title: Porous Coordination Polymer Based on Bipyridinium Carboxylate Linkers with High and Reversible Ammonia Uptake.
abstract: The zwitterionic bipyridinium carboxylate ligand 1,1'-bis(4-carboxyphenyl)-4,4'-bipyridinium (pc1) in the presence of cadmium chloride affords novel porous coordination polymers (PCPs): [Cd4(pc1)3Cl6]·CdCl4·guest (1) crystallizing in the P3̅1c space group. In the structure, [Cd4Cl6(CO2)6] building units are linked together by six pc1 ligands, leading to a 3D high-symmetrical network exhibiting hexagonal channels along the c axis. The walls of this PCP consist of cationic electron-acceptor bipyridinium units. The PCP 1 reversibly adsorbs H2O and CH3OH up to about 0.1 g/g at saturation showing the adsorption isotherms characteristic of a moderately hydrophilic sorbent. Adsorption of ammonia (NH3) follows a different pattern, reaching an exceptional uptake of 0.39 g/g (22.3 mmol/g) after the first adsorption cycle. Although the crystalline structure of 1 collapses after the first adsorption, the solid can be regenerated and maintains the capacity of 0.29 g/g (17 mmol/g) in the following cycles. We found that the high NH3 uptake is due to a combination of pore filling taking place below 150 h·Pa and chemisorption occurring at higher pressures. The latter process was shown to involve two phenomena: (i) coordination of NH3 molecules to Cd(2+) cations as follows from (113)Cd NMR and (ii) strong donor-acceptor interactions between NH3 molecules and pc1 ligands.
authors: MOLTECH Anjou, UMR-CNRS 6200, Université d'Angers , 2 Bd Lavoisier, 49045 Angers, France.
authors: Maxime
authors: M
authors: Leroux
authors: MOLTECH Anjou, UMR-CNRS 6200, Université d'Angers , 2 Bd Lavoisier, 49045 Angers, France.
authors: Nicolas
authors: N
authors: Mercier
authors: MOLTECH Anjou, UMR-CNRS 6200, Université d'Angers , 2 Bd Lavoisier, 49045 Angers, France.
authors: Magali
authors: M
authors: Allain
authors: MOLTECH Anjou, UMR-CNRS 6200, Université d'Angers , 2 Bd Lavoisier, 49045 Angers, France.
authors: Marie-Claire
authors: MC
authors: Dul
authors: IMMM, UMR-CNRS 6283, Université du Maine , Avenue O. Messiaen, 72085 Le Mans, France.
authors: Jens
authors: J
authors: Dittmer
authors: IMMM, UMR-CNRS 6283, Université du Maine , Avenue O. Messiaen, 72085 Le Mans, France.
authors: Abdel Hadi
authors: AH
authors: Kassiba
authors: ICB, UMR-CNRS 6303, Université de Bourgogne-Franche Comté , 9 A. Savary, 21078 Dijon, France.
authors: Jean-Pierre
authors: JP
authors: Bellat
authors: ICB, UMR-CNRS 6303, Université de Bourgogne-Franche Comté , 9 A. Savary, 21078 Dijon, France.
authors: Guy
authors: G
authors: Weber
authors: ICB, UMR-CNRS 6303, Université de Bourgogne-Franche Comté , 9 A. Savary, 21078 Dijon, France.
authors: Igor
authors: I
authors: Bezverkhyy