Observation of Rare Tri6Di9 Imine Cages Using Highly Fluorinated Building Blocks

Abstract

The first synthesis of an organic Tri6Di9 cage is presented. Two structurally distinct Tri6Di9 cages were synthesised by combining a highly fluorinated aldehyde with two ditopic amines. Although the pure compound could not be isolated despite many attempts, the information obtained is critical for the future design of large supramolecular structures. Computational and experimental methods indicate that the addition of perfluorinated aromatic linkers in the assembly of porous organic cages opens up new possibilities for influencing the reaction pathway towards rare and unknown structures.

Multifold Post‐Modification of Macrocycles and Cages by Isocyanate‐Induced Azadefluorination Cyclisation

“…For comparison, the synthesis of complex compounds, particularly those with three‐dimensional structures, is known to be quite difficult when their formation relies on stepwise irreversible reactions [1f,g] . As dynamic covalent chemistry (DCC) allows for error correction during the formation of the supramolecular structures, selectivities and yields are often high, [1d,f] and their reversible formation using imines, [2b–e,3] boronate esters, [4] and alkynes, amongst others, is very well established today [1f–h] . Modification of the building blocks for the self‐assembly, however, often leads to changes in the outcome of the reaction along kinetic or thermodynamic pathways, [3a] and many systems are susceptible to even the slightest changes in building block geometry [3b,4c] or electronic properties, [2b] stoichiometry, temperature, concentration, or solvent polarity [1d,f,3] .…”

“…As dynamic covalent chemistry (DCC) allows for error correction during the formation of the supramolecular structures, selectivities and yields are often high, [1d,f] and their reversible formation using imines, [2b–e,3] boronate esters, [4] and alkynes, amongst others, is very well established today [1f–h] . Modification of the building blocks for the self‐assembly, however, often leads to changes in the outcome of the reaction along kinetic or thermodynamic pathways, [3a] and many systems are susceptible to even the slightest changes in building block geometry [3b,4c] or electronic properties, [2b] stoichiometry, temperature, concentration, or solvent polarity [1d,f,3] . This is especially true for imine systems, which, formed by the reversible condensation between an amine and an aldehyde, display many ideal dynamic covalent bond characteristics [5] .…”

Mehrfache Postmodifizierung von Makrozyklen und Käfigen durch Isocyanat‐induzierte Azadefluorierungszyklisierung

“…Die dynamisch‐kovalente Chemie (DCC) ermöglicht Fehlerkorrektur während der Bildung der supramolekularen metallfreien Strukturen, dadurch sind Selektivitäten und Ausbeuten oft hoch [1d,f] . Ihre reversible Natur ist bei der Verwendung von Iminen, [2b–e,3] Boronatestern, [4] und Alkinen bereits sehr gut erforscht [1f–h] . Eine Veränderung der Bausteine für die Selbstassemblierung führt jedoch häufig zu Veränderungen des Reaktionsergebnisses entlang kinetischer oder thermodynamischer Pfade [3a] .…”

“…Eine Veränderung der Bausteine für die Selbstassemblierung führt jedoch häufig zu Veränderungen des Reaktionsergebnisses entlang kinetischer oder thermodynamischer Pfade [3a] . Viele Systeme sind selbst gegenüber geringster Veränderungen der Bausteingeometrie, [3b,4c] deren elektronischen Eigenschaften, [2b] Stöchiometrie, Temperatur, Konzentration oder der Polarität des Lösungsmittels anfällig [1d,f,3] . Dies gilt insbesondere für Iminsysteme, welche durch die reversible Kondensation zwischen einem Amin und einem Aldehyd gebildet werden und viele ideale dynamisch‐kovalente Bindungseigenschaften aufweisen [5] .…”