Rhenium‐Linked Multiporphyrin Assemblies — Synthesis and Properties

Abstract

Re(CO) 5 Cl readily reacts with pyridine-derivatized porphyrins to give molecular squares or planar dimers featuring fac-Re(CO) 3 (Cl) corners. Chelating ligands, in sequential combination with pyridine-derivatized porphyrins, can be used to obtain related cofacial porphyrin assemblies. Films and membranes displaying molecular-scale porosity can be generated from squares by: (1) van der Waals aggregation, (2) layer-bylayer assembly chemistry based on zirconium-phosphonate links, or (3) polymerization at liquid-liquid interfaces. In addition to molecular sieving, films, membranes, and free assemblies have been used for chemical sensing, oxidative catalysis, and light-to-electrical energy conversion. The assemblies have also been used to investigate fundamental aspects of light-induced energy and electron transfer.

Ion Transport through Lipid Bilayers by Synthetic Ionophores: Modulation of Activity and Selectivity

“…Low spin d 6 fac-{Re I Br(CO) 3 } metal fragments were used as corners, since they are known to form kinetically inert and thermodynamically stable bonds with pyridyl ligands, thus avoiding ligand exchange or scrambling. 36 The resulting adducts roughly define an empty cube that spans ca. half of the thickness of the phospholipid bilayer.…”

“…In our design, we chose a 10,20- meso -dipyridylporphyrin, a linear ligand that upon binding to a cis -coordinating metal fragment forms a 4 + 4 metallacycle about 2 nm large. Low spin d 6 fac -{Re I Br(CO) 3 } metal fragments were used as corners, since they are known to form kinetically inert and thermodynamically stable bonds with pyridyl ligands, thus avoiding ligand exchange or scrambling . The resulting adducts roughly define an empty cube that spans ca.…”

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

“…The design and synthesis of discrete metallosupramolecules such as helicates, mesocates, and two-dimensional (2D) and three-dimensional (3D) metallocycles with/without cavities and cages have attracted much attention not only due to their potential applications in various fields but also for providing hitherto unknown aesthetically pleasing simple to complex molecular architectures via simple combinations of pre-designed ligands and suitable metal ions or complex motifs. − Among the various metal ion sources, Re 2 (CO) 10 and [Re­(CO) 5 X] where X = Cl or Br are two of the versatile organometallic complexes used as pre-designed metal sources for assembling various types of fac -[Re­(CO) 3 ]- and fac -[Re­(CO) 3 X]-core-based supramolecules. − Due to their intrinsic properties such as kinetic stability, and phosphorescence, and their importance in host–guest chemistry, catalysis, photosensitizers in hydrogen evolution, carbon dioxide reduction, bioimaging, and anticancer agents, the research is being directed towards making new functional rheniumcarbonyl-based metallosupramolecules. − Although error-free synthetic principles are currently available to make desired rheniumcarbonyl-core-based molecular squares, rectangles, prisms, bowls, spheroids, and other cavity-containing metallomacrocycles, ,,,,− the synthetic approaches for self-assembling mononuclear-, dinuclear-, trinuclear-, and polynuclear-helicates are scarce . However, helicates and meso-helicates based on other metal ions and organic ligand strands are well-known and prevalent. − To the best of our knowledge, only a handful of fac -[Re­(CO) 3 ]-core-based helicates are known to date .…”