We have applied the CCSD(T)-F12a/cc-pVTZ-F12//CCSD(T)/cc-pVTZ level of theory to calculate energies for 22 reactions pertinent to the stability and reactivity of hardly isolable cyanoform (HC(CN)3). A number of exothermic processes has been indicated, especially the hydration. In the predicted mechanism for the gas-phase hydration of cyanoform, the H2O addition to the C≡N bond corresponds to a rate-limiting step, which is aided by an extra molecule of water. Also, for the cyanoform dihydrate (H2NC(OH)C(CN)CONH2) product, the experimentally identified compound, the more stable planar isomer exhibits intramolecular O-HO=C (not N-HO=C) H-bonding. Our calculated structures, binding energies, and NBO data for [HC(CN)3]n (n=2,4) clusters suggest that the non-conventional C-H…N H-bonds contribute to their stability. Among the surveyed structures of the C≡N group incorporating products of reactions examined, the CCSD(T)/cc-pVTZ molecular parameters of cyanocarbons C2(CN)4, C2(CN)6, and C6(CN)6 can be regarded as the most accurate gas-phase values up-to-date.

中文翻译：

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难以捉摸的氰基甲烷：使用精确的从头算方法对它的稳定性和反应性进行计算性探索。

我们已应用CCSD（T）-F12a / cc-pVTZ-F12 // CCSD（T）/ cc-pVTZ的理论水平来计算22种反应的能量，这些反应与难分离的氰基（HC（CN））的稳定性和反应性有关3）。已经表明了许多放热过程，特别是水合作用。在预期的氰基气相水合机理中，C 2 N键中的H2O加成相当于一个限速步骤，该步骤由多余的水分子辅助。同样，对于氰基二水合物（H2NC（OH）C（CN）CONH2）产物，经实验鉴定的化合物，更稳定的平面异构体表现出分子内OHO= C（不是NHO= C）H-粘接。我们为[HC（CN）3] n（n = 2,4）团簇计算的结构，结合能和NBO数据表明，非常规CH…N H键有助于其稳定性。