Preparation of an Organometallic Molecular Square by Self-Assembly of Phosphorus-Containing Building Blocks

Molecular squares are among the most common supramolecular architectures, but phospha‐organometallic complexes have not been used as building blocks for this type of structure. Herein we describe the formation of the molecular square [Au{Co(P2C2tBu2)2}]4 (1) by the self‐assembly of anionic 1,3‐diphosphacyclobutadiene cobalt complexes and gold(I) cations. The X‐ray crystallographic determination of the molecular structure of 1 is complemented by solid‐state 31P and 13C NMR investigations. High‐level DFT calculations confirm the assignment of the 31P and 13C NMR resonances. A square of gold: [Au{Co(P2C2tBu2)2}]4 is formed by the self‐assembly of gold(I) cations and anions comprising a cobalt center sandwiched by phosphorus‐containing moieties. X‐ray diffraction and NMR spectroscopy investigations confirm that the metal atoms form a C4 symmetrical arrangement. The results show the potential of phospha‐organometallic sandwich complexes as building blocks in supramolecular assemblies.