Is high electric field capable of selectively inducing a covalent-like bond between polar and non-polar molecular species?

摘要

It is demonstrated through the present ab initio theoretical investigation that an external electric field can bring about a phenomenal enhancement in the strength of the bond between water and carbon-dioxide molecules from a van der Waals type (binding energy ~0.085 eV), to strong covalent type (binding energy ~7.45 eV), resulting in an exotic molecular complex. The onset of this effect is characterized by an abrupt change in the dipole moment of the composite system at a particular field-value, concomitant with the O–C=O ? O=C–O resonance in the CO2 moiety of the complex. This field-induced bond formation is further confirmed by the emergence of a characteristic intermolecular stretching mode (~317 cm?1) in the vibrational response of the system. This exotic bond that exhibits a covalent-like character, which accompanied by a charge-transfer, renders the carbon atom a substantial negative charge.