Aromatic and Aliphatic CH Hydrogen Bonds Fight for Chloride while Competing Alongside Ion Pairing within Triazolophanes
作者:Yuran Hua、Raghunath O. Ramabhadran、Esther O. Uduehi、Jonathan A. Karty、Krishnan Raghavachari、Amar H. Flood
DOI:10.1002/chem.201002340
日期:2011.1.3
Triazolophanes are used as the venue to compete an aliphatic propylene CH hydrogen‐bond donor against an aromatic phenylene one. Longer aliphatic CH⋅⋅⋅Cl− hydrogen bonds were calculated from the location of the chloride within the propylene‐based triazolophane. The gas‐phase energetics of chloride binding (ΔGbind, ΔHbind, ΔSbind) and the configurational entropy (ΔSconfig) were computed by taking all
三唑烷用作竞争脂肪族丙烯CH氢键供体与芳香亚苯基竞争的场所。更长的脂肪族的C ħ ⋅⋅⋅氯-氢键从的基于丙烯的triazolophane内氯化物的位置计算。通过考虑所有低能构象,计算出氯离子结合的气相能(ΔG结合,ΔH结合,ΔS结合)和构型熵(ΔS config)。从Δ结合降低所计算的气相自由能的亚苯基和基于丙烯的triazolophanes节目之间的比较ģ绑定= -194到-182千焦摩尔-1,分别与适度的焓-比熵的补偿。对这些差异进行了实验研究。的1 H NMR光谱对丙烯triazolophane的结构研究的1:1个的氯化物络合物是用较弱的丙烯CH氢键相一致。为了量化在二氯甲烷两个triazolophanes之间的亲和力的差异,这是至关重要的,以获得准确的结合模型。确定了四个平衡点。除了1:1个复合及2:1夹心形成,所述四丁基氯化铵盐(TBA的离子配对+ ⋅氯- )和阳离子配对的TBA