{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,3]],"date-time":"2026-09-03T00:15:11Z","timestamp":1788394511609,"version":"build-2803163510"},"reference-count":19,"publisher":"American Chemical Society (ACS)","issue":"32","license":[{"start":{"date-parts":[[2015,7,18]],"date-time":"2015-07-18T00:00:00Z","timestamp":1437177600000},"content-version":"vor","delay-in-days":365,"URL":"https:\/\/pubs.acs.org\/page\/policy\/authorchoice_termsofuse.html"}],"funder":[{"DOI":"10.13039\/100000057","name":"National Institute of General Medical Sciences","doi-asserted-by":"publisher","award":["1 SC GM099635-02"],"award-info":[{"award-number":["1 SC GM099635-02"]}],"id":[{"id":"10.13039\/100000057","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2014,8,14]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>A method to separate the effects of Heisenberg spin exchange (HSE) and dipole\u2013dipole (DD) interactions on EPR spectra of nitroxide spin probes in solution by employing 15N and 14N nitroxide spin probes in parallel experiments is developed theoretically and tested experimentally. Comprehensive EPR measurements are reported of 4-oxo-2,2,6,6-tetramethylpiperidine-d16;1-15N-1-oxyl (perdeuterated 15N Tempone; 15pDT), in 70 wt % aqueous glycerol as functions of concentration and temperature. The method, termed the relative broadening constant method (RBCM), is demonstrated by using the present results together with those in the literature that employed perdeuterated 14N Tempone (14pDT) under identical conditions. In principle, the separation of DD and HSE is dependent on the model of diffusion and molecular-kinetic parameters; however, within present day experimental uncertainties, the RBCM method turns out to be insensitive to the model. The earlier methods to separate DD and HSE by measuring the dispersion component introduced by the two interactions shows general agreement with the RBCM; however, there are discrepancies larger than estimated uncertainties due to random errors. Thus, further support is found for Salikhov\u2019s recent theory of the effects of DD and HSE on EPR spectra ( Appl. Magn. Reson.2010, 38, 237.); however, detailed confirmation is still lacking. The RBCM affords a possible approach to separate HSE and DD in spectra complicated by slow motion and\/or overlap with other resonance lines, allowing the method to be used in situations more complicated than low-viscosity simple liquids.<\/jats:p>","DOI":"10.1021\/jp505346g","type":"journal-article","created":{"date-parts":[[2014,7,18]],"date-time":"2014-07-18T12:02:52Z","timestamp":1405684972000},"page":"6154-6162","source":"Crossref","is-referenced-by-count":13,"title":["EPR Line\nShifts and Line Shape Changes Due to Heisenberg Spin Exchange and\nDipole\u2013Dipole Interactions of Nitroxide Free Radicals in Liquids:\n9. An Alternative Method to Separate the Effects of the Two Interactions\nEmploying 15N and 14N"],"prefix":"10.1021","volume":"118","author":[{"given":"Barney L.","family":"Bales","sequence":"first","affiliation":[{"name":"California State University at Northridge , , ,","place":["Northridge, California, United States, 91330"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michelle","family":"Meyer","sequence":"additional","affiliation":[{"name":"California State University at Northridge , , ,","place":["Northridge, California, United States, 91330"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Miroslav","family":"Peric","sequence":"additional","affiliation":[{"name":"California State University at Northridge , , ,","place":["Northridge, California, United States, 91330"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"316","published-online":{"date-parts":[[2014,7,18]]},"reference":[{"key":"2026090219284380500_cit1","doi-asserted-by":"crossref","first-page":"8707","DOI":"10.1021\/jp970995g","article-title":"EPR Line Shifts and Line Shape Changes Due to Spin Exchange of Nitroxide\nFree Radicals in Liquids","volume":"101","author":"Bales","year":"1997","journal-title":"J. Phys. Chem. B"},{"key":"2026090219284380500_cit2","doi-asserted-by":"crossref","first-page":"4846","DOI":"10.1021\/jp014518g","article-title":"EPR Line Shifts and\nLine Shape Changes Due to Spin Exchange of Nitroxide Free Radicals\nin Liquids 2. Extension to High Spin Exchange Frequencies and Inhomogeneously\nBroadened Spectra","volume":"106","author":"Bales","year":"2002","journal-title":"J. Phys. Chem. A"},{"key":"2026090219284380500_cit3","doi-asserted-by":"crossref","first-page":"9086","DOI":"10.1021\/jp030726s","article-title":"EPR Line Shifts\nand Line Shape Changes Due to Spin Exchange of Nitroxide Free Radicals\nin Liquids 3. Extension to Five Hyperfine Lines. Additional Line Shifts\nDue to Re-encounters","volume":"107","author":"Bales","year":"2003","journal-title":"J. Phys. Chem. A"},{"key":"2026090219284380500_cit4","doi-asserted-by":"crossref","first-page":"2177","DOI":"10.1021\/jp7107494","article-title":"EPR Line Shifts and Line Shape Changes Due to Spin Exchange of Nitroxide-Free\nRadicals in Liquids 4. Test of a Method to Measure Re-encounter Rates\nin Liquids Employing 15N and 14N Nitroxide Spin\nProbes","volume":"112","author":"Bales","year":"2008","journal-title":"J. Phys. Chem. A"},{"key":"2026090219284380500_cit5","doi-asserted-by":"crossref","first-page":"242","DOI":"10.1007\/978-3-642-67666-6","volume-title":"Spin Exchange: Principles\nand Applications in Chemistry and Biology","author":"Molin","year":"1980"},{"key":"2026090219284380500_cit6","doi-asserted-by":"crossref","first-page":"279","DOI":"10.1006\/jmre.1998.1414","article-title":"Gaussian\nline broadening induced by unresolved proton hyperfine structure and\nby field modulation into the EPR spectrum of the proxyl spin probe","volume":"132","author":"Bales","year":"1998","journal-title":"J. Magn. Reson."},{"key":"2026090219284380500_cit7","first-page":"271","article-title":"The Contribution\nfrom Exchange Interaction to Line Shifts in ESR Spectra of Paramagnetic\nParticles in Solutions","volume":"63","author":"Salikhov","year":"1985","journal-title":"J. Magn. Reson."},{"key":"2026090219284380500_cit8","doi-asserted-by":"crossref","first-page":"064501","DOI":"10.1063\/1.2958922","article-title":"Nitroxide\nspin exchange due to re-encounter collisions in a series of n-alkanes","volume":"129","author":"Kurban","year":"2008","journal-title":"J. Chem. Phys."},{"key":"2026090219284380500_cit9","doi-asserted-by":"crossref","first-page":"4930","DOI":"10.1021\/jp8093947","article-title":"EPR Line Shifts and Line Shape Changes Due to Spin Exchange of Nitroxide-Free\nRadicals in Liquids 6. Separating Line Broadening Due to Spin Exchange\nand Dipolar Interactions","volume":"113","author":"Bales","year":"2009","journal-title":"J. Phys. Chem. A"},{"key":"2026090219284380500_cit10","first-page":"359","volume":"15","author":"Galeev","year":"1996","journal-title":"Chem. Phys. Rep."},{"key":"2026090219284380500_cit11","doi-asserted-by":"crossref","first-page":"237","DOI":"10.1007\/s00723-010-0128-x","article-title":"Contributions of Exchange and Dipole\u2013Dipole\nInteractions to the Shape of EPR Spectra of Free Radicals in Diluted\nSollutions","volume":"38","author":"Salikhov","year":"2010","journal-title":"Appl. Magn. Reson."},{"key":"2026090219284380500_cit12","doi-asserted-by":"crossref","first-page":"2855","DOI":"10.1021\/jp210057x","article-title":"Electron Paramagnetic\nLine Shifts and Line Shape Changes Due to Heisenberg Spin Exchange\nand Dipole\u2013Dipole Interactions of Nitroxide Free Radicals in\nLiquids 8. Further Experimental and Theoretical Efforts to Separate\nthe Effects of the Two Interactions","volume":"116","author":"Peric","year":"2012","journal-title":"J. Phys.\nChem. 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B"},{"key":"2026090219284380500_cit17","doi-asserted-by":"crossref","first-page":"255","DOI":"10.1007\/978-1-4613-0743-3_5","article-title":"Experimental Methods in Spin-Label Spectral Analysis","volume-title":"Spin Labeling: Theory and Applications","author":"Marsh","year":"1989"},{"key":"2026090219284380500_cit18","doi-asserted-by":"crossref","first-page":"12460","DOI":"10.1021\/jp310297d","article-title":"Bimolecular Encounters\nand Re-Encounters (Cage Effect) of a Spin-Labeled Analogue of Cholestane\nin a Series of n-Alkanes: Effect of Anisotropic Exchange\nIntegral","volume":"116","author":"Vandenberg","year":"2012","journal-title":"J. Phys. Chem. A"},{"key":"2026090219284380500_cit19","doi-asserted-by":"crossref","first-page":"10903","DOI":"10.1021\/jp207349s","article-title":"Experimental Method to Measure the\nEffect of Charge on Bimolecular Collision Rates in Electrolyte Solutions","volume":"115","author":"Bales","year":"2011","journal-title":"J. Phys. Chem. A"}],"container-title":["The Journal of Physical Chemistry A"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pubs.acs.org\/doi\/pdf\/10.1021\/jp505346g","content-type":"application\/pdf","content-version":"vor","intended-application":"unspecified"},{"URL":"https:\/\/pubs.acs.org\/jpcafh\/article-pdf\/118\/32\/6154\/14282108\/jp505346g.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/pubs.acs.org\/jpcafh\/article-pdf\/118\/32\/6154\/14282108\/jp505346g.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,2]],"date-time":"2026-09-02T23:28:50Z","timestamp":1788391730000},"score":1,"resource":{"primary":{"URL":"https:\/\/pubs.acs.org\/jpcafh\/article\/118\/32\/6154\/1373863\/EPR-Line-Shifts-and-Line-Shape-Changes-Due-to"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2014,7,18]]},"references-count":19,"journal-issue":{"issue":"32","published-online":{"date-parts":[[2014,7,18]]},"published-print":{"date-parts":[[2014,8,14]]}},"URL":"https:\/\/doi.org\/10.1021\/jp505346g","relation":{},"ISSN":["1089-5639","1520-5215"],"issn-type":[{"value":"1089-5639","type":"print"},{"value":"1520-5215","type":"electronic"}],"subject":[],"published":{"date-parts":[[2014,7,18]]}}}