Self‐assembly process of copper cation and 2,5‐bis(3‐pyridyl)‐1,3,4‐oxadiazole under electrospray ionization conditions

Abstract

Polyhedral oligomeric silsesquioxane (POSS) polymers were synthesized by the dehydrogenative condensation of (HSiO3/2)8 with water in the presence of diethylhydroxylamine followed by trimethylsilylation. Coating films were prepared by spin‐coating of the coating solution prepared by the dehydrogenative condensation of POSS. The hardness of the coating films was evaluated using a pencil‐hardness test and was found to increase up to 8H with increases in the curing temperature. Free‐standing film and silica gel powder were prepared by aging the coating solution at room temperature. The silica gel powder was subjected to heat treatment under air atmosphere to show a specific surface area of 440 m2 g−1 at 100 °C, which showed a maximum at 400 °C as 550 m2 g−1. Copyright © 2011 John Wiley & Sons, Ltd.

Fragmentation and skeletal rearrangements of 2‐arylylamino‐5‐aryl‐1,3,4‐oxadiazoles and their noncovalent complexes with cobalt cation and cyclodextrin studied by mass spectrometry

“…The complexes of 2,5‐diaryl‐ and 2,5‐dipyridyl‐1,3,4‐oxadiazoles with copper were discussed in previous papers, reporting the formation of complexes of the stoichiometry 1 : 1, 2 : 1 and 2 : 2 34–36. Similar results were obtained for other metal cations, e.g.…”

Detection of Binuclear Copper—Caffeine Complexes under Electrospray Ionization Condition

“…17 By using a cone voltage in the range 10-80 V and a desolvation temperature 100-360°c, the ions containing two copper ions were not detected when using cu(ooccH 3 ) 2 . It has been reported that the presence of a counter ion may be of crucial importance for formation of binuclear complexes and their detection by ESI-MS. 18 In addition to cu(ooccH 3 ) 2 , the following copper salts were tested for their ability to form binuclear copper-caffeine complexes: cu(clo 4 ) 2 , cu(No 3 ) 2 , cucl 2 and cuSo 4 . Benzoic acid, 4-ntrobenzoic acid and 3,5-dinitrobenzoic acid were added to the solutions analyzed because aromatic carboxylates are common bridging agents of copper atoms in binuclear caffeine complexes.…”

“…21 It has been described that the solvent used may be of crucial importance for complexes observed in the ESI conditions. 18,22 thus, in addition to methanol, the following solvents were tested: acetonitrile, acetonitrile / methanol 1 / 1, acetonitrile/ water 1 / 1, methanol / water 1 / 1 and methanol / chloroform 1 / 1. Acetonitrile or water containing solvents were found to be inappropriate to form copper-caffeine complexes.…”

Detection of Cu(III)‐containing [Diclofenac–H+CuNO3]+ ion by electrospray ionization mass spectrometry

“…[13] Therefore, sometimes in ESI mass spectra only copper(I)-containing ions are observed, whereas in the injected solution there are complexes of copper(II). [14,15] Thus it can be expected that copper(III) is very easily reduced under ESI conditions and detection of Cu(III)-containing ions is extremely difficult. However, Cu(III)-containing ions (at least formally) have been observed in ESI mass spectra.…”