Observation of Supramolecular Chirality in a Hierarchically Self‐Assembled Mixed‐Stack Charge‐Transfer Complex

Krishnan, Sumesh B.; Gopidas, Karical R.

doi:10.1002/chem.201701123

Cited by 9 publications

(14 citation statements)

References 88 publications

(11 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The intense CD signal due to the CT band in Figure b cannot be attributed to induced chirality due to β‐CD and we attribute this to supramolecular chirality resulting from twisted or helical structures formed by the hierarchical assembly of the CT complex as observed for PMDI@PYCD systems previously . We have confirmed the presence of nanostructures even in dilute solutions of NDIAD@PYCD through the observation of dynamic light scattering and tyndall effect experiments (Figure S18).…”

Section: Resultssupporting

confidence: 78%

“…Further self‐assembly occurs through cumulative CT interactions as shown in Scheme . Previously we have invoked similar schemes for the self‐assembly of PIAD/PYCD complexes ,. Scheme , however, does not explain the complex pattern observed for the adamantyl and pyrene protons in the NMR spectrum of NDIAD@PYCD and the bisignated CD signal.…”

Section: Resultsmentioning

confidence: 85%

“…For several AD derivatives association constants for inclusion binding (K IN ) in β‐CD are ∼10 4 M −1 . For the PIAD/PYCD system we reported, the association constant (K a ) determined using isothermal titration calorimetry (ITC) was 1.82 × 10 6 M −1 , which is the highest value reported so far for CT complexes . The major contribution to the high association constant came from the inclusion binding interaction.…”

Section: Introductionmentioning

confidence: 69%

“…Synthesis and characterization of PYCD and PYP were reported by us previously . NDIAD was synthesized as shown in Scheme S1.…”

Section: Resultsmentioning

confidence: 99%

“…Recently our group has shown that CT complexation between PY and pyromellitic diimide (PI) in aqueous solution proceeds with very high association constant if the PY is linked to β‐cyclodextrin (β‐CD) and the PI is linked to adamantane (AD) . For PY‐PI intermolecular systems, CT complexation was observed only at high concentrations for which the association constant K CT was estimated as < 10 2 M −1 .…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Hierarchical Self‐Assembly of Pyrene‐Linked Cyclodextrin and Adamantane‐Linked Naphthalene Diimide System: A Case of Inclusion‐Binding‐Assisted Charge‐Transfer Interaction

Jeevan

Gopidas

2019

ChemistrySelect

Self Cite

View full text Add to dashboard Cite

Mixed stack charge transfer complexation between pyrene donor linked to β‐cyclodextrin and naphthalene diimide acceptor linked to adamantane, where the charge transfer interaction is augmented by inclusion binding of the adamantane moiety in β‐cyclodextrin, is studied. The association constant for the charge transfer complexation was 3.64 × 107 M−1, which is the highest value reported so far for any charge transfer complex. Complex formation was probed using 1H NMR, isothermal titration calorimetry, and circular dichroism studies. The results suggested that within the charge transfer complex the donor and acceptor exist as alternating units at an inter‐planar distance of 3.7 Å with a dihedral angle > 50° between them with each donor‐acceptor pair rotated slightly with respect to the preceding and succeeding pairs. The charge transfer complex undergo hierarchical self‐assembly to give twisted nanofibers as confirmed by Atomic force microscopic and Transmission electron microscopic studies. The excited state relaxation process in the charge transfer complex was investigated by femtosecond time‐resolved pump‐probe spectroscopy.

show abstract

Section: Resultssupporting

confidence: 78%

Section: Resultsmentioning

confidence: 85%

Section: Introductionmentioning

confidence: 69%

“…Synthesis and characterization of PYCD and PYP were reported by us previously . NDIAD was synthesized as shown in Scheme S1.…”

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Hierarchical Self‐Assembly of Pyrene‐Linked Cyclodextrin and Adamantane‐Linked Naphthalene Diimide System: A Case of Inclusion‐Binding‐Assisted Charge‐Transfer Interaction

Jeevan

Gopidas

2019

ChemistrySelect

Self Cite

View full text Add to dashboard Cite

show abstract

Effect of N‐Alkyl Substituents on the Hierarchical Self‐Assembly of β‐Cyclodextrin‐Linked Pyrene‐Pyromellitic Diimide Charge‐Transfer Complexes

Krishnan

Gopidas

2018

Chemistry A European J

View full text Add to dashboard Cite

Hierarchical self-assemblies of β-cyclodextrin-linked pyrene and N-alkyl derivatives of pyromellitic diimides are studied in detail. The charge-transfer interaction between pyrene and pyromellitic diimide is augmented by β-cyclodextrin-pyromellitic diimide binding interactions in these cases. When the alkyl group is adamantyl, a 1:1 complex was formed with a very high association constant (K =1.82×10 m ). Here, the charge-transfer interaction is reinforced by inclusion binding of the adamantyl group in the β-cyclodextrin cavity leading to the formation of 2D sheets, which undergo twisting to give twisted fibres. When the alkyl group is tert-butyl, a 1:2 complex was formed with a high association constant (K =2.91×10 m ). A detailed analysis showed that the tert-butyl pyromellitic diimide undergoes both inclusion and rim-binding interactions with the β-cyclodextrin. The charge-transfer complex further self-assembled into chiral nanostructures as evident from SEM, TEM and AFM analysis. In the case of N-methyl-substituted pyromellitic diimide, the interaction with β-cyclodextrin-linked pyrene was only through rim binding, which resulted in the formation of a weak charge-transfer complex with K =4.2×10 m . Formation of a hierarchical assembly was not observed in this case. A rational mechanism for the self-assembly, which relies on the strength of the cyclodextrin-pyromellitic diimide complexation is presented.

show abstract

Synthesis, Stability, Meisenheimer Complex Formation, and Charge‐Transfer Properties of Ultra‐Electron‐Deficient Tetracyano‐Naphthalene Diimides

Yadav,

Kumar,

Husain

et al. 2024

Eur J Org Chem

View full text Add to dashboard Cite

Tetra‐cyano substituted naphthalene diimides (TCNDIs) with calculated LUMO of ‐5.2 eV, form one of the strongest electron‐acceptors known to date. However, the synthesis and isolation of this class of molecules remain challenging due to its reactivity emanating from its ultra‐electron‐deficiency. Herein we have established an improved synthetic methodology of TCNDIs with cost‐effective reagents and circumventing metallic catalysts. The synthesis is amenable to TCNDIs with the shortest axial alkyl groups, i.e., methyl group and also longer alkyl chains. We also gained insight on how axial alkyl chain lengths influence electron‐deficiency, Meisenheimer complex formation, reactivity, and charge‐transfer of TCNDIs from computation, spectroscopy, and electrochemical studies. The TCNDIs with Me/Et axial groups were found to be more susceptible to moist solvents vis‐à‐vis the TCNDIs with longer alkyl groups. The single crystal structures of the TCNDIs show infinitely π‐stacked structure, and a new C=O···C≡N or C≡N···π motif is discerned. Finally, toluene‐mediated charge‐transfer properties of TCNDIs in the single crystals as well as in solution have been examined.

show abstract

Observation of Supramolecular Chirality in a Hierarchically Self‐Assembled Mixed‐Stack Charge‐Transfer Complex

Cited by 9 publications

References 88 publications

Hierarchical Self‐Assembly of Pyrene‐Linked Cyclodextrin and Adamantane‐Linked Naphthalene Diimide System: A Case of Inclusion‐Binding‐Assisted Charge‐Transfer Interaction

Hierarchical Self‐Assembly of Pyrene‐Linked Cyclodextrin and Adamantane‐Linked Naphthalene Diimide System: A Case of Inclusion‐Binding‐Assisted Charge‐Transfer Interaction

Effect of N‐Alkyl Substituents on the Hierarchical Self‐Assembly of β‐Cyclodextrin‐Linked Pyrene‐Pyromellitic Diimide Charge‐Transfer Complexes

Synthesis, Stability, Meisenheimer Complex Formation, and Charge‐Transfer Properties of Ultra‐Electron‐Deficient Tetracyano‐Naphthalene Diimides

Contact Info

Product

Resources

About