title: Synthesis, crystal structure, conformational and vibrational properties of 6-acetyl-2,2-dimethyl-chromane.
abstract: The 6-acetyl-2,2-dimethyl-chromane compound was synthesized and characterized by IR, Raman, UV-Visible and (1)H NMR spectroscopies. Its solid state structure was determined by X-ray diffraction methods. The substance crystallizes in the triclinic P-1 space group with a=5.9622(5) Å, b=10.342(1) Å, c=10.464(1) Å, α=63.81(1)°, β=81.923(9)°, γ=82.645(9)°, and Z=2 molecules per unit cell. Due to extended π-bonding delocalization a substantial skeletal fragment of the molecule is planar. The vibrational modes were calculated at B3LYP/6-31G(d,p) level and all of them assigned in the IR and Raman spectra. The DFT calculated (1)H NMR spectrum (chemical shifts) were in good agreement with the experimental data. The electronic (UV-Visible) spectrum was calculated using TD-DFT method in gas phase and it was correlated with the experimental data. The assignment and analysis of the frontier HOMO and LUMO orbitals indicate that the absorption bands are mainly originated from π→π(*) transitions. According to DSC measurements the substance presents a melting point of 93°C and decomposes at temperatures higher than 196°C.
authors.affiliation: INQUINOA, CONICET, Instituto de Química Física, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, San Lorenzo 456, T4000CAN Tucumán, Argentina.
authors.forename: Emilio
authors.initials: E
authors.lastname: Lizarraga
authors.affiliation: INQUINOA, CONICET, Instituto de Química Física, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, San Lorenzo 456, T4000CAN Tucumán, Argentina.
authors.forename: Diego M
authors.initials: DM
authors.lastname: Gil
authors.affiliation: Departamento de Física, Facultad de Ciencias Exactas, Universidad Nacional de La Plata and Institute IFLP (CONICET, CCT-La Plata), C.C. 67, 1900 La Plata, Argentina.
authors.forename: Gustavo A
authors.initials: GA
authors.lastname: Echeverría
authors.affiliation: Departamento de Física, Facultad de Ciencias Exactas, Universidad Nacional de La Plata and Institute IFLP (CONICET, CCT-La Plata), C.C. 67, 1900 La Plata, Argentina.
authors.forename: Oscar E
authors.initials: OE
authors.lastname: Piro
authors.affiliation: INQUINOA, CONICET, Instituto de Química Orgánica, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Ayacucho 471, T4000INI Tucumán, Argentina.
authors.forename: César A N
authors.initials: CA
authors.lastname: Catalán
authors.affiliation: INQUINOA, CONICET, Instituto de Química Física, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, San Lorenzo 456, T4000CAN Tucumán, Argentina. Electronic address: altabef@fbqf.unt.edu.ar.
authors.forename: Aída
authors.initials: A
authors.lastname: Ben Altabef
mesh_terms: D002839:Chromans / Q000138:chemical synthesis* / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D013057:Spectrum Analysis
chemical_list: D002839:Chromans
keywords: 6-Acetyl-2,2-dimethyl-chromane; DFT calculations; IR and Raman spectroscopy; NBO analysis; X-ray crystal structure determination