TY - JOUR
T1 - Cu(I)/O 2 chemistry using a β-diketiminate supporting ligand derived from N,N-dimethylhydrazine
T2 - A [Cu 3O 2] 3+ complex with novel reactivity
AU - Gupta, Aalo K.
AU - Tolman, William B
PY - 2012/2/6
Y1 - 2012/2/6
N2 - A Cu(I) complex, LCu(CH 3CN), was prepared and characterized, where L - is a sterically unencumbered β-diketiminate ligand, the deprotonated version of 4-(2,2-dimethylhydrazino)dimethylhydrazone-3-penten-2- one (LH). Analysis of FTIR spectra of the products of the reaction of LCu(CH 3CN) with CO indicate that L - is strongly electron donating, and support an equilibrium in solution between monomeric and dimeric forms with terminal and bridging CO ligands, respectively. Low temperature oxygenation of LCu(CH 3CN) generated a bis(μ-oxo)tricopper complex with a S = 1 [Cu 3O 2] 3+ core that was identified on the basis of UV-vis (λ max (ε, M -1 cm -1 per Cu) = 328 (10700), 420 (1500), 590 (835) nm) and X-band electron paramagnetic resonance (EPR) spectroscopy (Δm s = 2 transition at 1500 G), electrospray ionization (ESI) mass spectrometry, and spectrophotometric titration (0.35(2) equiv of O 2 per copper atom), magnetic susceptibility (μ eff = 2.8(1) BM), and H 2O 2 detection experiments (no H 2O 2 evolved upon acidification). Unlike other reported variants supported by neutral N-donor ligands, L 3Cu 3O 2 is not reduced by ferrocene, does not abstract H-atoms from phenols or 1,2-dihydroanthracene, oxidizes PPh 3 to Ph 3P=O, and generates carbonate species upon exposure to CO 2. This unique reactivity for a [Cu 3O 2] 3+ complex may be traced to the anionic charge and strong electron donating characteristics of L -.
AB - A Cu(I) complex, LCu(CH 3CN), was prepared and characterized, where L - is a sterically unencumbered β-diketiminate ligand, the deprotonated version of 4-(2,2-dimethylhydrazino)dimethylhydrazone-3-penten-2- one (LH). Analysis of FTIR spectra of the products of the reaction of LCu(CH 3CN) with CO indicate that L - is strongly electron donating, and support an equilibrium in solution between monomeric and dimeric forms with terminal and bridging CO ligands, respectively. Low temperature oxygenation of LCu(CH 3CN) generated a bis(μ-oxo)tricopper complex with a S = 1 [Cu 3O 2] 3+ core that was identified on the basis of UV-vis (λ max (ε, M -1 cm -1 per Cu) = 328 (10700), 420 (1500), 590 (835) nm) and X-band electron paramagnetic resonance (EPR) spectroscopy (Δm s = 2 transition at 1500 G), electrospray ionization (ESI) mass spectrometry, and spectrophotometric titration (0.35(2) equiv of O 2 per copper atom), magnetic susceptibility (μ eff = 2.8(1) BM), and H 2O 2 detection experiments (no H 2O 2 evolved upon acidification). Unlike other reported variants supported by neutral N-donor ligands, L 3Cu 3O 2 is not reduced by ferrocene, does not abstract H-atoms from phenols or 1,2-dihydroanthracene, oxidizes PPh 3 to Ph 3P=O, and generates carbonate species upon exposure to CO 2. This unique reactivity for a [Cu 3O 2] 3+ complex may be traced to the anionic charge and strong electron donating characteristics of L -.
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U2 - 10.1021/ic202214c
DO - 10.1021/ic202214c
M3 - Article
C2 - 22268598
AN - SCOPUS:84856746703
SN - 0020-1669
VL - 51
SP - 1881
EP - 1888
JO - Inorganic chemistry
JF - Inorganic chemistry
IS - 3
ER -