A new access to the cyaphido (C≡Pˉ) and cyarsido (C≡Asˉ) ligand: Photochemical generation, characterization and follow-up chemistry of LnM-C≡P and LnM-C≡As complexes

• Applicant: Professor Dr. Christian Müller
• Subject Area: Inorganic Molecular Chemistry - Synthesis and Characterisation
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 452119696

In this continuation proposal, the previously very successful project on the chemistry of the cyaphido ligand is to be continued. Although important progress has been made recently in the synthesis, coordination chemistry and reactivity studies of the cyaphide (C≡P−) ion, the chemistry of this species, which is valence isoelectronic to the cyanide (C≡N−) ion, still remains poorly developed. The generation of the cyanide ion and its coordination compounds is synthetically challenging, since classical MCP (and also the heavy homologous MCAs) salts (M = alkali metal) are unknown. Our research group has recently developed two new approaches to cyaphido complexes. These are based i) on photochemical selective C-C bond activation in L2Pt(0)-η2(aryl-C≡P) complexes and ii) in the reaction of transition metal fluorides with Me3Si-C≡P. In the course of the first funding phase, it became apparent that many of the originally postulated ideas and concepts for the synthesis and subsequent chemistry of the cyaphido ligand could be implemented very successfully. The diversity of the results promises a very multifaceted chemistry in the second phase as well, whereby here, in addition to further research into the fundamental properties of the cyaphido ligand, the chemistry of the cyarsido ligand (C≡As−) as well as the chemistry of H-C≡P and H-C≡As in particular will be focused on. Main aspects of the second phase are: i) new approaches to cyaphido and cyarsido complexes and subsequent chemistry; ii) the chemistry of H-C≡P and H-C≡As; iii) generation of cyaphide salts; iv) bimetallic complexes with bridging cyaphido or cyarsido ligands; v) catalytic reactions with phosphaalkyne and arsaalkyne complexes; vi) establishment of a synthesis reactor on sustainability aspects in phosphorus and arsenic organic chemistry. The previous results and preliminary work from the first funding period promise a successful implementation of the planned extensive studies also in the second project phase.

• DFG Programme: Research Grants