Low-oxidation state cobalt–magnesium complexes: ion-pairing and reactivity
| Autor: | Ruth M. Gschwind, Robert Wolf, Johannes Gramüller, John A. Kelly |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
010405 organic chemistry
Chemistry Magnesium Ligand ddc:540 chemistry.chemical_element 010402 general chemistry 01 natural sciences Medicinal chemistry Toluene 0104 chemical sciences 3. Good health Inorganic Chemistry chemistry.chemical_compound Oxidation state Sandwich compound 540 Chemie Reactivity (chemistry) Homoleptic Cobalt |
| Zdroj: | Dalton Transactions (Cambridge, England : 2003) Dalton Transactions |
| ISSN: | 1477-9234 1477-9226 |
| Popis: | Magnesium cobaltates (Arnacnac)MgCo(COD)2 (1–3) were synthesised by reacting (Arnacnac)MgI(OEt2) with K[Co(η4-COD)2] (COD = 1,5-cyclooctadiene) [Arnacnac = CH(ArNCMe)2; Ar = 2,4,6-Me3-C6H2 (Mes), 2,6-Et2-C6H3 (Dep), 2,6-iPr2-C6H3Mes (Dipp)]. Compounds 1–3 form contact ion-pairs in toluene, while solvent separated ion-pairs are formed in THF. The effect of ion-pairing on the reactivity is illustrated by reaction of 2 with tert-butylphosphaalkyne, which affords distinct 1,3-diphosphacyclobutadiene complexes. The heteroleptic sandwich complex [(Depnacnac)MgCo(P2C2tBu2)]2 (4) is selectively formed in toluene, while the homoleptic bis(1,3-diphosphacyclobutadiene) complex [(Depnacnac)Mg(THF)3][Co(P2C2tBu2)2] (5) is obtained in THF. Complex 4 is a precursor to further unusual phosphaorganometallic compounds. Substitution of the labile COD ligand in 4 by white phosphorus (P4) enabled the synthesis of the phosphorus-rich sandwich compound [(Depnacnac)MgCoP4(P2C2tBu2)]2 (6). The heterobimetallic complex (Cp*NiP2C2tBu2)Co(COD) (7) was isolated after treatment of 4 with Cp*Ni(acac) (Cp* = C5Me5, acac = acetylacetonate). Ion-pairing strongly influence the reactivity of low-oxidation state transition metalate anions, enabling the synthesis of novel phosphaorganometallic compounds. |
| Databáze: | OpenAIRE |
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