A series of lanthanide–organic polymers incorporating nitrogen-heterocyclic and aliphatic carboxylate mixed-ligands: structures, luminescent and magnetic properties

Abstract

Seven new lanthanide-organic coordination polymers incorporating both nitrogen heterocyclic dicarboxylate and various auxiliary ligands, {[Ln(3)(Hpimda)(4)(mu(2)-HCOO).5H(2)O].H(2)O}(n)} Ln = Sm (1), Ln = Eu (2), Ln = Gd (3), Ln = Dy (4), Ln = Ho (5), {[Ce(2)(Hpimda)(2)(mu(4)-C(2)O(4)).8H(2)O].2H(2)O}(n) (6), {[Yb(2)(pyda)(mu(4)-C(2)O(4))(2).4H(2)O].3H(2)O}(n) (7) (H(3)pimda = 1H-2-propyl-4,5-imidazoledicarboxylic acid, H(2)pyda = 2,6-pyridinedicarboxylic acid) have been fabricated successfully and characterized systematically. Complexes 1-5 are isomorphous and isostructural, and are built from two-dimensional (2-D) double-decker networks based on the tetranuclear basic carboxylate as a secondary building unit (SBU). Both polymers 6 and 7 feature a (3,4)-connected 3-D framework consisting of 2-D lanthanide-organic hexagonal grids, which are further interlinked via the mu(4)-oxalate ligand. The results of magnetic determination show the same end-to-end bridging fashion of formate group results in different magnetic properties occurring between lanthanide centers. The luminescence emission spectra of the complexes vary depending on the lanthanide ion present.

Syntheses, structures and properties of four metal-organic frameworks from chlorophenyl imidazole dicarboxylates

“…Imidazole-4,5-dicarboxylic acid (H 3 IDC) having the above mentioned advantages has been explored to assemble MOFs [18][19][20][21][22][23], possessing six potential oxygen and nitrogen donors. Different substituents have also been introduced into the 2-position of H 3 IDC, such as ethyl, propyl, phenyl, hydroxymethyl, or pyridyl groups [24][25][26][27][28]. …”

Syntheses, Crystal Structure, Luminescence, Porosity and Magnetic Properties of Three‐Dimensional Lanthanide Coordination Polymers with 2‐Aminoterepthalic Acid

“…The Sm(III) ion has 6 H 5/2 ground term which gets splitted into six states by spin‐orbit coupling at room temperature. However, ground state 6 H 5/2 is not well separated from the excited ones so the higher excited states ( 6 H 7/2 , 6 H 9/2 , 6 H 11/2 , 6 H 13/2 , 6 H 15/2 ) get populated easily at room temperature . Van Vleck calculated the average χ M Τ value for isolated Sm(III) ion 0.31 cm 3 K mol −1 at 300 K taking into consideration the effects of crystal field and thermal population of excited states .…”

Crystal structure of poly[triaqua-µ2-sulfato-κ4O,O':O'',O'''-pyridine-3,5-dicarboxylato-κ4O,O':O'':O''']cerium(III) monohydrate, C7H11CeNO10S

“…We chose pyridine-3,5-dicarboxylate (3,5-DPA) as the organic ligand. The N-donor and O-donor ligands are able to afford multiple coordination sites with variable coordination modes [5]. Carboxylate groups at the 3-and 5-positions of the pyridine ring avoids the steric hindrance between the carboxylate groups.…”