title: From a Phosphaketenyl-Functionalized Germylene to 1,3-Digerma-2,4-diphosphacyclobutadiene.
abstract: The first 4π-electron resonance-stabilized 1,3-digerma-2,4-diphosphacyclobutadiene [L(H)2Ge2P2] 4 (L(H)=CH[CHNDipp]2 Dipp=2,6-(i)Pr2C6H3) with four-coordinate germanium supported by a β-diketiminate ligand and two-coordinate phosphorus atoms has been synthesized from the unprecedented phosphaketenyl-functionalized N-heterocyclic germylene [L(H)Ge-P=C=O] 2 a prepared by salt-metathesis reaction of sodium phosphaethynolate (P≡C-ONa) with the corresponding chlorogermylene [L(H)GeCl] 1 a. Under UV/Vis light irradiation at ambient temperature, release of CO from the P=C=O group of 2 a leads to the elusive germanium-phosphorus triply bonded species [L(H)Ge≡P] 3 a, which dimerizes spontaneously to yield black crystals of 4 as isolable product in 67% yield. Notably, release of CO from the bulkier substituted [L(tBu)Ge-P=C=O] 2 b (L(tBu)=CH[C((t)Bu)N-Dipp]2 ) furnishes, under concomitant extrusion of the diimine [Dipp-NC((t)Bu)]2, the bis-N,P-heterocyclic germylene [DippNC((t)Bu)C(H)PGe]2 5.
authors.affiliation: Department of Chemistry: Metalorganics and Inorganic Materials, Technische Universität Berlin, Strasse des 17. Juni 135, Sekr. C2, 10623, Berlin, Germany.
authors.forename: Shenglai
authors.initials: S
authors.lastname: Yao
authors.affiliation: Department of Chemistry: Metalorganics and Inorganic Materials, Technische Universität Berlin, Strasse des 17. Juni 135, Sekr. C2, 10623, Berlin, Germany.
authors.forename: Yun
authors.initials: Y
authors.lastname: Xiong
authors.affiliation: Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Szent Gellért tér 4, 1111, Budapest, Hungary.
authors.forename: Tibor
authors.initials: T
authors.lastname: Szilvási
authors.affiliation: Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog Weg 1, Hönggerberg, 8093, Zürich.
authors.forename: Hansjörg
authors.initials: H
authors.lastname: Grützmacher
authors.affiliation: Department of Chemistry: Metalorganics and Inorganic Materials, Technische Universität Berlin, Strasse des 17. Juni 135, Sekr. C2, 10623, Berlin, Germany. matthias.driess@tu-berlin.de.
authors.forename: Matthias
authors.identifier: http://orcid.org/0000-0002-9873-4103
authors.initials: M
authors.lastname: Driess
keywords: germylenes; main-group chemistry; multiple bonds; phosphagermyne; β-diketiminates