RSC Award lecture: From Chemical Curiosities to Versatile Reagents: Heavy Analogues of the Cyanate Ion

The 2-phosphaethynolate anion (PCO−; the phosphorus-containing analogue of cyanate) was first isolated by Becker and co-workers as a lithium salt in 1992.[1] Due to difficulties associated with its manipulation, the chemistry of this remarkable species laid dormant for decades. The report of a high yielding, multi-gram synthesis of [Na(dioxane)x][PCO] in 2014 rekindled the interest in this fundamental ion.[2] Since then, the reactivity of PCO− and its use in decarbonylative and deoxygenative processes has been extensively explored.[3]

Following Becker’s original report on the isolation of PCO–, heavier analogues have also become synthetically accessible (PnCCh− where Pn = P, As; Ch = O, S, Se).[4, 5] These ions are rare insomuch as they contain highly reactive pnictogen–carbon multiple bonds, yet can be manipulated with ease due to their negative charges, which preclude common decomposition pathways (e.g. oligomerization), associated with neutral valence-isoelectronic species. This talk will survey recent studies on this family of anions paying particular attention to their structure and bonding and their use in the synthesis of novel molecular compounds, clusters and materials.

References:
[1] G. Becker, W. Schwarz, N. Seidler, M. Westerhausen, Z. Anorg. Allg. Chem. 1992, 612, 72–82.
[2] D. Heift, Z. Benkő, H. Grützmacher, Dalton Trans. 2014, 43, 831–840.
[3] J. M. Goicoechea, H. Grützmacher, Angew. Chem. Int. Ed. 2018, 57, 16968–16994.
[4] A. Hinz, J. M. Goicoechea, Angew. Chem. Int. Ed. 2016, 55, 8536–8541.
[5] F. Tambornino, A. Hinz; R. Köppe, J. M. Goicoechea Angew. Chem. Int. Ed. 2018, 57, 8230−8234.