Employing Zinc Clusters as SBUs To Construct (3,8) and (3,14)-Connected Coordination Networks: Structures, Topologies, and Luminescence

Two new metal–organic frameworks (MOFs), [Zn2(OH)­(cpia)­(bipy)0.5]n (1) and {[Zn7(OH)2(HOMe)2(cpia)4(bib)]·5H2O}n (2) (bib = 1,4-bis­(imidazol-1-yl)­benzene, H3cpia = 5-(4-carboxyphenoxy)­isophthalic acid, bipy = 4,4′-bipyridine), have been solvothermally synthesized and structurally characterized. Both of them are based on zinc clusters as secondary building units (SBUs). Compound 1 presents an interesting three-dimensional 2-fold interpenetrated (3,8)-connected network constructed from tetranuclear [Zn4(OH)2]6+ clusters with (43)2(46·618·84) topology, while compound 2 can be described as a (3,14)-connected framework built from an unprecedented heptanuclear [Zn7(OH)2(HOMe)2]12+ cluster with {(420·652·76·813)­(43)4} topology. Detailed structural comparison of two compounds indicated that coligands play significant roles in tuning the nuclearity of metal clusters and the connectivity of specific networks. Furthermore, the thermal stabilities and luminescence properties of two compounds reveal that they all exhibit high thermal stability and strong luminescence emission bands in the solid state at room temperature

A New Supramolecular Assembly Based on Triple-Dawson-Type Polyoxometalate and 3d-4f Heterometallic Cluster

The introduction of hexavacant Dawson-type precursor K12[H2P2W12O48]·24H2O into a HOAc/NaOAc (OAc− = acetate) buffer system containing (NH4)2[CeIV(NO3)6] and MnII(OAc)2·4H2O led to the isolation of a new compound, Na20[CeIV3MnIV2O6(OAc)6(H2O)9]2[MnIII2P2W16O60]3·21H2O (1). Compound 1 contains unusual triple-Dawson-type polyoxoanions [MnIII2P2W16O60]324− and bipyramid-like 3d−4f heterometallic clusters [CeIV3MnIV2O6(OAc)6(H2O)9]2+, which are arranged in a 3-D supramolecular assembly with 1-D channels. The Na+ cations and solvent water molecules reside in the channels. Crystal data for 1 are as follows: hexagonal, P63/mcm (No. 193), a = 24.959(4) Å, c = 26.923(5) Å, γ = 120°, V = 14525(4) Å3, and Z = 2. The electrochemical and electrocatalytic properties of compound 1 have been investigated

A New 10-Connected Coordination Network with Pentanuclear Zinc Clusters as Secondary Building Units

An unusual 3D 10-connected metal–organic framework [Zn₅(μ₃-OH)₂(1,4-ndc)₄(1,4-bix)₂] (<b>1</b>, 1,4-ndc = 1,4-naphthalenedicarboxylic acid; 1,4-bix = 1,4-bis­(imidazol-1-ylmethyl)­benzene) has been hydrothermally synthesized and structurally characterized. Topological analysis indicates that <b>1</b> is a 3D 10-connected self-penetrating framework based on [Zn₅(μ₃-OH)₂] pentanuclear zinc clusters as secondary building units with the short Schläfli symbol of 3⁶4³⁴5³6². This represents highly connected a uninodal network topology presently known for self-penetrating systems. Moreover, the TGA and luminescence properties of <b>1</b> were investigated

Employing Zinc Clusters as SBUs To Construct (3,8) and (3,14)-Connected Coordination Networks: Structures, Topologies, and Luminescence

Two new metal–organic frameworks (MOFs), [Zn₂(OH)­(cpia)­(bipy)_0.5]_<i>n</i> (<b>1</b>) and {[Zn₇(OH)₂(HOMe)₂(cpia)₄(bib)]<b>·</b>5H₂O}_<i>n</i> (<b>2</b>) (bib = 1,4-bis­(imidazol-1-yl)­benzene, H₃cpia = 5-(4-carboxyphenoxy)­isophthalic acid, bipy = 4,4′-bipyridine), have been solvothermally synthesized and structurally characterized. Both of them are based on zinc clusters as secondary building units (SBUs). Compound <b>1</b> presents an interesting three-dimensional 2-fold interpenetrated (3,8)-connected network constructed from tetranuclear [Zn₄(OH)₂]⁶⁺ clusters with (4³)₂(4⁶·6¹⁸·8⁴) topology, while compound <b>2</b> can be described as a (3,14)-connected framework built from an unprecedented heptanuclear [Zn₇(OH)₂(HOMe)₂]¹²⁺ cluster with {(4²⁰·6⁵²·7⁶·8¹³)­(4³)₄} topology. Detailed structural comparison of two compounds indicated that coligands play significant roles in tuning the nuclearity of metal clusters and the connectivity of specific networks. Furthermore, the thermal stabilities and luminescence properties of two compounds reveal that they all exhibit high thermal stability and strong luminescence emission bands in the solid state at room temperature

Hetero-Phase MoO₂/Cu_2–<i>x</i>Se Nanocomposites Distributed in Porous Octahedral Carbon Networks for High-Performance Lithium Storage

Owing to the mixed insertion and multielectron conversion reaction mechanisms, nonstoichiometric copper selenide (Cu2–xSe) has been known as a potential anode for lithium-ion batteries. However, huge volume changes during discharge and charge limit its ability for lithium-ion storage. Constructing heterophase nanocomposite uniformly distributed in the carbon network has been recognized as an effective approach to address the above issue. In this work, polyoxometalate-based metal–organic frameworks were used as the self-template to derive octahedral mesoporous carbon-coated heterophase copper selenide and molybdenum dioxide (MoO2/Cu2–xSe@C) nanocomposites, and the phase transformation of copper selenides from CuSe to Cu2–xSe can be achieved by tuning the pyrolysis temperature, thus optimizing the electrochemical performance. As a result, the optimized electrode delivers a high reversible specific capacity of 864.8 mAh g–1 at 0.2 A g–1 after 100 cycles, an excellent rate capability with a capacity of 480.9 mAh g–1 at 2.0 A g–1, and a long-term stability up to 500 cycles with a capacity decay rate per cycle of only 0.003%. Also, the reaction mechanism and structural stability after cycling were analyzed in detail

A New Supramolecular Assembly Based on Triple-Dawson-Type Polyoxometalate and 3d-4f Heterometallic Cluster

The introduction of hexavacant Dawson-type precursor K12[H2P2W12O48]·24H2O into a HOAc/NaOAc (OAc− = acetate) buffer system containing (NH4)2[CeIV(NO3)6] and MnII(OAc)2·4H2O led to the isolation of a new compound, Na20[CeIV3MnIV2O6(OAc)6(H2O)9]2[MnIII2P2W16O60]3·21H2O (1). Compound 1 contains unusual triple-Dawson-type polyoxoanions [MnIII2P2W16O60]324− and bipyramid-like 3d−4f heterometallic clusters [CeIV3MnIV2O6(OAc)6(H2O)9]2+, which are arranged in a 3-D supramolecular assembly with 1-D channels. The Na+ cations and solvent water molecules reside in the channels. Crystal data for 1 are as follows: hexagonal, P63/mcm (No. 193), a = 24.959(4) Å, c = 26.923(5) Å, γ = 120°, V = 14525(4) Å3, and Z = 2. The electrochemical and electrocatalytic properties of compound 1 have been investigated

A New 10-Connected Coordination Network with Pentanuclear Zinc Clusters as Secondary Building Units

An unusual 3D 10-connected metal–organic framework [Zn₅(μ₃-OH)₂(1,4-ndc)₄(1,4-bix)₂] (<b>1</b>, 1,4-ndc = 1,4-naphthalenedicarboxylic acid; 1,4-bix = 1,4-bis­(imidazol-1-ylmethyl)­benzene) has been hydrothermally synthesized and structurally characterized. Topological analysis indicates that <b>1</b> is a 3D 10-connected self-penetrating framework based on [Zn₅(μ₃-OH)₂] pentanuclear zinc clusters as secondary building units with the short Schläfli symbol of 3⁶4³⁴5³6². This represents highly connected a uninodal network topology presently known for self-penetrating systems. Moreover, the TGA and luminescence properties of <b>1</b> were investigated

Structure Modulation in Zn(II)–1,4-Bis(imidazol-1-yl)benzene Frameworks by Varying Dicarboxylate Anions

In the field of metal–organic frameworks (MOFs), one of the challenges is the fabrication of novel materials that display/correlate the prediction of structures and functionality. Usually, the structures of MOFs are influenced by the skeleton of ligands. In this article, five different dicarboxylic acids, namely, fumaric dioic acid (H₂FUM), 2-aminoterephthalic acid (2-H₂ATA), 1,4-naphthalenedicarboxylic acid (1,4-H₂NAPDC), 1,2-benzenedicarboxylic acid (1,2-H₂BDC), and oxalic acid (H₂OX) are employed as the secondary auxiliary ligands to perform a systematic study on the structure diversities in the Zn­(II)–1,4-bis­(imidazol-1-yl)­benzene (<b>L</b>) frameworks. By introducing various secondary dicarboxylate anions in the Zn­(II)-<b>L</b> system, six new complexes {Zn­(<b>L</b>)­(FUM)}_∞ (<b>1</b>), {Zn₂(<b>L</b>)­(2-ATA)₂}_∞ (<b>2</b>), {Zn­(<b>L</b>)­(1,4-NAPDC)·H₂O}_∞ (<b>3</b>), {Zn₂(<b>L</b>)­(1,4-NAPDC)₂·2DMF}_∞ (<b>4</b>), {Zn­(<b>L</b>)­(1,2-BDC)}_∞ (<b>5</b>), and {Zn₃(<b>L</b>)₂(OX)₃·H₂O}_∞ (<b>6</b>) were obtained. Complexes <b>1</b> and <b>3</b> possess three-dimensional (3D) 5-fold interpenetrating diamond frameworks. Complex <b>2</b> is a 3D 3-fold interpenetrating α-Po framework constructed by dinucear {Zn₂} secondary building units (SBUs). Complex <b>4</b> exhibits a 3D 2-fold interpenetrating α-Po framework when DMF acts as the reaction solvent. Complex <b>5</b> shows a 3D framework with diamondoid topology, which includes <b>L</b>/Zn­(II)/<b>L</b> helical chains. Complex <b>6</b> presents an interesting 3D structure constructed from {Zn­(II)-OX-Zn­(II)} rod-shaped SBUs and <b>L</b> ligands as pillars. The diverse structures of these six complexes indicate that the skeleton of dicarboxylate anions plays a great role in the assembly of such different frameworks. Moreover, the fluorescence properties of the complexes <b>1</b>–<b>6</b> were investigated in the solid state

Space Craft-like Octanuclear Co(II)-Silsesquioxane Nanocages: Synthesis, Structure, Magnetic Properties, Solution Behavior, and Catalytic Activity for Hydroboration of Ketones

Two novel space craft-like octanuclear Co­(II)-silsesquioxane nanocages, {Co8[(MeSiO2)4]2­(dmpz)8} (SD/Co8a) and {Co8[(PhSiO2)4]2­(dmpz)8} (SD/Co8b) (SD = SunDi; Hdmpz = 3,5-dimethylpyrazole), have been constructed from two similar multidentate silsesquioxane ligands assisted with a pyrazole ligand. The Co8 skeleton consists of eight tetrahedral Co­(II) ions arranged in a ring and is further capped by two (MeSiO2)4 ligands up and down. The auxiliary dmpz– ligands seal the ring finally. Electrospray ionization mass spectrometry revealed SD/Co8a and SD/Co8b are highly stable in CH2Cl2. Magnetic analysis implies that SD/Co8a announces antiferromagnetic interactions between Co­(II) ions. Moreover, both of them display good homogeneous catalytic activity for hydroboration of ketones in the presence of pinacolborane under mild conditions

Structure Modulation in Zn(II)–1,4-Bis(imidazol-1-yl)benzene Frameworks by Varying Dicarboxylate Anions

In the field of metal–organic frameworks (MOFs), one of the challenges is the fabrication of novel materials that display/correlate the prediction of structures and functionality. Usually, the structures of MOFs are influenced by the skeleton of ligands. In this article, five different dicarboxylic acids, namely, fumaric dioic acid (H₂FUM), 2-aminoterephthalic acid (2-H₂ATA), 1,4-naphthalenedicarboxylic acid (1,4-H₂NAPDC), 1,2-benzenedicarboxylic acid (1,2-H₂BDC), and oxalic acid (H₂OX) are employed as the secondary auxiliary ligands to perform a systematic study on the structure diversities in the Zn­(II)–1,4-bis­(imidazol-1-yl)­benzene (<b>L</b>) frameworks. By introducing various secondary dicarboxylate anions in the Zn­(II)-<b>L</b> system, six new complexes {Zn­(<b>L</b>)­(FUM)}_∞ (<b>1</b>), {Zn₂(<b>L</b>)­(2-ATA)₂}_∞ (<b>2</b>), {Zn­(<b>L</b>)­(1,4-NAPDC)·H₂O}_∞ (<b>3</b>), {Zn₂(<b>L</b>)­(1,4-NAPDC)₂·2DMF}_∞ (<b>4</b>), {Zn­(<b>L</b>)­(1,2-BDC)}_∞ (<b>5</b>), and {Zn₃(<b>L</b>)₂(OX)₃·H₂O}_∞ (<b>6</b>) were obtained. Complexes <b>1</b> and <b>3</b> possess three-dimensional (3D) 5-fold interpenetrating diamond frameworks. Complex <b>2</b> is a 3D 3-fold interpenetrating α-Po framework constructed by dinucear {Zn₂} secondary building units (SBUs). Complex <b>4</b> exhibits a 3D 2-fold interpenetrating α-Po framework when DMF acts as the reaction solvent. Complex <b>5</b> shows a 3D framework with diamondoid topology, which includes <b>L</b>/Zn­(II)/<b>L</b> helical chains. Complex <b>6</b> presents an interesting 3D structure constructed from {Zn­(II)-OX-Zn­(II)} rod-shaped SBUs and <b>L</b> ligands as pillars. The diverse structures of these six complexes indicate that the skeleton of dicarboxylate anions plays a great role in the assembly of such different frameworks. Moreover, the fluorescence properties of the complexes <b>1</b>–<b>6</b> were investigated in the solid state