The first through fourth C-H stretching overtone regions of ethene were measured by photoacoustic spectroscopy of room-temperature molecules and action spectroscopy of jet-cooled molecules. The rotational cooling led to improved resolution in the action spectra, turning these spectra into key players in determining the multiple band appearance in each region, their types, and origins. These manifolds arise from strong couplings of the C-H stretches to doorway states and were analyzed in terms of a simplified joint local-mode/normal-mode (LM)/(NM) model and an equivalent NM model, accounting for principal resonances. The diagonalization of the LM/NM and NM vibrational Hamiltonians and the least-square fittings revealed model parameters, enabling assignment of A- and B-type bands. These bands behave differently through the V = 2-4 manifolds, showing coupling to doorway states for the former but not for the latter. The energy flow out of the fourth C-H overtone is governed by the interaction with bath states due to the increase in the density of states.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/jp0748011 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Ligand-Induced Intramolecular Cuprophilic and Argentophilic Interactions in Bimetallic Cu(I) and Ag(I) Phosphine Complexes and the Assessment of Their Antityrosinase and Antibacterial Effects.
Inorg Chem
January 2025
Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, 3012 Bern, Switzerland.
Binuclear silver(I) and copper(I) complexes, and , with bridging diphenylphosphine ligands were prepared. In , the silver(I) center is located inside a trigonal plane composed of three phosphorus donors from three separate and bridging dppm ligands. The fourth coordination site is filled with neighboring silver(I) ions.
View Article and Find Full Text PDFClinical outcome of curettage in atypical cartilaginous tumors of the long bones: a descriptive cohort study.
Acta Orthop
December 2024
Department of Orthopedics, University Hospital Ghent, Ghent, Belgium.
Background And Purpose: Despite evolving management strategies for atypical cartilaginous tumors (ACT)-shifting from radical resection to intralesional curettage and "wait-and-scan" approaches-there remains no universal consensus on optimal treatment. We primarily aimed to evaluate disease-specific and progression-free survival following intralesional curettage and adjuvant phenol treatment of ACTs. Secondary aims included assessing surgical complications, the need for additional interventions, and an overview of long-term follow-up.
View Article and Find Full Text PDFSynthesis of continuously substituted quinolines from -alkenyl aromatic isocyanides by palladium-catalyzed intramolecular imidoylative 6- cyclization.
Chem Commun (Camb)
January 2025
Department of Chemistry, School of Pharmacy, Air Force Medical University, Xi'an, 710032, China.
An efficient synthesis of continuously substituted quinoline derivatives palladium-catalyzed intramolecular 6- imidoylative cyclization of -alkenyl aryl isocyanides with (hetero)aryl halides or vinylic triflates has been developed. The reaction proceeds through the concerted metalation-deprotonation (CMD) mechanism by activation of a vinyl C-H bond with imidoylpalladium assisted by the carboxylate.
View Article and Find Full Text PDFSynthetic Breast Ultrasound Images: A Study to Overcome Medical Data Sharing Barriers.
Research (Wash D C)
December 2024
Department of Ultrasound, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 200025 Shanghai, China.
The vast potential of medical big data to enhance healthcare outcomes remains underutilized due to privacy concerns, which restrict cross-center data sharing and the construction of diverse, large-scale datasets. To address this challenge, we developed a deep generative model aimed at synthesizing medical data to overcome data sharing barriers, with a focus on breast ultrasound (US) image synthesis. Specifically, we introduce CoLDiT, a conditional latent diffusion model with a transformer backbone, to generate US images of breast lesions across various Breast Imaging Reporting and Data System (BI-RADS) categories.
View Article and Find Full Text PDFFormation of Planar π-Conjugated Sheets in Cocrystals of Bis(iodoethynyl)pyridines and Bipyrimidylalkynes: Cooperative C-H···N Hydrogen Bonds and sp-C-I···N Halogen Bonds.
Cryst Growth Des
November 2024
Department of Chemistry and Biochemistry, Missouri State University, 901 South National Avenue, Springfield, Missouri 65897, United States.
The cocrystallization of the ditopic halogen bond donors 2,5-, 2,6-, 3,5-bis(iodoethynyl)pyridines with the dipyrimidyls 1,2-bis(5-pyrimidyl)ethyne and 1,4-bis(5-pyrimidyl)butadiyne is explored. The cocrystal components have complementary shapes and functional groups so that the noncovalent C-I···N halogen bonding and C-H···N hydrogen bonding interactions are complementary resulting in 1:1 cocrystals with the ditopic halogen bond accepting bipyrimidyls. The cocrystals feature π-stacked planar sheets of alternating bis(iodoalkynes) and bipyrimidyls held together in one direction by I···N halogen bonds and in the roughly orthogonal direction by pyridine-pyridine and pyrimidine-pyrimidine C-H···N hydrogen bonds.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!