Sumanene Derivatives Research Articles

Expanding the library of sumanene molecular receptors for caesium-selective potentiometric sensors.

This paper reports the synthesis and characterization of eight sumanene molecular receptors for the selective recognition of caesium cations (Cs+). The sumanene derivatives differed in the number (from one to nine), type (electron donating or electron withdrawing) and method of the attachment (functionalization of sumanene at the benzylic or aromatic carbons) of substituents in the sumanene skeleton. The ultimate goal of this work was to investigate the prospective use of various sumanene derivatives in the design of Cs+-selective potentiometric sensors, thus, expanding the library of sumanene receptors for such applications. Spectroscopic fluorescence titration with caesium hexafluorophosphate revealed that the formation of sandwich complexes is highly favourable, but the steric hindrance of bulky substituents can disrupt this preference. In the case of triaryl-substituted sumanene derivatives, theoretical calculations show that, indeed, sandwich complexes are energetically more advantageous by 2.3 times than 1 : 1 complexes. Furthermore, such functionalization significantly increases receptor solubility in the polymeric membrane of the potentiometric sensors, which was quantitatively evaluated with the COSMO model.

Oxidation-derived anticancer potential of sumanene-ferrocene conjugates.

An effective synthetic protocol towards the oxidation of sumanene-ferrocene conjugates bearing one to four ferrocene moieties has been established. The oxidation protocol was based on the transformation of FeII from ferrocene to FeIII-containing ferrocenium cations by means of the treatment of the title organometallic buckybowls with a mild oxidant. Successful isolation of these ferrocenium-tethered sumanene derivatives 5-7 gave rise to the biological evaluation of the first, buckybowl-based anticancer agents, as elucidated by in vitro assays with human breast adenocarcinoma cells (MDA-MB-231) and embryotoxicity trials in zebrafish embryos supported with in silico toxicology studies. The designed ferrocenium-tethered sumanene derivatives featured attractive properties in terms of their use in cancer treatments in humans. The tetra-ferrocenium sumanene derivative 7 featured especially beneficial biological features, elucidated by low (<40% for 10 μM) viabilities of MDA-MB-231 cancer cells together with a 1.4-1.7-fold higher viability of normal cells (human mammary fibroblasts, HMF) for respective concentrations. Compound 7 featured significant cytotoxicity against cancer cells thanks to the presence of sumanene and ferrocenium moieties; the latter motif also provided the selectivity of anticancer action. The biological properties of 7 were also improved in comparison with those of native building blocks, which suggested the effects of the presence of the sumanene skeleton towards the anticancer action of this molecule. Ferrocenium-tethered sumanene derivatives exhibited potential towards the generation of reactive oxygen species (ROS), responsible for biological damage to the cancer cells, with the most efficient generation of the tetra-ferrocenium sumanene derivative 7. Derivative 7 also did not show any embryotoxicity in zebrafish embryos at the tested concentrations, which supports its potential as an effective and cancer-specific anticancer agent. In silico computational analysis also showed no chromosomal aberrations and no mutation with AMES tests for the compound 7 tested with and without microsomal rat liver fractions, which supports its further use as a potent drug candidate in detailed anticancer studies.

Sumanene-carbazole conjugate with push-pull structure and its chemoreceptor application.

The first-of-its-kind tetra-substituted sumanene derivative, featuring the push-pull chromophore architecture, has been successfully designed. The inclusion of both strong electron-withdrawing (CF3) and electron-donating (carbazole) moietiesin this buckybowl compound has enhanced the charge transfer characteristics of the molecule. This enhancement was supported by ultraviolet-visible (UV-Vis) and emission spectra analyses along with density functional theory (DFT) calculations. The application of the title sumanene-carbazole push-pull chromophore as a selective recognition material for cesium cations (Cs+) was also presented. The title compound exhibited effective and selective Cs+-trapping ability, characterized by a high apparent binding constant value (at the level of 105) and a low limit of detection (0.09-0.13 μM). Owing to the tuned optical properties of the title push-pull chromophore, this study marks the first time in sumanene-tethered chemoreceptor chemistry where efficient tracking of Cs+ binding was possible with both absorption and fluorescence spectroscopies. This work introduces a new approach toward tuning the structure of bowl-shaped optical chemoreceptors.

Circular dichroism simulations of chiral buckybowls by means curvature analyses

A detailed understanding and interpretation of chiral properties of molecular systems, especially in condensed phase, often requires computational models that allow their structural and electronic features to be connected to the observed experimental spectra. The present paper is focused on modelling the circular dichroism spectra of chiral buckybowls, combining topological aspects and the density functional theory. For the first time Ball Pivoting Algorithm was proposed to hook up the chemical topology to the DFT through the surface reconstruction. Particularly, the gaussian curvature of a constructed probe set of corannulene and sumanene derivatives was used as discriminant parameter to benchmark a list of 10 functionals (B3LYP, B97D, M06-2X, HSEH1PBE, wB97XD, CAM-B3LYP, LC-wPBE, TPSSTPSS, mPW1PW91 and APFD). The latter provide to be noticeably accurate to reproduce the curvature effect of the considered molecules. A TD-DFT/BOMD mixed approach provided a comprehensive overview of the spectral chiral pattern prediction trends when multiple DFT functionals are scanned. The preliminary topological analysis efforts were then recompensed with the very precise computed CD spectra, again APFD confirmed as the leader functional, this time for TD-DFT vertical transition calculations. Therefore, we strongly recommend the use of the of dispersion embedded APFD functional coupled with the 6–311++G(2d,2p) basis set for the computation of the functionalized chiral buckybowls ECD spectra.© 2017 Elsevier Inc. All rights reserved.

Collective bending motion of a two-dimensionally correlated bowl-stacked columnar liquid crystalline assembly under a shear force.

Stacked teacups inspired the idea that columnar assemblies of stacked bowl-shaped molecules may exhibit a unique dynamic behavior, unlike usual assemblies of planar disc- and rod-shaped molecules. On the basis of the molecular design concept for creating higher-order discotic liquid crystals, found in our group, we synthesized a sumanene derivative with octyloxycarbonyl side chains. This molecule forms an ordered hexagonal columnar mesophase, but unexpectedly, the columnar assembly is very soft, similar to sugar syrup. It displays, upon application of a shear force on solid substrates, a flexible bending motion with continuous angle variations of bowl-stacked columns while preserving the two-dimensional hexagonal order. In general, alignment control of higher-order liquid crystals is difficult to achieve due to their high viscosity. The present system that brings together higher structural order and mechanical softness will spark interest in bowl-shaped molecules as a component for developing higher-order liquid crystals with unique mechanical and stimuli-responsive properties.

Application of Monoferrocenylsumanenes Derived from Sonogashira Cross-Coupling or Click Chemistry Reactions in Highly Sensitive and Selective Cesium Cation Electrochemical Sensors.

This paper reports the synthesis and characterization of novel monoferrocenylsumanenes obtained by means of the Sonogashira cross-coupling or click chemistry reaction as well as their application in cesium cation electrochemical sensors. A new synthetic protocol based on Sonogashira cross-coupling was developed for the synthesis of monoferrocenylsumanene or ethynylsumanene. The click chemistry reaction was introduced to the sumanene chemistry through the synthesis of 1,2,3-triazole containing monoferrocenylsumanene. The designed synthetic methods for the modification of sumanene at the aromatic position proved to be efficient and proceeded under mild conditions. The synthesized sumanene derivatives were characterized by detailed spectroscopic analyses of the synthesized sumanene derivatives. The supramolecular interactions between cesium cations and the synthesized monoferrocenylsumanenes were spectroscopically and electrochemically investigated. Furthermore, the design of the highly selective and sensitive cesium cation fluorescence and electrochemical sensors comprising the synthesized monoferrocenylsumanenes as receptor compounds was analyzed. The tested cesium cation electrochemical sensors showed excellent limit of detection values in the range of 6.0-9.0 nM. In addition, the interactions between the synthesized monoferrocenylsumanenes and cesium cations were highly selective, which was confirmed by emission spectroscopy, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), and cyclic voltammetry.

Theoretical study on the relationship between the molecular structures and optoelectronic properties of aromatic-fluorinated sumanene derivatives

The relationship between the structures and optoelectronic properties of sumanene and its aromatic-fluorinated derivatives has been systematically studied in depth.

(Invited) Sumanenyl Cations As Redox-Active Buckybowls

Sumanene is one of the pristine buckybowls, which possesses C3v symmetric fragment of C60. The most characteristic feature of its structure is that sumanene has three benzylic positions on its periphery, therefore, potentially 6 electron redox systems are considered from the corresponding trianions to trications. In this presentation, I demonstrate the generation of the trication or monocation species of aryl-substituted sumanene derivatives, and show some properties including the redox propertiy.

Structural Symmetry and Spin Multiplicity of Sumanene Derivative Radical Molecules

Structural Symmetry and Spin Multiplicity of Sumanene Derivative Radical Molecules

Insights on Redox Properties of Sumanene Derivatives for High-Performance Organic Cathodes.

Despite the potential of large organic molecules for insoluble cathode materials in lithium-ion batteries, they have attracted less attention owing to the penalty in the molecular weight. Herein, an advanced computational modeling approach is employed to comprehensively explore the electrochemical characteristics and theoretical charge/energy storage capability for a series of sumanene derivatives. It is highlighted from this investigation that the carbonyl moiety is generally beneficial to the improvement of the redox properties for the sumanenes. The sumanene with hexagon rings fully functionalized by six carbonyls particularly exhibits both the remarkably high redox potential (3.53 V vs Li/Li+) and performance parameters (454 mAh/g and 1129 mWh/g), implying its candidacy as high-potential organic cathodes. It is further demonstrated from a universal relationship of redox potential-electronic property-solvation property that a sumanene derivative would experience a two-stage discharging behavior. This indicates that the sumanene derivative would be cathodically inactive due to a sudden increase of solvation energy.

Tris(ferrocenylmethidene)sumanene: synthesis, photophysical properties and applications for efficient caesium cation recognition in water.

The synthesis of a sumanene derivative bearing three ferrocenyl substituents is presented. This conjugated compound is solution-processable, shows red-light emission with high fluorescence quantum yield and can be used for the construction of the first buckybowl-based sensor for the selective and effective recognition of caesium cations (Cs+) in aqueous solution.

(Invited) Synthesis and Redox Property of Sumanenyl Trication

Sumanene, a bowl-shaped aromatic molecule, possesses the partial structure of C60 and shows unique structural and physical properties based on its curved pi-conjugated system. One of the characteristic features of sumanene is the presence of three benzylic carbons, which allow us to generate the corresponding cation, anion, and carbene species. Here we report the successful generateon, isolateon and redox property of sumanenyl tri-cations. Sumanenyl tri-cations (1) were obtained in high yield by acid-triggered generateon o\\from the corresponding hydroxyl-substituted sumanene derivative as a precursor. 1 reacted with the hydride donor, giving a tri-phenyl sumanene (2, 2’) and quinoidal sumanene (3’) in the presence and the absence of acid, respectively. Cyclic voltammetry revealed multi-step redox property of 1. Reductive wave at −1.28 V was observed as 2 electrons reduction without acid. In contrast, reductive wave at −1.17 V and −1.68 V were observed as 1 electron reduction with acid. Figure 1

Correction: Sumanene derivatives functionalized at the internal carbon.

Correction for 'Sumanene derivatives functionalized at the internal carbon' by Niti Ngamsomprasert et al., Chem. Commun., 2017, 53, 697-700.

A Hydrogen‐Bonded Hexagonal Buckybowl Framework

AbstractA hydrogen‐bonded two‐dimensionally networked buckybowl architecture is presented. Two types of hexagonal network (HexNet) structures (CPSM‐1 and CPSM‐2) have been achieved based on a sumanene derivative (CPSM) possessing 4,4′‐dicarboxy‐o‐terphenyl groups in the periphery. CPSM‐1 has a waved HexNet structure with an alternate alignment of upward and downward bowls. CPSM‐2 has a bilayered HexNet structure composed of hamburger‐shaped dimers of the bowls. This demonstrates that non‐planar π‐systems can be networked two‐dimensionally by an appropriate supramolecular synthon to achieve structurally well‐defined unique bumpy π‐sheets. Furthermore, we revealed that CPSM‐2 undergoes anisotropic shrinking along the c axis by 11 % under high pressure conditions (970 MPa). The shrinkage is brought about by offset sliding between bumpy π‐surfaces of the bilayered HexNet sheets.

A Hydrogen-Bonded Hexagonal Buckybowl Framework.

A hydrogen-bonded two-dimensionally networked buckybowl architecture is presented. Two types of hexagonal network (HexNet) structures (CPSM-1 and CPSM-2) have been achieved based on a sumanene derivative (CPSM) possessing 4,4'-dicarboxy-o-terphenyl groups in the periphery. CPSM-1 has a waved HexNet structure with an alternate alignment of upward and downward bowls. CPSM-2 has a bilayered HexNet structure composed of hamburger-shaped dimers of the bowls. This demonstrates that non-planar π-systems can be networked two-dimensionally by an appropriate supramolecular synthon to achieve structurally well-defined unique bumpy π-sheets. Furthermore, we revealed that CPSM-2 undergoes anisotropic shrinking along the c axis by 11 % under high pressure conditions (970 MPa). The shrinkage is brought about by offset sliding between bumpy π-surfaces of the bilayered HexNet sheets.

(Invited) Design of Bowl-Shaped Molecules Toward Dielectric Responsive Materials

Organic dielectric materials that can respond to electric fields have drawn much attention because of their potential applications to memory and sensing devices. One of the essential requirements for organic dielectric materials is the ability of changing the overall dipole moment in response to external electric fields. In this context, sumanene derivatives featuring a bowl-shaped skeleton are attractive, because they undergo a bowl-to-bowl inversion, which is accompanied by the inversion of the molecular dipole. As the bowl-to-bowl inversion would be facilitated in soft mesophases, liquid-crystalline (LC) sumanenes, for example, are expected to provide an interesting building block for the design of organic dielectric materials. While many examples of crystalline sumanenes have so far been reported, there is no sumanene derivative that can exhibit an LC mesophase. We recently found that sumanene, when carrying six alkyl side chains, successfully shows an LC mesophase over a wide temperature range. Herein, we report the synthesis, assembly structure, and dielectric properties of the new hexa-substituted sumanenes. Figure 1

Intercolumnar Interactions Control the Local Orientations within Columnar Stacks of Sumanene and Sumanene Derivatives

Density functional theory, symmetry-adapted perturbation theory, and classical molecular dynamics simulations were used to understand the local orientations within columnar stacks of sumanene, sumaneneone, sumanenedione, and sumanenetrione, which can impact the electronic properties of the resulting materials. Unlike sumanene and sumaneneone, which pack in staggered columnar arrangements, sumanenetrione adopts an eclipsed configuration in the solid state. Reliable quantum chemical computations on stacked dimers and trimers of these molecules reveal that all four systems prefer staggered configurations. The tendency of sumanenetrione to pack in an eclipsed configuration was explained based on repulsive intercolumnar O···O interactions that override the inherent tendency of stacked columns to be staggered. Sumanenedione, for which crystal structure data are not available, was predicted to exhibit columnar packing with mixed staggered and eclipsed orientations.

A bowl-shaped sumanene derivative with dense convex-concave columnar packing for high-performance organic field-effect transistors.

The charge transport properties of a bowl-shaped sumanene derivative with dense convex-concave columnar packing were studied. Single-crystal microribbons were grown by solution casting. Organic field-effect transistors based on individual single-crystal ribbons displayed a high hole mobility up to 0.37 cm2 V-1 s-1, which was one of the highest mobilities for buckybowl aromatics.

Sumanene derivatives functionalized at the internal carbon.

The first sumanene derivatives functionalized at the convex face of the internal carbon were reported. The structure of racemic hydroxysumanenone was confirmed by X-ray crystal analysis. The obtained structure was composed of the single enantiomer.

How the substituents in corannulene and sumanene derivatives alter their molecular assemblings and charge transport properties?--A theoretical study with a dimer model.

The substituent effects on the structures, intermolecular interactions and charge transport properties of a series of corannulene and sumanene derivatives were investigated by DFT method. The intermolecular interaction energy and the potential energy surface of the dimers were also calculated and analyzed in detail, which showed several local energy minima and demonstrated the possible dimer structures in experiment. In addition, the reorganization energy, transfer integral, and carrier mobility were explored to measure the charge transport properties of these substituted corannulenes and sumanenes at different configurations for investigating the substituent effects. Our study is closely related to the experiment and previous theoretical investigation and provides a better understanding of the structure-property relationships for these substituted corannulenes and sumanenes.