We report the free-jet rotational spectra of methylsalicylate, a molecule with a possible tautomeric and conformational equilibrium. In the ground electronic state, the molecule adopts a form stabilized by an intramolecular hydrogen bond between the phenolic hydrogen and the carbonylic oxygen, and this structure is characterized as the lowest-energy form by quantum chemical calculations. All rotational transitions are split because of the internal rotation of the methyl group, and the value of the barrier for this motion was determined to be V(3) = 5.38 kJ mol(-1).
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Insects
March 2023
Forest Pest Methods Laboratory, USDA-APHIS-PPQ, 1398 W. Truck Rd., Buzzards Bay, MA 02542, USA.
A mark-release-recapture experiment was conducted to evaluate the orientation of spotted lanternfly (SLF) White (Hemiptera: Fulgoridae) nymphs when released equidistant between two trees. The experiment was repeated weekly for eight weeks in a heavily infested area with mature tree-of-heaven (Mill.) Swingle (Sapindales: Simaroubaceae) planted in rows as ornamental street trees in Beijing, China.
View Article and Find Full Text PDFPhys Chem Chem Phys
March 2019
Departamento de Química Física y Química Inorgánica, Facultad de Ciencias, Universidad de Valladolid, 47011 Valladolid, Spain.
The conformation of ortho-anisic acid and its monohydrated clusters generated in a supersonic jet has been studied by rotational spectroscopy to analyze the structural implications of ortho substitution. The dominant monomer species shows a trans-COOH arrangement stabilized by an intramolecular O-HO hydrogen bond from the acid to the methoxy group. The spectra of two non-planar skeleton monomer forms with a cis-COOH arrangement have also been detected.
View Article and Find Full Text PDFMutat Res
December 2017
Key Laboratory of Ion Beam Bio-Engineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences, P.O. Box 1138, Hefei, Anhui, 230031, PR China. Electronic address:
Controlled ecological life support systems (CELSS) will be an important feature of long-duration space missions of which higher plants are one of the indispensable components. Because of its pivotal role in enabling plants to cope with environmental stress, interplant communication might have important implications for the ecological stability of such CELSS. However, the manifestations of interplant communication in microgravity conditions have yet to be fully elucidated.
View Article and Find Full Text PDFJ Phys Chem B
February 2015
Departamento de Química Física Aplicada, Universidad Autónoma de Madrid , Cantoblanco, 28049 Madrid, Spain.
The fluorescent behavior of the methyl-5-R-salicylates is analyzed in media of negligible acidity and basicity so that the methyl-5-R-salicylates may undergo solvent dipolarity changes or not in a controlled manner based on the following guidelines: (i) The molecular forms of these methyl-5-R-salicylates possessing an intramolecular hydrogen bond (IMHB) between their hydroxyl group and ether type oxygen (rotated tautomer) undergo no excited-state intramolecular proton transfer (ESIPT) in their first excited electronic state; (ii) on the other hand, the molecular species with an IMHB between its hydroxyl group and carbonyl oxygen (normal tautomer) exhibits both ESIPT and normal emission when charge transfer (CT) from the R-substituent to the phenol group is slight to moderate, but only normal emission is monitored when CT is strong. The special insensitivity of the first UV absorption band for the normal tautomer of methylsalicylate (MS, with R = H) to the polarity of the solvent is not echoed by the normal forms of methyl-5-R-salicylates containing substituents R with a substantial effect of CT in the IMHB of the compound. These solvatochromic features of MS are shared by the emissions of its derivatives.
View Article and Find Full Text PDFActa Crystallogr Sect E Struct Rep Online
May 2012
In the title compound, C(17)H(16)O(6), the two methyl salicylate moieties are related by crystallographic twofold rotational symmetry with the two benzene rings close to being perpendicular [inter-ring dihedral angle = 86.6 (8)°]. Intra-molecular phenolic O-H⋯O hydrogen bonds with carboxyl O-atom acceptors are present, with these groups also involved in centrosymmetric cyclic inter-molecular O-H⋯O hydrogen-bonding associations [graph set R(2) (2)(4)], giving infinite chains extending across (101).
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