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The CH Activation/1,3‐Diyne Strategy: Highly Selective Direct Synthesis of Diverse Bisheterocycles by RhIII Catalysis 下载免费PDF全文
Dr. Da‐Gang Yu Francisco de Azambuja Tobias Gensch Dr. Constantin G. Daniliuc Prof. Dr. Frank Glorius 《Angewandte Chemie (International ed. in English)》2014,53(36):9650-9654
The reactivity and selectivity of 1,3‐diynes in transition‐metal‐catalyzed C? H activation is exploited to quickly assemble diverse polysubstituted bisheterocycles, which are highly important but difficult to access. By using the C? H activation/1,3‐diyne strategy, we overcame the challenges of selectivity (chemo‐, regio‐, and mono‐/diannulation) and constructed seven kinds of adjacent bisheterocycles through the formation of four strategic bonds with high efficiency and high selectivity. 相似文献
155.
Dr. Juri Möbus Dr. Anzhela Galstyan Andreas Feldmann Dr. Constantin G. Daniliuc Dr. Roland Fröhlich Dr. Cristian A. Strassert Dr. Gerald Kehr Prof. Dr. Gerhard Erker 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(37):11883-11893
In this study the scope of the 1,1‐carboboration reaction was extended to the preparation of mixed heterole‐based conjugated π‐systems. Two arylbis(alkynyl)phosphane starting materials 2 were synthesized bearing two thiophene isomers at the alkyne units and the bulky tipp‐substituent (tipp=2,4,6‐triisopropylphenyl) at the phosphorous atom. The bis(thienylethynyl)phosphanes 2 were converted into the corresponding 2,5‐thienyl‐substituted 3‐borylphospholes 4 in a double 1,1‐carboboration reaction sequence employing the strongly electrophilic B(C6F5)3 reagent under mild reaction conditions. Subsequent Suzuki–Miyaura type cross‐coupling yielded the corresponding 3‐phenylphospholes 7 in a one‐pot procedure from phosphanes 2 in high yields. Phospholes 7 were converted into the respective phosphole oxides 8 . A photophysical characterization of derivatives 7 and 8 was carried out. The results presented here demonstrate the suitability of the 1,1‐carboboration reaction for the preparation of phosphole‐/thiophene‐based, light‐emitting systems. 相似文献
156.
Fang Ge Dr. Gerald Kehr Dr. Constantin G. Daniliuc Prof. Dr. Gerhard Erker 《化学:亚洲杂志》2013,8(9):2227-2234
The bis(alkynyl)diisopropyl‐aminoboranes 7 were prepared by treatment of iPr2NBCl2 with two molar equivalents of 1‐pentynyl lithium or lithium phenylacetylenide, respectively. Their reaction with one molar equivalent of B(C6F5)3 resulted in the formation of the 1,1‐carboboration products 8 that were subsequently stabilized by adduct formation ( 9 ) with tert‐butyl isocyanide. Thermolysis of 8a (R=nPr) proceeded with hydride transfer from a N‐isopropyl substituent to the distal carbon atom of the remaining pentynyl unit at boron to give the zwitterionic five‐membered heterocyclic product 10a in good yield. The analogous product 10b (R=Ph) was obtained upon photolysis of 8b . The compounds 7b , 9b , 10a , and 10b were characterized by X‐ray crystal structure analysis. 相似文献
157.
The gauche conformation of the 1,2-difluoroethane motif is known to involve stabilising hyperconjugative interactions between donor (bonding, σC–H) and acceptor (antibonding, σ*C–F) orbitals. This model rationalises the generic conformational preference of F–Cβ–Cα–X systems (φFCCX ≈ 60°), where X is an electron deficient substituent containing a Period 2 atom. Little is known about the corresponding Period 3 systems, such as sulfur and phosphorus, where multiple oxidation states are possible. Conformational analyses of β-fluorosulfides, -sulfoxides and -sulfones are disclosed here, thus extending the scope of the fluorine gauche effect to the 3rd Period (F–C–C–S(O)n; φFCCS ≈ 60°). Synergy between experiment and computation has revealed that the gauche effect is only pronounced in structures bearing an electropositive vicinal sulfur atom (S+–O–, SO2). 相似文献
158.
René Liedtke Sabrina Surmiak Xiaoming Jie Constantin G. Daniliuc Gerald Kehr Gerhard Erker 《Helvetica chimica acta》2021,104(11):e2100149
1,2,4,5-Tetrakis(trimethylsilylethynyl)benzene reacted with two molar equivalents of the boranes R−B(C6F5)2 (R=C6F5, Me, Ph) in a series of sequential 1,1-carboboration reactions to give ca. 1 : 1 mixtures of the two-fold benzannulated products, namely the respective C2h and C2v symmetric tetra-silyl, bis-boryl substituted anthracenes. Their active B(C6F5)2 substituents were used for consecutive Suzuki-Miyaura C−C coupling reactions to give boron-free phenyl or 2-pyridyl substituted anthracene products. 相似文献
159.
Steffen Riebe Dr. Suliman Adam Dr. Bibhisan Roy Dr. Iván Maisuls Dr. Constantin G. Daniliuc Justin Dubbert Prof. Dr. Cristian A. Strassert Prof. Dr. Igor Schapiro Prof. Dr. Jens Voskuhl 《化学:亚洲杂志》2021,16(16):2307-2313
In this contribution, we report on a class of emitters based on bridged oxo- and/or thioethers revealing striking photoluminescence properties in fluid solution and in the solid state. In total, nine compounds were investigated concerning their photophysical properties, which were interpreted by quantum chemical calculations. To our delight, we discovered compounds possessing nearly identical photoluminescence quantum yields (ΦF) in solution and in the solid state, which has been rarely reported so far. Besides these efforts, we shed light on the influence of polymorphism and solvent polarity on the emission properties. In addition, an in-depth X-ray diffractometric analysis was conducted to correlate molecular packing in the crystal with differences in the photophysical properties. 相似文献
160.
采用逐步蔓延采样点和三角形的方法,给出了3个算法用于隐函数曲面的采样和三角化,这些算法使得隐函数曲面的重复绘制和控制都能实时进行,其采样方法具有局部适应性,能随着曲率的变化自动控制采样点的疏密程度,从而使得采样点尽量少,但又不至于遗漏表面细节,提出的三角化方法能用于其它散乱数据点的表面重构,它的算法复杂度仅为O(n)。 相似文献