φ键

原子的f轨道恰当的对齐，重叠形成φ键

φ键由两个f轨道六重交叠而成，电子云以“面对面”的形式叠加，所形成的分子轨道称为φ轨道。由于δ键的存在，理论化学家推测会有由两个f轨道叠加形成的φ键。2005年化学家声称已发现φ键，存在于双铀分子（U₂）的铀-铀键^[1]。可是，其后从自旋轨道相互作用研究发现键级为4^[2]^[3]^[4]。截至2020年，人们仍未发现确认有φ键的分子。

另见

共价键
- σ键、π键、δ键

参考

^ Gagliardi, Laura; Roos, Björn O. Quantum chemical calculations show that the uranium molecule U2 has a quintuple bond. Nature. 2005, 433: 848–851 [2013-03-29]. Bibcode:2005Natur.433..848G. doi:10.1038/nature03249. （原始内容存档于2019-05-30）.
^ T. A. Manz. Introducing DDEC6 atomic population analysis: part 3. Comprehensive method to compute bond orders. RSC Adv. 2017, 7 (72): 45552–45581. Bibcode:2017RSCAd...745552M. doi:10.1039/c7ra07400j .
^ The diuranium molecule has a quadruple bond. chab.ethz.ch. [2020-03-21]. （原始内容存档于2020-03-21）（英语）.
^ Knecht, Stefan; Jensen, Hans Jørgen Aa; Saue, Trond. Relativistic quantum chemical calculations show that the uranium molecule U 2 has a quadruple bond. Nature Chemistry. January 2019, 11 (1): 40–44 [2022-04-21]. ISSN 1755-4349. PMID 30374039. S2CID 53112083. doi:10.1038/s41557-018-0158-9. （原始内容存档于2020-08-12）（英语）.

[1] Gagliardi, Laura; Roos, Björn O. Quantum chemical calculations show that the uranium molecule U2 has a quintuple bond. Nature. 2005, 433: 848–851 [2013-03-29]. Bibcode:2005Natur.433..848G. doi:10.1038/nature03249. （原始内容存档于2019-05-30）.

[Manz2017-2] T. A. Manz. Introducing DDEC6 atomic population analysis: part 3. Comprehensive method to compute bond orders. RSC Adv. 2017, 7 (72): 45552–45581. Bibcode:2017RSCAd...745552M. doi:10.1039/c7ra07400j .

[3] The diuranium molecule has a quadruple bond. chab.ethz.ch. [2020-03-21]. （原始内容存档于2020-03-21）（英语）.

[:0-4] Knecht, Stefan; Jensen, Hans Jørgen Aa; Saue, Trond. Relativistic quantum chemical calculations show that the uranium molecule U 2 has a quadruple bond. Nature Chemistry. January 2019, 11 (1): 40–44 [2022-04-21]. ISSN 1755-4349. PMID 30374039. S2CID 53112083. doi:10.1038/s41557-018-0158-9. （原始内容存档于2020-08-12）（英语）.

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