Jet-cooled acetaminophen (AAP)-water clusters, AAP-(HO), were investigated by mass-selected resonant two-photon ionization (R2PI), ultraviolet-ultraviolet hole-burning (UV-UV HB), infrared-dip (IR-dip), and infrared-ultraviolet hole-burning (IR-UV HB) spectroscopy. Each syn- and anti-AAP rotamer has three distinctive binding sites (-OH, >CO, and >NH) for a water molecule, thus 6 different AAP-(HO) conformers are expected to exist in the molecular beam. The origin bands of the AAP(OH)-(HO) and AAP(CO)-(HO) conformers (including their syn- and anti-conformers) in the R2PI spectrum are shifted to red and blue compared to those of the AAP monomer, respectively. These frequency shifts upon complexation between a water molecule and a specific binding site of AAP are also predicted by theoretical calculations. The spectral assignments of the origin bands in the R2PI spectra and the IR vibrational bands in the IR-dip spectra of the four lowest-energy conformers of AAP-(HO), [syn- and anti-AAP(OH)-(HO) and syn- and anti-AAP(CO)-(HO)], are aided by ab initio and time-dependent density functional theory (TDDFT) calculations. Further investigation of the IR-dip spectra has revealed a hydrogen-bonded NH stretching mode, supporting the presence of the syn-AAP(NH)-(HO) conformer. Moreover, by employing IR-UV HB spectroscopy, we have reconfirmed the existence of the syn-AAP(NH)-(HO) conformer, which happened to be buried underneath the broad background contributed by the AAP(OH)-(HO) conformers. These observations have led us to conclude that all of the possible conformers of AAP-(HO) have been found in this study.
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http://dx.doi.org/10.1039/c6cp06863d | DOI Listing |
Zhongguo Zhong Yao Za Zhi
December 2024
Xinjiang Key Laboratory of Clean Conversion and High Value Utilization of Biomass Resources,School of Chemistry and Chemical Engineering, Yili Normal University Yining 835000, China School of Health, Jiangxi Normal University Nanchang 330022, China.
Ten compounds were separated by various modern chromatographic methods from mastic. They were identified by HR-ESI-MS, IR, UV, NMR, quantum chemical calculation of NMR(qcc-NMR) and comparison with reported data in literature as 17β-hydroxy-28-norolean-18-en-3-one(1), 28-norolean-12,17-dien-3,11-dione(2), 28-norolean-16,18-dien-3-one(3),(24Z)-26-hydroxy-7,24-dientirucalla-3-one(4), masticadienonic acid(5)、masticadienolic acid(6)、erythrodiol(7), 3β,28-dihydroxyoleana-11,13(18)-diene(8), 3-oxo-olean-9(11),12-dien-28-oic acid(9), and 12-oleane-3,11-dione(10). Among them, compound 1 was a novel compound and compound 2 was a novel natural product.
View Article and Find Full Text PDFTurk J Chem
October 2024
Supramolecular Compounds Division, Institute of General and Inorganic Chemistry, Uzbekistan Academy of Sciences, Tashkent, Uzbekistan.
The cocrystal (or supramolecular complex) between the Cu(II) complex of salicylic acid and uncoordinated piracetam has been synthesized. Its structure is characterized by elemental analysis, FT-IR, UV-Vis spectroscopy, and X-ray crystallography. Spectroscopic methods confirm the formation of the metal complex, while X-ray crystallography establishes the molecular and crystal structure of the obtained compound.
View Article and Find Full Text PDFAntibiotics (Basel)
November 2024
Department of Microbiology, Faculty of Biology, University of Bucharest, 1-3 Aleea Portocalelor St., 060101 Bucharest, Romania.
New haloaminopyrazole derivatives differing in the number of pyrazole nuclei - and -, respectively, were synthesized and characterized by H-NMR, C-NMR, IR, UV-Vis, and elemental analysis. The single-crystal X-ray diffraction method was used to describe compounds and . When tested on normal NCTC fibroblasts in vitro, the newly synthesized derivatives were shown to be non-cytotoxic at a dosage of 25 μg/mL.
View Article and Find Full Text PDFDalton Trans
January 2025
Department of Chemistry and Bioscience, Kumoh National Institute of Technology, Gumi 39177, Republic of Korea.
Porphyrin-based two-dimensional porous materials (SnP-H2TCPP, SnP-ZnTCPP) composed of robust Sn(IV)-porphyrin linkages have been synthesized by reacting -dihydroxo[5,10,15,20-tetraphenylporphyrinato]tin(IV) (SnP) with [5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin] (HTCPP) and [5,10,15,20-tetrakis(4-carboxyphenyl)porphyrinato]zinc(II) (ZnTCPP), respectively. The strength of the interaction between the carboxylic acid group of the monomeric porphyrins (HTCPP and ZnTCPP) and the axial hydroxyl moiety of SnP enables the construction of highly stable framework materials, which were characterized by FT-IR, UV-vis, and emmission spectroscopy, powder XRD, elemental analysis, and thermogravimetric analysis (TGA). SnP-H2TCPP and SnP-ZnTCPP absorb visible light strongly over a wide range, demonstrating weak perturbation in the electronic ground state structures of the π-conjugated aromatic moieties compared to the starting monomeric units.
View Article and Find Full Text PDFJ Inorg Biochem
March 2025
Department of Chemistry, National Institute of Technology, Rourkela, 769008, Odisha, India. Electronic address:
Three stable oxidovanadium(IV) [VOL] complexes (1-3) were synthesized through the incorporation of unsymmetrical salen ligands (HL). All the ligands are synthesized, and their vanadium compounds were thoroughly characterized by CHNS analysis, various spectroscopy methods (IR, UV-Vis, NMR spectroscopy), and HR-ESI-MS. The structures of 1-3 were validated through the single-crystal X-ray analysis.
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