Synthesis and characterization of a family of solvated sodium aryloxide compounds

A family of crystallographically characterized solvated sodium alkoxides ([(solv)(x)Na(OR)](n)) was synthesized from the reaction of sodium bis(trimethylsilyl)amide with a series of sterically varied aryl alcohols (H-OAr): 2-alkyl phenol [alkyl = methyl (oMP), iso-propyl (oPP), and tert-butyl (oBP)] or 2,6-di-alkyl phenol [alkyl = methyl (DMP), iso-propyl (DIP), and tert-butyl (DBP)]. Single crystal X-ray experiments revealed the structure of the products to be highly dependent on the ligand set employed and the solvent used (THF or py). The [(solv)(x)Na(OAr)](n) products were identified as: [(THF)Na(mu(3)-oMP)](6) (1), [(THF)(4)Na-6(mu(3)-oPP)(4)(mu(4)-PP)(2)] (2), [(THF)Na(mu(3)-oBP)](4) (3).THF, [(THF)Na(mu(3)-DMP)](4) (4), [(THF)(2)Na(mu(3)-DIP)](2) (5), [(THF)(2)Na(mu-DBP)](2) (6), {[Na(mu-DPhP-eta(x))](2)}(n) (7), [(py)(5)Na-6(mu(3)-oMP)(4)(mu(4)-oMP)(2)](2)[(py)(4)Na-6(mu(3)-oMP)(4)(mu(4)-oMP)(2)] (5), [(py)(6)Na-4(mu(3)-oPP)(4)] (5) py, [(py)Na(mu(3)-DMP)](4) (11), [(py)(2)Na(mu-DIP)](2) (12), [(py)(4)Na(DBP)] (13). Crystals could not be isolated for the Na/oBP/py (10) system but the powder was assigned the '[(py)Na(oBP)](4)' structure based on the available analytical data. In addition, under similar conditions, the neo-pentoxide (ONep) derivatives were isolated and characterized as [(solv)(4)Na-6(mu(3)-ONep)(4)(mu(4)-ONep)(2)] (solv = THF, 14; py 15). A number of complex structures (monomers, squares, cubes, fused-cubes, hexagons) were observed for this family of [(solv)(x)Na(OAr)](n) compounds. The solution behaviors of these compounds were studied using heteronuclear Na-23 NMR. A comparison of these [(solv)(x)A(OR)](n) A = Li, Na, K, Rb, Cs structural motifs is also presented. (C) 2013 Elsevier B.V. All rights reserved.