Search results for "Methanol"
showing 10 items of 1026 documents
CCDC 1942681: Experimental Crystal Structure Determination
2019
Related Article: Júlia Mayans, Mercé Font-Bardia, Albert Escuer|2019|Dalton Trans.|48|16158|doi:10.1039/C9DT03600H
CCDC 658149: Experimental Crystal Structure Determination
2008
Related Article: D.Schollmeyer, O.V.Shishkin, T.Ruhl, M.O.Vysotsky|2008|CrystEngComm|10|715|doi:10.1039/b716442d
CCDC 755833: Experimental Crystal Structure Determination
2011
Related Article: A.N.Georgopoulou, R.Adam, C.P.Raptopoulou, V.Psycharis, R.Ballesteros, B.Abarca, A.K.Boudalis|2010|Dalton Trans.|39|5020|doi:10.1039/b925525g
Pressurized liquid extraction followed by liquid chromatography–mass spectrometry for determination of zearalenone in cereal flours
2010
Abstract A method for determination of zearalenone in cereal flour has been developed applying pressurized liquid extraction (PLE) using methanol/acetonitrile (50:50 v/v) as the extraction solvent. The extracted samples were analyzed with liquid chromatography coupled to mass spectrometry (LC–MS) with an electro spray ionisation interface (ESI). The method was validated as a quantitative confirmatory method according to the Eu Commission Decision 2002/657/EC. Recoveries of the extraction step data were satisfactory with values higher then 70%. Quantification limits (LOQ) were 5 μg/kg for ESI (+) and 1 μg/kg for ESI (−). Twenty one flour samples produced in different countries were extracted…
C,N-chelated organotin(IV) trifluoroacetates. Instability of the mono- and diorganotin(IV) derivatives.
2011
Abstract The C,N-chelated tri-, di- and monoorganotin(IV) halides react with equimolar amounts of CF3COOAg to give corresponding C,N-chelated organotin(IV) trifluoroacetates. The set of prepared tri-, di- and monoorganotin(IV) trifluoroacetates bearing the LCN ligand (where LCN is 2-(N,N-dimethylaminomethyl)phenyl-) was structurally characterized by X-ray diffraction analyses, multinuclear NMR and IR spectroscopy. In the case of triorganotin(IV) trifluoroacetates and (LCN)2Sn(OC(O)CF3)2, no tendency to form hydrolytic products, or instability towards the moisture was observed. LCNRSn(OC(O)CF3)2 (where R is n-Bu or Ph) and LCNSn(OC(O)CF3)3 forms upon crystallization from THF in the air mainl…
The chemical composition of the aerial parts of Stachys spreitzenhoferi (Lamiaceae) growing in Kythira Island (Greece), and their antioxidant, antimi…
2022
The Stachys L. genus has been used in traditional medicine to treat skin inflammations, stomach disorders, and stress. The aim of this study was to investigate the chemical profile and biological activity of the methanolic extract of Stachys spreitzenhoferi Heldr. (Lamiaceae) aerial parts, collected on the island of Kythira, South Greece. The analysis by liquid chromatography coupled with electrospray ionization and high-resolution mass spectrometry [LC-(-)ESI/HRMSn] of the methanol extract revealed the occurrence of thirty-six compounds - flavonoids, phenylethanoid glycosides, iridoids, quinic acid derivatives, aliphatic alcohol glycosides, and oligosaccharides - highlighting the substanti…
[Fe III (bztpen)(OCH 3 )](PF 6 ) 2 : Stable Methoxide–Iron(III) Complex Exhibiting Spin Crossover Behavior in the Solid State
2010
Complex [Fe III (bztpen)(OCH 3 )](PF 6 ) 2 (1) crystallizes as the major yellow-brown product from spontaneous oxidation of its corresponding iron(II) counterpart in methanol solution. Magnetic measurements and EPR spectra demonstrate that 1 undergoes a poorly cooperative 6 A 1 ↔ 2 T 2 spin conversion in the temperature range 300-50 K, with characteristic thermodynamic parameters ΔH = 6.15 kJ mol -1 , ΔS = 39.88 J K -1 mol -1 , and T 1/2 = 154 K. The crystal structure of 1 has been investigated at 100 and 293 K.
Mass spectra of halogenated esters. Part IX—methyl esters of 2-butenoic acids containing chlorine and/or bromine atom(s)
1990
The electron impact mass spectra of methyl esters of chloro-, bromo-, dichloro-, bromochloro- and dibromo-2-butenoic acids (13 esters at all) have been investigated. Generally, the peaks due to the following fragments are abundant: M+·, [M OCH3]+, [M CH3OH]+·, [M X]+, [M OCH3 CO]+ or [M COOCH3]+, [M X CH3OH]+ or [M OCH3 HX]+, [M OCH3 CO HX]+, [M OCH3 X X]+ and [M OCH3 CO X X]+. Characteristic for the 2- and 4-halo isomers are the primary losses of a methyl radical and methanol, and for the 3-halo isomers the loss of X· from M+·. Disparities between the spectra of the E and Z isomers are shown, the effect of position of halogen substitution being much more pronounced, as reported previously …
Reactivity of di-tert-butyldimethoxystannane with carbon dioxide and methanol: X-ray structure of the resulting complex
2006
Abstract The synthesis of dimethyl carbonate from carbon dioxide and methanol was studied with ditert-butyldimethoxystannane under pressure at temperatures ⩽423 K. The formation of dimethyl carbonate is accompanied by transformation of the stannane into a trinuclear complex, the structure of which has been determined by single-crystal X-ray diffraction technique. The relevance of this specie in the catalytic cycle is demonstrated by conducting recycling runs. A preliminary kinetic study underlines the steric influence of the tert-butyl ancillary ligands in the stabilisation of intermediates, by comparison with the n-butyl homologue.
Can Green Dimethyl Carbonate Synthesis be More Effective? A Catalyst Recycling Study Benefiting from Experimental Kinetics and DFT Modeling
2014
Dibutyldimethoxystannanes are known to catalyze the reaction between carbon dioxide and methanol leading to dimethyl carbonate. Despite similarities between din-butyl- and ditert-butyldimethoxystannane, the recycled complexes have different structural features. In the din-butyl series, a decatin(IV) complex has been characterized and is less active than the stannane precursor. Kinetic experiments likely indicate that all the tin centers are not active, which is confirmed in comparing with the related dinuclear 1,3-dimethoxytetran-butyldistannoxane complex. In the ditert-butyl series, the tritin(IV) complex isolated upon recycling features the steric effect of bulky tBu ancillary ligands. In…