Open AccessInfrared Spectroscopy of Gas-Phase M+(CO2)n (M = Co, Rh, Ir) Ion–Molecule Complexes
Author(s) -
Andreas Iskra,
Alexander S. Gentleman,
Aras Kartouzian,
M. Kent,
A P Sharp,
Stuart R. Mackenzie
Publication year - 2017
Publication title -
the journal of physical chemistry. a/the journal of physical chemistry. a.
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.756
H-Index - 235
eISSN - 1520-5215
pISSN - 1089-5639
DOI - 10.1021/acs.jpca.6b10902
Subject(s) - photodissociation , infrared spectroscopy , chemistry , ion , molecule , infrared , spectroscopy , density functional theory , analytical chemistry (journal) , metal , phase (matter) , crystallography , photochemistry , computational chemistry , physics , organic chemistry , chromatography , quantum mechanics , optics
The structures of gas-phase M + (CO 2 ) n (M = Co, Rh, Ir; n = 2-15) ion-molecule complexes have been investigated using a combination of infrared resonance-enhanced photodissociation (IR-REPD) spectroscopy and density functional theory. The results provide insight into fundamental metal ion-CO 2 interactions, highlighting the trends with increasing ligand number and with different group 9 ions. Spectra have been recorded in the region of the CO 2 asymmetric stretch around 2350 cm -1 using the inert messenger technique and their interpretation has been aided by comparison with simulated infrared spectra of calculated low-energy isomeric structures. All vibrational bands in the smaller complexes are blue-shifted relative to the asymmetric stretch in free CO 2 , consistent with direct binding to the metal center dominated by charge-quadrupole interactions. For all three metal ions, a core [M + (CO 2 ) 2 ] structure is identified to which subsequent ligands are less strongly bound. No evidence is observed in this size regime for complete activation or insertion reactions.