title: P3F9(2-): an all-pseudo-π* 2π-aromatic.
abstract: A qualitative MO analysis suggests (PH3)3(2-) as a candidate for an all-pseudo-π* 2π-aromatic; however computational studies rule out its existence. Fluorine substitution which increases the contribution of p orbitals on P in the pseudo-π* MO makes (PF3)3(2-) a minimum and an aromatic. The 2π aromaticity arising from the bonding combination of the three pseudo-π* fragment MOs is comparable to that in C3O3(2-) and is another example for the analogy between CO and PF3. The dianion (PF3)3(2-) forms the first example of a three-membered ring with all the vertices constituted by pentacoordinate phosphorus. The ability of PF3 to form the all-pseudo-π* 2π-aromatic system is not shared by the heavier analogues, AsF3 and SbF3.
authors.affiliation: School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram , CET Campus, Thiruvananthapuram, 695 016, Kerala, India.
authors.forename: Chakkingal P
authors.initials: CP
authors.lastname: Priyakumari
authors.forename: Eluvathingal D
authors.initials: ED
authors.lastname: Jemmis