{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,14]],"date-time":"2026-01-14T17:34:58Z","timestamp":1768412098716,"version":"3.49.0"},"reference-count":85,"publisher":"MDPI AG","issue":"21","license":[{"start":{"date-parts":[[2020,10,23]],"date-time":"2020-10-23T00:00:00Z","timestamp":1603411200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["UIDB\/00313\/2020"],"award-info":[{"award-number":["UIDB\/00313\/2020"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["UIDP\/00313\/2020"],"award-info":[{"award-number":["UIDP\/00313\/2020"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>This article presents a detailed comprehensive investigation of the ortho fluoro- and chloro- substituted benzoic acids both, as isolated molecules and in the crystalline phase. Quantum chemical calculations performed within the density functional theory (DFT) formalism are used to investigate the potential energy landscapes of the molecules, taking into special consideration the effects of the interactions between the carboxylic group and the ortho halogen substituents, as well as the nature of these later on the structure and properties of the investigated systems. The structures of the relevant conformers of the molecules are discussed in comparative terms, and used to rationalize experimental data obtained for the compounds in the gas phase and isolated in low-temperature inert matrices. The UV-induced photofragmentation reactions of two of the compounds isolated in cryogenic inert matrices were studied as illustrative cases. The structures of the crystals reported previously in the literature are revisited and discussed also in a comparative basis. Particular emphasis is given to the analysis of the intermolecular interactions in the different crystals, using Hirshfeld surface analysis, the CE-B3LYP energy decomposition model and the HOMA index, and to their correlation with thermodynamic data.<\/jats:p>","DOI":"10.3390\/molecules25214908","type":"journal-article","created":{"date-parts":[[2020,10,23]],"date-time":"2020-10-23T08:59:28Z","timestamp":1603443568000},"page":"4908","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":14,"title":["Structural Aspects of the Ortho Chloro- and Fluoro- Substituted Benzoic Acids: Implications on Chemical Properties"],"prefix":"10.3390","volume":"25","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7827-5050","authenticated-orcid":false,"given":"Gulce","family":"Ogruc Ildiz","sequence":"first","affiliation":[{"name":"Department of Chemistry, University of Coimbra, CQC, P 3004\u2212535 Coimbra, Portugal"},{"name":"Department of Physics, Faculty of Sciences and Letters, Atakoy Campus, Istanbul Kultur University, 34156 Bakirkoy, Istanbul, Turkey"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8264-6854","authenticated-orcid":false,"given":"Rui","family":"Fausto","sequence":"additional","affiliation":[{"name":"Department of Chemistry, University of Coimbra, CQC, P 3004\u2212535 Coimbra, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2020,10,23]]},"reference":[{"key":"ref_1","unstructured":"Maki, T., and Takeda, K. (2002). Benzoic Acid and Derivatives. Ullmann\u2019s Encyclopedia of Industrial Chemistry, Wiley-VCH."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"2445","DOI":"10.1021\/es961007c","article-title":"Fluorinated Organics in the Biosphere","volume":"31","author":"Key","year":"1997","journal-title":"Environ. Sci. Technol."},{"key":"ref_3","unstructured":"Holder, B.R., and Reuter, W.M. (2018). Perkin Elmer Application Note \u201cAnalysis of Fluorobenzoic Acids via UHPLC-MS\/MS for Water Tracer Studies\u201d, PerkinElmer, Inc."},{"key":"ref_4","first-page":"22","article-title":"Water Tracers in Oilfield Applications: Guidelines","volume":"98\u201399","author":"Allanic","year":"2012","journal-title":"J. Petrol. Sci. Eng."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"5872","DOI":"10.1016\/j.chroma.2011.06.028","article-title":"Direct Sensitive Simultaneous Determination of Fluorinated Benzoic Acids in Oil Reservoir Waters by Ultra High-performance Liquid Chromatography-tandem Mass Spectrometry","volume":"1218","author":"Lobinski","year":"2011","journal-title":"J. Chromatogr. A"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"178","DOI":"10.1016\/0003-9861(67)90295-0","article-title":"Fluorine Containing Metabolites Formed from 2-Fluorobenzoic Acid by Pseudomonas Species","volume":"118","author":"Goldman","year":"1967","journal-title":"Arch. Biochem. Biophys."},{"key":"ref_7","first-page":"102","article-title":"Isolation and Properties of a Pure Bacterial Strain Capable of Fluorobenzene Degradation as Sole Carbon and Energy Source","volume":"68","author":"MCarvalho","year":"2002","journal-title":"Appl. Environ. Microbiol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"5374","DOI":"10.1016\/S0021-9258(18)91959-9","article-title":"The Metabolism of 2-Fluorobenzoic acid","volume":"243","author":"Milne","year":"1968","journal-title":"J. Biol. Chem."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"68","DOI":"10.1128\/aem.39.1.68-73.1980","article-title":"Adaptation of Alcaligenes eutrophus B9 and Pseudomonas sp. B13 to 2-Fluorobenzoate as Growth Substrate","volume":"39","author":"Engesser","year":"1980","journal-title":"Appl. Environ. Microbiol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"249","DOI":"10.1007\/BF01571323","article-title":"Degradation of 2-Fluorobenzoate by a Pseudomonas","volume":"17","author":"Vora","year":"1988","journal-title":"Curr. Microbiol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"215","DOI":"10.1111\/j.1574-6968.1994.tb06703.x","article-title":"Mineralization of Monofluorobenzoate by a Diculture under Sulfate-reducing Conditions","volume":"116","author":"Drzyzga","year":"1994","journal-title":"FEMS Microbiol. Lett."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"143","DOI":"10.1111\/j.1574-6968.1989.tb03434.x","article-title":"Degradation of 2-Bromo-, 2-Chloro- and 2-Fluorobenzoate by Pseudomonas putida CLB 250","volume":"60","author":"Engesser","year":"1989","journal-title":"FEMS Microbiol. Lett."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"754","DOI":"10.1021\/ac60125a004","article-title":"Spectrophotometric Determination of Iron with 2-Fluorobenzoic Acid","volume":"29","author":"Buchanan","year":"1957","journal-title":"Anal. Chem."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"799","DOI":"10.1081\/SCC-200050946","article-title":"Ortholithiation of Unprotected Benzoic Acids: Application for Novel 2-Chloro-6-Substituted Benzoic Acid Syntheses","volume":"35","author":"Gohier","year":"2005","journal-title":"Synth. Commun."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Vardanyan, R.S., and Hruby, V.J. (2006). Local Anesthetics. Synthesis of Essential Drugs, Elsevier Science. Chapter 2.","DOI":"10.1016\/B978-044452166-8\/50002-9"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"124305","DOI":"10.1063\/1.4978794","article-title":"Effects of the Matrix and Intramolecular Interactions on the Stability of the Higher-energy Conformers of 2-Fluorobenzoic Acid","volume":"146","author":"Fausto","year":"2017","journal-title":"J. Chem. Phys."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"7041","DOI":"10.1021\/jp0717600","article-title":"Intramolecular Hydrogen Atom Tunneling in 2-Chlorobenzoic Acid Studied by Low-Temperature Matrix-Isolation Infrared Spectroscopy","volume":"111","author":"Nishino","year":"2007","journal-title":"J. Phys. Chem. A"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"144303","DOI":"10.1063\/1.4917031","article-title":"Gas Phase Measurements of Mono-fluoro-benzoic Acids and the Dimer of 3-Fluoro-benzoic Acid","volume":"142","author":"Daly","year":"2015","journal-title":"J. Chem. Phys."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"235","DOI":"10.1016\/j.saa.2015.03.058","article-title":"Vibrational Spectra, NLO Analysis, and HOMO\u2013LUMO Studies of 2-Chloro-6-Fluorobenzoic Acid and 3,4-Dichlorobenzoic Acid by Density Functional Method","volume":"147","author":"Kumar","year":"2015","journal-title":"Spectrochim. Acta Part A Mol. Biomol. Spectrosc."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"12852","DOI":"10.1021\/jp2039866","article-title":"Extending the Supramolecular Synthon Based Fragment Approach (SBFA) for Transferability of Multipole Charge Density Parameters to Monofluorobenzoic Acids and their Cocrystals with Isonicotinamide: Importance of C-H\u2026O, C-H\u2026F, and F\u2026F Intermolecular Regions","volume":"115","author":"Hathwar","year":"2011","journal-title":"J. Phys. Chem. A"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1848","DOI":"10.1039\/b811438b","article-title":"The Crystal Structures of Chloro and Methyl ortho-benzoic Acids and their Co-crystal: Rationalizing Similarities and Differences","volume":"10","author":"Polito","year":"2008","journal-title":"CrystEngComm"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"o2109","DOI":"10.1107\/S1600536810028758","article-title":"2,6-Difluorobenzoic Acid","volume":"66","author":"Wahab","year":"2010","journal-title":"Acta Cryst. E"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"181","DOI":"10.1023\/A:1023597409468","article-title":"Crystal Structures of 2,6- and 3,5-Dichlorobenzoic acids: Nonbonded Cl\u2026Cl Contacts","volume":"33","author":"Pinkus","year":"2003","journal-title":"J. Chem. Crystall."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"o1329","DOI":"10.1107\/S1600536811016734","article-title":"2-Chloro-6-fluorobenzoic Acid","volume":"67","author":"Betz","year":"2011","journal-title":"Acta Cryst. E"},{"key":"ref_25","unstructured":"(2020, August 25). 2-Fluorobenzoic Acid. Wikipedia. Available online: https:\/\/en.wikipedia.org\/wiki\/2-Fluorobenzoic_acid."},{"key":"ref_26","unstructured":"(2020, August 25). 2,6-Difluorobenzoic Acid. Chemical Book. Available online: https:\/\/www.chemicalbook.com\/ProductList_En.aspx?kwd=2,6-difluorobenzoic%20acid."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"569","DOI":"10.6028\/jres.060.057","article-title":"Relative Strengths of Forty Aromatic Carboxylic Acids in Benzene at 25 \u00b0C","volume":"60","author":"Davis","year":"1958","journal-title":"J. Res. Natl. Bur. Stand."},{"key":"ref_28","unstructured":"(2020, August 25). 2,6-Dichlorobenzoic Acid. Chemical Book. Available online: https:\/\/www.chemicalbook.com\/ProductMSDSDetailCB1673902_EN.htm#2."},{"key":"ref_29","unstructured":"(2020, August 25). 2-Chloro-6-Fluorobenzoic Acid. Chemical Book. Available online: https:\/\/www.chemicalbook.com\/ChemicalProductProperty_EN_CB1688854.htm."},{"key":"ref_30","first-page":"215","article-title":"The Crystal Structure of Benzoic Acid: A Redetermination with X-rays at Room Temperature; a Summary of Neutron-diffraction Work at Temperatures Down to 5 K","volume":"157","author":"Feld","year":"1981","journal-title":"Zeitsch. Kristall."},{"key":"ref_31","unstructured":"Carver, C.D. (1982). The Coblentz Society Desk Book of Infrared Spectra. The Coblentz Society Desk Book of Infrared Spectra, The Coblentz Society. [2nd ed.]."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"3098","DOI":"10.1103\/PhysRevA.38.3098","article-title":"Density-functional Exchange-energy Approximation with Correct Asymptotic Behavior","volume":"38","author":"Becke","year":"1988","journal-title":"Phys. Rev. A"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"785","DOI":"10.1103\/PhysRevB.37.785","article-title":"Development of the Colle-Salvetti Correlation-energy Formula into a Functional of the Electron Density","volume":"37","author":"Lee","year":"1988","journal-title":"Phys. Rev. B"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1200","DOI":"10.1139\/p80-159","article-title":"Accurate Spin-dependent Electron Liquid Correlation Energies for Local Spin Density Calculations: A Critical Analysis","volume":"58","author":"Vosko","year":"1980","journal-title":"Can. J. Phys."},{"key":"ref_35","unstructured":"Frisch, M.J., Trucks, G.W., Schlegel, H.B., Scuseria, G.E., Robb, M.A., Cheeseman, J.R., Scalmani, G., Barone, V., Mennucci, B., and Petersson, G.A. (2009). Gaussian 09, Revision A.02, Gaussian, Inc."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"5639","DOI":"10.1063\/1.438980","article-title":"Contracted Gaussian Basis Sets for Molecular Calculations. I. Second Row Atoms, Z=11\u201318","volume":"72","author":"McLean","year":"1980","journal-title":"J. Chem. Phys."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"650","DOI":"10.1063\/1.438955","article-title":"Self-consistent Molecular Orbital Methods. XX. A Basis Set for Correlated Wave Functions","volume":"72","author":"Raghavachari","year":"1980","journal-title":"J. Chem. Phys."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"3265","DOI":"10.1063\/1.447079","article-title":"Self-consistent Molecular Orbital Methods 25. Supplementary Functions for Gaussian Basis Sets","volume":"80","author":"Frisch","year":"1984","journal-title":"J. Chem. Phys."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"104303","DOI":"10.1063\/1.5118332","article-title":"UV-Induced Conformational Isomerization and Photochemistry of 3-Chloro-4-methoxybenzaldehyde in Cryogenic Inert Matrices","volume":"151","author":"Ildiz","year":"2019","journal-title":"J. Chem. Phys."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"207","DOI":"10.1016\/j.saa.2016.08.002","article-title":"Matrix Isolation Infrared Spectroscopic Study of 4-Pyridinecarboxaldehyde and of its UV-induced Photochemistry","volume":"171","author":"Cluyts","year":"2017","journal-title":"Spectrochim. Acta Part A Mol. Biomol. Spectrosc."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"5914","DOI":"10.1016\/j.tet.2016.08.032","article-title":"First Observation of Methane Photochemical Generation from an N,N-dimethylamino-substituted Arene: The case of 4-(N,N-dimethylamino) benzaldehyde (DMABA)","volume":"72","author":"Sharma","year":"2016","journal-title":"Tetrahedron"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"1614","DOI":"10.1021\/acs.jctc.7b01200","article-title":"Accurate Lattice Energies for Molecular Crystals from Experimental Crystal Structures","volume":"14","author":"Thomas","year":"2018","journal-title":"J. Chem. Theory Comput."},{"key":"ref_43","unstructured":"Turner, M.J., McKinnon, J.J., Wolff, S.K., Grimwood, D.J., Spackman, P.R., Jayatilaka, D., Spackman, M.A., and University of Western Australia (2020, October 22). CrystalExplorer17. Available online: http:\/\/hirshfeldsurface.net."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"054103","DOI":"10.1063\/1.4738961","article-title":"A Benchmark for Non-Covalent Interactions in Solids","volume":"137","author":"Johnson","year":"2012","journal-title":"J. Chem. Phys."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"024705","DOI":"10.1063\/1.4812819","article-title":"Understanding the Role of Vibrations, Exact Exchange, and Many-body van der Waals Interactions in the Cohesive Properties of Molecular Crystals","volume":"139","author":"Reilly","year":"2013","journal-title":"J. Chem. Phys."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"3340","DOI":"10.1021\/acs.jctc.6b00304","article-title":"Assessment of Different Quantum Mechanical Methods for the Prediction of Structure and Cohesive Energy of Molecular Crystals","volume":"12","author":"Cutini","year":"2016","journal-title":"J. Chem. Theory Comput."},{"key":"ref_47","unstructured":"Gavezzotti, A. (1997). Theoretical Aspects and Computer Modeling of the Molecular Solid Stat, Wiley."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"4676","DOI":"10.1021\/acs.cgd.7b00582","article-title":"Thermochemistry of Racemic and Enantiopure Organic Crystals for Predicting Enantiomer Separation","volume":"17","author":"Buchholz","year":"2017","journal-title":"Cryst. Growth Des."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"1945","DOI":"10.1039\/f29898501945","article-title":"S-cis and S-trans Conformers of Formic, Thioformic and Dithioformic Acids. An Ab Initio Study","volume":"85","author":"Fausto","year":"1989","journal-title":"J. Chem. Soc. Faraday Trans."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"123","DOI":"10.1016\/0166-1280(94)03787-L","article-title":"Bonding in Carbonyl and Thiocarbonyl Compounds: An Ab Initio Charge Density Study of H2C=X and HC(=X)YH (X,Y= O or S)","volume":"315","author":"Fausto","year":"1994","journal-title":"J. Mol. Struct. (Theochem.)"},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1016\/0022-2860(86)85001-3","article-title":"A Molecular Mechanics Force Field for Conformational Analysis of Simple Acyl Chlorides, Carboxylic Acids and Esters","volume":"144","author":"Fausto","year":"1986","journal-title":"J. Mol. Struct."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"9014","DOI":"10.1021\/jp0620825","article-title":"Molecular Structures of Benzoic Acid and 2-Hydroxybenzoic Acid, Obtained by Gas-Phase Electron Diffraction and Theoretical Calculations","volume":"110","author":"Aarset","year":"2006","journal-title":"J. Phys. Chem. A"},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"301","DOI":"10.1016\/S0022-2860(98)00675-9","article-title":"Microwave Spectrum of Benzoic Acid","volume":"482\u2013483","author":"Onda","year":"1999","journal-title":"J. Mol. Struct."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"123","DOI":"10.1016\/0924-2031(95)00068-2","article-title":"Infrared Spectra of Benzoic Acid Monomers and Dimers in Argon Matrix","volume":"11","author":"Stepanian","year":"1996","journal-title":"Vibrat. Spectrosc."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"337","DOI":"10.1016\/0022-2860(95)08778-T","article-title":"An Infrared Study on Matrix-Isolated Benzoic Acid","volume":"349","author":"Reva","year":"1995","journal-title":"J. Mol. Struct."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"11180","DOI":"10.1063\/1.1622657","article-title":"The Infrared Absorption Spectrum of the Gas Phase Neutral Benzoic Acid Monomer and Dimer","volume":"119","author":"Bakker","year":"2003","journal-title":"J. Chem. Phys."},{"key":"ref_57","unstructured":"Arendorf, J.R.T. (2011). A Study of Some Non-Covalent Functional Group Interactions. [Ph.D. Thesis, University College]."},{"key":"ref_58","first-page":"315","article-title":"Structural Characterization and Photochemistry of 2-Chloro-6-fluorobenzoic Acid Isolated in a Xenon Matrix","volume":"18","year":"2017","journal-title":"Anadolu Univ. J. Sci. Techn. A Appl. Sci. Eng."},{"key":"ref_59","unstructured":"Harris, D. (2010). Quantitative Chemical Analysis, W. H. Freeman and Company. [8th ed.]."},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"5994","DOI":"10.1021\/jp505335c","article-title":"Molecular Structure, Infrared Spectra, Photochemistry, and Thermal Properties of 1-Methylhydantoin","volume":"118","author":"Nogueira","year":"2014","journal-title":"J. Phys. Chem. A"},{"key":"ref_61","first-page":"803","article-title":"Kerr Constants and Structure of Benzoic Acid in Dioxane and CCl4","volume":"43","author":"Timosheva","year":"1994","journal-title":"Russ. Chem. Bull."},{"key":"ref_62","unstructured":"(2020, August 25). 2-Fluorobenzoic Acid, Home Page of R. Stenutz. Available online: http:\/\/www.stenutz.eu\/chem\/solv6.php?name=2-fluorobenzoic%20acid."},{"key":"ref_63","unstructured":"(2020, October 22). ChemCraft (Version 1.8)\u2014Graphical Software for Visualization of Quantum Chemistry Computations. Available online: https:\/\/www.chemcraftprog.com."},{"key":"ref_64","unstructured":"(2020, September 09). Wiley Spectrabase. Available online: https:\/\/spectrabase.com\/spectrum\/pk7U3jDypt."},{"key":"ref_65","doi-asserted-by":"crossref","first-page":"3380","DOI":"10.1021\/jp037840v","article-title":"Photochemistry and Vibrational Spectroscopy of the trans and cis Conformers of Acetic Acid in Solid Argon","volume":"108","author":"Kriachtchev","year":"2004","journal-title":"J. Phys. Chem. A"},{"key":"ref_66","doi-asserted-by":"crossref","unstructured":"Khriachtchev, L. (2011). Conformational Changes in Cryogenic Matrices. Physics and Chemistry at Low Temperatures, World Scientific.. Chapter 3.","DOI":"10.1201\/b11403"},{"key":"ref_67","doi-asserted-by":"crossref","first-page":"154311","DOI":"10.1063\/1.4898085","article-title":"Mechanistic Photodecarboxylation of Pyruvic Acid: Excited-state Proton Transfer and Three-state Intersection","volume":"141","author":"Chang","year":"2014","journal-title":"J. Chem. Phys."},{"key":"ref_68","doi-asserted-by":"crossref","first-page":"695","DOI":"10.1021\/j100365a034","article-title":"Laser Photolysis of Carboxylic Acids in the Gas Phase. Direct Determination of the OH Quantum Yield at 222 nm","volume":"94","author":"Singleton","year":"1990","journal-title":"J. Phys. Chem."},{"key":"ref_69","doi-asserted-by":"crossref","first-page":"7718","DOI":"10.1021\/jp052837s","article-title":"Probing Photophysical and Photochemical Processes of Benzoic Acid from ab Initio Calculations","volume":"109","author":"Li","year":"2005","journal-title":"J. Phys. Chem. A"},{"key":"ref_70","doi-asserted-by":"crossref","first-page":"215","DOI":"10.1016\/S0009-2614(97)00100-0","article-title":"A Novel Definition of a Molecule in a Crystal","volume":"267","author":"Spackman","year":"1997","journal-title":"Chem. Phys. Lett."},{"key":"ref_71","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1039\/B818330A","article-title":"Hirshfeld Surface Analysis","volume":"11","author":"Spackman","year":"2009","journal-title":"CrystEngComm"},{"key":"ref_72","doi-asserted-by":"crossref","first-page":"2136","DOI":"10.1002\/(SICI)1521-3765(19981102)4:11<2136::AID-CHEM2136>3.0.CO;2-G","article-title":"Hirshfeld Surfaces: A New Tool for Visualising and Exploring Molecular Crystals","volume":"4","author":"McKinnon","year":"1998","journal-title":"Chem. Eur. J."},{"key":"ref_73","doi-asserted-by":"crossref","first-page":"378","DOI":"10.1039\/B203191B","article-title":"Fingerprinting Intermolecular Interactions in Molecular Crystals","volume":"4","author":"Spackman","year":"2002","journal-title":"CrystEngComm"},{"key":"ref_74","doi-asserted-by":"crossref","first-page":"4517","DOI":"10.1021\/cg8005212","article-title":"Hirshfeld Surfaces Identify Inadequacies in Computations of Intermolecular Interactions in Crystals: Pentamorphic 1,8-Dihydroxyanthraquinone","volume":"8","author":"Rohl","year":"2008","journal-title":"Cryst. Growth Des."},{"key":"ref_75","doi-asserted-by":"crossref","first-page":"648","DOI":"10.1039\/b704177b","article-title":"Comparing Entire Crystal Structures: Structural Genetic Fingerprinting","volume":"9","author":"Parkin","year":"2007","journal-title":"CrystEngComm"},{"key":"ref_76","doi-asserted-by":"crossref","unstructured":"(The UnscramblerTM, 2018). The UnscramblerTM, Version 10.5.","DOI":"10.1016\/S0262-1762(19)30210-X"},{"key":"ref_77","doi-asserted-by":"crossref","first-page":"236","DOI":"10.1080\/01621459.1963.10500845","article-title":"Hierarchical Grouping to Optimize an Objective Function","volume":"58","author":"Ward","year":"1963","journal-title":"J. Am. Stat. Assoc."},{"key":"ref_78","doi-asserted-by":"crossref","first-page":"3533","DOI":"10.1021\/ja00905a001","article-title":"Hard and Soft Acids and Bases","volume":"85","author":"Pearson","year":"1963","journal-title":"J. Am. Chem. Soc."},{"key":"ref_79","doi-asserted-by":"crossref","first-page":"15383","DOI":"10.1021\/jp960693z","article-title":"Dependence of the Hardness of Atoms in Molecules on the Local Environment: An ab Initio Study","volume":"100","author":"Toufar","year":"1996","journal-title":"J. Phys. Chem."},{"key":"ref_80","doi-asserted-by":"crossref","first-page":"125102","DOI":"10.1088\/0957-0233\/19\/12\/125102","article-title":"Apparatus for Determination of Vapor Pressures at Ambient Temperatures Employing a Knudsen Effusion Cell and Quartz Crystal Microbalance","volume":"19","author":"Freedman","year":"2008","journal-title":"Meas. Sci. Technol."},{"key":"ref_81","doi-asserted-by":"crossref","first-page":"1727","DOI":"10.1006\/jcht.2000.0705","article-title":"Thermodynamic Study on the Sublimation of the Three Iodobenzoic Acids and of 2-Fluoro- and 3-Fluorobenzoic Acids","volume":"32","author":"Monte","year":"2000","journal-title":"J. Chem. Thermodyn."},{"key":"ref_82","doi-asserted-by":"crossref","first-page":"194","DOI":"10.1515\/zpch-1938-3912","article-title":"Uber Sublimationswarmen","volume":"39","author":"Wolf","year":"1938","journal-title":"Z. Phys. Chem."},{"key":"ref_83","doi-asserted-by":"crossref","first-page":"3839","DOI":"10.1016\/S0040-4039(01)94175-9","article-title":"Definition of aromaticity basing on the harmonic oscillator model","volume":"13","author":"Kruszewski","year":"1972","journal-title":"Tetrahedron Lett."},{"key":"ref_84","doi-asserted-by":"crossref","first-page":"1385","DOI":"10.1021\/cr990326u","article-title":"Structural Aspects of Aromaticity","volume":"101","author":"Krygowski","year":"2001","journal-title":"Chem. Rev."},{"key":"ref_85","doi-asserted-by":"crossref","first-page":"3773","DOI":"10.1021\/cr0300845","article-title":"Energetic Aspects of Cyclic Pi-Electron Delocalization:\u2009 Evaluation of the Methods of Estimating Aromatic Stabilization Energies","volume":"105","year":"2005","journal-title":"Chem. Rev."}],"container-title":["Molecules"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1420-3049\/25\/21\/4908\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T10:26:55Z","timestamp":1760178415000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1420-3049\/25\/21\/4908"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,10,23]]},"references-count":85,"journal-issue":{"issue":"21","published-online":{"date-parts":[[2020,11]]}},"alternative-id":["molecules25214908"],"URL":"https:\/\/doi.org\/10.3390\/molecules25214908","relation":{},"ISSN":["1420-3049"],"issn-type":[{"value":"1420-3049","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,10,23]]}}}