Calix[4]arene-Analogous Technetium Supramolecules

Abstract

Calix­[4]­arene-analogous technetium supramolecules (1 and 2) were assembled using (NBu4)­[Tc2(μ-Cl)3(CO)6] and neutral flexible bidentate nitrogen-donor ligands (L1 and L2) consisting of four arene units covalently joined via methylene units. The neutral homoleptic technetium macrocycles adopt a partial cone/cone-shaped conformation in the solid state. These supramolecules are the first example of fac-[Tc­(CO)3]+ core-based metallocalix[4]­arenes and second example of fac-[Tc­(CO)3]+ core-based metallomacrocycles. Structurally similar fac-[Re­(CO)3]+ core-based macrocycles (3 and 4) were also prepared using [Re­(CO)5X] (where X = Cl or Br) and L1 or L2. The products were characterized spectroscopically and by X-ray analysis.

Self-Assembly of Rhenium(I) Double-Stranded Helicate and Mesocate from Flexible Ditopic Benzimidazolyl/Naphthanoimidazolyl N-Donor and Rigid Bis-Chelating Hydroxyphenylbenzimidazolyl N∩OH-Donor Ligands: Synthesis, Characterization, and Photophysical and B-DNA Docking Studies

“…Then 2-(2-hydroxyphenyl)-1 H -benzimidazole, naphtho­[2,3- d ]­imidazole, 2,4-bis­(bromomethyl)-1,3,5-trimethylbenzene, bis-(mesityl)­methane, and bis­(3-(bromomethyl)-2,4,6-trimethylphenyl)­methane were synthesized according to the literature methods. Bis­(3-((1 H -benzoimidazol-1-yl)­methyl)-2,4,6-trimethylphenyl)­methane (L 2 ), bis­(3-((1 H -naphtho­[2,3- d ]­imidazol-1-yl)­methyl)-2,4,6-trimethylphenyl)­methane (L 3 ), bis­(4-(naphtho­[2,3- d ]­imidazol-1-yl-methyl)­phenyl)­methane (L 4 ), and 1,4-bis­(2-(2-hydroxyphenyl)­benzimidazole-1-yl-methyl)­benzene (L , 1 H 2 -RBC), were synthesized by previously reported methods. Toluene, hexane, and tetrahydrofuran (THF) were purified and distilled using the conventional procedure.…”

Solvent-Directed Rhenium(I) Metallocyclic Tubes, Dimeric Capsule, and Intercalated Dimers

“…Among the many metal–organic macrocycles, bowl-shaped molecules, known as metallocavitands, synthesized from various naked/partially protected metal ions have attracted much research interest. − For instance, considerable attention has been devoted to the construction of fac -[Re(CO) 3 ] core-based metallocycles. − Over the past few years, neutral flexible bidentate donors consisting of diphenylmethane (−Ph–CH 2 –Ph−) or dimesitylenemethane as the central spacer and two terminal heterocycles, (benzimidazolyl/naphthanoimidazolyl/2-alkyl- or 2-phenyl-substituted benzimidazolyl), have been used in the self-assembly of dinuclear heteroleptic or mononuclear homoleptic metallocavitands. This assembly is achieved using a rigid bis-chelating donor, flexible bidentate ligands, and rhenium sources in the presence of high-boiling aromatic solvents via a one-pot solvothermal approach . The depth, size, and nature of the hydrophobic inner cavity of the metallocavitands can be tuned by modulating either the substituents on the flexible ligand or bis-chelating donors.…”

Pyrene-Based Cationic Fluorophores with High Affinity for BF4–, PF6–, and ClO4– Anions: Detection and Removal

“…. Among them, the electrostatic interaction occurs between cations and anions with a relatively strong interaction without direction and is one of the important driving forces for the formation of supramolecular architectures, molecular recognition, and protein folding …”

“…Molecular self-assembly is spontaneous behavior via weak intra-/intermolecular interactions (such as electrostatic interactions, van der Waals forces, H-bonding, etc.). 1 Among them, the electrostatic interaction occurs between cations and anions with a relatively strong interaction without direction and is one of the important driving forces for the formation of supramolecular architectures, 2 molecular recognition, 3 and protein folding. 4 Anions illustrating a 3D spatial structure, such as BF 4 − and PF 6…”