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

Abstract

Neutral flexible bidentate nitrogen donor ligands L n (L bim and L nim ) were designed, synthesized, and utilized as structural frameworks to construct solvent-directed rhenium(I) metallocyclic tubes, dimeric capsules, and intercalated dimers in the solid state. The combination of Re 2 (CO) 10 , 6,11-dihydroxy-5,12-naphthacenedione (H 2 -dhnq) or 1,4dihydroxyanthraquinone (H 2 -dhaq), and L bim or L nim in the presence of benzene (Bz), mesitylene (Mes), or p-xylene (p-xyl) resulted in neutral heteroleptic metallocyclic tubes fac-[{(CO) 3 Re(μ−dhnq)Re(CO) 3 }(μ− L bim )] (1), fac-[{(CO) 3 Re(μ−dhnq)Re(CO) 3 }(μ−L nim )] (2), or fac-[{(CO) 3 Re(μ−dhaq)Re(CO) 3 }(μ−L nim )] ( 3) with/without encapsulated guest solvent(s) depending on the nature of the solvent. Metallocyclic tubes 1 and 3 crystallized with solvent guest molecule(s) as (Bz) 2 @1, (Mes) 2 @1, (Bz)@3, and (p-xyl) 2 @3. On the other hand, metallocyclic tube 1 crystallized as a dimeric capsule (p-xyl)@1 2 in the presence of p-xylene, which acts as a glue between the two metallocyclic tubes stabilized via noncovalent interactions in the solid state. Metallocyclic tubes 2 and 3 in the presence of the mesitylene solvent crystallized as an intercalated dimeric assembly 2 2 •4(Mes) and 3 2 •4(Mes) in the solid state. The results reveal that along with the ligand motifs, the size and shape of methyl-and nonmethyl-substituted aromatic solvents influence the formation of the tubular architecture, dimeric capsule, or intercalated dimers. All of the compounds were confirmed by single-crystal X-ray diffraction analysis and characterized by various analytical and spectroscopic methods. The thermal stability of the assembled host−guest structures was studied by thermogravimetric analysis.

Dinuclear Rhenium(I) Tricarbonyl Complexes as Anticancer Drug Candidates

“…Notably, we have recently reported the crystal structure of the metal complexes. [16] The purity was confirmed by elemental analysis. Remarkably, the herein described double-linked dinuclear rhenium(I) tricarbonyl complexes were easily obtained via one-pot synthesis while other reported dinuclear rhenium(I) tricarbonyl complexes often require several synthetic and purification steps to be obtained.…”