Novel Polyoxometalate-Templated, 3-D Supramolecular Networks Based on Lanthanide Dimers:  Synthesis, Structure, and Fluorescent Properties of [Ln₂(DNBA)₄(DMF)₈][Mo₆O₁₉] (DNBA = 3,5-Dinitrobenzoate)

Abstract

The spherical Lindquist type polyoxometalate, Mo(6)O(19)(2)(-), has been used as a noncoordinating anionic template for the construction of novel three-dimensional lanthanide-aromatic monocarboxylate dimer supramolecular networks [Ln(2)(DNBA)(4)(DMF)(8)][Mo(6)O(19)] (Ln = La 1, Ce 2, and Eu 3, DNBA = 3,5-dinitrobenzoate, DMF = dimethylformamide). The title compounds are characterized by elemental analyses, IR, and single-crystal X-ray diffractions. X-ray diffraction experiments reveal that two Ln(III) ions are bridged by four 3,5-dinitrobenzoate anions as asymmetrically bridging ligands, leading to dimeric cores, [Ln(2)(DNBA)(4)(DMF)(8)](2+); [Ln(2)(DNBA)(4)(DMF)(8)](2+) groups are joined together by pi-pi stacking interactions between the aromatic groups to form a two-dimensional grid-like network; the 2-D supramolecular layers are further extended into 3-D supramolecular networks with 1-D box-like channels by hydrogen-bonding interactions, in which hexamolybdate polyanions reside. The compounds represent the first examples of 3-D carboxylate-bridged lanthanide dimer supramolecular "host" networks formed by pi-pi stacking and hydrogen-bonding interactions encapsulating noncoordinating "guest" polyoxoanion species. The fluorescent activity of compound 3 is reported.

Self-assembly of a 1D helical manganese coordination polymer and a tetranuclear lanthanum complex with 1,10-phenanthroline and 3,5-dinitrosalicylato dianion

“…The coordination mode and La-O(N) bond lengths ranging from 2.356(4) to 2.743(4) Å are similar to that of the polymer La 2 (dipic) 3 (H 2 O) 3 (dipic = 2,6-pyridinedicarboxylate) [37]. To form coordination polymers lanthanum with high coordination numbers need more ligands around, and some slight steric hindrance ligands such as water and dimethylformamide are needed when there are simultaneity some steric hindrance ligands coordinate with lanthanum, for example, [{Ln(L 1 ) 3 [39]. The 3,5-dinitrosalicylic acid lost both of its protons and behaves as a bridging ligand in (2).…”

Three manganese(II) coordination polymers based on 1,10-phenanthroline derivatives and mono-, bi-, or trimetallic cores

“…Consequently, a number of coordination polymers with various topological architectures have been constructed [13][14][15][16][17][18]. Generally, coordination-bonded interactions for the construction of coordination polymers are the most effective force.…”

Synthesis, structure and electrochemical properties of a polyoxometalate-templated compound with 2D twofold interpenetrating network

“…To the best of our knowledge, these neutral N-containing organic ligands used in the POM-based compounds are usually based on rigid organic ligands, such as bipyridine and triazole [17][18][19][20][21], or flexible organic ligands, such as bis(imidazole) and bis(triazole) [22][23][24][25]. However, examples that employ semi-rigid neutral organic amine ligands [26,27] to construct POM-templated compounds have not been reported before.…”