dc.contributor.author | Constantinides, Christos P. | en |
dc.contributor.author | Berezin, Andrey A. | en |
dc.contributor.author | Manoli, Maria | en |
dc.contributor.author | Leitus, G. M. | en |
dc.contributor.author | Zissimou, Georgia A. | en |
dc.contributor.author | Bendikov, M. | en |
dc.contributor.author | Rawson, J. M. | en |
dc.contributor.author | Koutentis, Panayiotis Andreas | en |
dc.creator | Constantinides, Christos P. | en |
dc.creator | Berezin, Andrey A. | en |
dc.creator | Manoli, Maria | en |
dc.creator | Leitus, G. M. | en |
dc.creator | Zissimou, Georgia A. | en |
dc.creator | Bendikov, M. | en |
dc.creator | Rawson, J. M. | en |
dc.creator | Koutentis, Panayiotis Andreas | en |
dc.date.accessioned | 2019-11-21T06:17:48Z | |
dc.date.available | 2019-11-21T06:17:48Z | |
dc.date.issued | 2014 | |
dc.identifier.uri | http://gnosis.library.ucy.ac.cy/handle/7/55355 | |
dc.description.abstract | 1,3,7,8-Tetraphenyl-4,8-dihydro-1H-imidazolo[4,5g][1,2,4]benzotriazin-4-yl (5), 8-(4-bromophenyl)-1,3,7-triphenyl-4,8-dihydro-1H-imidazolo[4,5g][1,2,4] benzotriazin-4-yl (6), and 8-(4-methoxyphenyl)-1,3,7-triphenyl-4,8-dihydro-1H- imidazolo[4,5g][1,2,4]benzotriazin-4-yl (7) were characterized by using X-ray diffraction crystallography, variable-temperature magnetic susceptibility studies, and DFT calculations. Radicals 5-7 pack in 1 D π stacks made of radical pairs with alternate short and long interplanar distances. The magnetic susceptibility (χ vs. T) of radicals 5 and 6 exhibit broad maxima at (50±2) and (50±4) K, respectively, and are interpreted in terms of an alternating antiferromagnetic Heisenberg linear chain model with average exchange-interaction values of J=-31.3 and -35.4 cm-1 (g solid=2.0030 and 2.0028) and an alternation parameter a=0.15 and 0.38 for 5 and 6, respectively. However, radical 7 forms 1 D columns of radical pairs with alternating distances | en |
dc.description.abstract | one of the interplanar distances is significantly longer than the other, which decreases the magnetic dimensionality and leads to discrete dimers with a ferromagnetic exchange interaction between the radicals (2J=23.6 cm-1, 2zJ′=-2.8 cm-1, g solid=2.0028). Magnetic exchange-coupling interactions in 1,2,4-benzotriazinyl radicals are sensitive to the degree of slippage and inter-radical separation, and such subtle changes in structure alter the fine balance between ferro- and antiferromagnetic interactions. Bigger is stronger: π-Extension of 1,2,4-benzotriazin-4-yl radicals leads to an enhanced overlap between SOMO orbitals and, therefore, to a strong effective exchange coupling within alternating 1 D chains of imidazolo-benzotriazinyls. However, subtle changes in interplanar distances and slippage angles switch the observed magnetic properties (see figure). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. | en |
dc.source | Chemistry - A European Journal | en |
dc.source.uri | https://www.scopus.com/inward/record.uri?eid=2-s2.0-84899636406&doi=10.1002%2fchem.201304538&partnerID=40&md5=b5a98c9226d06ba7afca7cdcce13251e | |
dc.subject | Magnetic susceptibility | en |
dc.subject | X ray diffraction | en |
dc.subject | Antiferro-magnetic interactions | en |
dc.subject | antiferromagnetism | en |
dc.subject | Effective exchange couplings | en |
dc.subject | exchange interactions | en |
dc.subject | Exchange-coupling interaction | en |
dc.subject | Ferromagnetic exchange interaction | en |
dc.subject | ferromagnetism | en |
dc.subject | heterocycles | en |
dc.subject | radicals | en |
dc.subject | Variable temperature | en |
dc.subject | X-ray diffraction crystallography | en |
dc.title | Structural, magnetic, and computational correlations of some imidazolo-fused 1,2,4-benzotriazinyl radicals | en |
dc.type | info:eu-repo/semantics/article | |
dc.identifier.doi | 10.1002/chem.201304538 | |
dc.description.volume | 20 | |
dc.description.issue | 18 | |
dc.description.startingpage | 5388 | |
dc.description.endingpage | 5396 | |
dc.author.faculty | 002 Σχολή Θετικών και Εφαρμοσμένων Επιστημών / Faculty of Pure and Applied Sciences | |
dc.author.department | Τμήμα Χημείας / Department of Chemistry | |
dc.type.uhtype | Article | en |
dc.description.notes | <p>Cited By :13</p> | en |
dc.source.abbreviation | Chem.Eur.J. | en |
dc.contributor.orcid | Koutentis, Panayiotis Andreas [0000-0002-4652-7567] | |
dc.contributor.orcid | Constantinides, Christos P. [0000-0001-6364-1102] | |
dc.contributor.orcid | Zissimou, Georgia A. [0000-0003-4821-9469] | |
dc.gnosis.orcid | 0000-0002-4652-7567 | |
dc.gnosis.orcid | 0000-0001-6364-1102 | |
dc.gnosis.orcid | 0000-0003-4821-9469 | |