Exceptionally large “through-space” nuclear spin coupling in a 2,4,6-tri(phosphanyl)–1,3,5-triphosphabenzene

Journal article

We describe the synthesis of a phosphanyl-functionalized 1,3,5-triphosphabenzene that exhibits remarkably large indirect spin–spin coupling (432 Hz) between phosphorus-31 nuclei. The magnitude of this coupling interaction is indicative of highly effective orbital overlap between two lone-pair type orbitals, each of which possesses significant s-orbital character. This was probed computationally using density functional theory calculations in order to deconvolute individual transmission pathways by dividing these into “through-space” and “through-bond” type interactions. The “through-space” transmission pathway can be chemically disrupted by oxidation of the pendant phosphanyl groups using either elemental sulfur or selenium. By engaging the phosphanyl s-orbitals in bonds to the chalcogen elements, the indirect interaction is perturbed, and the NMR spectra of the resulting compounds exhibit conventional “through-bond” coupling.

Authors: Meier, DC; García-Romero, Á; González-Pinardo, D; Rees, NH; Lovstedt, A

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Royal Society of Chemistry
• Journal: Chemical Science
• Publication date: 2025-11-04
• Acceptance date: 2025-10-31
• DOI: 10.1039/d5sc07729j
• EISSN: 2041-6539
• ISSN: 2041-6520
• Language: English