A Molecular Precursor to Phosphaethyne and Its Application in Synthesis of the Aromatic 1,2,3,4-Phosphatriazolate Anion

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• 作者：Wesley J. Transue ; Alexandra Velian ; Matthew Nava ; Marie-Aline Martin-Drumel ; Caroline C. Womack ; Jun Jiang ; Gao-Lei Hou ; Xue-Bin Wang ; Michael C. McCarthy ; Robert W. Field ; Christopher C. Cummins
• 刊名：Journal of the American Chemical Society
• 出版年：2016
• 出版时间：June 1, 2016
• 年：2016
• 卷：138
• 期：21
• 页码：6731-6734
• 全文大小：313K
• 年卷期：0
• ISSN：1520-5126

文摘

Dibenzo-7-phosphanorbornadiene Ph₃PC(H)PA (1, A = C₁₄H₁₀, 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^⧧ = 25.5 kcal/mol and ΔS^⧧ = −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 HCPN₃^– has been assessed using nucleus-independent chemical shift, quantum theory of atoms in molecules, and natural bond orbital methods.