Negative ion photoelectron spectroscopy of P₂N₃⁻: electron affinity and electronic structures of P₂N₃˙

Abstract

The newly synthesized P2N3–, a planar all-inorganic aromatic molecule is investigated by negative ion photoelectron spectroscopy and high-level ab initio electronic structure calculations.

A Joint Experimental and Computational Study of the Negative Ion Photoelectron Spectroscopy of the 1-Phospha-2,3,4-triazolate Anion, HCPN3–

“…However, the 266 nm spectrum still contains at least six closely spaced peaks. As in our recent NIPES study of P 2 N 3 − , 20 these closely spaced peaks suggest that this region of the spectrum may contain transitions to more than one state of the HCPN 3…”

“…19 The IE of (CH) 2 20 Comparisons of the (CH) 2 N 3 anion and radical with the previously studied (CH) 4 N 21 and (CH) 3 N 2 22,23 species found that substitution of each CH group in C 5 H 5 −/• by an isoelectronic N atom has a significant effect on the chemistry and thermodynamic properties, such as the C−H bond dissociation energies and gas-phase acidities, of these three nitrogen-containing analogues of C 5 24 This anion can be viewed as the n = 1 member of the series, (CH) 2-n P n N 3 − (n = 0−2). Nucleus-independent chemical shift (NICS) and quantum theory of atoms in molecules (QTAIM) calculations showed that HCPN 3 − is aromatic, with its aromaticity being intermediate between that of the n = 0 [(CH) 2 N 3 − ] and the n = 2 (P 2 N 3 − ) members of this series.…”

Pentapnictogen heterocyclic monoanions: Structure, stability, and aromaticity

“…Most of them adopt configuration I except that P 3 N 2 − , As 3 N 2 − , P 2 N 3 − , Bi 3 Sb 2 − , and Bi 2 Sb 3 − favor the alternative configuration II (Scheme , Figure ). The optimized singlet structure of P 2 N 3 − ( I ) is consistent with that in the single‐crystal [Na‐kryptofix‐221] [P 2 N 3 ] salt and DFT results . However, it is 19.5 kcal/mol higher in energy than the singlet isomer II (Table S2), suggesting that the latter is thermodynamically more favorable as an isolated cluster.…”

“…DFT has been widely used in recent works to study the structures, energies, and aromaticities of several pentapnictogen ring anions, yielding rather reasonable results comparable with the expensive coupled‐cluster calculations . It is thus the best choice of theory for current work because there is a large number of ring systems to compute (vide infra).…”

“…In 2015, P 2 N 3 − was successfully prepared by mixing P 2 (C 14 H 10 ) 2 with excess [ n Bu 4 N][N 3 ] in tetrahydrofuran solution and structurally characterized in its salt form . Its high aromaticity and stability were confirmed by the calculations and observed large adiabatic detachment energy . Recently, Mandal et al selectively investigated eight all‐pnictogen heterocyclic anions (ie, P 2 N 3 − , As 2 P 3 − , Sb 2 As 3 − , Bi 2 Sb 3 − , P 3 N 2 − , As 3 P 2 − , Sb 3 As 2 − , and Bi 3 Sb 2 − ) by means of density functional theory (DFT) calculations and demonstrated their stability and aromaticity .…”