Guest Molecule Release Triggers Changes in the Catalytic and Magnetic Properties of a Fe^II-Based 3D Metal–Organic Framework

A Fe^II-based metal–organic framework (MOF), {[Fe₂(pbt)₂(H₂O)₂]·2H₂O}_<i>n</i>, undergoes an irreversible dehydration, which triggers changes in the catalytic and magnetic properties of the MOF. These property changes are attributed to the high-spin to low-spin transition of 7.1% center Fe^II, which is demonstrated by ⁵⁷Fe Mössbauer, X-ray photoelectron spectroscopy, and UV/vis absorption spectra

Effect of Organic Polycarboxylate Ligands on the Structures of a Series of Zinc(II) Coordination Polymers Based on a Conformational Bis-triazole Ligand

To explore the influence of six structurally different polycarboxylate ligands H₂L¹ to H₄L⁶ in the system Zn­(II)/btmx, six coordination polymers, formulated as [Zn­(btmx)­(L¹)]_<i>n</i> (<b>1</b>), {[Zn­(btmx)­(L²)]·2H₂O}_<i>n</i> (<b>2</b>), {[Zn­(btmx)­(L³)]·1.5H₂O}_<i>n</i> (<b>3</b>), [Zn­(btmx)­(L⁴)]_<i>n</i> (<b>4</b>), {[Zn₄(btmx)₃(L⁵)₄(H₂O)₂]·4H₂O}_<i>n</i> (<b>5</b>), and [Zn­(btmx)­(H₂L⁶)]_<i>n</i> (<b>6</b>), have been obtained under similar conditions (btmx = 1,4-bis­(1,2,4-triazol-1-ylmethyl)-2,3,5,6-tetramethylbenzene, H₂L¹ = 1,3-benzenedicarboxylic acid, H₂L² = 1,4-benzenedicarboxylic acid, H₂L³ = 1,3-adamantanedicarboxylic acid, H₂L⁴ <b>=</b> 1,3-adamantanediacetic acid, H₂L⁵ = 4,4′-oxidibenzoic acid, and H₄L⁶ = 3,3′,4,4′-benzophenone tetracarboxylic acid). The structure determination reveals that complexes <b>1</b> and <b>4</b> are two-dimensional (2D) layered networks and exhibit typical (4,4) topological nets. Complex <b>2</b> shows an undulating 2D (4,4)-network with 2-fold interpenetration. Complex <b>3</b> possesses a three-dimensional (3D) 3-fold interpenetrating 4-connected framework of 6⁶-<b>dia</b> topology. Both <b>5</b> and <b>6</b> have different 3D interpenetrated motifs generated by 2D → 3D interpenetration. Complex <b>5</b> belongs to a 3D framework built from the interpenetration of 2D bilayers in an inclined mode, while <b>6</b> involves a parallel interpenetration between the adjacent 2D (4,4) layers. This work markedly indicates that the effect of polycarboxylate ligands is significant in the construction of these networks

Polynuclear Cd^II Polymers: Crystal Structures, Topologies, and the Photodegradation for Organic Dye Contaminants

To systematically explore the effect of polynuclear complexes on photocatalytic degradation of the organic dyes, a series of coordination complexes containing Cd^II clusters, formulated as {[Cd₃L₂(H₂O)₅]·H₂O}_<i>n</i> (<b>1</b>), {[Cd₃L₂(hbmb)­(H₂O)₂]·2.5H₂O}_<i>n</i> (<b>2</b>), {[Cd₃L₂(btbb)­(H₂O)₂]·2EtOH·1.5H₂O}_<i>n</i> (<b>3</b>), and {[Cd₆L₄(bipy)₂(H₂O)₆]·3H₂O}_<i>n</i> (<b>4</b>) (H₃L = 3,4-bi­(4-carboxyphenyl)-benzoic acid, hbmb = 1,1′-(1,6-hexane)­bis­(2-methylbenzimidazole), btbb = 1,4-bis­(2-(4-thiazolyl)­benzimidazole-1-ylmethyl)­benzene, 4,4′-bipy = 4,4′-bipyridine), have been designed and synthesized. Complex <b>1</b> based on trinuclear Cd^II clusters exhibits a new (3,3,6)-connected 3D framework. <b>2</b> belongs to a (3,3,8,8)-connected tfz-d topology net with pillar-layered frameworks assembled by two kinds of trinuclear Cd^II clusters. <b>3</b> is a 3D pillar-layered framework, which features a (3,8)-connected tfz-d net based upon one kind of trinuclear Cd^II cluster. <b>4</b> presents a new 3D (3,6,10)-connected framework with dinuclear and tetranuclear clusters. The photocatalytic properties of complexes <b>1</b>–<b>4</b> have been studied in detail. Remarkably, <b>1</b>–<b>4</b> all reveal good photocatalytic activity in MB/MO degradation. The optical energy gap calculated by the diffuse reflectivity spectra of <b>1</b>–<b>4</b> are consistent with their degradation rates. Moreover, the experimental results further demonstrate that the cluster complexes containing different kinds of nuclei may exert different impact on the decomposition of disparate organic dyes

Template-Assisted Synthesis of Co,Mn-MOFs with Magnetic Properties Based on Pyridinedicarboxylic Acid

To investigate the influence of organic molecules with reactive functional groups as templates on the structures of the resulting MOFs, four novel complexes based on the pyridyl carboxylic acid ligand 5-(pyridin-4-yl)­isophthalic acid (H₂pyip), namely, [Mn₃(pyip)₂(HCOO)₂(H₂O)₂]_<i>n</i> (<b>1</b>), {[Co­(pyip)­(H₂O)]·H₂O}_<i>n</i> (<b>2</b>), {[Mn₂(pyip)₂(H₂O)₄]·5H₂O}_<i>n</i> (<b>3</b>), and [Co­(pyip)­(EtOH)­(H₂O)]_<i>n</i> (<b>4</b>), have been synthesized under solvothermal conditions. In the presence of 4,4′-bipyridyl as the template, 3D coordination framework <b>1</b> with the Schläfli symbol of (4·6·7) (4²·5·6⁵·7³·8²·9·11) was obtained. Using cyanoacetic acid as the template, we obtained 2D double-layered structure <b>2</b> with the Schläfli symbol of (4³) (4⁶·6⁶·8³). <b>3</b> and <b>4</b> are prepared in the absence of a templating agent. <b>3</b> features an infinite 2D network with a 1D water chain penetrating the 1D channel and further results in a 3D supramolecule through hydrogen-bond interactions. <b>4</b> contains two independent 2D networks that are further connected to a 2D double-layered supramolecular framework by hydrogen bonds. The template-assisted method is a potential approach for obtaining specific intriguing complexes that might be difficult to access by routine synthetic methods. Magnetic investigations revealed that both <b>1</b> and <b>2</b> exhibit weak antiferromagnetic interactions mediated by pyip^2–

Template-Assisted Synthesis of Co,Mn-MOFs with Magnetic Properties Based on Pyridinedicarboxylic Acid

To investigate the influence of organic molecules with reactive functional groups as templates on the structures of the resulting MOFs, four novel complexes based on the pyridyl carboxylic acid ligand 5-(pyridin-4-yl)­isophthalic acid (H₂pyip), namely, [Mn₃(pyip)₂(HCOO)₂(H₂O)₂]_<i>n</i> (<b>1</b>), {[Co­(pyip)­(H₂O)]·H₂O}_<i>n</i> (<b>2</b>), {[Mn₂(pyip)₂(H₂O)₄]·5H₂O}_<i>n</i> (<b>3</b>), and [Co­(pyip)­(EtOH)­(H₂O)]_<i>n</i> (<b>4</b>), have been synthesized under solvothermal conditions. In the presence of 4,4′-bipyridyl as the template, 3D coordination framework <b>1</b> with the Schläfli symbol of (4·6·7) (4²·5·6⁵·7³·8²·9·11) was obtained. Using cyanoacetic acid as the template, we obtained 2D double-layered structure <b>2</b> with the Schläfli symbol of (4³) (4⁶·6⁶·8³). <b>3</b> and <b>4</b> are prepared in the absence of a templating agent. <b>3</b> features an infinite 2D network with a 1D water chain penetrating the 1D channel and further results in a 3D supramolecule through hydrogen-bond interactions. <b>4</b> contains two independent 2D networks that are further connected to a 2D double-layered supramolecular framework by hydrogen bonds. The template-assisted method is a potential approach for obtaining specific intriguing complexes that might be difficult to access by routine synthetic methods. Magnetic investigations revealed that both <b>1</b> and <b>2</b> exhibit weak antiferromagnetic interactions mediated by pyip^2–

Syntheses, Characterizations, and Properties of Five Interpenetrating Complexes Based on 1,4-Benzenedicarboxylic Acid and a Series of Benzimidazole-Based Linkers

Five interesting interpenetrating networks, namely, [Co­(<i>p</i>-bdc)­(beb)_0.5]_<i>n</i> (<b>1</b>), {[Co­(<i>p</i>-bdc)­(bmb)]·H₂O}_<i>n</i> (<b>2</b>), {[Co­(<i>p</i>-bdc)­(bmp)]·H₂O}_<i>n</i> (<b>3</b>), {[Zn­(<i>p</i>-bdc)­(bmp)]·H₂O}_<i>n</i> (<b>4</b>), and [Zn₂(<i>p</i>-bdc)₂(bmp)­(H₂O)₂]_<i>n</i> (<b>5</b>) [<i>p</i>-H₂bdc = 1,4-benzenedicarboxylic acid, beb = 1,4-bis­(2-ethylbenzimidazol-1-ylmethyl)­benzene, bmb = 1,4-bis­(2-methylbenzimidazol-1-ylmethyl)­benzene, and bmp = 1,5-bis­(2-methylbenzimidazol) pentane], have been synthesized by employing mixed ligands of various benzimidazole-based ligands with <i>p</i>-H₂bdc. Complex <b>1</b> possesses a 2-fold interpenetrating 3D framework with (4¹²·6³)-pcu topology. Complex <b>2</b> exhibits a 3-fold interpenetrating 3D network with 6⁶-dia topology, and complex <b>3</b> displays a 4-fold interpenetrating 3D diamond network containing Co/bmp left- and right-handed helical chains. Obviously, with the reducing of the steric hindrance of the N-donor ligand, complexes <b>1</b>–<b>3</b> show interpenetrating networks from 2-fold to 3-fold and 4-fold. Complex <b>4</b> is isostructural to <b>3</b> and also forms a 4-connected 3D framework with a diamond topology. Complex <b>5</b> features a 3D framework generated by 2D → 3D interpenetration and exhibits (8²·10)₂ topology. Our study shows that the steric hindrance changing of ligands can tune the final interpenetrating networks directly

Series of Cd(II) Metal–Organic Frameworks Based on a Flexible Tripodal Ligand and Polycarboxylate Acids: Syntheses, Structures, and Photoluminescent Properties

Five novel metal–organic frameworks with a 1,3,5-tris­(triazol-1-ylmethyl)-2,4,6-trimethylbenzene (tttmb) flexible tripodal block, namely, {[Cd­(tttmb)­(atc)]·1.5H₂O}<i>_n</i> (<b>1</b>), {[Cd₅(tttmb)₂(tbi)₅(H₂O)₄]·2H₂O}<i>_n</i> (<b>2</b>), {[Cd₃(tttmb)₂(bdc)₃(H₂O)₃]·0.5H₂O}<i>_n</i> (<b>3</b>), {[Cd₂(tttmb)₂(btc)­Cl]·3H₂O}_<i>n</i> (<b>4</b>), and {[Cd₂(tttmb)₂(btec)­(H₂O)₃]·H₂O}_<i>n</i> (<b>5</b>) (H₂atc = 1,3-adamantanedicarboxylic acid, H₂tbi = 5-<i>tert</i>-butylisophthalic acid, H₂bdc = 1,4-benzenedicarboxylic acid, H₃btc = 1,2,4-benzenetricarboxylic acid, and H₄btec = 1,2,4,5-benzenetetracarboxylic acid), have been synthesized. Complex <b>1</b> exhibits a two-dimensional structure with left- and right-handed helical chains arranged alternately. Complex <b>2</b> displays an intricate two-dimensional framework containing three layers with a 3,4,7-connected topology. It is notable that tbi^2– takes on five different coordination modes in <b>2</b>. Complex <b>3</b> presents a 3D 3,4-connected network with a point symbol of (6³)₂(6⁴·8²)₂(6³·8³). The structure of complex <b>4</b> is a self-penetrating 3D 3,4,8-connected framework with left- and right-handed helical chains arranged alternately. Complex <b>5</b> shows a 3D pillar-layered framework, which can be simplified as a 3,4,5-connected 3D topology with a Schläfli symbol of (5³)­(5²·6²·7·9)­(5⁵·6²·7²·8). Moreover, the investigation of photoluminescence properties reveals that complexes <b>1</b>–<b>5</b> show different fluorescent behaviors

Series of Cd(II) Metal–Organic Frameworks Based on a Flexible Tripodal Ligand and Polycarboxylate Acids: Syntheses, Structures, and Photoluminescent Properties

Five novel metal–organic frameworks with a 1,3,5-tris­(triazol-1-ylmethyl)-2,4,6-trimethylbenzene (tttmb) flexible tripodal block, namely, {[Cd­(tttmb)­(atc)]·1.5H₂O}<i>_n</i> (<b>1</b>), {[Cd₅(tttmb)₂(tbi)₅(H₂O)₄]·2H₂O}<i>_n</i> (<b>2</b>), {[Cd₃(tttmb)₂(bdc)₃(H₂O)₃]·0.5H₂O}<i>_n</i> (<b>3</b>), {[Cd₂(tttmb)₂(btc)­Cl]·3H₂O}_<i>n</i> (<b>4</b>), and {[Cd₂(tttmb)₂(btec)­(H₂O)₃]·H₂O}_<i>n</i> (<b>5</b>) (H₂atc = 1,3-adamantanedicarboxylic acid, H₂tbi = 5-<i>tert</i>-butylisophthalic acid, H₂bdc = 1,4-benzenedicarboxylic acid, H₃btc = 1,2,4-benzenetricarboxylic acid, and H₄btec = 1,2,4,5-benzenetetracarboxylic acid), have been synthesized. Complex <b>1</b> exhibits a two-dimensional structure with left- and right-handed helical chains arranged alternately. Complex <b>2</b> displays an intricate two-dimensional framework containing three layers with a 3,4,7-connected topology. It is notable that tbi^2– takes on five different coordination modes in <b>2</b>. Complex <b>3</b> presents a 3D 3,4-connected network with a point symbol of (6³)₂(6⁴·8²)₂(6³·8³). The structure of complex <b>4</b> is a self-penetrating 3D 3,4,8-connected framework with left- and right-handed helical chains arranged alternately. Complex <b>5</b> shows a 3D pillar-layered framework, which can be simplified as a 3,4,5-connected 3D topology with a Schläfli symbol of (5³)­(5²·6²·7·9)­(5⁵·6²·7²·8). Moreover, the investigation of photoluminescence properties reveals that complexes <b>1</b>–<b>5</b> show different fluorescent behaviors

Structural Diversity for a Series of Novel Zn Metal–Organic Frameworks Based on Different Secondary Building Units

The secondary building unit (SBU) has been identified as a useful tool in the synthesis of metal–organic frameworks (MOFs). Herein, we synthesized six novel Zn complexes, namely, {[Zn₃(tci)₂(DMF)₂)]·2DMF·2CH₃OH}_<i>n</i> (<b>1</b>), {[Zn₃(tci)₂(DMSO)₂(H₂O)₂]·2DMSO·3H₂O}_<i>n</i> (<b>2</b>), {[ZnNa­(tci)­(H₂O)]·2H₂O}_<i>n</i> (<b>3</b>), {[Zn₅(tci)₂(OH)₄(H₂O)₂]·2H₂O}_<i>n</i> (<b>4</b>), {[Zn₃(tci)₂(phen)₂(H₂O)₂]·4H₂O}_<i>n</i> (<b>5</b>), and {[Zn₃(tci)₂(btb)₂(H₂O)₂]·6H₂O}_<i>n</i> (<b>6</b>) by utilizing different SBUs (tci = tris­(2-carboxyethyl) isocyanurate, phen = 1,10-phenanthroline, btb = 1,4-bis (1,2,4-triazole-1-ylmethyl) benzene). Complexes <b>1</b>–<b>4</b> were synthesized only by changing solvents, and complexes <b>5</b> and <b>6</b> were obtained by adding different auxiliary ligands on the same conditions. Structural analyses show that complexes <b>1</b> and <b>2</b> possess two-dimensional (2D) structures based on linear and triangular trinuclear Zn clusters. Complexes <b>3</b> and <b>4</b> exhibit 2D and three-dimensional (3D) frameworks built on rare infinite rod-shaped SBUs, while complex <b>5</b> belongs to a 3D framework with two kinds of left- and right-helical chains built from discrete dinuclear Zn clusters and mononuclear Zn atoms. Complex <b>6</b> exhibits high-connected 3D framework based on extended linear trinuclear Zn clusters

Ni(II) Coordination Polymers Constructed from the Flexible Tetracarboxylic Acid and Different N‑Donor Ligands: Structural Diversity and Catalytic Activity

To seek the effect that condition of the complexes has on the manufacture of the biaryl compounds, seven Ni­(II) complexes, namely, {[Ni­(L)_0.5(bpa)­(H₂O)]·2H₂O}_<i>n</i> (<b>1</b>), {[Ni₂(L)­(dpp)₂­(H₂O)]·4H₂O}_<i>n</i> (<b>2</b>), {[Ni­(L)_0.5(pbmb)­(H₂O)]·H₂O}_<i>n</i> (<b>3</b>), {[Ni₂(L)­(bmp)₂­(H₂O)]·7H₂O}_<i>n</i> (<b>4</b>), {[Ni­(L)_0.5­(pbib)_1.5]·2H₂O}_<i>n</i> (<b>5</b>), {[Ni₂(L)­(pbib)_1.5]·3H₂O}_<i>n</i> (<b>6</b>), and [Ni­(L)_0.5­(beb)₂­(H₂O)]_<i>n</i> (<b>7</b>) (bpa = 1,2-bis­(4-pyridyl)­ethane, dpp = 1,3-di­(4-pyridyl)­propane, pbmb = 1,1′-(1,3-propane)­bis­(2-methylbenzimidazole), bmp = 1,5-bis­(2-methylbenzimidazol) pentane, pbib = 1,4-bis­(imidazol-1-ylmethyl)­benzene, beb = 1,4-bis­(2-ethylbenzimidazol-1-ylmethyl)­benzene), have been gained through hydro­(solvo)­thermal reactions of 5,5′-(hexane-1,6-diyl)-bis­(oxy)­diisophthalic acid ligand (H₄L) with Ni­(II) metal ions under the regulation and control of six N-donor ligands. 3-fold interpenetrating complex <b>1</b> belongs to a (4,4)-connected 3D <i>bbf</i> net with a vertex symbol of (6⁴·8²)­(6⁶) topology. 3-fold interpenetrating complex <b>2</b> presents a (4,4,4)-connected 3D <i>bbf</i> net with a Schläfli symbol of (6⁶)₂(6⁴·8²) topology. <b>3</b> features a (3,4)-connected <i>3,4L13</i> topology with a Schläfli symbol of (4·6²)­(4²·6²·8²) topology. <b>4</b> possesses a (4,4,4)-connected <i>mog Moganite</i> 3D network fabric, and the vertex symbol is (4·6⁴·8)₂­(4²·6²·8²). <b>5</b> takes on a (4,5)-connected architecture, and the point symbol is (4·6⁹)­(4²·6⁶·8²). <b>6</b> is a (4,7)-connected framework, and the Schläfli symbol is (4⁵·5)­(4⁷·5³·6¹¹). <b>7</b> has a (4,4)-connected <i>4,4L28</i> topology, and the point (Schläfli) symbol is (4²·6⁴)­(4·6⁴·8). A systematic structural comparison of <b>1</b>–<b>7</b> signifies that their frameworks can be regulated through varied conformations of the flexible H₄L ligand and diverse N-donor ligands. Between the proximal Ni­(II) ions, the variable-temperature (2–300 K) magnetic susceptibilities of <b>6</b> display overall weak antiferromagnetic coupling. In the complexes-catalyzed homocoupling reaction of iodobenzene, <b>3</b>, <b>5</b>, <b>6</b>, and <b>7</b> have been verified to be effectual catalysts for the synthesis of the biaryl compounds