Chiral Macrocyclic Schiff Bases: An Overview.

Srimurugan, Sankareswaran; Suresh, Paulsamy; Babu, Balaji; Pati, Hari N.

doi:10.2174/157019308785161657

Cited by 36 publications

(13 citation statements)

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“…The synthetic method providing such compounds relies on thermodynamically driven cycloimination of dialdehydes with vicinal diamines of the trans ‐1,2‐diaminocyclohexane or threo ‐1,2‐diphenyl‐1,2‐diaminoethane type . The first successful, quantitative synthesis of triangular hexaimine 1 ( trianglimine ), by Gawronski and coworkers, received a wide attention in scientific community as a convenient and efficient method for synthesis of poly‐aza macrocycles of different shapes and stoichiometry …”

Section: Introductionmentioning

confidence: 99%

Electronic and vibrational exciton coupling in oxidized trianglimines

Szymkowiak

Kwit

2017

Chirality

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Readily available chiral trianglimine and their (poly)oxygenated congeners represent a unique class of macrocyclic rigid compounds optimal for testing electronic and vibrational circular dichroism exciton chirality methods. Electronic and vibrational circular dichroism spectra of such trianglimines are strongly affected by polar substituents in macrocycle skeletons. Double substitution by OH groups in each aromatic fragment of the macrocycle causes sign reversal of the exciton couplet in the region of the strongest UV absorption. On the other hand, electronic circular dichroism spectrum of the macrocycle having 2 methoxy groups shows 2 exciton couplets-the long-wavelength positive and the second of the negative sign, observed at the shorter wavelengths. VCD spectra of macrocyclic imines show vibrational exciton couplets in the region of strong C=N stretches. The signs of these couplets are positive and the opposite of the diamine chirality. For trianglimine macrocycles the interpretation of VCD spectra in terms of excitons is much more convincing than for electronic circular dichroism spectra. By contrast, trans-1,2-diaminocyclohexane-based vicinal diimines, being a one-third of the respective macrocycle, do not exhibit any vibrational exciton effect. Experimental data were confronted with DFT calculations. We observed good-to-excellent agreement between experimental and computed data.

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Section: Introductionmentioning

confidence: 99%

Electronic and vibrational exciton coupling in oxidized trianglimines

Szymkowiak

Kwit

2017

Chirality

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“…The reaction mixture was then heated under reflux for 2-4 h (monitored by thin-layer chromatography). The solvent was then removed in vacuo, and the remaining solid was crystallized from acetic acid to give gray solids of 4a-r. 3,8,19,16,28,2,4]-triazolo [4,3-f:3,4-j]dipyrazolo[b,n]- [1,18,5,6,13,14,8,11] Scheme 1. Synthetic process of the title compounds.…”

Section: Methodsmentioning

confidence: 99%

“…Macrocycles have received much attention in the areas of host–guest complexation, molecular self‐assembly, and specific receptor activity. The successful design, synthesis, and use of macrocyclic ligands capable of the selective recognition of other species were of great interest to workers in catalysis, separation, enzyme mimics, and other areas of involving molecular recognition . Macrocycles with heterocyclic groups incorporated in the macrocyclic ring provided rigidity and could form strong and selective interactions with various charged and neutral moleculars through their soft donor atoms .…”

Section: Introductionmentioning

confidence: 99%

Synthesis of New Macrocyclic Schiff Bases Containing Pyrazole and Triazole as Subcyclic Units

Chen

Liu

2014

Journal of Heterocyclic Chem

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“…The formation of macrocycles is favorized over linear oligomerization if both partners are structurally predisposed for cyclization. For instance, condensation of the 1,2‐diaminocyclohexane and aromatic dialdehydes has led to shape‐persistent imine macrocycles which have attracted much attention in the last years due to their exotic shapes and potential application in supramolecular chemistry and materials science as host‐guest complexes, chiral recognition, tubular channels, porous organic solids, and so forth . They can be built through template or metal‐free cyclocondensation of rigid diamines with π‐conjugated dialdehydes via dynamic covalent chemistry of imine bond formation.…”

Section: Introductionmentioning

confidence: 99%

Imine polymers containing chiral nanohoops in the backbone obtained through [2 + 2] cyclocondensation

Vacareanu¹,

Negru²,

Grigoraş³

2018

J. Polym. Sci. Part A: Polym. Chem.

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A simple method for synthesis of polymers containing shape persistent imine macrocycles as nanohoops in the main chain is studied. It is based on the cyclocondensation reaction carried out in solution and room temperature of triphenylamine‐based tetraaldehyde compounds with (R,R)‐trans‐1,2‐diaminocyclohexane. The pristine polymer P1 bearing long alkyl groups is soluble during the synthesis but becomes insoluble after precipitation due to the strong and multiple CH/π and π‐π stacking intermolecular interactions from arene–arene species and entanglement and interpenetrating of flexible alkyl groups inside of rigid macrocycle hollow. Polymer without any solubilizing groups (P2) separates during the polymerization as an insoluble material. Both polymers are amorphous and have good thermal and environmental stability. They have a low surface area because discrete nanovoids introduced by macrocycles are disconnected in the amorphous polymers and non‐accessible for gas adsorption. Polymers have inherent luminescent properties due to triphenylamine groups and chirality derived from (R,R)‐conformation of the cyclohexane skeleton. In presence of picric acid (PA), the polymer fluorescence in solid state or suspension is strongly quenched, thus the polymers can work as efficient fluorescent probes toward nitrophenolic compounds. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 2565–2573

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Chiral Macrocyclic Schiff Bases: An Overview.

Cited by 36 publications

References 0 publications

Electronic and vibrational exciton coupling in oxidized trianglimines

Electronic and vibrational exciton coupling in oxidized trianglimines

Synthesis of New Macrocyclic Schiff Bases Containing Pyrazole and Triazole as Subcyclic Units

Imine polymers containing chiral nanohoops in the backbone obtained through [2 + 2] cyclocondensation

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