Bernès Sylvain, Hernández Guadalupe, Vázquez Jaime, Tovar Alejandra, Gutiérrez René
Acta Crystallogr Sect E Struct Rep Online. 2011 May 1;67(Pt 5):o1257. doi: 10.1107/S1600536811012980. Epub 2011 Apr 29.
In the title chiral aldimine, C(19)H(17)N, the azomethine group is not fully conjugated with the phenyl substituent: the dihedral angle between phenyl and C()-N=C mean planes is ϕ(3) = 23.0 (2)°. Compared with the earlier DFT-B3LYP/6-31 G(d) computations from the literature, the C=N-C()-C(naph-thyl) torsion angle, found at ϕ(2) = -118.0 (2)° in the X-ray structure, does not match the angle calculated for the potential minimum energy at ϕ(2) = 0°. However, this angle is close to the second potential energy minimum at ϕ(2) = -120° which is ca. 8.5 kJ mol(-1) above the global energy minimum. Thus, the reported X-ray structure corresponds to the second most likely (according to DFT) conformer, allowing the existence of other polymorphs to be anti-cipated.
在手性醛亚胺C(19)H(17)N的标题中,偶氮甲碱基团与苯基取代基并非完全共轭:苯基与C()-N=C平均平面之间的二面角为ϕ(3)=23.0 (2)°。与文献中早期的DFT-B3LYP/6-31 G(d)计算结果相比,在X射线结构中发现的C=N-C()-C(萘基)扭转角为ϕ(2)= -118.0 (2)°,与在ϕ(2)=0°时计算得到的势能最小值角度不匹配。然而,该角度接近在ϕ(2)= -120°时的第二个势能最小值,此值比全局能量最小值高约8.5 kJ mol(-1)。因此,所报道的X射线结构对应于第二最可能(根据DFT)的构象异构体,这使得可以预期存在其他多晶型物。