10.1021/jp108544v.s001
Brian G. Alberding
Brian G.
Alberding
Malcolm H. Chisholm
Malcolm H.
Chisholm
Terry L. Gustafson
Terry L.
Gustafson
Yao Liu
Yao
Liu
Carly R. Reed
Carly R.
Reed
Claudia Turro
Claudia
Turro
Photophysical Studies of <i>trans</i>-Bis(phenylethynyldiisopropylamidinato)bis(acetato)dimetal Complexes Involving MM Quadruple Bonds Where M = Mo or W
American Chemical Society
2010
T 1 states
II T 1
absorption
MM Quadruple Bonds
S 1 states
S 1
Mo
emission
compound
1 MLCT
T 1 state
2010-12-09 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Photophysical_Studies_of_i_trans_i_Bis_phenylethynyldiisopropylamidinato_bis_acetato_dimetal_Complexes_Involving_MM_Quadruple_Bonds_Where_M_Mo_or_W/2706277
The title compounds <i>trans</i>-M<sub>2</sub>(O<sub>2</sub>CMe)<sub>2</sub>[C(<i><sup>i</sup></i>PrN)<sub>2</sub>CCPh]<sub>2</sub>, <b>I</b> (M = Mo) and <b>II</b> (M = W), show electronic absorptions in the visible region of the spectrum assignable to <sup>1</sup>MLCT [M<sub>2</sub>δ to phenylethynylamidinate π*]. These compounds show dual emission from S<sub>1</sub> and T<sub>1</sub> states. For both <b>I</b> and <b>II</b>, S<sub>1</sub> is <sup>1</sup>MLCT, but for <b>I</b> the T<sub>1</sub> state is shown to be MMδδ* while for <b>II</b> T<sub>1</sub> is <sup>3</sup>MLCT. The lifetimes of the S<sub>1</sub> and T<sub>1</sub> states have been determined by femtosecond and nanosecond transient absorption spectroscopy: for <b>I</b> S<sub>1</sub> ∼ 20 ps and T<sub>1</sub> ∼ 100 μs and for <b>II</b> S<sub>1</sub> ∼ 6 ps and T<sub>1</sub> ∼ 5 μs. From solvent dependence of the absorption and emission spectra, we suggest that the S<sub>1</sub> states are localized on one amidinate ligand though the initial absorption is to a delocalized state.