Investigation of the structural characterization and reversible oxygenation mechanism of oxygenated cobalt-3-(4-thiazolyl)-l-alanine and cobalt-histidine complexes using electrospray tandem mass spectrometry
Fu J.,Key Laboratory of Oil and Gas Fine Chemicals |
Fu P.,Shaanxi Land Engineering Construction Group Co. |
Yue F.,Key Laboratory of Oil and Gas Fine Chemicals |
Zhang X.,Key Laboratory of Oil and Gas Fine Chemicals |
And 2 more authors.
Analytical Methods | Year: 2016
The reversibility of dioxygen uptake by a complex is highly dependent on the stability of its superoxo- or dinuclear peroxo-intermediates. It is important to characterize oxygenated intermediates for the mechanistic investigation of reversible dioxygen uptake by complexes. Although the oxygenated complexes can be investigated by conventional techniques, the oxygenated species can only be identified indirectly. Thus new techniques for the direct differentiation of the oxygenated species are required to prove the existence of oxygenated species in complexes. In this paper, the electrospray mass spectrometry (ESI-MS) method was developed to directly identify oxygenated species. The newly reported cobalt-3-(4-thiazolyl)-l-alanine (Co-Tza) and the well-known cobalt-histidine (Co-His) complexes were used as targets. Fragmented ions of the dinuclear oxygenated complexes of Co-Tza and Co-His in aqueous samples were evident in ESI-MS spectra. The ESI mass spectra of Co-Tza and Co-His suggested the formation of dinuclear peroxo complexes, [CoIIIL2]2(O2), and the spectrum of Zn-His only showed the fragments of a mononuclear Zn(His)2 complex. The results also revealed that in the electrospray positive ion detection mode, the Co-Tza and Co-His complexes had similar fragmentation patterns, resulting likely from the similarities in the ligand structure and coordination modes between the complexes. The fragmented structures of sodium and potassium adducts of Co-Tza and Co-His were almost identical, indirectly confirming the rationality of the proposed fragmentation patterns. For comparison, theoretical modeling computations and volumetry were used to examine the oxygenation of Co-Tza. The results revealed that ESI-MS can be a useful and powerful technique for characterizing oxygenated complexes and investigating oxygenation mechanisms. © 2016 The Royal Society of Chemistry.
Mamtimin X.,Key Laboratory of Oil and Gas Fine Chemicals |
Matsidik R.,Key Laboratory of Oil and Gas Fine Chemicals |
Nurulla I.,Key Laboratory of Oil and Gas Fine Chemicals
Polymer | Year: 2010
A new type - π-conjugated copolymers of 2-amino-pyrimidine was prepared between 2-amino-4,6-diiodidepyrimidine and 1,4-dibromo-2,5-dialkoxybenzene by Sonogashira polycondensation. The structures of the copolymers were elucidated by FT-IR, 1H NMR and 13C NMR, fluorescence spectroscopy, gel permeation chromatography, thermal analysis and element analysis. The derived polymers were soluble in common organic solvents and trifloroacetic acid and exhibited good thermal stability. They emitted green light under UV irradiation in solid state and blue or green light in solution phase, respectively. Electrochemical behavior of these new polymers depicted facile p-doping and good electron-transporting properties. These polymers displayed bathochromic shift when protonated with CH3SO3H acid in chloroform solutions or m-cresol solutions and the red-shifted peaks were observed from 490 nm to 652 nm. XRD patterns of copolymers showed that the intensity of peaks was enhanced with increasing alkyloxy chain length. © 2009 Elsevier Ltd. All rights reserved.
Zhang Y.,Key Laboratory of Oil and Gas Fine Chemicals |
Jiang X.,Key Laboratory of Oil and Gas Fine Chemicals |
Wu R.,Key Laboratory of Oil and Gas Fine Chemicals |
Wang W.,Xinjiang UniversityUrumqi830046 China
Journal of Applied Polymer Science | Year: 2016
Thermo-induced multishape memory polymers are a growing focus of smart materials because of its promising applications. Multishape memory effect is generally attained by using polymers with broad phase transition and multiphase polymers. The latter is of particular interest for copolymerization and polymer compositing. One requirement has to be fulfilled to achieve multishape memory effect, which is to have two reversible phase transitions. In this study, we report synthesis of polymer composite composed of strong segregated polymers by using reaction-induced phase separation. We demonstrate the method by using polyurethane (PU) and poly(methacrylic acid) (PMAA). With adjusting the weight ratio, the polymer composites exhibit a phase spectrum from phase separation to miscible composite. The composite with PU/PMAA =3:1 demonstrated triple-shape memory effect. Based on the results, we argued the effect of segregation on the shape memory effect for polymer composites. With the addition of PMAA, the polymer composite also exhibits pH/water-induced shape memory effect. © 2016 Wiley Periodicals, Inc.
Liu C.-J.,Xi'an Jiaotong University |
Liu C.-J.,Key Laboratory of Oil and Gas Fine Chemicals |
Wang J.-D.,Xi'an Jiaotong University |
Wang J.-D.,Key Laboratory of Oil and Gas Fine Chemicals
Molecules | Year: 2010
An efficient synthesis of novel 4-(2-phenyl-1,2,3-triazol-4-yl)-3,4- dihydropyrimidin2(1H)-(thio)ones from 1,3-dicarbonyl compounds, 2-phenyl-1,2,3-triazole-4carbaldehyde and urea or thiourea under ultrasound irradiation and using samarium perchlorate as catalyst is described. Compared with conventional methods, the main advantages of the present methodology are milder conditions, shorter reaction times and higher yields. Copyright © 2010 by the authors.