全文获取类型
收费全文 | 386篇 |
免费 | 21篇 |
国内免费 | 75篇 |
专业分类
化学 | 464篇 |
晶体学 | 6篇 |
综合类 | 2篇 |
物理学 | 10篇 |
出版年
2024年 | 3篇 |
2023年 | 4篇 |
2022年 | 18篇 |
2021年 | 15篇 |
2020年 | 16篇 |
2019年 | 15篇 |
2018年 | 11篇 |
2017年 | 17篇 |
2016年 | 20篇 |
2015年 | 15篇 |
2014年 | 22篇 |
2013年 | 48篇 |
2012年 | 39篇 |
2011年 | 19篇 |
2010年 | 16篇 |
2009年 | 22篇 |
2008年 | 27篇 |
2007年 | 23篇 |
2006年 | 14篇 |
2005年 | 19篇 |
2004年 | 16篇 |
2003年 | 14篇 |
2002年 | 24篇 |
2001年 | 9篇 |
2000年 | 5篇 |
1999年 | 7篇 |
1998年 | 7篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1978年 | 1篇 |
排序方式: 共有482条查询结果,搜索用时 15 毫秒
401.
A facile and rapid method for the synthesis of novel imidazole and benzimidazole aromatic acyclic nucleosides is described. Synchronous N-alkylation of imidazole or benzimidazole and potassium aryloxide with methylene iodide in the presence of triethylamine and a catalytic amount of tetrabutylammonium bromide (TBAB) in dry acetonitrile or acetone gave moderate yields of the acycloaromatic nucleoside analogs. 相似文献
402.
Haifeng Zhu Hui Tong Yongyang Gong Shiyang Shao Chunmei Deng Wang Zhang Yuan Yongming Zhang 《Journal of polymer science. Part A, Polymer chemistry》2012,50(11):2172-2181
Blue light‐emitting materials are receiving considerable academic and industrial interest due to their potential applications in optoelectronic devices. In this study, blue light‐emitting copolymers based on 9,9′ ‐ dioctylfluorene and 2,2′‐(1,4‐phenylene)‐bis(benzimidazole) moieties were synthesized through palladium‐catalyzed Suzuki coupling reaction. While the copolymer consisting of unsubstituted benzimidazoles (PFBI0) is insoluble in common organic solvents, its counterpart with N‐octyl substituted benzimidazoles (PFBI8) enjoys good solubility in toluene, tetrahydrofuran, dichloromethane (DCM), and chloroform. The PFBI8 copolymer shows good thermal stability, whose glass transition temperature and onset decomposition temperature are 103 and 428 °C, respectively. Its solutions emit blue light efficiently, with the quantum yield up to 99% in chloroform. The electroluminescence (EL) device of PFBI8 with the configuration of indium‐tin oxide/poly(ethylenedioxythiophene):poly(styrene sulfonic acid)/PFBI8/1,3,5‐tris(1‐phenyl‐1H‐benzimidazole‐2‐yl)benzene/LiF/Al emits blue light with the maximum at 448 nm. Such unoptimized polymer light‐emitting diode (PLED) exhibits a maximum luminance of 1534 cd/m2 with the current efficiency and power efficiency of 0.67 cd/A and 0.20 lm/W, respectively. The efficient blue emission and good EL performance make PFBI8 promising for optoelectronic applications. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
403.
通过水热法合成了一个新的超分子化合物[PyBImH2]?[SnCl6] (PyBIm=2-(4-吡啶基)苯并咪唑), 并用元素分析、红外光谱、荧光光谱及X射线单晶衍射对其进行了分析测试。化合物属于正交晶系,Pbcn空间群,晶胞参数:a = 7.1468(3),b = 15.0493(6),c = 16.1195(8) ?,V = 1733.72(13) ?3,Z = 4,Dc = 2.025 g/cm3,Mr = 528.63,μ(MoKα) = 2.395 mm-1,F(000) = 1024,R1= 0.0264,wR2 = 0.0665。Sn4+与6个氯离子配位,形成八面体的配位几何。配位阴离子[SnCl6]2-与[2-(4-吡啶基)苯并咪唑阳离子通过氢键及π-π 堆积作用形成三维超分子结构。 相似文献
404.
Syntheses and Characterization of Three New Compounds Based on Terephthalate and 2‐(2‐Pyridin‐4‐yl‐vinyl)benzimidazole Ligands
下载免费PDF全文
![点击此处可从《无机化学与普通化学杂志》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Three new compounds based on H2BDC and PyBImE [H2BDC = 1,4‐benzenedicarboxylatic acid, PyBImE = 2‐(2‐pyridin‐4‐yl‐vinyl)benzimidazole], namely, [Co(PyBImE)(BDC)(H2O)2] ( 1 ), [Co(PyBImE)2(HBDC)(BDC)0.5] ( 2 ), and [(HPyBImE)+ · (BDC)2–0.5 · (H2BDC)0.5] ( 3 ), were synthesized by hydrothermal methods and characterized by single‐crystal X‐ray diffraction. Compound 1 is a one‐dimensional chain bridged by terephthalate in a bis(monodentate) fashion. In the complex the nitrogen atom from NBIm and the coordination water molecule complete the coordination sphere. In complex 2 , the dinuclear cobalt units are bridged by terephthalate in a bis(bidentate) fashion into a one‐dimensional chain, but different from complex 1 , the nitrogen atom from NPy and the oxygen atom from hydrogenterephthalate complete the coordination sphere. Complex 3 is a co‐crystal with PyBImE and H2BDC in a 1:1 ratio and the transfer of hydrogen atoms leads the complex into a salt. Interesting supramolecular structures are shown due to the hydrogen bonding as well as π ··· π interactions in the three complexes. Thermal and magnetic properties of 1 and 2 were also studied. 相似文献
405.
Ishani I. Sahay 《合成通讯》2017,47(8):825-834
One pot click chemistry is used to link triazole and benzimidazole pharmacophore to get N-((1-((1H-benzo[d]imidazol-2-yl)methyl)-1H-1,2,3-triazol-4-yl)methyl)aniline and its derivatives. Flexible linkages in the form of –CH2–R or –O–R/–N–R were designed during synthesis. All the newly synthesized compounds were characterized by FT-IR and NMR spectroscopy as well as high-resolution mass spectrometry. Selected compounds were screened for in vitro anti-proliferative activity using National Cancer Institute (NCI)-60 human tumor cell line screening program. The most potent structure N-((1-((1H-benzo[d]imidazol-2-yl)methyl)-1H-1,2,3-triazol-4-yl)methyl)-4-chloroaniline 7e showed 40% growth inhibition in renal cancer cell line (UO-31) at 10?µM concentration. 相似文献
406.
Acid‐Base Switchable [2]‐ and [3]Rotaxane Molecular Shuttles with Benzimidazolium and Bis(pyridinium) Recognition Sites
下载免费PDF全文
![点击此处可从《化学:亚洲杂志》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Prof. Dr. Kelong Zhu Dr. V. Nicholas Vukotic Prof. Dr. Stephen J. Loeb 《化学:亚洲杂志》2016,11(22):3258-3266
For the purpose of developing higher level mechanically interlocked molecules (MIMs), such as molecular switches and machines, a new rotaxane system was designed in which both the 1,2‐bis(pyridinium)ethane and benzimidazolium recognition templating motifs were combined. These two very different recognition sites were successfully incorporated into [2]rotaxane and [3]rotaxane molecular shuttles which were fully characterized by 1H NMR, 2D EXSY, single‐crystal X‐ray diffraction and VT NMR analysis. By utilizing benzimidazolium as both a recognition site and stoppering group it was possible to create not only an acid/base switchable [2]rotaxane molecular shuttle (energy barrier 20.9 kcal?mol?1) but also a [3]rotaxane molecular shuttle that displays unique dynamic behavior involving the simultaneous motion of two macrocyclic wheels on a single dumbbell. This study provides new insights into the design of switchable molecular shuttles. Due to the unique properties of benzimidazoles, such as fluorescence and metal coordination, this new type of molecular shuttle may find further applications in developing functional molecular machines and materials. 相似文献
407.
Qiu-Ying Huang Xiao-Yi Lin Xiang-Ru Meng 《Acta Crystallographica. Section C, Structural Chemistry》2016,72(6):480-484
The N‐heterocyclic ligand 2‐[(1H‐imidazol‐1‐yl)methyl]‐1H‐benzimidazole (imb) has a rich variety of coordination modes and can lead to polymers with intriguing structures and interesting properties. In the coordination polymer catena‐poly[[cadmium(II)‐bis[μ‐benzene‐1,2‐dicarboxylato‐κ4O1,O1′:O2,O2′]‐cadmium(II)‐bis{μ‐2‐[(1H‐imidazol‐1‐yl)methyl]‐1H‐benzimidazole}‐κ2N2:N3;κ2N3:N2] dimethylformamide disolvate], {[Cd(C8H4O4)(C11H10N4)]·C3H7NO}n, (I), each CdII ion exhibits an irregular octahedral CdO4N2 coordination geometry and is coordinated by four O atoms from two symmetry‐related benzene‐1,2‐dicarboxylate (1,2‐bdic2−) ligands and two N atoms from two symmetry‐related imb ligands. Two CdII ions are connected by two benzene‐1,2‐dicarboxylate ligands to generate a binuclear [Cd2(1,2‐bdic)2] unit. The binuclear units are further connected into a one‐dimensional chain by pairs of bridging imb ligands. These one‐dimensional chains are further connected through N—H…O hydrogen bonds and π–π interactions, leading to a two‐dimensional layered structure. The dimethylformamide solvent molecules are organized in dimeric pairs via weak interactions. In addition, the title polymer exhibits good fluorescence properties in the solid state at room temperature. 相似文献
408.
《化学:亚洲杂志》2017,12(9):996-1004
A new series of benzimidazole ( BIm )‐based dyes ( SC32 and SC33 ) and pyridoimidazole‐( PIm ) based dyes ( SC35, SC36N and SC36 ) were synthesized as sensitizers for dye‐sensitized solar cells (DSSCs). The N‐substituent and C‐substituent at the BIm and PIm cores were found to be the dominating factor in determining the electronic properties of the dyes and their DSSCs performance. The efficiency of BIm ‐based dyes ( SC35 and SC36 ) was found to be higher than that of the PIm ‐based dyes ( SC32 and SC33 ) due to better light harvesting. The C‐substituents in SC36 , a 4‐hexylloxybenzene and a hexyl chain, are beneficial to dark current suppression, and hence SC36 achieves the best efficiency of 7.38 % (≈85 % of N719 ). The two BIm dyes have better cell efficiencies than their congeners with a bithiophene entity between the BIm and the anchor due to better light harvesting of the former. 相似文献
409.
《Arabian Journal of Chemistry》2022,15(1):103505
New benzimidazole analogues (1–18) were synthesized and characterized through different spectroscopic techniques such as 1H NMR, 13C NMR and HREI-MS. All analogues were screened for β-glucuronidase inhibitory potential. All analogues showed varied degree of inhibitory potentials with IC50 values ranging between 1.10 ± 0.10 to 39.60 ± 0.70 μM when compared with standard D-saccharic acid-1,4- lactone having IC50 value 48.30 μM. Analogues 17, 11, 9, 6, 1 and 13 having IC50 values 1.10 ± 0.10, 1.70 ± 0.10, 2.30 ± 0.10, 5.30 ± 0.20, 6.20 ± 0.20 and 8.10 ± 0.20 μM respectively, showed excellent β-glucuronidase inhibitory potential many folds better than the standard. All other analogues also showed good inhibitory potential better as compared to standard. Structure activity relationships (SAR) has been established for all compounds. The results from molecular docking studies supports the established SAR and developed a strong correlation with the results from in to vitro assay. The molecular docking results clearly highlighted how substituents like nitro and chloro affect the binding position of the active compounds in the active site. The docking results were also used to properly establish the effect of bulky substituents of least active compounds on reduced β-glucuronidase inhibitory activity. Compounds 1–18 were found non-toxic. 相似文献
410.