**Bruno Therrien**

Institute of Chemistry, University of Neuchatel, Avenue de Bellevaux 51, CH-2000 Neuchatel, Switzerland; bruno.therrien@unine.ch; Tel.: +41-32-718-2499

Received: 6 April 2020; Accepted: 18 May 2020; Published: 8 June 2020

**Abstract:** In Nature, metal ions play critical roles at different levels, and they are often found in proteins. Therefore, metal ions are naturally incorporated in hydrogen-bonded systems. In addition, the combination of metal coordination and hydrogen bonds have been used extensively to develop supramolecular materials. However, despite this win-win combination between coordination and hydrogen bonds in many supramolecular systems, the same combination remains scarce in the field of coordination-driven self-assemblies. Indeed, as illustrated in this mini-review, only a few discrete supramolecular metalla-assemblies combining coordination and hydrogen bonds can be found in the literature, but that figure might change rapidly.

**Keywords:** coordination chemistry; hydrogen bonds; supramolecular chemistry; metalla-assemblies; coordination-driven self-assembly; orthogonality; ligands; metal ions
