Assembly of InCl 3 with 1,3,5-benzenetricarboxylic acid (H 3 btc) and pyridine or pyridine derivatives under hydrothermal conditions produces a series of isostructural coordination polymers with the interesting frameworks: {(HL)[In 4 (OH) 4 (btc) 3 ]·L·3H 2 O} n , L=pyridine (1); L=2-picoline (2); L=4-picoline (3) and {(Hdpea)[In 4 (OH) 4 (btc) 3 ]·3H 2 O} n (4) (dpea=1,2-di(4-pyridyl)ethane). In these four complexes, carboxyl and hydroxyl oxygen atoms bridge indium(III) centers to form octahedral chain-like sinusoidal curves, which are further interlinked by btc 3− moieties to generate 3-D frameworks with 1-D channels. The protonated guests HL in 1–3 located at the channels can be fully exchanged by K + ion or partially exchanged by Sr 2+ , and Ba 2+ ions.