Analysis and calculation of the ³¹P and ¹⁹F NMR spectra of hexafluorocyclotriphosphazene

Abstract

The higher order high-resolution (31)P and (19)F NMR spectra of hexafluorocyclotriphosphazene (F(2)PN)(3) were measured at 183 K and interpreted using subspectral analysis and iterative fitting computation. (F(2)PN)(3) forms a rigid nine-spin system [A[X](2)](3) with D(3h) symmetry. Two complete and very similar sets of six experimental spin-spin coupling constants, (1)J(P,F), (2)J(P,P), (2)J(F,F), (3)J(P,F), (4)J(F,F)(cis) and (4)J(F,F)(trans), were determined for the first time. Theoretical DFT calculations of chemical shifts and coupling constants were performed to assess their predictive value. The PP/aug-cc-pVDZ treatment rendered the best agreement with experimental data.

Computational 19F NMR. 1. General features

“…Some early computational work (aimed at benchmarking and validation) included F 2 as test molecule, which proved to be challenging [26][27][28]. Interest in modeling 19 F shifts has steadily continued, and several papers have appeared in the last decade aimed at general structural issues, solution chemistry and physical organic chemistry, [29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46] solid-state issues (especially the prediction of chemical shift tensors), [47][48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64] J-couplings [65][66][67][68][69][70][71][72]…”

Theoretical study of some λ5‐phosphinines and their NMR spectra

“…----−342.7 193.1 9 P(2,4,6) 9.3, [33] 2.8, [34] 10.16, [35] 10.58, [36] 13.9, [37] ----286.8 N(1,3,5) −314.5 [33] −310.5 154.2 F −70.12, [33] −68.86, [35] −71.9 [37] −64.3 221.8 10 P(2,4,6) 20.0 [33] ----286.7 N(1,3,5) −258.8 [33] −256.1 83.7…”

Comprehensive Mechanistic Analysis of the Ring-Opening Polymerization of [PCl2N]3 Using Quantum Mechanical Calculations

“…Previous computational efforts have primarily focused on analyzing the experimentally proven products in Scheme , , assuming the validity of the proposed S N 1 mechanism. Although computational analysis of the discrete polymer, cyclic compounds, and monomer has been performed, ,,− , the role of [PCl 2 N] 3 in the ROP and RR equilibrium polymerization has never been systematically addressed using QM calculation methods. Here, we investigate the ROP mechanism starting with two and three [PCl 2 N] 3 rings by systematically mapping reaction pathways on the potential energy surface (PES), without assuming a predetermined mechanism.…”