Dipole-bound and dispersion-bound anions supported by the asymmetric tautomers of aminophosphine: H3NPH and HNPH3 Original Research Article

The binding of an excess electron to the ylides H3NPH and HNPH3 was studied at the coupled cluster level of theory with single, double, and non-iterative triple excitations and with extended basis sets to accommodate the loosely bound excess electron. It was found that these asymmetric tautomers of aminophosphine bind an excess electron to form stable anions. The vertical electron detachment energies corresponding to the H3NPH and HNPH3 forms were calculated to be 1816 and 32 cm−1, respectively. It was found that while the H3NPH tautomer forms a typical dipole-bound anion, the electron binding energy for the HNPH3 tautomer calculated at the electrostatic Koopmansʹ theorem level is cancelled when the correlation correction to the dipole moment of the neutral is taken into account at the MP2 level. Therefore, we consider the (HNPH3) anion as dispersion-bound since its stability is caused only by additional electron correlation effects, which are dominated by dispersion interaction.