Related Experiment Video
Updated: Jan 18, 2026

Measurement and Analysis of Atomic Hydrogen and Diatomic Molecular AlO, C2, CN, and TiO Spectra Following Laser-induced Optical Breakdown
Published on: February 14, 2014
Spectroscopy and Theory of Acetylene Coupling Reactions in Ti+(C2H2)n Complexes
Anna G Poncelet1, John R C Blais1, Richard B Odonkor1
1Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States.
None:
Ti+(C2H2)n complexes produced by laser vaporization in a supersonic expansion are investigated with mass spectrometry, infrared laser photodissociation spectroscopy, and UV laser photodissociation. The mass distributions of the cluster ions produced are found to vary significantly with the sample rod mounting configuration in the source. For infrared spectroscopy experiments, the so-called "offset" rod mounting produces colder conditions than the "cutaway" configuration, which allows tagging the ions with one or more argon atoms for the n = 1 and 2 complexes. Infrared photodissociation spectra for these ions allow the identification of cation-π complexes (n = 1, 2) and reaction products from acetylene coupling (n = 2). A TiC4 metallacycle ion is identified by experiment and theory as the dominant reaction product. Larger complexes could not be tagged with argon under our conditions and therefore infrared spectra could not be measured. Under warmer expansion conditions with the cutaway rod configuration, prominent Ti+(C2H2)3 and Ti+(C2H2)6 ions are formed. UV photodissociation patterns for these ions are found to be almost identical to those for the corresponding Ti+(C6H6) and Ti+(C6H6)2 ions, suggesting that acetylene cyclization reactions have produced benzene and di-benzene complexes. Reaction path computations for both the n = 2 and 3 complexes investigate the energetics of the cyclization reactions in these systems.
More Related Videos
07:49Characterizing Lewis Pairs Using Titration Coupled with In Situ Infrared Spectroscopy
Published on: February 20, 2020
08:54Vibrational Spectra of a N719-Chromophore/Titania Interface from Empirical-Potential Molecular-Dynamics Simulation, Solvated by a Room Temperature Ionic Liquid
Published on: January 25, 2020
Related Concept Videos
¹H NMR: Long-Range Coupling
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene...
IR and UV–Vis Spectroscopy of Aldehydes and Ketones
¹H NMR: Complex Splitting
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied...
Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
Photochemical Electrocyclic Reactions: Stereochemistry
Selection Rules: Photochemical Activation
UV–Vis Spectroscopy: Molecular Electronic Transitions