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101.
Qi‐Wei Zhang Yi‐Hang Wen Yun‐Long Feng 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(6):m255-m257
The title compound, [Zn2(C5H6O4)2(C13H14N2)]n or [Zn2(glu)2(bpp)]n, is a novel zinc polymer based on mixed flexible glutarate (glu) and 1,3‐di‐4‐pyridylpropane (bpp) ligands. The ZnII center has a distorted tetrahedral geometry and the central atom of the bpp ligand is located at a special site with a C2 axis passing through it. A layer is formed by Zn–glu bonding. Such layers are pillared by bpp ligands, forming a three‐dimensional framework with large channels. The inverted interpenetration of two three‐dimensional frameworks completes the molecular structure. 相似文献
102.
Preparation and Characterization of Microencapsulated Hexadecane Used for Thermal Energy Storage 总被引:3,自引:0,他引:3
GuangLongZOU ZhiChengTAN XiaoZhengLAN LiXianSUN TaoZHANG 《中国化学快报》2004,15(6):729-732
Polyurea microcapsules about 2.5μm in diameter containing phase change material for thermal energy storage application were synthesized and characterized by interfacial polycondensation method with toluene-2,4-diisocyanate and ethylenediamine as monomers in an emulsion system. Hexadecane was used as a phase change material and OP, which is nonionic surfactant, and used as an emulsifier. The chemical structure and thermal behavior of the microcapsules were investigated by FTIR and thermal analysis respectively. The results show encapsulated hexadecane has a good potential as a solar energy storage material. 相似文献
103.
Ye Xu Dr. Huifeng Yao Lijiao Ma Ling Hong Jiayao Li Qing Liao Yunfei Zu Jingwen Wang Mengyuan Gao Prof. Long Ye Prof. Jianhui Hou 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(23):9089-9095
Decreasing the energy loss is one of the most feasible ways to improve the efficiencies of organic photovoltaic (OPV) cells. Recent studies have suggested that non-radiative energy loss ( ) is the dominant factor that hinders further improvements in state-of-the-art OPV cells. However, there is no rational molecular design strategy for OPV materials with suppressed . Herein, taking molecular surface electrostatic potential (ESP) as a quantitative parameter, we establish a general relationship between chemical structure and intermolecular interactions. The results reveal that increasing the ESP difference between donor and acceptor will enhance the intermolecular interaction. In the OPV cells, the enhanced intermolecular interaction will increase the charge-transfer (CT) state ratio in its hybridization with the local exciton state to facilitate charge generation, but simultaneously result in a larger . These results suggest that finely tuning the ESP of OPV materials is a feasible method to further improve the efficiencies of OPV cells. 相似文献
104.
Octahedral coordination of molybdenum(III) is achieved by limiting the amount of cyanide available upon complex formation. Reaction of Mo(CF(3)SO(3))(3) with LiCN in DMF affords Li(3)[Mo(CN)(6)] x 6DMF (1), featuring the previously unknown octahedral complex [Mo(CN)(6)](3-). The complex exhibits a room-temperature moment of mu(eff) = 3.80 mu(B), and assignment of its absorption bands leads to the ligand field parameters Delta(o) = 24800 cm(-1) and B = 247 cm(-1). Further restricting the available cyanide in a reaction between Mo(CF(3)SO(3))(3) and (Et(4)N)CN in DMF, followed by recrystallization from DMF/MeOH, yields (Et(4)N)(5)[Mo(2)(CN)(11)] x 2DMF x 2MeOH (2). The dinuclear [Mo(2)(CN)(11)](5-) complex featured therein contains two octahedrally coordinated Mo(III) centers spanned by a bridging cyanide ligand. A fit to the magnetic susceptibility data for 2, gives J = -113 cm(-1) and g = 2.33, representing the strongest antiferromagnetic coupling yet observed through a cyanide bridge. Efforts to incorporate these new complexes in magnetic Prussian blue-type solids are ongoing. 相似文献
105.
The M?ssbauer effect spectra for a series of small [Fe(eta(5)-C(5)H(5))(CO)(x)()] substituted metallaborane complexes are reported, where x = 1 or 2. The pentaborane cage in compounds [Fe(eta(5)-C(5)H(5))(CO)(2)B(5)H(7)P(C(6)H(5))(2)] (1), [Fe(eta(5)-C(5)H(5))(CO)(2)B(5)H(8)] (2), and [(Fe(eta(5)-C(5)H(5))(CO)(2))(2)B(5)H(7)] (3) was found to act as a significantly better donor ligand than the ligands in a comparison group of previously reported [Fe(eta(5)-C(5)H(5))(CO)LX] complexes, where L = CO or PPh(3) and X = halide, pseudohalide, or alkyl ligands. These metallaborane complexes were found to most resemble their silyl analogues in M?ssbauer spectral parameters and the electronic distribution around the iron centers. In addition, the M?ssbauer data showed that the [&mgr;-2,3-(P(C(6)H(5))(2)B(5)H(7)](-) ligand was a superior donor to the corresponding unsubstituted [B(5)H(8)](-) ligand. The M?ssbauer spectral results for the metallaborane complexes studied were found to be in general agreement with the anticipated donor and accepting bonding considerations for the cage ligands based upon their infrared and (11)B NMR spectra and X-ray structural features. The M?ssbauer data for the [Fe(eta(5)-C(5)H(5))(CO)B(4)H(6)(P(C(6)H(5))(2))] (4) and [Fe(eta(5)-C(5)H(5))(CO)B(3)H(7)(P(C(6)H(5))(2))] (5) complexes, in comparison with compound 1, showed that as the borane cage becomes progressively smaller, it becomes a poorer donor ligand. A qualitative relationship was found between the observed M?ssbauer isomer shift data and the number of boron cage vertices for the structurally related [Fe(eta(5)-C(5)H(5))(CO)(x)B(y)H(z)P(C(6)H(5))(2)] complexes, where x = 1 or 2, y = 3-5, and z = 6 or 7. The X-ray crystallographic data for compounds 1, 2, 5, and [Fe(eta(5)-C(5)H(5))(CO)B(5)H(8)] (6) were also found to agree with the trends observed in the M?ssbauer spectra which showed that the s-electron density on the iron nucleus increases in the order 5 < 6 < 2 < 1. The X-ray crystal structure of complex 2 is also reported. Crystallographic data for 2: space group P2(1)/c (No. 14, monoclinic), a = 6.084(3) ?, b = 15.045(8) ?, c = 13.449(7) ?, beta = 99.69(5) degrees, V = 1213(1) ?(3), Z = 4 molecules/cell. 相似文献
106.
Isotachophoretic zone formation of serum albumin in different free fluid electrophoresis instruments
The isotachophoretic behavior of a model protein, serum albumin, was examined (i) by computer simulation, (ii) by capillary isotachophoresis in HPE 100 and Tachophor 2127, (iii) by continuous flow isotachophoresis in Elphor VaP 22 and the BIO-STREAM Separator and (iv) by recycling isotachophoresis in an apparatus of our own design. Variations in monitored zone shapes can be explained by differences in engineering aspects and fluid stabilization principles of the instruments. 相似文献
107.
108.
锆助剂对低温液相合成甲醇用铜铬硅催化剂性能的影响 总被引:3,自引:2,他引:3
考察了含锆的铜铬硅催化剂低温液相合成甲醇性能,并进行了BET、TPR-H2、TPD-H2、TPD-CO、XRD和XPS表征。结果表明,锆作为结构助剂及电子助剂对催化剂在低温液相合成甲醇反应中具有显著的促进作用,反应活性可提高32.25 %。锆助剂能有效提高催化剂的比表面积,促进催化剂中铜铬组分的分散及表面富集。ZrO2加入在催化剂表面产生的Cu+与催化活性的改善密切相关,Zr4+、Cr3+、Cu+可形成复合中心,为价态的稳定性提供微环境,在H2活化及C O键的断裂等反应步骤中起重要作用。 相似文献
109.
IntroductionItiswellknownthatmetallocenesactivatedwithmethylaluminoxane (MAO)arehighlyactivehomogeneousZiegler Nattacatalyststhatproducepolyolefinwithcon trolledstereoregularityandnarrowmolecularweightdistri bution ,1 4 however,themolecularweightofthepolym… 相似文献
110.
Eight tris(organotin)-substituted Keggin tungstosilicate heteropolyanions have been synthesized and characterized by elemental analysis, infrared and M?ssbauer spectroscopy, multinuclear NMR, and X-ray crystallography. The new anions contain alpha- or beta-SiW(9)O(34)(10)(-) moieties and are of two structural types, [(RSn)(3)(SiW(9)O(37))](7)(-) (R, isomer: Ph, alpha-, 1; n-Bu, alpha-, 2; Ph, beta-, 3; n-Bu, beta-, 4) and [(RSnOH)(3)(SiW(9)O(34))(2)](14)(-) (Ph, alpha-, 5; n-Bu, alpha-, 6; Ph, beta-, 7; n-Bu, beta-, 8). Crystals of Cs(4)H(3)[(PhSn)(3)(SiW(9)O(37))].8H(2)O (anion 3) are monoclinic, space group C2/c, with lattice constants a = 48.91(2) ?, b = 12.111(3) ?, c = 20.334(9) ?, beta = 102.30 degrees, and Z = 8. The anion has nominal C(3)(v)() symmetry and has a structure with three corner-shared WO(6) octahedra of the beta-Keggin anion replaced by three PhSnO(5) groups. Crystals of Cs(9)H(5)[(BuSnOH)(3)(SiW(9)O(34))(2)].36H(2)O (anion 6) are tetragonal, space group P&fourmacr;2(1)m, with lattice constants a = b = 29.005(4) ?, c = 13.412(4) ?, and Z = 4. The anion has the anticipated D(3)(h)() symmetry and contains three BuSnOH groups sandwiched between A,alpha-SiW(9)O(34)(10)(-) anions. 相似文献