Department of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210-1185, United States.
J Phys Chem A. 2010 Dec 9;114(48):12675-81. doi: 10.1021/jp108544v. Epub 2010 Nov 10.
The title compounds trans-M(2)(O(2)CMe)(2)C((i)PrN)(2)C≡C-Ph, I (M = Mo) and II (M = W), show electronic absorptions in the visible region of the spectrum assignable to (1)MLCT [M(2)δ to phenylethynylamidinate π*]. These compounds show dual emission from S(1) and T(1) states. For both I and II, S(1) is (1)MLCT, but for I the T(1) state is shown to be MMδδ* while for II T(1) is (3)MLCT. The lifetimes of the S(1) and T(1) states have been determined by femtosecond and nanosecond transient absorption spectroscopy: for I S(1) ∼ 20 ps and T(1) ∼ 100 μs and for II S(1) ∼ 6 ps and T(1) ∼ 5 μs. From solvent dependence of the absorption and emission spectra, we suggest that the S(1) states are localized on one amidinate ligand though the initial absorption is to a delocalized state.
标题化合物 trans-M(2)(O(2)CMe)(2)C((i)PrN)(2)C≡C-Ph, I (M = Mo) 和 II (M = W)，在光谱的可见区域显示出可归因于 (1)MLCT [M(2)δ 到苯乙炔基氨基甲酸盐 π*] 的电子吸收。这些化合物显示来自 S(1)和 T(1)态的双重发射。对于 I 和 II，S(1)都是 (1)MLCT，但对于 I，T(1)态被证明是 MMδδ*，而对于 II，T(1)是 (3)MLCT。通过飞秒和纳秒瞬态吸收光谱法确定了 S(1)和 T(1)态的寿命：对于 I，S(1) ∼ 20 ps 和 T(1) ∼ 100 μs，对于 II，S(1) ∼ 6 ps 和 T(1) ∼ 5 μs。从吸收和发射光谱对溶剂的依赖性来看，我们认为 S(1)态局域在一个酰胺基配体上，尽管初始吸收是到一个离域态。
