- Heterobimetallic activation of dioxygen: Characterization and reactivity of novel Cu(I)-Ge(II) complexes
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Reaction of the known germylene Ge[N(SiMe3)2] 2 and a new heterocyclic variant Ge[(NMes)2(CH) 2] with [LMe2Cu]2 (LMe2 = the β-diketiminate derived from 2-(2,6-dimethylphenyl)amino-4-(2,6- dimethylphenyl)imino-2-pentene) yielded novel Cu(I)-Ge(II) complexes L Me2Cu-Ge[(NMes)2(CH)2] (1a) and L Me2Cu-Ge[N(SiMe3)2]2 (1b), which were characterized by spectroscopy and X-ray crystallography. The lability of the Cu(I)-Ge(II) bond in 1a and b was probed by studies of their reactivity with benzil, PPh3, and a N-heterocyclic carbene (NHC). Notably, both complexes are cleaved rapidly by PPh3 and the NHC to yield stable Cu(I) adducts (characterized by X-ray diffraction) and the free germylene. In addition, the complexes are highly reactive with O2 and exhibit chemistry which depends on the bound germylene. Thus, oxygenation of 1a results in scission and formation of thermally unstable LMe2CuO2, which subsequently decays to [(LMe2Cu)2(μ-O) 2], while 1b yields LMe2Cu(μ-O) 2Ge[N(SiMe3)2]2, a novel heterobimetallic intermediate having a [CuIII(μ-O) 2GeIV]3+ core. The isolation of the latter species by direct oxygenation of a Cu-(I)-Ge(II) precursor represents a new route to heterobimetallic oxidants comprising copper.
- York, John T.,Young Jr., Victor G.,Tolman, William B.
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p. 4191 - 4198
(2008/10/09)
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- Synthesis and reactivity of a novel palladium germylene system
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The synthesis of three novel Pd germylene complexes is reported. (Ph3P)2PdGe[N(SiMe3)2]2 (1) was synthesized by ligand substitution of (Ph3P)4Pd, whereas (Et3P)PdGe[N(SiMe3)2]2 (2) and {appePdGe[N(SiMe3)2]2}2 (3b) (dppe = (diphenylphosphino)ethane) were synthesized by photolytic reduction of their corresponding phosphine oxalato complexes followed by addition of the germylene ligand. In solution, 3b exists in equilibrium with the monomeric dppePdGe[N(SiMe3)2]2 (3a). The germylene ligand of 2 was found to be 1 order of magnitude more labile than the analogous Pt system and 2 orders of magnitude less labile than the analogous Ni system. The reactivity of these new palladium germylenes toward O2 is described.
- Cygan, Zuzanna T.,Bender IV, John E.,Litz, Kyle E.,Kampf, Jeff W.,Banaszak Holl, Mark M.
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p. 5373 - 5381
(2008/10/08)
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