Structural Variations of Potassium Aryloxides

A series of potassium aryloxides (KOAr) were isolated from the reaction of a potassium amide (KN(SiMe3)2) and the desired substituted phenoxide (oMP, 2-methyl; oPP, 2-iso-propyl; oBP, 2-tert-butyl; DMP, 2,6-di-methyl; DIP, 2,6-di-iso-propyl; DBP, 2,6-di-tert-butyl) in tetrahydrofuran (THF) or pyridine (py) as the following: {([K((mu)4-oMP)(THF)][K((mu)3-oMP)])5} (1), {[K6(((eta)^6,(mu)3-oMP)4((eta)^6, (mu)4-oMP)2(py)4]·[K6((eta)^6,(mu)3-oMP)6(6-py)4]} (2), [K((mu)3-oPP)]4(THF)3 (3), {K4((eta)^6,(mu)3-oPP)2((mu)3-oPP)2(py)3} (4), [K ((mu)3-oBP)(THF)]6 (5), {K6(6,3-oBP)2(3-oBP)4(py)4} (6), {K3(6,3-DMP)2(-DMP)(THF)} (7), {[K((eta)6,(mu)-DMP)(py)]2} (8), {K((eta)6, (mu)-DIP)} (9), {K(6,-DBP)} (10). Further exploration of the aryl interactions led to the investigation of the diphenylethoxide (DPE) derivative which was isolated as [K((mu)3-DPE)(THF)]4 (11) or [K((mu)3-DPE)(py)]4·py2 (12) depending on the solvent used. In general, the less sterically demanding ligands (oMP, oPP, oBP, and DMP) were solvated polymeric species; however, increasing the steric bulk (DIP and DBP) led to unsolvated polymers and not discrete molecules. For most of this novel family of compounds, the K atoms were bound to the aryl rings of the neighboring phenoxide derivatives to fill their coordination sites. The synthesss and characterization of these compounds are described in detail.