Hydrothermal reactions of benzene-1,3,5-triyltris(methylene)triphosphonic acid (H 6 L 1 ) or (2,4,6-trimethylbenzene-1,3,5-triyl)tris(methylene)triphosphonic acid (H 6 L 2 ) with metal sulfates, 4,49-bipyridyl (4,49-bipy), 2,29-bipyridyl (2,29-bipy), 1,10-phenanthroline (1,10-phen) and 1,2-di(4-pyridyl)ethylene (dpe), afforded eight new transition metal trisphosphonates, namely, [Cu 2 (H 8). The single-crystal X-ray diffraction measurements indicate that compounds 2 and 8 are isostructural and feature 3D framework structures with (5,6,8)-net topology; 1, 5 and 6 exhibit 2D layered structures; whereas 3, 4 and 7 have 0D dimer structures. The trisphosphonate ligands (H 6 L 1 and H 6 L 2 ) in these eight compounds adopt either cis-cis-cis or cis-trans-trans conformation with or without the existence of an auxiliary N-containing ligand. The attachment of methyl groups to the benzene core can enhance the crystallinity and enrich the structure diversity. The introduction of 2,29-bipy and 1,10-phen usually result in low dimensionality whereas 4,49-bipy can extend the structure to a higher dimensionality. The activated sample of compound 5 has a permanent 1D nanoporous structure and shows high selective adsorption of CO 2 over CH 4 .