A Molecular Precursor to Phosphaethyne and Its Application in Synthesis of the Aromatic 1,2,3,4-Phosphatriazolate Anion
Dibenzo-7-phosphanorbornadiene Ph[subscript 3]PC(H)PA (1, A = C[subscript 14]H[subscript 10], anthracene) is reported here as a molecular precursor to phosphaethyne (HC≡P), produced together with anthracene and triphenylphosphine. HCP generated by thermolysis of 1 has been observed by molecular beam...
| Main Authors: | , , , , , , , , , , |
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| Other Authors: | |
| Format: | Article |
| Language: | en_US |
| Published: |
American Chemical Society (ACS)
2017
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| Online Access: | http://hdl.handle.net/1721.1/107727 https://orcid.org/0000-0001-7445-5663 https://orcid.org/0000-0002-9239-7505 https://orcid.org/0000-0002-3526-3797 https://orcid.org/0000-0002-7609-4205 https://orcid.org/0000-0003-2568-3269 |
| Summary: | Dibenzo-7-phosphanorbornadiene Ph[subscript 3]PC(H)PA (1, A = C[subscript 14]H[subscript 10], anthracene) is reported here as a molecular precursor to phosphaethyne (HC≡P), produced together with anthracene and triphenylphosphine. HCP generated by thermolysis of 1 has been observed by molecular beam mass spectrometry, laser-induced fluorescence, microwave spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy. In toluene, fragmentation of 1 has been found to proceed with activation parameters of ΔH[superscript ⧧] = 25.5 kcal/mol and ΔS[superscript ⧧] = −2.43 eu and is accompanied by formation of an orange insoluble precipitate. Results from computational studies of the mechanism of HCP generation are in good agreement with experimental data. This high-temperature method of HCP generation has pointed to new reaction chemistry with azide anion to produce the 1,2,3,4-phosphatriazolate anion, HCPN3–, for which structural data have been obtained in a single-crystal X-ray diffraction study. Negative-ion photoelectron spectroscopy has shown the adiabatic detachment energy for this anion to be 3.555(10) eV. The aromaticity of HCPN[subscript 3]– has been assessed using nucleus-independent chemical shift, quantum theory of atoms in molecules, and natural bond orbital methods. |
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