An MP2/6-311++G(3df,3pd) computational study of a series of hydrogen-bonded complexes X₃CH...YZ (X = Cl, F, CN; YZ = FLi, BF, CO, N₂) was undertaken to assess the trends in the relative stability and other molecular properties with variation of both the X group and the chemical hardness of the Y atom of YZ. The red- and blue-shifting propensities of the proton donor X₃CH were investigated by considering the C-H bond length change and its associated vibrational frequency shift. The proton donor Cl₃CH, which has a positive dipole moment derivative with respect to C-H bond extension, tends to form red-shifted complexes, this tendency being modified by the hardness (and dipole moment) associated with the proton acceptor. On the other hand, F₃CH has a negative dipole moment derivative and tends to form blue-shifted complexes, suggesting that as X becomes more electron-withdrawing, the proton donor should have a negative dipole moment derivative and form blue-shifted complexes. Surprisingly, the most polar proton donor (NC)₃CH was found to have a positive dipole moment derivative and produces red-shifted complexes. A perturbative model was found useful in rationalizing the trends for the C-H bond length change and associated frequency shift.

一系列氢键配合物X ₃ CH ... YZ（X = Cl，F，CN; YZ = FLi，BF，CO，N ₂的MP2 / 6-311 ++ G（3df，3pd）计算研究）的目的是评估相对稳定性和其他分子特性随X基团和YZ Y原子化学硬度的变化而变化的趋势。通过考虑CH键长度的变化及其相关的振动频率偏移，研究了质子供体X ₃ CH的红移和蓝移倾向。质子供体Cl ₃CH相对于CH键的延伸具有正的偶极矩导数，它趋于形成红移复合物，这种趋势会因与质子受体相关的硬度（和偶极矩）而改变。另一方面，F ₃ CH具有负的偶极矩导数并趋于形成蓝移配合物，这表明随着X的吸电子性增加，质子供体应具有负的偶极矩导数并形成蓝移配合物。出乎意料的是，发现极性最大的质子供体（NC）₃ CH具有正偶极矩导数并产生红移复合物。发现扰动模型可用于合理化CH键长度变化和相关频移的趋势。