This is the first report of charge transfer band for crown-axel H-bonding interaction in acetonitrile medium. Monte Carlo simulation established external association of small cavity crown with BBIM-propane dication axels. Resonance energy, binding constant and ratiometric detection of association of xanthenocrown-5 (1) and bis-napthalenocrown-6 (2) with bis-(benzimidazolium)propane borontetrafluoride (3a-3d) in acetonitrile determined the effect of steric factor towards association. © 2016 Elsevier B.V. All rights reserved.

CHHANDA MUKHOPADHYAY

Chemistry

T CHAUDHURI

A KARMAKAR

K KUNDU

S GHOSH

S K NAYAK

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

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It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy

ICT based ratiometric sensing due to H-bonding interaction among three different crown ethers (C): Dibenzo-24-crown-8 (DB24C8 or C1), Benzo-15-crown-5 (B15C5 or C2) and 4′-Nitrobenzo-15-crown-5 (4′-NB15C5 or C3) along with the axle bis(benzimidazolium)propane borontetrafluoride (BBIM-propane) (3a-3d) have been studied. The association were initially ascertained from isosbestic formation and later corroborated by iso-emissive formation where C3 fails to establish iso-emissive. Stoichiometry of adducts were 1:1 both in the ground as well as in excited state. The threading or external association was finally distinguished by Monte Carlo simulation and frontier molecular orbital interaction. © 2015 Elsevier B.V. All rights reserved.

Journal of Luminescence

Molecular recognition of 4â€²-Nitrobenzo-15-crown-5 by bis(benzimidazolium)propane borontetra fluoride in acetonitrile

Pseudorotaxanes from the self-assembly of simple 2,2′-bis(benzimidazolium) dications and DB24C8 is a first of its kind when a protonated bis(benzimidazole) without a methylene spacer between the two benzimidazolium units (a very rigid axle without flexibility) thread DB24C8 as a result of H-bonding interactions. The formation of these pseudorotaxanes was first ascertained from 1H NMR spectroscopy and later corroborated by HRMS, 2D NMR and finally supported by rigorous DFT calculations. © 2014 Elsevier Ltd. All rights reserved.

Tetrahedron

A 2,2â€²-bis(benzimidazolium)-dibenzo[24]crown[8] rigid pseudorotaxane system

A new [2]pseudorotaxane containing a benzimidazolium hydrogen-bonding station for a dibenzo-24-crown-8 (DB24C8) macrocycle is described. The structure of the [2]pseudorotaxane formed is established by 1H NMR spectroscopy, 2D NOESY and a Monte Carlo protocol (including an anion for the first time). © 2014 the Partner Organisations.

RSC Advances

The new threading system 2-benzyl-5,6-dimethyl-1H-benzo[d]imidazolium- dibenzo-24-crown-8: A model for Monte Carlo calculations incorporating an anion for the first time in threaded structures

"Three methylene spacer" bis(benzimidazolium) derivatives act as a new template for threading dibenzo-24-crown-8 into [2]pseudorotaxanes. In this Article we sought to unveil the difference in the extent of threading of various "three methylene spacer" bis-benzimidazolium moieties based on differences in aromatic methyl substituent positions and anions through the macrocycle dibenzo-24-crown-8. The temperature of the systems were also varied (low temperatures of 240 K and 253 K), when such interwinding of the thread and crown were not detected at room temperature of 308 K. The presence of such threaded complexes was determined based on 1H-NMR initially and finally corroborated by high resolution mass spectrometry and DFT calculations. 2D-NMR experiments ( 1H- 1H-NOESY) proved to be a very important tool in elucidating the interaction present between the components of the pseudorotaxanes. The dethreading/rethreading process was studied. DFT optimized structures suggest lower energy H-bonding orientations and compare the effect of methyl substituents on the axle. © 2012 The Royal Society of Chemistry.

Journal	Data powered by TypesetSpectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy
Publisher	Data powered by TypesetElsevier
ISSN	1386-1425
Open Access	No