM) realized by the flow injection technique were applied. Specifically, a flow manifold was used for construction of a set of nonlinear calibration graphs in different chemical conditions...
2018: Monatshefte Für Chemie
Tomasz Majchrzak, Wojciech Wojnowski, Tomasz Dymerski, Jacek Gębicki, Jacek Namieśnik
To safeguard the consumers' well-being, it is necessary to develop novel methods for determination of carcinogens in food, including volatiles generated during frying. The currently used procedures for analysis of volatile fraction of vegetable oils are not based on real-time measurements and thus do not enable the determination of carcinogenic compounds in frying fumes; instead, only the headspace or liquid fraction is sampled. In this article, described is an approach in which proton transfer reaction mass spectrometry with time-of-flight analyser (PTR-TOFMS) was used for real-time monitoring of carcinogenic compounds generated during thermal degradation of rapeseed oil...
2018: Monatshefte Für Chemie
Wojciech Wojnowski, Justyna Płotka-Wasylka, Kaja Kalinowska, Tomasz Majchrzak, Tomasz Dymerski, Piotr Szweda, Jacek Namieśnik
To supplement the currently used methods for poultry meat shelf life assessment, it might be necessary to develop a technique for rapid headspace analysis of volatiles with no prior sample preparation step. Biogenic amines, in particular cadaverine, are considered meat spoilage indicators. Described in this article are the results of a preliminary investigation of the applicability of proton transfer reaction mass spectrometry in the determination of cadaverine concentration in the volatile fraction of poultry meat samples stored in aerobic conditions...
2018: Monatshefte Für Chemie
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