| Popis: |
The sequential bond dissociation energies for Li+(CO)x (x = 1−3), Na+(CO)x (x = 1,2), and K+(CO) are determined by examining the collision-induced dissociation reactions with argon in a guided ion beam mass spectrometer. Analysis of the kinetic energy dependent cross sections yield values for the (CO)x−1M+CO bond dissociation energies (BDEs) of 0.57 ± 0.13, 0.37 ± 0.04 and 0.36 ± 0.04 eV for M Li (x = 1–3, respectively), 0.33 ± 0.08 and 0.25 ± 0.03 eV for M Na (x = 1 and 2, respectively), and 0.19 ± 0.05 eV for K+CO. In addition, the M+Ar BDEs are determined by examining the ligand exchange reaction of M+(CO) with Ar and are found to be 0.34 ± 0.14, 0.16 ± 0.09 and 0.14 ± 0.07 eV for M Li, Na and K, respectively. The trends in BDEs can be explained readily in terms of electrostatic bonding interactions. A comparison of the alkali metal ion—CO BDEs with those of transition metal ion carbonyls reveals the contributions of s-dσ hybridization and d-π∗ back-donation in the chemical bonding of the latter systems. |
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