Potassium aryloxides

The uranium(III) complexes Cp2UI2(THF)3 and Cp UI2(py)3 have been structurally characterized [393b]. The similar tribromide complex Cp ThBr3(THF)3 [111] provides a convenient entry into the chemistry of mono(pentamethylcyclopentadienyl) derivatives of thorium. Aryloxide and alkyl derivatives may be readily prepared by treatment of Cp RhBr3(THF)3 with potassium aryloxide or alkyl Grignard reagents, respectively [373], for example (5.58)-(5.60) ... 

Unusual coordination around potassium was observed in the 2-dimensional layered structure of the ate complex K[Cp2Nd(/i-OC6H3Me2-2,6)2] n [208]. No close K O contact was found, however, aryloxide ligands bridge the metal centers through arene interactions as in homoleptic ate complexes [69]. 

Recently (33, 59), soluble monomeric alkoxides (aryloxides) of calcium and barium have been synthesized by the reactions of their iodides with the potassium salts of sterically hindered alcohols (phenols). 

The unsubstituted para-t-butyl calixarenes themselves complex metals via their aryloxide groups. Since aryloxide complexes are frequently oligomeric, the simple calixarenes do not give monomeric complexes. Aryloxides are hard ligands, therefore they readily form complexes with oxo-philic hard metal ions such as alkali metals, early transition metals, lanthanides, and actinides. Complexation is often inferred because the calixarene acts as a carrier for the metal ion from an aqueous to an organic phase. With the /wa-/-butylcalix[ ]arenes in alkaline solution, a value of n = 6 gives the best carrier for lithium(I), sodium(I), and potassium(I), with a value of n 8 giving the best carrier for rubidium(I) and caesium(I).15,16 Titanium(IV) complexes have been characterized,17-19 as well as those of niobium(V) and tantalum(V).20-22 These complexes are classified as... 

Both chlorine atoms of 2,3-dichloroquinoxalines are readily displaced by alkoxide and aryloxide ions to give the corresponding dialkoxy- and diaryloxyquinoxalines." Violent reaction, accompanied by pyrotechnic effects, is reported to occur between 2,3-dichloroquinoxaline and the potassium salts of o-nitrophenol and 2,4-dinitrophenol. Quinoxaline-... 

Chloroquinoxalines are converted into 2-phenoxyquinoxalines by treatment with phenol in which potassium hydroxide has been dissol-ved. " - When 2-chloroquinoxaline is heated with a sodium aryloxide in... 

In other systems, N—cleavage gives bis(/i-nitrido)dimetal diamond cores as the products of N2 cleavage. A reduced niobium complex of calix[4]arene reduces N2 in the presence of sodium metal, and a number of intermediates can be isolated. A related tridentate aryloxide ligand also splits N2 to give a diamond core with lithium ions bound to the nitrides. A vanadium diamidoamine complex reacts with N2 to give a product with a similar core structure, which may be further reduced by potassium graphite to a compound with one unpaired electron. This... 

The derivatisation of both 2,6-bis(3-tert-butyl-5-methyl-2-hydroxybenzyl)-4-methylphenol and its 3,5-di-tert-butyl congener as mono- and dimeric lithium and sodium aryloxides has afforded structures in which the metal ions are supported by weak interactions with the 4-methylphenoxide ring. Moreover, evidence for interactions between sodium or potassium ions and aromatic n-systems has recently formed the basis of a review article. ... 

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