The chemical structure of heavy oil fractions obtained by liquid-solid adsorption chromatography was character-ized by 1 H nuclear magnetic resonance and X-ray diffraction.The molecular weight and molecular formula of...The chemical structure of heavy oil fractions obtained by liquid-solid adsorption chromatography was character-ized by 1 H nuclear magnetic resonance and X-ray diffraction.The molecular weight and molecular formula of asphaltene molecules were estimated by combining 1 H nuclear magnetic resonance and X-ray diffraction analyses,and were also ob-tained from vapor pressure osmometry and elemental analysis.Heteroatoms,such as S,N,and O atoms,were considered in the construction of average molecular structure of heavy oils.Two important structural parameters were proposed,including the number of alkyl chain substituents to aromatic rings and the number of total rings with heteroatoms.Ultimately,the av-erage molecular structures of polycyclic aromatics,heavy resins and asphaltene molecules were constructed.The number of α-,β-,γ-,and aromatic hydrogen atoms of the constructed average molecular structures fits well with the number of hydro-gen atoms derived from the experimental spectral data.展开更多
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
Heteracalixaromatics are an emerging generation of macrocyclic host molecules in supramolecular chemistry. As a typical example of heteracalixaromatics, oxacalix[2]arene[2]triazine adopts a shape-persistent 1,3-altern...Heteracalixaromatics are an emerging generation of macrocyclic host molecules in supramolecular chemistry. As a typical example of heteracalixaromatics, oxacalix[2]arene[2]triazine adopts a shape-persistent 1,3-alternate conformation and can be easily functionalized. Taking it as a platform, a series of oxacalix[2]arene[2]triazine-based amphiphiles bearing long alkyl chains were synthesized through post-macrocyclization functionalization or 3＋1 fragment coupling protocols. The self-assembly behavior of these arnphiphiles in a mixture of tetrahydrofuran （THF） and water was investigated. Dynamic light scattering （DLS） measurements revealed that the size of the self-assembled aggregates is dependent on the structure of the amphiphiles. The long alkyl chain substituents and/or interrnolecular hydrogen bonds were found to promote the self-assembly.展开更多
基金the funding of the National Basic Research Program of China (Grant No.2006CB202505)
文摘The chemical structure of heavy oil fractions obtained by liquid-solid adsorption chromatography was character-ized by 1 H nuclear magnetic resonance and X-ray diffraction.The molecular weight and molecular formula of asphaltene molecules were estimated by combining 1 H nuclear magnetic resonance and X-ray diffraction analyses,and were also ob-tained from vapor pressure osmometry and elemental analysis.Heteroatoms,such as S,N,and O atoms,were considered in the construction of average molecular structure of heavy oils.Two important structural parameters were proposed,including the number of alkyl chain substituents to aromatic rings and the number of total rings with heteroatoms.Ultimately,the av-erage molecular structures of polycyclic aromatics,heavy resins and asphaltene molecules were constructed.The number of α-,β-,γ-,and aromatic hydrogen atoms of the constructed average molecular structures fits well with the number of hydro-gen atoms derived from the experimental spectral data.
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(21272239,91427301,21521002)Ministry of Science and Technology(2013CB834504)
文摘Heteracalixaromatics are an emerging generation of macrocyclic host molecules in supramolecular chemistry. As a typical example of heteracalixaromatics, oxacalix[2]arene[2]triazine adopts a shape-persistent 1,3-alternate conformation and can be easily functionalized. Taking it as a platform, a series of oxacalix[2]arene[2]triazine-based amphiphiles bearing long alkyl chains were synthesized through post-macrocyclization functionalization or 3＋1 fragment coupling protocols. The self-assembly behavior of these arnphiphiles in a mixture of tetrahydrofuran （THF） and water was investigated. Dynamic light scattering （DLS） measurements revealed that the size of the self-assembled aggregates is dependent on the structure of the amphiphiles. The long alkyl chain substituents and/or interrnolecular hydrogen bonds were found to promote the self-assembly.
