我们合成了包含两种的水溶性分子夹AC蒽 通过半刚性脂族单元连接到侧壁的侧壁 苯 承载两个的桥 硫酸钠取代基。为了比较,已经合成了具有萘而不是蒽侧壁的类似夹具NC。在甲醇溶液中,两个夹子都以单体形式存在,而在水溶液中,蒽夹子AC自组装以提供高度稳定的二聚体,log K dim = 5.1(对于萘夹子NC,log K dim = 2.5)。二聚体的1 H NMR光谱证明了两个相互交织的垂直夹分子的相互作用。非缔合的夹子AC表现出蒽发色单元典型的非常强的蓝色荧光。(AC)2二聚体具有更宽的吸收光谱和更弱的红移发射带。除此之外乙酰胆碱导致二聚体(AC)2的破坏和单体夹子AC典型的非常强的荧光的复兴。两个剪辑都与烟酰胺 腺嘌呤二核苷酸(NAD +)在pH = 7.2的缓冲水溶液中。阿1 H NMR分析表明,该萘剪辑NC形成1:1的复合物与NAD +包括夹子腔内辅因子的活性位点。在甲醇,在AC和附
observed in the UV/vis spectra of the clip quinones 2, 3, and 1 and the "half-clip" quinones 4, 5, and 6 with an increasing number of rings in the anellated aromatic unit (from benzene to anthracene) is the result of an increasing configuration interactionbetween a n --> pi* excitation of the quinoid component and a pi --> pi* excitation with intramolecular charge transfer (CT) character. The initial
experiments at various temperatures the self-assembly of 2a and 4a and their strong binding to NMNA 8 observed in aqueous solution are enthalpy driven (DeltaH << 0); the enthalpic drivingforce is partially compensated by an unfavorable entropy (TDeltaS < 0). Self-assembly and the host-guest binding are therefore beautiful examples of the nonclassical hydrophobiceffect.
provide attractive pi-pi interactions between the aromatic guest molecule and the two anthracene sidewalls in the complex. The compression and expansion of aromatic sidewalls are calculated by molecular mechanics to be low-energy processes, so the energy required for compression of the anthracene sidewalls during complex formation is apparently overcompensated by the gain in energy resulting from the attractive
inside the clip cavity. In methanol, formation of a stable 1 : 1 adduct between AC and a fluorescent first-generation dendrimer containing four dansyl groups appended to a 1,4-diaminobutane core is driven by acid addition. In such adduct, a very efficient energy transfer takes place from the excited anthracene units of the clip to the dansyl chromophores of the dendrimer. The adduct can be reversibly disassembled
我们合成了包含两种的水溶性分子夹AC蒽 通过半刚性脂族单元连接到侧壁的侧壁 苯 承载两个的桥 硫酸钠取代基。为了比较,已经合成了具有萘而不是蒽侧壁的类似夹具NC。在甲醇溶液中,两个夹子都以单体形式存在,而在水溶液中,蒽夹子AC自组装以提供高度稳定的二聚体,log K dim = 5.1(对于萘夹子NC,log K dim = 2.5)。二聚体的1 H NMR光谱证明了两个相互交织的垂直夹分子的相互作用。非缔合的夹子AC表现出蒽发色单元典型的非常强的蓝色荧光。(AC)2二聚体具有更宽的吸收光谱和更弱的红移发射带。除此之外乙酰胆碱导致二聚体(AC)2的破坏和单体夹子AC典型的非常强的荧光的复兴。两个剪辑都与烟酰胺 腺嘌呤二核苷酸(NAD +)在pH = 7.2的缓冲水溶液中。阿1 H NMR分析表明,该萘剪辑NC形成1:1的复合物与NAD +包括夹子腔内辅因子的活性位点。在甲醇,在AC和附