Self-Assembly of Tetraphenol and Its Complexes with Aromatic Diamines: Novel Interpenetrating and Noninterpenetrating Organic Assemblies

The solid-state self-assembly of tetraphenol 1 and its complexes with 4,4‘-bipyridine (bpy), trans-1,2-bis(4-pyridyl)ethylene (bpy-ethe), and 1,2-bis(4-pyridyl)ethane (bpy-etha) is reported. Forces such as O−H···N, O−H···O and weak interactions prevalent in the structures promote the formation of interpenetrating and noninterpenetrating supramolecular assemblies. The crystal structure of tetraphenol 1 is characterized by the formation of hydrogen-bonded eight-membered cyclic structures. A diamondoid network was observed in the crystal lattice of 1·bpy with tetraphenol as the node and 4,4‘-bipyridine as the spacer. The resulting superadamantane framework is filled via self-clathration to give an 8-fold interpenetrating network. 1·bpy-ethe self-assembled into a stepladder-type arrangement with the bpy-ethe linkers forming the rungs of the ladder. In the lattice of complex 1·bpy-etha, ladder-type and cyclic structures organized adjacent to each other and the water molecules present inside the lattice stabilized the assembly through hydrogen bonding. No interpenetrating networks were observed in the lattices of 1·bpy-ethe and 1·bpy-etha. The C3 symmetry of tetraphenol 1, orientation of the -OH groups, and the rigidity or the flexibility of the linking aza compounds together with the interplay of hydrogen bonds and packing forces facilitate the formation of stable supramolecular architectures

Formation of Interesting Organic Supramolecular Structures in the Solid-State Self-Assembly of Triphenol Adducts

Utilization of the interplay of dimensionality (1D, 2D, 3D), orientation of functional groups of the building blocks, influence of rigid/flexible linking groups, and weak interactions provides an interesting route for the creation of novel supramolecular architectures in the crystal lattice. Molecular complexes of triphenol 1 with aza compounds such as pyrazine (pyz), 1,10-phenanthroline (phen), 4,4‘-bipyridyl (bpy), trans-1,2-bis(4-pyridyl)ethylene (bpy-ethe), and 1,2-bis(4-pyridyl)ethane (bpy-etha) have been investigated using X-ray diffraction techniques. The rigid 3D triphenol 1 self-assembles to form a distorted ladder, which organizes into columns via O−H···O hydrogen bonds. Self-assembly of complexes 1·pyz and 1·bpy-ethe result in ladder-type structures with pyz and bpy-ethe molecules forming the rungs of the ladder. The molecular components in complex 1·phen aggregate into 1D hydrogen-bonded chains. A 4-fold self-clathration was observed in the crystal lattice of 1·bpy. Owing to the expanded lattice of the complex 1·bpy-etha, one of the reactant molecules of bpy-etha fills the spaces as guest molecules. The nature of the aza groups helps to enhance the overall volume of the crystal lattice thus leading to the formation of various supramolecular assemblies

Self-Assembly of Tetraphenol and Its Complexes with Aromatic Diamines: Novel Interpenetrating and Noninterpenetrating Organic Assemblies

The solid-state self-assembly of tetraphenol 1 and its complexes with 4,4‘-bipyridine (bpy), trans-1,2-bis(4-pyridyl)ethylene (bpy-ethe), and 1,2-bis(4-pyridyl)ethane (bpy-etha) is reported. Forces such as O−H···N, O−H···O and weak interactions prevalent in the structures promote the formation of interpenetrating and noninterpenetrating supramolecular assemblies. The crystal structure of tetraphenol 1 is characterized by the formation of hydrogen-bonded eight-membered cyclic structures. A diamondoid network was observed in the crystal lattice of 1·bpy with tetraphenol as the node and 4,4‘-bipyridine as the spacer. The resulting superadamantane framework is filled via self-clathration to give an 8-fold interpenetrating network. 1·bpy-ethe self-assembled into a stepladder-type arrangement with the bpy-ethe linkers forming the rungs of the ladder. In the lattice of complex 1·bpy-etha, ladder-type and cyclic structures organized adjacent to each other and the water molecules present inside the lattice stabilized the assembly through hydrogen bonding. No interpenetrating networks were observed in the lattices of 1·bpy-ethe and 1·bpy-etha. The C3 symmetry of tetraphenol 1, orientation of the -OH groups, and the rigidity or the flexibility of the linking aza compounds together with the interplay of hydrogen bonds and packing forces facilitate the formation of stable supramolecular architectures

Characterization of Pseudopolymorphs of a Hydroxybenzoic Acid Derivative

Hydroxybenzoic acid is used in many applications, including medicine and polymer synthesis. The synthesis, self-assembly, and characterization of three pseudopolymorphs of a derivative of a widely used 4-hydroxybenzoic acid (1) are described in detail. In this investigation, we have incorporated hydrophobic (biphenyl groups) and hydrophilic (-OH and -CO2H) groups on an aromatic ring to influence the self-assembly in the solid lattice. Compound 1 crystallizes into three crystalline forms:  (i) monoclinic from a solution of DMSO (1A), (ii) triclinic from a 1:1 solution of DMSO/hot ethyl acetate (1B), and (iii) triclinic from pyridine solution (1C). The formation of these pseudopolymorphs and the structural similarities in their packing motifs can be rationalized through a few multipoint solute−solvent interactions. In all three structures, the crystallographic aspects pertaining to the influence of solvent molecules towards the formation of hydrogen bonded network structures are described. In addition to the strong hydrogen bonds, intermolecular C−H···O, C−H···π, and π···π interactions were found to stabilize the crystal structures

Self-Assembly of Pentaphenol Adducts: Formation of 3D Network and Ladder-type Supramolecular Structures in the Solid State

The interplay of strong and weak hydrogen bonds has been used to produce self-assembled architectures by the complexation of pentaphenol 1 with the diaza compounds such as pyrazine (pyz), 4,4‘-bipyridine (bpy), trans-1,2-bis(4-pyridyl)ethylene (bpy-ethe), and 1,2-bis(4-pyridyl)ethane (bpy-etha). In all cases, the primary recognition patterns involve O−H···N and O−H···O hydrogen bonds. The crystal structure of complex 1·pyz involves ladder structures stabilized by π···π stacking between the benzene rings of 1 and pyz. Interpenetrating ladder architectures were observed in the crystal lattice of complex 1·bpy. A network of cyclic cavities and ladder structures dominated the solid lattice of complexes 1·bpy-ethe and 1·bpy-etha. Both complexes are isomorphous; they crystallize as dihydrates and also have the same space group, P1̄. In the complex 1·bpy-ethe, the existence of C−H···π interactions involving the double bond of the ethene moiety provides additional stabilization to the three-dimensional (3D) network structure. The formation of various supramolecular motifs from the complexes can be attributed to the 3D structure of molecule 1 and the flexibility of the linking aza molecules in the crystal lattice

Formation of Interesting Organic Supramolecular Structures in the Solid-State Self-Assembly of Triphenol Adducts

Utilization of the interplay of dimensionality (1D, 2D, 3D), orientation of functional groups of the building blocks, influence of rigid/flexible linking groups, and weak interactions provides an interesting route for the creation of novel supramolecular architectures in the crystal lattice. Molecular complexes of triphenol 1 with aza compounds such as pyrazine (pyz), 1,10-phenanthroline (phen), 4,4‘-bipyridyl (bpy), trans-1,2-bis(4-pyridyl)ethylene (bpy-ethe), and 1,2-bis(4-pyridyl)ethane (bpy-etha) have been investigated using X-ray diffraction techniques. The rigid 3D triphenol 1 self-assembles to form a distorted ladder, which organizes into columns via O−H···O hydrogen bonds. Self-assembly of complexes 1·pyz and 1·bpy-ethe result in ladder-type structures with pyz and bpy-ethe molecules forming the rungs of the ladder. The molecular components in complex 1·phen aggregate into 1D hydrogen-bonded chains. A 4-fold self-clathration was observed in the crystal lattice of 1·bpy. Owing to the expanded lattice of the complex 1·bpy-etha, one of the reactant molecules of bpy-etha fills the spaces as guest molecules. The nature of the aza groups helps to enhance the overall volume of the crystal lattice thus leading to the formation of various supramolecular assemblies

Characterization of Pseudopolymorphs of a Hydroxybenzoic Acid Derivative

Hydroxybenzoic acid is used in many applications, including medicine and polymer synthesis. The synthesis, self-assembly, and characterization of three pseudopolymorphs of a derivative of a widely used 4-hydroxybenzoic acid (1) are described in detail. In this investigation, we have incorporated hydrophobic (biphenyl groups) and hydrophilic (-OH and -CO2H) groups on an aromatic ring to influence the self-assembly in the solid lattice. Compound 1 crystallizes into three crystalline forms:  (i) monoclinic from a solution of DMSO (1A), (ii) triclinic from a 1:1 solution of DMSO/hot ethyl acetate (1B), and (iii) triclinic from pyridine solution (1C). The formation of these pseudopolymorphs and the structural similarities in their packing motifs can be rationalized through a few multipoint solute−solvent interactions. In all three structures, the crystallographic aspects pertaining to the influence of solvent molecules towards the formation of hydrogen bonded network structures are described. In addition to the strong hydrogen bonds, intermolecular C−H···O, C−H···π, and π···π interactions were found to stabilize the crystal structures

Formation of Interesting Organic Supramolecular Structures in the Solid-State Self-Assembly of Triphenol Adducts

Utilization of the interplay of dimensionality (1D, 2D, 3D), orientation of functional groups of the building blocks, influence of rigid/flexible linking groups, and weak interactions provides an interesting route for the creation of novel supramolecular architectures in the crystal lattice. Molecular complexes of triphenol 1 with aza compounds such as pyrazine (pyz), 1,10-phenanthroline (phen), 4,4‘-bipyridyl (bpy), trans-1,2-bis(4-pyridyl)ethylene (bpy-ethe), and 1,2-bis(4-pyridyl)ethane (bpy-etha) have been investigated using X-ray diffraction techniques. The rigid 3D triphenol 1 self-assembles to form a distorted ladder, which organizes into columns via O−H···O hydrogen bonds. Self-assembly of complexes 1·pyz and 1·bpy-ethe result in ladder-type structures with pyz and bpy-ethe molecules forming the rungs of the ladder. The molecular components in complex 1·phen aggregate into 1D hydrogen-bonded chains. A 4-fold self-clathration was observed in the crystal lattice of 1·bpy. Owing to the expanded lattice of the complex 1·bpy-etha, one of the reactant molecules of bpy-etha fills the spaces as guest molecules. The nature of the aza groups helps to enhance the overall volume of the crystal lattice thus leading to the formation of various supramolecular assemblies

Self-Assembly of Pentaphenol Adducts: Formation of 3D Network and Ladder-type Supramolecular Structures in the Solid State

The interplay of strong and weak hydrogen bonds has been used to produce self-assembled architectures by the complexation of pentaphenol 1 with the diaza compounds such as pyrazine (pyz), 4,4‘-bipyridine (bpy), trans-1,2-bis(4-pyridyl)ethylene (bpy-ethe), and 1,2-bis(4-pyridyl)ethane (bpy-etha). In all cases, the primary recognition patterns involve O−H···N and O−H···O hydrogen bonds. The crystal structure of complex 1·pyz involves ladder structures stabilized by π···π stacking between the benzene rings of 1 and pyz. Interpenetrating ladder architectures were observed in the crystal lattice of complex 1·bpy. A network of cyclic cavities and ladder structures dominated the solid lattice of complexes 1·bpy-ethe and 1·bpy-etha. Both complexes are isomorphous; they crystallize as dihydrates and also have the same space group, P1̄. In the complex 1·bpy-ethe, the existence of C−H···π interactions involving the double bond of the ethene moiety provides additional stabilization to the three-dimensional (3D) network structure. The formation of various supramolecular motifs from the complexes can be attributed to the 3D structure of molecule 1 and the flexibility of the linking aza molecules in the crystal lattice

Formation of Interesting Organic Supramolecular Structures in the Solid-State Self-Assembly of Triphenol Adducts

Utilization of the interplay of dimensionality (1D, 2D, 3D), orientation of functional groups of the building blocks, influence of rigid/flexible linking groups, and weak interactions provides an interesting route for the creation of novel supramolecular architectures in the crystal lattice. Molecular complexes of triphenol 1 with aza compounds such as pyrazine (pyz), 1,10-phenanthroline (phen), 4,4‘-bipyridyl (bpy), trans-1,2-bis(4-pyridyl)ethylene (bpy-ethe), and 1,2-bis(4-pyridyl)ethane (bpy-etha) have been investigated using X-ray diffraction techniques. The rigid 3D triphenol 1 self-assembles to form a distorted ladder, which organizes into columns via O−H···O hydrogen bonds. Self-assembly of complexes 1·pyz and 1·bpy-ethe result in ladder-type structures with pyz and bpy-ethe molecules forming the rungs of the ladder. The molecular components in complex 1·phen aggregate into 1D hydrogen-bonded chains. A 4-fold self-clathration was observed in the crystal lattice of 1·bpy. Owing to the expanded lattice of the complex 1·bpy-etha, one of the reactant molecules of bpy-etha fills the spaces as guest molecules. The nature of the aza groups helps to enhance the overall volume of the crystal lattice thus leading to the formation of various supramolecular assemblies