General strategy for lanthanide coordination polymers constructed from 1,1′-ferrocenedicarboxylic acid under hydrothermal conditions

Abstract

Twenty-six lanthanide coordination polymers (CPs), Ln₂(fcd)₂(phen)₂(NO₃)₂ (Ln = Nd (1-Nd)), [Ln₂(fcd)₃(phen)₂]·(CH₃OH)₂ (Ln = Sm (2-Sm), Eu (2-Eu), Gd (2-Gd), and Tb (2-Tb)), Ln₂(fcd)₂(Hfcd)₂(phen)₂ (Ln = La (3-La), Ce (3-Ce), Pr (3-Pr), Nd (3-Nd), Sm (3-Sm), and Gd (3-Gd)), [Ln₂(fcd)₃(CH₃CH₂OH)₂(H₂O)₂]·H₂O (Ln = La (4-La), Ce (4-Ce), Pr (4-Pr), Nd (4-Nd), Sm (4-Sm), Eu (4-Eu), Gd (4-Gd), Tb (4-Tb), Dy (4-Dy), Er (4-Er), Tm (4-Tm) and Yb (4-Yb)), and [Ln₄(fcd)₆(H₂O)₂]·nCH₃CH₂OH (Ln = Sm (5-Sm), Eu (5-Eu) and Tb (5-Tb)), were obtained from the reaction between 1,1′-ferrocenedicarboxylic acid (H₂fcd), 1,10-phenanthroline (phen) and the corresponding lanthanide salts under hydrothermal conditions. Ln₂(fcd)₂(phen)₂(NO₃)₂ (1-Nd) was constructed from discrete and neutral 0D dimeric units; [Ln₂(fcd)₃(phen)₂]·(CH₃OH)₂ (2-Sm/Eu/Gd/Tb) and Ln₂(fcd)₂(Hfcd)₂(phen)₂ (3-La/Ce/Pr/Nd/Sm/Gd) were built up of 1D infinite chains, while [Ln₂(fcd)₃(CH₃CH₂OH)₂(H₂O)₂]·H₂O (4-La/Ce/Pr/Nd/Sm/Eu/Gd/Tb/Dy/Er/Tm/Yb) and [Ln₄(fcd)₆(H₂O)₂]·nCH₃CH₂OH (5-Sm, n = 0.33; 5-Eu, n = 0.31; 5-Tb, n = 0.30) were made up of 2D sheets. The different structures of these twenty-six CPs can be attributed to the variable conformations of fcd resulting from different reaction conditions like different counterions, ancillary ligands, temperatures, and solvents. Furthermore, the photoluminescence and magnetic properties of selected CPs have been characterized and discussed.