The linkage of aromatic ring structures in vacuum residues was important for the refining process. The Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS) combined with collision-induced dissociatio...The linkage of aromatic ring structures in vacuum residues was important for the refining process. The Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS) combined with collision-induced dissociation(CID) is a powerful method to characterize the molecular structure of petroleum fractions. In this work, model compounds with different aromatic ring structures were measured by CID FT-ICR MS. The cracking of the parent ions and the generated fragment ions were able to distinguish different linkage of the model compounds. Then, vacuum residues were separated into saturates, aromatics, resins and asphaltenes fractions(SARA), and each fraction was characterized by CID technology. According to the experimental results, the aromatic rings in saturates and aromatics fractions were mainly of the island-type structures, while the aromatic rings in resins and asphaltenes fractions had a significant amount of archipelago-type structures.展开更多
A series of crescent aromatic oligothioamides(4, 6, 8, 15, and 18) bearing different number of sulfur atoms were designed and synthesized via thionation of their corresponding aromatic oligoamides(3, 5, and 7) using L...A series of crescent aromatic oligothioamides(4, 6, 8, 15, and 18) bearing different number of sulfur atoms were designed and synthesized via thionation of their corresponding aromatic oligoamides(3, 5, and 7) using Lawesson's reagent. The X-ray structure of a trimeric analogue(13) revealed the presence of intramolecular three-center hydrogen bonds that are responsible for the rigidification of the molecular backbone. The extraction by these novel receptors toward some representative heavy metal cations(Zn2+, Cd2+, Co2+, Ni2+, Pb2+, and Cu2+) and alkali and alkaline earth metal cations(Li+, Na+, K+, Rb+, Cs+, Ca2+, and Sr2+) demonstrated high efficiency(83.5%–96.4%) and superior selectivity for Cu2+ over other selected metal cations. Particularly, the extractability was correlated to both the number of sulfur atoms and orientation of thiocarbonyl groups as revealed in the order: 6 > 4 > 18 > 15. This is in stark contrast to the oligoamides that only gave much lower extractability(5.9%–16.4%), suggestive of the importance of replacement of carbonyl oxygen atoms with sulfur atoms in the extraction of Cu2+. The complexation behavior of 4, 6, and 8 with Cu2+ was also examined by UV-Vis and NMR techniques.展开更多
基金supported by the Major State Basic Research Development Program of China (973 Program, No. 2012CB224801)
文摘The linkage of aromatic ring structures in vacuum residues was important for the refining process. The Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS) combined with collision-induced dissociation(CID) is a powerful method to characterize the molecular structure of petroleum fractions. In this work, model compounds with different aromatic ring structures were measured by CID FT-ICR MS. The cracking of the parent ions and the generated fragment ions were able to distinguish different linkage of the model compounds. Then, vacuum residues were separated into saturates, aromatics, resins and asphaltenes fractions(SARA), and each fraction was characterized by CID technology. According to the experimental results, the aromatic rings in saturates and aromatics fractions were mainly of the island-type structures, while the aromatic rings in resins and asphaltenes fractions had a significant amount of archipelago-type structures.
基金supported by the National Natural Science Foundation of China(21172158)the Joint Fund of National Natural Science Foundation of China and the China Academy of Engineering Physics(11076018)+3 种基金the Doctoral Program of the Ministry of Education of China(20130181110023)the National Science Foundation for Fostering Talents in Basic Research of the National Natural Science Foundation of China(J1210004,J1103315)Open Project of State Key Laboratory of Supramolecular Structure and Materials(SKLSSM201408)Open Project of State Key Laboratory of Structural Chemistry(20140013)
文摘A series of crescent aromatic oligothioamides(4, 6, 8, 15, and 18) bearing different number of sulfur atoms were designed and synthesized via thionation of their corresponding aromatic oligoamides(3, 5, and 7) using Lawesson's reagent. The X-ray structure of a trimeric analogue(13) revealed the presence of intramolecular three-center hydrogen bonds that are responsible for the rigidification of the molecular backbone. The extraction by these novel receptors toward some representative heavy metal cations(Zn2+, Cd2+, Co2+, Ni2+, Pb2+, and Cu2+) and alkali and alkaline earth metal cations(Li+, Na+, K+, Rb+, Cs+, Ca2+, and Sr2+) demonstrated high efficiency(83.5%–96.4%) and superior selectivity for Cu2+ over other selected metal cations. Particularly, the extractability was correlated to both the number of sulfur atoms and orientation of thiocarbonyl groups as revealed in the order: 6 > 4 > 18 > 15. This is in stark contrast to the oligoamides that only gave much lower extractability(5.9%–16.4%), suggestive of the importance of replacement of carbonyl oxygen atoms with sulfur atoms in the extraction of Cu2+. The complexation behavior of 4, 6, and 8 with Cu2+ was also examined by UV-Vis and NMR techniques.