Quantum-Theoretical Study on the Bond Angle for a Single Bond between Carbon Atoms

Bond energies and bond lengths of the single, double, and triple bonds between carbon atoms were studied with nonempirical calculations by one of the authors with the scheme of the electronic configurations of fictitious diatomic molecules; ≡C–C≡, –C–C–, and –C≡C–, where open bonds of the atoms were treated as suitably hybridized orbitals taking into account all possible spins. This treatment is examined for the bond angle of a single bond between carbon atoms. The result shows that the tetrahedrally hybridized bonding is the most stable.