1. Selective P4 Activation by a Highly Reduced Cobaltate: Synthesis of Dicobalt Tetraphosphido Complexes.
- Author
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Pelties, Stefan, Maier, Thomas, Herrmann, Dirk, de Bruin, Bas, Rebreyend, Christophe, Gärtner, Stefanie, Shenderovich, Ilya G., and Wolf, Robert
- Subjects
PHOSPHORUS ,LIGAND exchange reactions ,ACETONITRILE ,RECRYSTALLIZATION (Metallurgy) ,X-ray crystallography ,NUCLEAR magnetic resonance - Abstract
Although the chemistry of transition metal polyphosphide anions has attracted significant attention, there are few reports of studies in which such species have been synthesized directly from white phosphorus. [K(OEt
2 )2 {Co(BIAN)(cod)}] ( 1, BIAN=1,2-bis(2,6-diisopropylphenylimino)acenaphthene, cod=1,5-cyclooctadiene), which is readily prepared by ligand exchange from [K(thf)x {Co(cod)2 }], reacts with P4 to afford [{K(thf)}2 {(BIAN)Co}2 (μ-η4 :η4 -P4 )] ( 2 a) in 61 % yield (isolated product). [{K(OEt2 )}2 {(BIAN)Co}2 (μ-η4 :η4 -P4 )] ( 2 b) and [K([18]crown-6)(MeCN)]2 [{(BIAN)Co}2 (μ-η4 :η4 -P4 )] ( 2 c) were obtained by recrystallizing 2 a from diethyl ether and acetonitrile (and using [18]crown-6 in case of 2 c). Oxidation of 2 a with [Cp2 Fe]BArF 4 (one equivalent) and subsequent recrystallization of the product from different solvents gave [K(OEt2 ){(BIAN)Co}2 (μ-η4 :η4 -P4 )] ( 3 a) and [K(dme)4 ][{(BIAN)Co}2 (μ-η4 :η4 -P4 )] ( 3 b; dme=1,2-dimethoxyethane). Neutral [{(BIAN)Co}2 (μ-η4 :η4 -P4 )] ( 4) was obtained in moderate yield by oxidizing 2 a with two equivalents of [Cp2 Fe]BArF 4 . The new complexes were characterized by NMR, EPR (in the case of 3 a), and UV/Vis spectroscopy, and elemental analysis. The molecular structures revealed by X-ray crystallography display planar cyclic or open-chain P4 4− units sandwiched between {(BIAN)Co} fragments. [ABSTRACT FROM AUTHOR]- Published
- 2017
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