Geometry and Spectral Properties of the Protonated Homodinner of Pyridine in the Liquid and Solid States. A Combined NMR, X-ray Diffraction and Inelastic Neutron Scattering Study
Geometry and Spectral Properties of the Protonated Homodinner of Pyridine in the Liquid and Solid States. A Combined NMR, X-ray Diffraction and Inelastic Neutron Scattering Study
复制标题
DOI：
10.1021/jp203543g
复制
发表时间：
2011-07-14
影响因子：
2.9
通讯作者：
Shenderovich, I. G.
中科院分区：
文献类型：
--
作者：
Kong, S.;Borissova, A. O.;Shenderovich, I. G.
已在低至 120 K 的 CDF3/CDClF2 溶液中和单晶中研究了吡啶与配位性差的阴离子复合物中质子化同二体的结构和光谱特征。在两个相中，氢键都是不对称的。在该溶液中，质子参与快速可逆转移，从而确定 NMR 信号的多重性以及 -0.95 ppm 的主要 H/D 同位素效应的符号。质子在 21.73 ppm 处共振，该值高于过去报道的任何值，并且表明氢键非常短。结合X射线衍射分析和模型计算，定义晶体中质子的位置为d(N-H)=1.123埃和d(H中心点中心点中心点N)=1.532埃。使用 N-15 NMR 相关性估计了相同的距离。质子面外弯曲模式的频率为822 cm(-1)，与Novak 的相关性一致。
The structure and spectral signatures of the protonated homodirner of pyridine in its complex with a poorly coordinating anion have been studied in solution in CDF3/CDClF2 down to 120 K and in a single crystal. In both phases, the hydrogen bond is asymmetric. In the solution, the proton is involved in a fast reversible transfer that determines the multiplicity of NMR signals and the sign of the primary H/D isotope effect of -0.95 ppm. The proton resonates at 21.73 ppm that is above any value reported in the past and is indicative of a very short hydrogen bond. By combining X-ray diffraction analysis With model computations, the position of the proton in the crystal has,been defined as d(N-H) = 1.123 angstrom and d(H center dot center dot center dot N) = 1.532 angstrom. The same distances have been estimated using a N-15 NMR correlation. The frequency of the protonic out-of-plane bending mode is 822 cm(-1) in agreement with Novak's correlation.