Cyclic monoterpenes trapped in a polyaromatic capsule: unusual selectivity, isomerization, and volatility suppression

Abstract

Cyclic monoterpenes (CMTs) are intractable natural products with high volatility and strong odors so that there has been no molecular receptor capable of selectively and tightly trapping CMTs in both...

Caged bulky organic dyes in a polyaromatic framework and their spectroscopic peculiarities

“…1b) shows efficient/selective binding abilities toward various synthetic compounds 8 as well as biomolecules in aqueous solution, through efficient hydrophobic effect and multipoint π–π/CH–π/hydrogen-bonding interactions. 6,9 However, like other coordination cages reported previously, 4 capsule 2 exhibits no binding ability toward synthetic dyes with multiple bulky substituents , whose sizes are larger than that of the cavity ( d = 1.2 nm), owing to the closed spherical framework (Fig. 1d).…”

Protection and Transformation of Natural Products within Aqueous Metal‐Organic Cages

“…The potential of the spherical cavity of capsule 9 to induce new behavior and protection was also demonstrated for cyclic monoterpene guests (CMTs) [51] . Terpenes, including their acyclic and cyclic derivatives, are highly abundant in nature and many of them display medicinal use [52] and several industrial applications [53,54] .…”

“…Terpenes, including their acyclic and cyclic derivatives, are highly abundant in nature and many of them display medicinal use [52] and several industrial applications [53,54] . In water, the Pt(II)‐based capsule 9 was observed to bind in 1 : 1 fashion diverse CMTs such as menthone ( MTO ), p ‐menthane ( MTA ), (−)‐camphor ( CMP ), menthol ( MTL ), or (−)‐borneol ( BNL ) [51] . Competitive studies revealed a binding affinity order in favor of menthone ( MTO ≫ MTA > MTL > CMP ≫ BNL ); arising from the complementarity of the guest size/shape to the cavity and host‐guest interactions (Figure 4a).…”

Supramolecular Singlet Fission of Pentacene Dimers within Polyaromatic Capsules

“…The resultant host–guest complexes with polyaromatic frameworks (i.e., naphthalene, anthracene, and phenanthrene) displayed high quantum yields of the triplet pairs and individual triplet (up to 179% and 53% yields, respectively) under high dilution conditions, due to a significant increase in local concentration (so-called concentration effect). Furthermore, a covalently linked pentacene dimer with similar bulky groups clearly exhibited two triplet pair intermediates in excellent total quantum yields (≥190%), upon encapsulation (via compression effect) − by the polyaromatic capsules in water. The tuning of the SF characters of not only the covalent dimer but also the noncovalent one was demonstrated for the first time using our capsules.…”