Ligands in which multiple metal-binding domains are linked by a metal-containing moiety rather than a conventional organic group are described as “expanded ligands”. The use of 4, 4′-difunctionalised {Ru (tpy) 2} units provides a linear spacer between metal-binding domains and we have extended this motif to expanded ligands containing two carboxylic acid metal-binding domains. In this paper, we describe the synthesis and structural ...