A traditionally good chelating motif has been incorporated into a ligand for the synthesis of coordination polymers with vacant amine sites. A novel tetracarboxylic acid diamine ligand, isolated as N,N,N′,N′-tetra(4-carboxybenzyl)-1,3-diaminopropane dihydrochloride trihydrate (H6L1)Cl2·3H2O, has been prepared, structurally characterised, and subsequently used in the formation of three new coordination polymers. Poly-[Cu2(L1)(OH2)2]·6DMF·3H2O 1 consists of (4,4) sheets formed by each L1 ligand coordinating to four copper(ii) 'paddlewheel' dinuclear clusters. The amines of the ligand are non-coordinating. After solvent exchange and evacuation, 1 was found to adsorb approximately 23 cm3(STP) g-1 of CO2 at atmospheric pressure at 273 K. The isostructural compounds poly-[Zn(H2L1)(OH2)]·DMF·4H2O and poly-[Cd(H2L1)(OH2)]·DMF·3H2O 2Zn/2Cd are self-penetrating (10,3) coordination polymers containing square-shaped one-dimensional solvent channels. After solvent exchange it was found that 2Zn and 2Cd lost crystallinity, which accounts for the low N2 and CO2 uptakes observed.