A molecule containing a stable carbon atom with all four bonds directed toward the same side of the nucleus

The molecule H@C20H19 containing one stable carbon atom with all four single bonds directed toward the same side of the nucleus is reported here. Its geometry, electronic properties, vibrational frequencies and heat of formation have been calculated at the B3LYP/6-311+G(d,p) level of theory. The vibrational bands in the IR intensity of them have been discussed to be compared with future experimental identification. At the B3LYP/6-311+G(d,p) level, the heat of formation has been calculated using isodesmic reaction, 74.2 kcal mol−1, larger than that of dodecahedrane, but smaller than that of the cubane C8H8. Thus we believe that H@C20H19 has sufficient stability to allow its experimental preparation.