Self-assembled Structure of Inorganic–Organic Hybrid Crystals Based on Keggin Polyoxometallates [SMo₁₂O₄₀^2–] and Supramolecular Cations

To investigate the network structure of inorganic–organic hybrid crystals, we synthesized a series of assemblies based on polyoxometallates (POMs) [SMo₁₂O₄₀^2–] and different supramolecular cations consisting of anilinium and crown ether derivatives. The compounds [(<i>m</i>-XAni⁺)­(B­[18]­crown-6)]₂­[SMo₁₂O₄₀^2–] (Ani⁺ = anilinium; B[18]­crown-6 = benzo[18]­crown-6; X = F (<b>1</b>), Cl (<b>2</b>), Br (<b>3</b>), or I (<b>4</b>)), [(4-MeAni⁺)­(B­[18]­crown-6)]₂­[SMo₁₂O₄₀^2–]·CH₃CN (<b>5</b>), [(4-MeAni⁺)­(DB­[18]­crown-6)]₂­[SMo₁₂O₄₀^2–]·2CH₃CN (<b>6</b>), [(3-F-4-MeAni⁺)­(DB­[18]­crown-6)]₂­[SMo₁₂O₄₀^2–]·2CH₃CN (<b>7</b>), and [(3-F-4-MeAni⁺)₂­(DB­[30]­crown-10)]­[SMo₁₂O₄₀^2–]·2CH₃CN (<b>8</b>) (4-MeAni⁺ = 4-methylanilinium; DB[18]­crown-6 = dibenzo[18]­crown-6; 3-F-4-MeAni⁺ = 3-fluoro-4-methyl­anilinium; DB[30]­crown-10 = dibenzo[30]­crown-10) were synthesized. Their crystal architectures were characterized according to the size and charge of the supramolecular cations. In <b>1</b>–<b>4</b>, two adjacent supramolecular cations ([(<i>m</i>-XAni⁺)­(B­[18]­crown-6)]) were connected through π···π interactions forming sandwich-type dimers with the cations that were stacked in an antiparallel manner. In <b>8</b>, DB[30]­crown-10 included two cations constructing a larger divalent supramolecular cation [(3-F-4-MeAni⁺)₂­(DB­[30]­crown-10)]. In <b>1</b>–<b>4</b> and <b>8</b>, the ratio between [SMo₁₂O₄₀^2–] and the supramolecular cations was 1:1, and the latter formed rectangular-assembled structures. In <b>5</b>, the π···π stacking interaction was present in the adjacent B[18]­crown-6. Monovalent supramolecular cations were present in <b>5</b>–<b>7</b> with a ratio of 1:2 between [SMo₁₂O₄₀^2–] and the supramolecular cations. The supramolecular cations formed hexagonal-assembled structures

Rational Synthesis of a Porous Copper(II) Coordination Polymer Bridged by Weak Lewis-Base Inorganic Monoanions Using an Anion-Mixing Method

The use of divalent Cu^II ions and an anion-mixing method led to the rational construction of a porous coordination polymer bridged by weak Lewis-base inorganic CF₃SO₃^– monoanions

Rational Synthesis of a Porous Copper(II) Coordination Polymer Bridged by Weak Lewis-Base Inorganic Monoanions Using an Anion-Mixing Method

The use of divalent Cu^II ions and an anion-mixing method led to the rational construction of a porous coordination polymer bridged by weak Lewis-base inorganic CF₃SO₃^– monoanions

Rational Synthesis of a Porous Copper(II) Coordination Polymer Bridged by Weak Lewis-Base Inorganic Monoanions Using an Anion-Mixing Method

The use of divalent Cu^II ions and an anion-mixing method led to the rational construction of a porous coordination polymer bridged by weak Lewis-base inorganic CF₃SO₃^– monoanions

Rational Synthesis of a Porous Copper(II) Coordination Polymer Bridged by Weak Lewis-Base Inorganic Monoanions Using an Anion-Mixing Method

The use of divalent Cu^II ions and an anion-mixing method led to the rational construction of a porous coordination polymer bridged by weak Lewis-base inorganic CF₃SO₃^– monoanions

Design of Crystalline Spaces for Molecular Rotations in Crystals

4-Methylanilinium derivatives were used to introduce spaces for molecular rotation in crystals. The [Ni­(dmit)₂]⁻ (dmit^2– = 2-thioxo-1,3-dithiole-4,5-dithiolate) salts with supramolecular cations of dibenzo[18]­crown-6 (DB[18]­crown-6) and 4-methylanilinium derivatives, (4-methylanilinium⁺)­(DB­[18]­crown-6)­[Ni­(dmit)₂]⁻ (<b>1</b>), (2-fluoro-4-methylanilinium⁺)­(DB­[18]­crown-6)­[Ni­(dmit)₂]⁻ (<b>2</b>), and (3-fluoro-4-methylanilinium⁺)­(DB­[18]­crown-6)­[Ni­(dmit)₂]⁻ (<b>3</b>) were synthesized. The potential energy curves for the molecular rotations of the cations in the crystals had double minimum shapes with maxima of 100, 210, and 230 kJ mol^–1 for crystals <b>1</b>, <b>2</b>, and <b>3</b>, respectively. Introduction of a methyl substituent at the <i>p</i>-position was effective in reducing the potential energy maxima. For crystals <b>2</b> and <b>3</b>, large dielectric responses originating from the flip-flop motions of the cationic molecules were observed upon applying an AC voltage. The temperature-dependent magnetic susceptibilities of complexes <b>1</b>, <b>2</b>, and <b>3</b> followed the Curie–Weiss law, showing weak antiferromagnetic interactions

Supramolecular Rotators of (Aniliniums)([18]crown-6) in Electrically Conducting [Ni(dmit)₂] Crystals

Supramolecular assemblies of anilinium (Ani⁺) and fluoroanilinium derivatives (FAni⁺) with [18]­crown-6 were introduced into electrically conducting [Ni­(dmit)₂] crystals (dmit^2– is 2-thioxo-1,3-dithiole-4,5-dithiolate). The crystal structures, electrical conductivities, and magnetic susceptibilities of four new crystals of (Ani⁺)­([18]­crown-6)­[Ni­(dmit)₂]₃ (<b>1</b>), (<i>o</i>-FAni⁺)­([18]­crown-6)­[Ni­(dmit)₂]₃ (<b>2</b>), (<i>m</i>-FAni⁺)­([18]­crown-6)­[Ni­(dmit)₂]₃ (<b>3</b>), and (<i>p</i>-FAni⁺)­([18]­crown-6)­[Ni­(dmit)₂]₃ (<b>4</b>) were examined from the viewpoint of dynamic supramolecular rotator structures within the crystals. The crystal structures, electrical conduction, and magnetic properties were classified into group-<b>I</b> (crystals <b>1</b> and <b>4</b>) and group-<b>II</b> (crystals <b>2</b> and <b>3</b>). The hydrogen-bonding interaction between -NH₃⁺ and the oxygen atoms of [18]­crown-6 formed the stand-up configuration of rotator-stator structures of (Ani⁺)­([18]­crown-6) and (FAni⁺)­([18]­crown-6) supramolecules. The potential energy barriers for the 2-fold flip-flop motion of phenyl- and <i>p</i>-fluorophenyl-rings in crystals <b>1</b> and <b>4</b> had a relatively small magnitude of ∼150 kJmol^–1, suggesting that rotations of Ani⁺ and <i>p</i>-FAni⁺ cations around the C-NH₃⁺ axis occurred in the crystals. In contrast, a large magnitude of the potential energy barriers for the rotations of <i>o</i>-FAni⁺ and <i>m</i>-FAni⁺ cations in crystals <b>2</b> and <b>3</b> (>600 kJmol^–1) resulted in static supramolecular cationic structures. The cation:anion ratio of 1:3 in these crystals yielded a trimer π-stack of [Ni­(dmit)₂] with a semiconductor-like temperature dependence. The magnetic susceptibilities of the static crystals <b>2</b> and <b>3</b> were reproduced by the one-dimensional antiferromagnetic linear Heisenberg chain through the one-dimensional linear trimer arrangement. The magnetic susceptibilities of dynamic crystals <b>1</b> and <b>4</b> enhanced electron delocalization through the intratrimer and intertrimer interactions within the trimer stack, where the molecular rotations of Ani⁺ and <i>p</i>-FAni⁺ cations played an important role

Porous Coordination Polymer Polymorphs with Different Flexible Pores Using a Structurally Flexible and Bent 1,3-Bis(4-pyridyl)propane Ligand

Porous coordination polymer (PCP) polymorphs with the formula [Cu­(CF₃SO₃)₂(bpp)₂]_<i>n</i> [<b>1</b> and <b>2</b>, where bpp = 1,3-bis­(4-pyridyl)­propane] have been synthesized and crystallographically characterized, and their distinguishable porous properties have been investigated. <b>1</b> was obtained by the removal of guest acetone molecules from one-dimensional PCP {[Cu­(CF₃SO₃)­(bpp)₂]·CF₃SO₃·2acetone}_<i>n</i> (<b>1</b>⊃2acetone), while <b>2</b> was derived from two-dimensional PCP {[Cu­(CF₃SO₃)₂(bpp)₂]·H₂O}_<i>n</i> (<b>2</b>⊃H₂O) by the loss of guest H₂O molecules. The desolvated PCPs <b>1</b> and <b>2</b> with the same formula [Cu­(CF₃SO₃)₂(bpp)₂] showed distinguishable structures, suggesting PCP polymorphs. In addition, their adsorption behaviors were completely different: <b>1</b> showed adsorption with the structural transformation from closed to open forms, while <b>2</b> appeared to expand its framework for only as long as was required for the passage of guest molecules. To the best of our knowledge, PCP polymorphs showing either of two different types of flexible pores are very rare

Porous Coordination Polymer Polymorphs with Different Flexible Pores Using a Structurally Flexible and Bent 1,3-Bis(4-pyridyl)propane Ligand

Porous coordination polymer (PCP) polymorphs with the formula [Cu­(CF₃SO₃)₂(bpp)₂]_<i>n</i> [<b>1</b> and <b>2</b>, where bpp = 1,3-bis­(4-pyridyl)­propane] have been synthesized and crystallographically characterized, and their distinguishable porous properties have been investigated. <b>1</b> was obtained by the removal of guest acetone molecules from one-dimensional PCP {[Cu­(CF₃SO₃)­(bpp)₂]·CF₃SO₃·2acetone}_<i>n</i> (<b>1</b>⊃2acetone), while <b>2</b> was derived from two-dimensional PCP {[Cu­(CF₃SO₃)₂(bpp)₂]·H₂O}_<i>n</i> (<b>2</b>⊃H₂O) by the loss of guest H₂O molecules. The desolvated PCPs <b>1</b> and <b>2</b> with the same formula [Cu­(CF₃SO₃)₂(bpp)₂] showed distinguishable structures, suggesting PCP polymorphs. In addition, their adsorption behaviors were completely different: <b>1</b> showed adsorption with the structural transformation from closed to open forms, while <b>2</b> appeared to expand its framework for only as long as was required for the passage of guest molecules. To the best of our knowledge, PCP polymorphs showing either of two different types of flexible pores are very rare

Porous Coordination Polymer Polymorphs with Different Flexible Pores Using a Structurally Flexible and Bent 1,3-Bis(4-pyridyl)propane Ligand

Porous coordination polymer (PCP) polymorphs with the formula [Cu­(CF₃SO₃)₂(bpp)₂]_<i>n</i> [<b>1</b> and <b>2</b>, where bpp = 1,3-bis­(4-pyridyl)­propane] have been synthesized and crystallographically characterized, and their distinguishable porous properties have been investigated. <b>1</b> was obtained by the removal of guest acetone molecules from one-dimensional PCP {[Cu­(CF₃SO₃)­(bpp)₂]·CF₃SO₃·2acetone}_<i>n</i> (<b>1</b>⊃2acetone), while <b>2</b> was derived from two-dimensional PCP {[Cu­(CF₃SO₃)₂(bpp)₂]·H₂O}_<i>n</i> (<b>2</b>⊃H₂O) by the loss of guest H₂O molecules. The desolvated PCPs <b>1</b> and <b>2</b> with the same formula [Cu­(CF₃SO₃)₂(bpp)₂] showed distinguishable structures, suggesting PCP polymorphs. In addition, their adsorption behaviors were completely different: <b>1</b> showed adsorption with the structural transformation from closed to open forms, while <b>2</b> appeared to expand its framework for only as long as was required for the passage of guest molecules. To the best of our knowledge, PCP polymorphs showing either of two different types of flexible pores are very rare