{"id":"https://openalex.org/W2055415916","doi":"https://doi.org/10.1063/1.469151","title":"Understanding barriers to internal rotation in substituted toluenes and their cations","display_name":"Understanding barriers to internal rotation in substituted toluenes and their cations","publication_year":1995,"publication_date":"1995-05-01","ids":{"openalex":"https://openalex.org/W2055415916","doi":"https://doi.org/10.1063/1.469151","mag":"2055415916"},"language":"en","primary_location":{"id":"doi:10.1063/1.469151","doi":"https://doi.org/10.1063/1.469151","is_oa":false,"landing_page_url":"https://doi.org/10.1063/1.469151","pdf_url":null,"source":{"id":"https://openalex.org/S77047749","display_name":"The Journal of Chemical Physics","issn_l":"0021-9606","issn":["0021-9606","1089-7690","1520-9032"],"is_oa":false,"is_in_doaj":false,"is_core":true,"listed_in":["anvur-scientific","cwts-core","dongbi-b","jufo-1","ki-jl-1","medline","norway-1","poland-100","russia-white-list-2","vabb-shw"],"host_organization":"https://openalex.org/P4310320257","host_organization_name":"American Institute of Physics","host_organization_lineage":["https://openalex.org/P4310320257"],"host_organization_lineage_names":["American Institute of Physics"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"The Journal of Chemical Physics","raw_type":"journal-article"},"volume":null,"type":"article","indexed_in":["crossref"],"open_access":{"is_oa":false,"oa_status":"closed","oa_url":null,"any_repository_has_fulltext":false},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5112236261","display_name":"Kueih\u2010Tzu Lu","orcid":null,"observed_orcids":[]},"institutions":[{"id":"https://openalex.org/I135310074","display_name":"University of Wisconsin\u2013Madison","ror":"https://ror.org/01y2jtd41","country_code":"US","type":"education","lineage":["https://openalex.org/I135310074"]}],"countries":["US"],"is_corresponding":false,"raw_author_name":"Kueih-Tzu Lu","raw_affiliation_strings":["Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706","institution_ids":["https://openalex.org/I135310074"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5028194420","display_name":"Frank Weinhold","orcid":"https://orcid.org/0000-0002-9580-054X","observed_orcids":["https://orcid.org/0000-0002-9580-054X"]},"institutions":[{"id":"https://openalex.org/I135310074","display_name":"University of Wisconsin\u2013Madison","ror":"https://ror.org/01y2jtd41","country_code":"US","type":"education","lineage":["https://openalex.org/I135310074"]}],"countries":["US"],"is_corresponding":false,"raw_author_name":"Frank Weinhold","raw_affiliation_strings":["Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706","institution_ids":["https://openalex.org/I135310074"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5077564904","display_name":"James C. Weisshaar","orcid":"https://orcid.org/0000-0002-0922-5113","observed_orcids":["https://orcid.org/0000-0002-0922-5113"]},"institutions":[{"id":"https://openalex.org/I135310074","display_name":"University of Wisconsin\u2013Madison","ror":"https://ror.org/01y2jtd41","country_code":"US","type":"education","lineage":["https://openalex.org/I135310074"]}],"countries":["US"],"is_corresponding":false,"raw_author_name":"James C. Weisshaar","raw_affiliation_strings":["Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706","institution_ids":["https://openalex.org/I135310074"]}]}],"institutions":[],"countries_distinct_count":1,"institutions_distinct_count":1,"corresponding_author_ids":[],"corresponding_institution_ids":["https://openalex.org/I135310074"],"apc_list":{"value":3500,"currency":"USD","value_usd":3500},"apc_paid":null,"fwci":5.9434,"has_fulltext":false,"cited_by_count":110,"citation_normalized_percentile":{"value":0.97492625,"is_in_top_1_percent":false,"is_in_top_10_percent":true},"cited_by_percentile_year":{"min":89,"max":98},"biblio":{"volume":"102","issue":"17","first_page":"6787","last_page":"6805"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T12967","display_name":"Molecular Spectroscopy and Structure","score":0.4343000054359436,"subfield":{"id":"https://openalex.org/subfields/1607","display_name":"Spectroscopy"},"field":{"id":"https://openalex.org/fields/16","display_name":"Chemistry"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},"topics":[{"id":"https://openalex.org/T12967","display_name":"Molecular Spectroscopy and Structure","score":0.4343000054359436,"subfield":{"id":"https://openalex.org/subfields/1607","display_name":"Spectroscopy"},"field":{"id":"https://openalex.org/fields/16","display_name":"Chemistry"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T10002","display_name":"Advanced Chemical Physics Studies","score":0.3578999936580658,"subfield":{"id":"https://openalex.org/subfields/3107","display_name":"Atomic and Molecular Physics, and Optics"},"field":{"id":"https://openalex.org/fields/31","display_name":"Physics and Astronomy"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T13253","display_name":"Chemical Reactions and Mechanisms","score":0.04010000079870224,"subfield":{"id":"https://openalex.org/subfields/1606","display_name":"Physical and Theoretical Chemistry"},"field":{"id":"https://openalex.org/fields/16","display_name":"Chemistry"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}}],"keywords":[{"id":"https://openalex.org/keywords/substituent-effects","display_name":"substituent effects","score":0.6039999723434448},{"id":"https://openalex.org/keywords/conformational-energy-barrier","display_name":"conformational barriers","score":0.5350000262260437},{"id":"https://openalex.org/keywords/steric-interactions","display_name":"steric interactions","score":0.6480000019073486},{"id":"https://openalex.org/keywords/donor-acceptor-interactions","display_name":"donor-acceptor interactions","score":0.9259999990463257},{"id":"https://openalex.org/keywords/pi-bond-order","display_name":"\u03c0-bond order","score":0.8100000023841858},{"id":"https://openalex.org/keywords/ring-geometry","display_name":"ring geometry","score":0.527999997138977},{"id":"https://openalex.org/keywords/electronically-excited-states","display_name":"excited electronic states","score":0.492000013589859},{"id":"https://openalex.org/keywords/s1-excited-state","display_name":"S1 excited state","score":0.5979999899864197},{"id":"https://openalex.org/keywords/natural-resonance-theory","display_name":"natural resonance theory","score":0.6129999756813049},{"id":"https://openalex.org/keywords/molecular-orbital-theory","display_name":"molecular orbital theory","score":0.48899999260902405}],"concepts":[{"id":"https://openalex.org/C201194858","wikidata":"https://www.wikidata.org/wiki/Q898238","display_name":"Steric effects","level":2,"score":0.7614028453826904},{"id":"https://openalex.org/C185592680","wikidata":"https://www.wikidata.org/wiki/Q2329","display_name":"Chemistry","level":0,"score":0.7329456806182861},{"id":"https://openalex.org/C46000676","wikidata":"https://www.wikidata.org/wiki/Q804644","display_name":"Lone pair","level":3,"score":0.6388601064682007},{"id":"https://openalex.org/C2780378348","wikidata":"https://www.wikidata.org/wiki/Q25351438","display_name":"Ring (chemistry)","level":2,"score":0.552493691444397},{"id":"https://openalex.org/C2778565081","wikidata":"https://www.wikidata.org/wiki/Q4407","display_name":"Methyl group","level":3,"score":0.5323513150215149},{"id":"https://openalex.org/C2779892579","wikidata":"https://www.wikidata.org/wiki/Q912138","display_name":"Acceptor","level":2,"score":0.49058690667152405},{"id":"https://openalex.org/C124600460","wikidata":"https://www.wikidata.org/wiki/Q842809","display_name":"Bond order","level":4,"score":0.48523640632629395},{"id":"https://openalex.org/C2781442258","wikidata":"https://www.wikidata.org/wiki/Q46310","display_name":"Ab initio","level":2,"score":0.4480368494987488},{"id":"https://openalex.org/C147597530","wikidata":"https://www.wikidata.org/wiki/Q369472","display_name":"Computational chemistry","level":1,"score":0.440920352935791},{"id":"https://openalex.org/C8010536","wikidata":"https://www.wikidata.org/wiki/Q160398","display_name":"Crystallography","level":1,"score":0.43261367082595825},{"id":"https://openalex.org/C155860418","wikidata":"https://www.wikidata.org/wiki/Q863695","display_name":"Bond length","level":3,"score":0.3418470025062561},{"id":"https://openalex.org/C71240020","wikidata":"https://www.wikidata.org/wiki/Q186011","display_name":"Stereochemistry","level":1,"score":0.26488858461380005},{"id":"https://openalex.org/C32909587","wikidata":"https://www.wikidata.org/wiki/Q11369","display_name":"Molecule","level":2,"score":0.20918402075767517},{"id":"https://openalex.org/C115624301","wikidata":"https://www.wikidata.org/wiki/Q895901","display_name":"Crystal structure","level":2,"score":0.1200728714466095},{"id":"https://openalex.org/C2781311116","wikidata":"https://www.wikidata.org/wiki/Q83306","display_name":"Group (periodic table)","level":2,"score":0.1154148280620575},{"id":"https://openalex.org/C178790620","wikidata":"https://www.wikidata.org/wiki/Q11351","display_name":"Organic chemistry","level":1,"score":0.08879050612449646},{"id":"https://openalex.org/C121332964","wikidata":"https://www.wikidata.org/wiki/Q413","display_name":"Physics","level":0,"score":0.07820475101470947},{"id":"https://openalex.org/C26873012","wikidata":"https://www.wikidata.org/wiki/Q214781","display_name":"Condensed matter physics","level":1,"score":0.0}],"mesh":[],"locations_count":1,"locations":[{"id":"doi:10.1063/1.469151","doi":"https://doi.org/10.1063/1.469151","is_oa":false,"landing_page_url":"https://doi.org/10.1063/1.469151","pdf_url":null,"source":{"id":"https://openalex.org/S77047749","display_name":"The Journal of Chemical Physics","issn_l":"0021-9606","issn":["0021-9606","1089-7690","1520-9032"],"is_oa":false,"is_in_doaj":false,"is_core":true,"listed_in":["anvur-scientific","cwts-core","dongbi-b","jufo-1","ki-jl-1","medline","norway-1","poland-100","russia-white-list-2","vabb-shw"],"host_organization":"https://openalex.org/P4310320257","host_organization_name":"American Institute of Physics","host_organization_lineage":["https://openalex.org/P4310320257"],"host_organization_lineage_names":["American Institute of Physics"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"The Journal of Chemical Physics","raw_type":"journal-article"}],"best_oa_location":null,"sustainable_development_goals":[],"study_designs":[],"awards":[],"funders":[],"has_content":{"pdf":false,"grobid_xml":false},"content_urls":null,"referenced_works_count":30,"referenced_works":["https://openalex.org/W571489779","https://openalex.org/W603778946","https://openalex.org/W1971327187","https://openalex.org/W1974463737","https://openalex.org/W1986718517","https://openalex.org/W1986755296","https://openalex.org/W1987681037","https://openalex.org/W2005148229","https://openalex.org/W2010423687","https://openalex.org/W2011080345","https://openalex.org/W2012165976","https://openalex.org/W2013053011","https://openalex.org/W2018010252","https://openalex.org/W2019461491","https://openalex.org/W2027616314","https://openalex.org/W2028984846","https://openalex.org/W2030877624","https://openalex.org/W2038546983","https://openalex.org/W2038767330","https://openalex.org/W2047054780","https://openalex.org/W2067122510","https://openalex.org/W2068242707","https://openalex.org/W2075850942","https://openalex.org/W2079171782","https://openalex.org/W2081585466","https://openalex.org/W2082821702","https://openalex.org/W2093048175","https://openalex.org/W2093697685","https://openalex.org/W2170877608","https://openalex.org/W2401734124"],"related_works":["https://openalex.org/W1985841426","https://openalex.org/W2018354500","https://openalex.org/W2003253111","https://openalex.org/W2043289261","https://openalex.org/W2487173269","https://openalex.org/W2049962149","https://openalex.org/W2006910233","https://openalex.org/W1978653078","https://openalex.org/W1973172782","https://openalex.org/W2028035719"],"abstract_inverted_index":{"In":[0,52,105,212],"substituted":[1],"toluenes,":[2,108],"the":[3,12,18,21,30,46,84,87,90,93,100,121,126,137,145,153,159,172,188,192,198,207,232,257,264,269,286,292,298,303,320],"potential":[4],"energy":[5],"barrier":[6,101,150,167,282,325],"to":[7,114,135,171,197,206,297,316],"internal":[8],"methyl":[9,14,25,73,127,270],"rotation":[10],"and":[11,27,54,125,221,239,295,332],"preferred":[13],"conformation":[15,189,294],"depend":[16],"on":[17,29,327],"position":[19],"of":[20,45,61,79,86,92,148,179,202,210,219,246,256,259,276,289,300,330],"fluorine,":[22],"amino,":[23],"or":[24,36],"substituents":[26],"also":[28],"electronic":[31,47,58],"state,":[32],"either":[33],"S0,":[34],"S1,":[35],"ground":[37],"state":[38],"cation.":[39],"We":[40],"present":[41],"a":[42,76,217,280,310],"unified":[43],"picture":[44,245],"factors":[48],"controlling":[49],"these":[50],"effects.":[51],"S0":[53,106],"cation,":[55],"ab":[56],"initio":[57],"structure":[59],"calculations":[60],"modest":[62],"scale":[63],"produce":[64],"rotor":[65,94,149,193],"potentials":[66],"in":[67,89,155,324],"good":[68,96],"agreement":[69],"with":[70,177],"experiment.":[71],"The":[72,166],"group":[74,271],"provides":[75],"sensitive":[77],"probe":[78],"local":[80,97],"ring":[81,88,161,199,223,273],"geometry.":[82],"When":[83,140,266],"geometry":[85],"vicinity":[91],"has":[95],"C2v":[98],"symmetry,":[99],"is":[102,152,169],"invariably":[103],"small.":[104],"ortho-substituted":[107],"we":[109,307],"use":[110],"natural":[111,249],"steric":[112,118,141],"analysis":[113],"show":[115],"that":[116,190,309],"repulsive":[117],"interactions":[119,134,142,186],"between":[120,158,272],"halogen":[122],"lone":[123],"pair":[124],"CH":[128,194],"bonds":[129,163,275],"dominate":[130],"over":[131],"attractive":[132],"donor\u2013acceptor":[133,185],"favor":[136,187],"pseudo-trans":[138,304],"conformation.":[139,305],"are":[143],"unimportant,":[144],"key":[146],"determinant":[147],"height":[151,168,326],"difference":[154],"\u03c0-bond":[156],"order":[157,175],"two":[160],"CC":[162,200,224,260,274],"nearest":[164],"methyl.":[165],"proportional":[170],"calculated":[173,236],"bond":[174,195,201,261],"difference,":[176],"slope":[178],"950":[180],"cm\u22121":[181],"per":[182],"bond.":[183],"Attractive":[184],"places":[191,268],"cis":[196],"higher":[203],"order,":[204,279],"analogous":[205],"localized":[208,244],"case":[209],"2-methylpropene.":[211],"toluene":[213,241],"cations,":[214],"\u03c0-ionization":[215,267],"creates":[216],"pattern":[218],"long":[220],"short":[222],"bonds.":[225],"Simple":[226],"molecular":[227,312],"orbital":[228,313],"theory":[229,251],"readily":[230],"explains":[231,252,285],"coarse":[233],"bond-order":[234],"patterns":[235],"for":[237,291,302],"ortho-":[238,331],"meta-substituted":[240,333],"cations.":[242],"A":[243],"\u03c0-bonding":[247],"from":[248],"resonance":[250],"more":[253],"subtle":[254],"details":[255],"distribution":[258],"orders":[262],"about":[263],"ring.":[265],"quite":[277],"different":[278],"substantial":[281],"results.":[283],"This":[284],"strong":[287],"preference":[288,299],"m-fluorotoluene+":[290],"pseudo-cis":[293],"contributes":[296],"o-fluorotoluene+":[301],"Finally,":[306],"speculate":[308],"similar":[311],"argument":[314],"applied":[315],"S1":[317],"might":[318],"explain":[319],"observed":[321],"characteristic":[322],"changes":[323],"S1\u2013S0":[328],"excitation":[329],"toluenes.":[334]},"counts_by_year":[{"year":2025,"cited_by_count":1},{"year":2023,"cited_by_count":2},{"year":2022,"cited_by_count":1},{"year":2021,"cited_by_count":2},{"year":2020,"cited_by_count":2},{"year":2019,"cited_by_count":3},{"year":2018,"cited_by_count":2},{"year":2017,"cited_by_count":2},{"year":2015,"cited_by_count":3},{"year":2014,"cited_by_count":2},{"year":2013,"cited_by_count":6},{"year":2012,"cited_by_count":1}],"updated_date":"2026-05-21T06:26:12.895304","created_date":"2016-06-24T00:00:00"}