中长链甘油三酯(medium and long-chain triacylglycerols,MLCT)是一类具有特殊理化性质和营养功能的结构脂质。随着MLCT在食品、医药、保健品、母乳脂等行业中的需求不断增长,酶法制备MLCT的研究也逐渐成为热点。文章对MLCT的酶合成策...中长链甘油三酯(medium and long-chain triacylglycerols,MLCT)是一类具有特殊理化性质和营养功能的结构脂质。随着MLCT在食品、医药、保健品、母乳脂等行业中的需求不断增长,酶法制备MLCT的研究也逐渐成为热点。文章对MLCT的酶合成策略,包括对合成途径、脂肪酶种类、催化反应体系和产品分离纯化等方面进行了总结、分析和探讨,以期为MLCT的酶法制备的研究与应用提供参考。展开更多
The molecular structure, the Natural Bond orbital (NBO) and the Time Dependent-DFT of both isomers cis or γ-Cl and trans or δ-Cl of RuCl2(L)2, where L stands respectively for 2-phenylazopyridine (Azpy), 2,4-dimethyl...The molecular structure, the Natural Bond orbital (NBO) and the Time Dependent-DFT of both isomers cis or γ-Cl and trans or δ-Cl of RuCl2(L)2, where L stands respectively for 2-phenylazopyridine (Azpy), 2,4-dimethyl-6-[phenylazo]pyridine (Dazpy), 2-[(3,5-dimethylphenyl)azopyridine] (Mazpy) and 2-pyridylazonaphtol (Nazpy) were calculated with DFT method at B3LYP/LANL2DZ level. The prediction of the frontier orbitals (Highest Occupied Molecular Orbital or HOMO and Lowest Unoccupied Molecular Orbital or LUMO) shows that the most active complexes suitable for electronic reactions are admitted to be the trans isomers. Moreover, δ-RuCl2 (Azpy)2 is discovered to react more actively as photo-sensitizer since its energy gap is the minimum. Besides, electronic structures of all complexes through NBO calculation indicate that Ru-N bonds are made of delocalization of occupancies from lone pair orbital of N atoms to the ruthenium. Moreover, Ru was assumed to have almost the same charge regardless the structure of the azopyridine ligands in the complex indicating that the ligands provide only a steric effect that is responsible for the ruthenium’s selectivity. Concerning the transition state, NBO analysis also highlights that the transition LP(Ru) π*(N1-N2) does correspond to t2g?π*(L). This transition is assumed to correspond to Metal to Ligand Charge Transfer (MLCT) that is responsible for the photo-sensitiveness of the metallic complex. Besides, TDDFT calculation of complexes showed that δ-RuCl2(Nazpy)2 displays the largest band during the absorption. For that reason, it is admitted to be the best photosensitizer due to a large system of conjugation provided by Nazpy ligand.展开更多
An unprecedented oxo-centered, trinuclear iron nicotinato cluster, [Fe30o （C6NO2Hs）6（H20）3][Fe（H30）2C16]＇12H20＂6Br （1）, has been prepared via hydrothermal reac- tions and structurally characterized by X-ray ...An unprecedented oxo-centered, trinuclear iron nicotinato cluster, [Fe30o （C6NO2Hs）6（H20）3][Fe（H30）2C16]＇12H20＂6Br （1）, has been prepared via hydrothermal reac- tions and structurally characterized by X-ray diffraction. Compound 1 crystallizes in the R-3c space group of rhombohedral system with a = 21.763（4）, c = 24.361（3） A, V = 9992（3） A3, C36H66Br6C16Fe4N6030, Mr = 1978.51, De. = 11973 g/cms, S = 1.006,/（MoKa） = 4.778 mm-1, F（000） = 5880, Z = 6, R = 0.0591 and wR = 0.1054. The title complex features an isolated structure, based on one discrete [Fe30（C6NO2H5）6（H20）3]7＋ cation, one [Fe（H30）2C16]- anion, twelve lattice water molecules and six isolated bromine anions. These isolated moieties are interconnected via hydrogen bonds to yield a three-dimensional （3-D） supramolecular network. Photoluminescent investigation reveals that the title complex exhibits an emission in the purple region. Theoretical study reveals that the emission is attributed to the metal to ligand charge-transfer （MLCT） interaction.展开更多
n this work, we present synthesis of the compounds trans-[Ru(NH<sub>3</sub>)<sub>4</sub>L(bpa)]<sup>2+</sup> where L is pyridine ligands: pyridine (py), isonicotinamide (isn), 4-ace...n this work, we present synthesis of the compounds trans-[Ru(NH<sub>3</sub>)<sub>4</sub>L(bpa)]<sup>2+</sup> where L is pyridine ligands: pyridine (py), isonicotinamide (isn), 4-acetylpyridine (4-acpy) and 4-picoline (4-pic) and 1,2-bis (4-pyridyl) ethane (bpa), their characterization by UV-visible spectroscopy and electrochemical properties. This series shows intense bands in the region between 400 and 515 nm, allocated bands charge transfer (MLCT), the influence of substituents on the pyridine ring (4-acpy and isn), and the interaction between the ligand and the metal, causing a second MLCT band, which is lighter and has more energy. The compound is characterized by spectroscopy by Fourier transform infrared spectroscopy (FTIR). The displacement observed in the symmetrical stretching of ν<sub>s</sub>(CCN) group in the complex compared with the ν<sub>s</sub>(CCN) group in the free ligand is indicative of coordination of the pyridine group to the Ruthenium (II) metallic center. The electrochemical data (cyclic voltammetry) show that reversibility criteria are well defined and formal E<sub>f</sub> potential, indicating the influence of the pyridine ring substituent.展开更多
基金the Science and Technology Department of Jiangsu Province (grantnos.BK2010551)National Natural Science Foundation of China for financial support( grantnos.21071080)~~
文摘中长链甘油三酯(medium and long-chain triacylglycerols,MLCT)是一类具有特殊理化性质和营养功能的结构脂质。随着MLCT在食品、医药、保健品、母乳脂等行业中的需求不断增长,酶法制备MLCT的研究也逐渐成为热点。文章对MLCT的酶合成策略,包括对合成途径、脂肪酶种类、催化反应体系和产品分离纯化等方面进行了总结、分析和探讨,以期为MLCT的酶法制备的研究与应用提供参考。
文摘The molecular structure, the Natural Bond orbital (NBO) and the Time Dependent-DFT of both isomers cis or γ-Cl and trans or δ-Cl of RuCl2(L)2, where L stands respectively for 2-phenylazopyridine (Azpy), 2,4-dimethyl-6-[phenylazo]pyridine (Dazpy), 2-[(3,5-dimethylphenyl)azopyridine] (Mazpy) and 2-pyridylazonaphtol (Nazpy) were calculated with DFT method at B3LYP/LANL2DZ level. The prediction of the frontier orbitals (Highest Occupied Molecular Orbital or HOMO and Lowest Unoccupied Molecular Orbital or LUMO) shows that the most active complexes suitable for electronic reactions are admitted to be the trans isomers. Moreover, δ-RuCl2 (Azpy)2 is discovered to react more actively as photo-sensitizer since its energy gap is the minimum. Besides, electronic structures of all complexes through NBO calculation indicate that Ru-N bonds are made of delocalization of occupancies from lone pair orbital of N atoms to the ruthenium. Moreover, Ru was assumed to have almost the same charge regardless the structure of the azopyridine ligands in the complex indicating that the ligands provide only a steric effect that is responsible for the ruthenium’s selectivity. Concerning the transition state, NBO analysis also highlights that the transition LP(Ru) π*(N1-N2) does correspond to t2g?π*(L). This transition is assumed to correspond to Metal to Ligand Charge Transfer (MLCT) that is responsible for the photo-sensitiveness of the metallic complex. Besides, TDDFT calculation of complexes showed that δ-RuCl2(Nazpy)2 displays the largest band during the absorption. For that reason, it is admitted to be the best photosensitizer due to a large system of conjugation provided by Nazpy ligand.
基金supported by the National Science and Technology Support Program of the Ministry of Science and Technology of China(No.2012BAC11B01)the Open Foundation(No.20130014)of the State Key Laboratory of Structural Chemistry,Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences
文摘An unprecedented oxo-centered, trinuclear iron nicotinato cluster, [Fe30o （C6NO2Hs）6（H20）3][Fe（H30）2C16]＇12H20＂6Br （1）, has been prepared via hydrothermal reac- tions and structurally characterized by X-ray diffraction. Compound 1 crystallizes in the R-3c space group of rhombohedral system with a = 21.763（4）, c = 24.361（3） A, V = 9992（3） A3, C36H66Br6C16Fe4N6030, Mr = 1978.51, De. = 11973 g/cms, S = 1.006,/（MoKa） = 4.778 mm-1, F（000） = 5880, Z = 6, R = 0.0591 and wR = 0.1054. The title complex features an isolated structure, based on one discrete [Fe30（C6NO2H5）6（H20）3]7＋ cation, one [Fe（H30）2C16]- anion, twelve lattice water molecules and six isolated bromine anions. These isolated moieties are interconnected via hydrogen bonds to yield a three-dimensional （3-D） supramolecular network. Photoluminescent investigation reveals that the title complex exhibits an emission in the purple region. Theoretical study reveals that the emission is attributed to the metal to ligand charge-transfer （MLCT） interaction.
文摘n this work, we present synthesis of the compounds trans-[Ru(NH<sub>3</sub>)<sub>4</sub>L(bpa)]<sup>2+</sup> where L is pyridine ligands: pyridine (py), isonicotinamide (isn), 4-acetylpyridine (4-acpy) and 4-picoline (4-pic) and 1,2-bis (4-pyridyl) ethane (bpa), their characterization by UV-visible spectroscopy and electrochemical properties. This series shows intense bands in the region between 400 and 515 nm, allocated bands charge transfer (MLCT), the influence of substituents on the pyridine ring (4-acpy and isn), and the interaction between the ligand and the metal, causing a second MLCT band, which is lighter and has more energy. The compound is characterized by spectroscopy by Fourier transform infrared spectroscopy (FTIR). The displacement observed in the symmetrical stretching of ν<sub>s</sub>(CCN) group in the complex compared with the ν<sub>s</sub>(CCN) group in the free ligand is indicative of coordination of the pyridine group to the Ruthenium (II) metallic center. The electrochemical data (cyclic voltammetry) show that reversibility criteria are well defined and formal E<sub>f</sub> potential, indicating the influence of the pyridine ring substituent.
