Electronic excitation of [(μ4-η2-alkyne)Rh4(CO)8(μ-CO)2]: an in situ UV/Vis spectroscopy, spectral reconstruction and DFT study.
Reactions of three alkynes, namely, 1-heptyne, 3-hexyne and 1-phenyl-1-butyne, with [Rh(4)(CO)(9)(μ-CO)(3)] are performed in anhydrous hexane under argon atmosphere with multiple perturbations of alkynes and [Rh(4)(CO)(9)(μ-CO)(3)]. The reactions are monitored by in situ UV/Vis spectroscopy, and the collected electronic spectra are further analyzed with the band-target entropy minimization (BTEM) family of algorithms to reconstruct the pure component spectra. Three BTEM estimates of [(μ(4)-η(2)-alkyne)Rh(4)(CO)(8)(μ-CO)(2)], in addition to that of [Rh(4)(CO)(9)(μ-CO)(3)], are successfully reconstructed from the experimental spectra. Time-dependent density functional theory (TD-DFT) predicted spectra at the PBE0/DGDZVP level are consistent with the corresponding BTEM estimates. The present study demonstrates that: 1) the BTEM family of algorithms is successful in analyzing multi-component UV/Vis spectra and results in good spectral estimates of the trace organometallics present; and 2) the subsequent DFT/TD-DFT methods provide an interpretation of the nature of the electronic excitation and can be used to predict the electronic spectra of similar transition organometallic complexes.
Institute of Chemical and Engineering Sciences, A*STAR (Agency for Science Technology and Research), 1 Pesek Road, Jurong Island, Singapore, 627833, Singapore. gao_feng@ices.a-star.edu.sg
Feng
F
Gao
Michael B
MB
Sullivan
Gulnara M
GM
Kuramshina
Liangfeng
L
Guo
Marc
M
Garland