Charge Density Distribution in the “Proton Sponge” Compound 1,8-Bis(dimethylamino)naphthalene
Charge Density Distribution in the “Proton Sponge” Compound 1,8-Bis(dimethylamino)naphthalene
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“质子海绵”化合物 1,8-双（二甲氨基）萘中的电荷密度分布
DOI：
10.1021/ja983393z
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发表时间：
1999
影响因子：
15
通讯作者：
and Dmitrii S. Yufit
中科院分区：
文献类型：
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作者：
P. Mallinson;K. Woźniak;Chick C. Wilson;A. McCormack;and Dmitrii S. Yufit
这是第一个低温，高分辨率的X射线和中子衍射研究电荷分布在一个未络合的质子海绵化合物。在这类母体化合物1，8-双（二甲氨基）萘（DMAN）中，萘部分的小程度不对称性是由弱的不对称分子间相互作用引起的。这种不对称性的唯一表现是在电荷分布的拉普拉斯水平上。将DMAN分子与其阳离子进行比较，可以看出质子化的结果，例如C−C缩短，C（ar）−H和C−N键长延长。这些变化在CP性质中甚至更明显，阳离子中的平均ρB比中性分子中的小。CP与结构参数ρB与Laplacian、Laplacian与键长以及ρB与键长的关系取决于键的类型，并且对于DMAN及其阳离子是不同的。与从头计算值的比较揭示了一些系统的差异。只有两个CR…
This is the first low-temperature, high-resolution X-ray and neutron diffraction study of charge distribution in an uncomplexed proton sponge compound. In the parent compound of this class, 1,8-bis(dimethylamino)naphthalene (DMAN), a small degree of asymmetry of the naphthalene moiety is induced by weak, asymmetric intermolecular interactions. The only manifestation of this asymmetry is at the level of the Laplacian of the charge distribution. Comparing the DMAN molecule with its cation shows the consequences of protonation, such as shortening of the C−C, and lengthening of the C(ar)−H and C−N bond lengths. These changes are even more apparent in CP properties, with ρb on average smaller in the cation than in the neutral molecule. Relationships between CP and structural parameters viz. ρb vs Laplacian, Laplacian vs bond length, and ρb vs bond length depend on bond type, and are different for DMAN and its cation. Comparison with ab initio calculated values reveals some systematic discrepancies. Only two cr...