Abstract
Quantum chemical calculations using density functional theory BP86 and M06-2X functionals in conjunction with def2-TZVPP basis sets have been carried out on the title molecules. The calculation results reveal that the N-imides R 3 NNX are always clearly higher in energy than the imine isomers R 2 NN(X)R. In the case of phosphane imides R 3 PNX and the isomers R 2 PN(X)R, the substituent R plays a critical role in determining their relative stabilities. When R is hydrogen or phenyl group, R 3 PNX are always higher in energy than R 2 PN(X)R but the former are more stable than the latter when R = Cl. Interestingly, the Me 3 PNX and Me 2 PN(X)Me are quite close in energy. The energy decomposition analysis suggests that the P–N bond in the phosphane imides R 3 PNX (R = H, Cl, Me, Ph; X = H, F, Cl) should be described in terms of an electron-sharing single bond between two charged fragments R 3 P + -NX − that is supported by (R 3 P) + ←(NX) − π-backdonation. The π-bond contributes 14–21% of the total orbital interactions while the σ-bond provides 60–68% of ΔE orb .
Original language | English |
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Pages (from-to) | 1306-1314 |
Number of pages | 9 |
Journal | Molecular Physics |
Volume | 117 |
Issue number | 9-12 |
DOIs | |
State | Published - 18 Jun 2019 |
Keywords
- Chemical bond
- DFT
- N-imides
- energy decomposition analysis
- phosphane imides