{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T02:16:49Z","timestamp":1760235409582,"version":"build-2065373602"},"reference-count":38,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2021,8,13]],"date-time":"2021-08-13T00:00:00Z","timestamp":1628812800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>The dynamics of 2-methoxybenzaldehyde, 4-methoxybenzaldehyde, and 4-ethoxybenzaldehyde in the solid state are assessed through INS spectroscopy combined with periodic DFT calculations. In the absence of experimental data for 4-ethoxybenzaldehyde, a tentative crystal structure, based on its similarity with 4-methoxybenzaldehyde, is considered and evaluated. The excellent agreement between calculated and experimental spectra allows a confident assignment of the vibrational modes. Several spectral features in the INS spectra are unambiguously assigned and torsional potential barriers for the methyl groups are derived from experimental frequencies. The intramolecular nature of the potential energy barrier for methyl rotation about O\u2013CH3 bonds compares with the one reported for torsion about saturated C\u2013CH3 bonds. On the other hand, the intermolecular contribution to the potential energy barrier may represent 1\/3 of the barrier height in these systems.<\/jats:p>","DOI":"10.3390\/ma14164561","type":"journal-article","created":{"date-parts":[[2021,8,13]],"date-time":"2021-08-13T09:22:38Z","timestamp":1628846558000},"page":"4561","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["New Insights on the Vibrational Dynamics of 2-Methoxy-, 4-Methoxy- and 4-Ethoxy-Benzaldehyde from INS Spectra and Periodic DFT Calculations"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5171-2153","authenticated-orcid":false,"given":"Paulo J. A.","family":"Ribeiro-Claro","sequence":"first","affiliation":[{"name":"CICECO, Departamento de Qu\u00edmica, Universidade de Aveiro, 3810-193 Aveiro, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9720-9801","authenticated-orcid":false,"given":"Pedro D.","family":"Vaz","sequence":"additional","affiliation":[{"name":"Champalimaud Centre for the Unknown, Champalimaud Foundation, 1400-038 Lisboa, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4622-5307","authenticated-orcid":false,"given":"Mariela M.","family":"Nolasco","sequence":"additional","affiliation":[{"name":"CICECO, Departamento de Qu\u00edmica, Universidade de Aveiro, 3810-193 Aveiro, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7546-0288","authenticated-orcid":false,"given":"Francisco P. S. C.","family":"Gil","sequence":"additional","affiliation":[{"name":"Departamento de F\u00edsica, Universidade de Coimbra, 3004-516 Coimbra, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8059-8537","authenticated-orcid":false,"given":"Lu\u00eds A. E. Batista","family":"de Carvalho","sequence":"additional","affiliation":[{"name":"Qu\u00edmica-F\u00edsica Molecular, Departamento de Qu\u00edmica, Universidade de Coimbra, 3004-535 Coimbra, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8391-0055","authenticated-orcid":false,"given":"Maria Paula M.","family":"Marques","sequence":"additional","affiliation":[{"name":"Qu\u00edmica-F\u00edsica Molecular, Departamento de Qu\u00edmica, Universidade de Coimbra, 3004-535 Coimbra, Portugal"},{"name":"Departamento de Ci\u00eancias da Vida, Universidade de Coimbra, 3000-456 Coimbra, Portugal"}]},{"given":"Ana M.","family":"Amado","sequence":"additional","affiliation":[{"name":"Qu\u00edmica-F\u00edsica Molecular, Departamento de Qu\u00edmica, Universidade de Coimbra, 3004-535 Coimbra, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2021,8,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1305","DOI":"10.1021\/acs.biomac.8b00110","article-title":"Hydrogen Bond Dynamics of Cellulose through Inelastic Neutron Scattering Spectroscopy","volume":"19","author":"Araujo","year":"2018","journal-title":"Biomacromolecules"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"3515","DOI":"10.1021\/acs.macromol.8b00192","article-title":"Inside PEF: Chain conformation and dynamics in crystalline and amorphous domains","volume":"51","author":"Araujo","year":"2018","journal-title":"Macromolecules"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1142","DOI":"10.1002\/ejic.201800914","article-title":"Synthesis, computational studies, inelastic neutron scattering, infrared and raman spectroscopy of ruthenocene","volume":"2019","author":"Parker","year":"2019","journal-title":"Eur. J. Inorg. Chem."},{"doi-asserted-by":"crossref","unstructured":"Nolasco, M.M., Araujo, C.F., Vaz, P.D., Amado, A.M., and Ribeiro-Claro, P. (2020). Vibrational dynamics of crystalline 4-phenylbenzaldehyde from INS spectra and periodic DFT calculations. Molecules, 25.","key":"ref_4","DOI":"10.3390\/molecules25061374"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"2776","DOI":"10.1021\/acs.jpcb.7b01090","article-title":"Molecular and vibrational dynamics in the cholesterol-lowering agent lovastatin: Solid-state NMR, inelastic neutron scattering, and periodic DFT Study","volume":"121","author":"Bilski","year":"2017","journal-title":"J. Phys. Chem. B"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"37","DOI":"10.1016\/j.vibspec.2015.11.008","article-title":"INS, DFT and temperature dependent IR studies on dynamical properties of acetylcholine chloride","volume":"82","year":"2016","journal-title":"Vib. Spectrosc."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1681","DOI":"10.1021\/jp507241j","article-title":"Polymorphism of resorcinol explored by complementary vibrational spectroscopy (FT-RS, THz-TDS, INS) and first-principles solid-state computations (Plane-Wave DFT)","volume":"119","author":"Mikuli","year":"2015","journal-title":"J. Phys. Chem. B"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"181363","DOI":"10.1098\/rsos.181363","article-title":"Structure and vibrational spectroscopy of methanesulfonic acid","volume":"5","author":"Zhong","year":"2018","journal-title":"R. Soc. Open Sci."},{"key":"ref_9","first-page":"100006","article-title":"Vibrational dynamics of 4-fluorobenzaldehyde from periodic DFT calculations","volume":"2","author":"Vaz","year":"2019","journal-title":"Chem. Phys. Lett. X"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2424","DOI":"10.1021\/acs.macromol.6b02410","article-title":"Identifying Atomic Scale Structure in Undoped\/Doped Semicrystalline P3HT Using Inelastic Neutron Scattering","volume":"50","author":"Harrelson","year":"2017","journal-title":"Macromolecules"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1380","DOI":"10.1021\/acs.macromol.9b02449","article-title":"Asymmetric monomer, amorphous polymer structure\u2013property relationships in 2,4-FDCA and 2,4-PEF","volume":"53","author":"Nolasco","year":"2020","journal-title":"Macromolecules"},{"doi-asserted-by":"crossref","unstructured":"Vilela, C., Freire, C.S.R., Ara\u00fajo, C., Rudi\u0107, S., Silvestre, A.J.D., Vaz, P.D., Ribeiro-Claro, P.J.A., and Nolasco, M.M. (2020). Understanding the structure and dynamics of nanocellulose-based composites with neutral and ionic poly(methacrylate) derivatives using inelastic neutron scattering and DFT calculations. Molecules, 25.","key":"ref_12","DOI":"10.3390\/molecules25071689"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"318","DOI":"10.1016\/S0009-2614(02)00337-8","article-title":"C-H\u22efO bonded dimers in 2-methoxy-benzaldehyde studied by X-ray crystallography, vibrational spectroscopy, and ab initio calculations","volume":"356","author":"Drew","year":"2002","journal-title":"Chem. Phys. Lett."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"387","DOI":"10.1107\/S0108270111035840","article-title":"Weak C-H\u22efO hydrogen bonds in anisaldehyde, salicyl-aldehyde and cinnamaldehyde","volume":"67","author":"Kirchner","year":"2011","journal-title":"Acta Crystallogr. Sect. C Cryst. Struct. Commun."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1325","DOI":"10.1366\/11-06456","article-title":"Vibrational Spectroscopy with Neutrons: A Review of New Directions","volume":"65","author":"Parker","year":"2011","journal-title":"Appl. Spectrosc."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"012003","DOI":"10.1088\/1742-6596\/554\/1\/012003","article-title":"Recent and future developments on TOSCA at ISIS","volume":"554","author":"Parker","year":"2014","journal-title":"J. Phys. Conf. Ser."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"156","DOI":"10.1016\/j.nima.2014.07.029","article-title":"Mantid-Data analysis and visualization package for neutron scattering and mu SR experiments","volume":"764","author":"Arnold","year":"2014","journal-title":"Nucl. Instrum. Methods Phys. Res. Sect. A Accel. Spectrometers Detect. Assoc. Equip."},{"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_18"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"567","DOI":"10.1524\/zkri.220.5.567.65075","article-title":"First principles methods using CASTEP","volume":"220","author":"Clark","year":"2005","journal-title":"Z. Krist. Cryst. Mater."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"73","DOI":"10.1103\/PhysRevB.73.155114","article-title":"Variational density-functional perturbation theory for dielectrics and lattice dynamics","volume":"73","author":"Refson","year":"2006","journal-title":"Phys. Rev. B"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"3865","DOI":"10.1103\/PhysRevLett.77.3865","article-title":"Generalized gradient approximation made simple","volume":"77","author":"Perdew","year":"1996","journal-title":"Phys. Rev. Lett."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"452","DOI":"10.1016\/j.saa.2018.06.073","article-title":"Understanding the vibrational spectra of crystalline isoniazid: Raman, IR and INS spectroscopy and solid-state DFT study","volume":"204","author":"Vaz","year":"2018","journal-title":"Spectrochim. Acta Part A Mol. Biomol. Spectrosc."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"073005","DOI":"10.1103\/PhysRevLett.102.073005","article-title":"Accurate molecular van der Waals interactions from ground-state electron density and free-atom reference data","volume":"102","author":"Tkatchenko","year":"2009","journal-title":"Phys. Rev. Lett."},{"unstructured":"Jmol Development Team (2021, August 08). Jmol. Available online: http:\/\/jmol.sourceforge.net\/.","key":"ref_24"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"443","DOI":"10.1016\/j.physb.2018.02.034","article-title":"AbINS: The modern software for INS interpretation","volume":"551","author":"Dymkowski","year":"2018","journal-title":"Phys. B Condens. Matter"},{"unstructured":"Groner, P. (2021, August 08). Program Barrier. Available online: http:\/\/www.ifpan.edu.pl\/~kisiel\/prospe.htm.","key":"ref_26"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"2817","DOI":"10.1021\/acs.cgd.5b00251","article-title":"Computationally assisted (solid-state density functional theory) structural (X-ray) and vibrational spectroscopy (FT-IR, FT-RS, TDs-THz) characterization of the cardiovascular drug lacidipine","volume":"15","author":"Mielcarek","year":"2015","journal-title":"Cryst. Growth Des."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"151","DOI":"10.1016\/j.molstruc.2016.01.068","article-title":"Molecular structure, vibrational spectral assignments (FT-IR and FT-RAMAN), NMR, NBO, HOMO-LUMO and NLO properties of O-methoxybenzaldehyde based on DFT calculations","volume":"1111","author":"Vennila","year":"2016","journal-title":"J. Mol. Struct."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"867","DOI":"10.1002\/(SICI)1097-4555(199711)28:11<867::AID-JRS175>3.0.CO;2-6","article-title":"Evidence of dimerization through C-H\u22efO interactions in liquid 4-methoxybenzaldehyde from raman spectra and Ab Initio calculations","volume":"28","author":"Amado","year":"1997","journal-title":"J. Raman Spectrosc."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"550","DOI":"10.1016\/j.saa.2007.07.050","article-title":"Vibrational spectroscopy investigation using ab initio and density functional theory on p-anisaldehyde","volume":"70","author":"Gunasekaran","year":"2008","journal-title":"Spectrochim. Acta Part A Mol. Biomol. Spectrosc."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"590","DOI":"10.1016\/j.molstruc.2016.09.035","article-title":"Structural and spectroscopic (UV\u2013Vis, IR, Raman, and NMR) characteristics of anisaldehydes that are flavoring food additives: A density functional study in comparison with experiments","volume":"1128","author":"Altun","year":"2017","journal-title":"J. Mol. Struct."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1301","DOI":"10.1016\/0584-8539(86)80230-6","article-title":"Vibrational spectra of monosubstituted benzaldehydes\u2014o-ethoxy-, p-ethoxy-, p-carboxy- and p-cyanobenzaldehydes","volume":"42","author":"Venkoji","year":"1986","journal-title":"Spectrochim. Acta Part A Mol. Spectrosc."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1855","DOI":"10.1002\/cphc.201700276","article-title":"Methyl internal rotation in the microwave spectrum of o-methyl anisole","volume":"18","author":"Ferres","year":"2017","journal-title":"ChemPhysChem"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"44","DOI":"10.1016\/j.jms.2017.09.008","article-title":"The effect of internal rotation in p-methyl anisole studied by microwave spectroscopy","volume":"343","author":"Ferres","year":"2018","journal-title":"J. Mol. Spectrosc."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"374","DOI":"10.1006\/jmsp.1997.7391","article-title":"Millimeter-wave absorption free jet spectrum, barriers to internal rotation, and torsional relaxation in p-anisaldehyde","volume":"185","author":"Melandri","year":"1997","journal-title":"J. Mol. Spectrosc."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"107","DOI":"10.1016\/0022-2860(92)85065-O","article-title":"Rotational spectra of para-anisaldehyde\u2014Assignment of the planar conformers and observation of torsionally excited states","volume":"268","author":"Bohn","year":"1992","journal-title":"J. Mol. Struct."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"2755","DOI":"10.1021\/acsomega.9b03351","article-title":"The methyl torsion in unsaturated compounds","volume":"5","author":"Zachariou","year":"2020","journal-title":"ACS Omega"},{"doi-asserted-by":"crossref","unstructured":"Adilina, I.B., Aulia, F., Fitriady, M.A., Oemry, F., Widjaya, R.R., and Parker, S.F. (2020). Computational and spectroscopic studies of carbon disulfide. Molecules, 25.","key":"ref_38","DOI":"10.3390\/molecules25081901"}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/14\/16\/4561\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T06:45:41Z","timestamp":1760165141000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/14\/16\/4561"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,8,13]]},"references-count":38,"journal-issue":{"issue":"16","published-online":{"date-parts":[[2021,8]]}},"alternative-id":["ma14164561"],"URL":"https:\/\/doi.org\/10.3390\/ma14164561","relation":{},"ISSN":["1996-1944"],"issn-type":[{"type":"electronic","value":"1996-1944"}],"subject":[],"published":{"date-parts":[[2021,8,13]]}}}