Structural diversities and related properties of four coordination polymers synthesized from original ligand of 3,3′,5,5′-azobenzenetetracarboxylic acid

Abstract

Four new coordination polymers, namely [Co(H2O2abtc)(bibp)]n (), {[Mn1.5(Oabtc)(H2O)2]·(H2bmib)0.5·H2O}n (), {[Cd1.5(O2abtc)]·(H2bmib)0.5·2H2O}n (), and {[Cd(nip)(bibp)]·0.5H2O}n (),were constructed under solvothermal conditions in the presence of two bis(imidazole) bridging linkers (bimb = 1,4-bis(2-methylimidazol-1-ylmethyl)benzene, bibp = 4,4'-bis(imidazol-1-yl)biphenyl). The unstable azo ligand of 3,3',5,5'-azobenzenetetracarboxylic acid (H4abtc) could be oxidized and resulted in three oxidized derivatives of H4Oabtc (one N atom was oxidized), H4O2abtc (two N atoms were oxidized), and H2nip (one H4abtc was oxidized to two 5-nitroisophthalic acids). Their structures were determined by single-crystal X-ray diffraction and further characterized by elemental analyses, IR spectroscopy, powder X-ray diffraction (PXRD), and thermogravimetric (TG) analysis. Complex exhibited an interestingly 2D + 2D → 3D parallel entangled network based on 4-connected (4(4)·6(2))-sql sheets. Complex was found to be a {Mn3(COO)6} trinuclear SBU based 2D (3,6)-connected (4(3))2(4(6)·6(6)·8(3))-kgd sheet. While complex displays a {Cd3(COO)8} trinuclear SBUs based 3D (4,8)-connected (4(6))2(4(12)·6(12)·8(4))-flu network. Complex can be regard as a {Cd2(COO)2} binuclear SBUs based 6-connected (4(4)·6(11))-6T8 framework. In addition, the magnetic property of complexes , and the luminescence properties of complexes , were investigated.

Bound Flavin Model Suggests Similar Electron‐Transfer Mechanisms in Shewanella and Geobacter

“…The ancillary ligands containing N‐donor such as bipyridine have been used widely with polycarboxylates together to construct the desired structures. For example, bipyridine linker as an N‐donor ligand is beneficial to the syntheses of extended CPs and can generate high dimensional structures owing to its simple bridging mode and strong coordination ability, while the utilization of bis(imidazole) linkers as coligands to react with polycarboxylates was rarely reported in detail16–21 and the cis or trans configuration of bis(imidazole) linkers often causes the structural diversity when they coordinate to central metal atoms 22–25…”

Modular Construction, Structures, and Magnetic Properties of Two Manganese Coordination Polymers Based on 3,5‐Bis(2–carboxylphenoxy)benzoic Acid

“…With the temperature decreasing, the χ M T value shows a small decrease to 4.22 cm 3 · K · mol –1 at 2 K. The temperature dependence χ M also followed the Curie‐Weiss law χ M = C /( T – θ ) with C = 4.41 cm 3 · K · mol –1 , θ = –4.05 K (Figure S7, Supporting Information). The negative value of θ indicates the presence of the antiferromagnetic interactions between the nearest Mn II cations in complexes 1 and 2 ,…”

“…However, the different coordination atoms (O or N) of those ligands endow the linkers distinct coordination preferences when interacted with metal ions . Thus, the mixed ligands strategy seems an efficient routine to build CPs for this strategy can taking advantages of both polycarboxylates and N‐donors . It is noteworthy that the flexible polycarboxylates based CPs containing interestingly “breathing effects” sometimes, and usually exhibiting crystal structural transformations in the solid state , .…”

Syntheses, Crystal Structures, and Magnetic Properties of Two Cobalt Coordination Polymers Constructed From 1,3‐Bis(2,4‐dicarboxyphenyl) Benzene and Bis(imidazole) Linkers

“…For example, bipyridine linker as an N-donor ligand is beneficial to the syntheses of extended CPs and can generate high dimensional structures owing to its simple bridging mode and strong coordination ability, while the utilization of bis(imidazole) linkers as coligands to react with polycarboxylates was rarely reported in detail [16][17][18][19][20][21] and the cis or trans configuration of bis(imidazole) linkers often causes the structural diversity when they coordinate to central metal atoms. [22][23][24][25] Thus, these considerations inspired us to explore new coordination networks with 1,3-bis(2Ј,4Ј-dicarboxylphenyl)benzene (H 4 DDB) ligand and cobalt(II) salts under solvothermal conditions in the presence of bis(imidazole) linkers (shown in Scheme 1). In this paper, we report the syntheses and characterizations of two novel cobalt(II) CPs, namely [Co 1.5 (HDDB)(1,4-bib) 1 2 ) net for 2, respectively.…”