High temperature synthesis of some strontium and barium 2,6-dibenzylphenolates

Direct treatment of HOdbp (= 2,6-dibenzylphenol) with strontium or barium metal in the absence of solvent at high temperature provides the corresponding phenolates Sr(OdbP)(2) and Ba(OdbP)(2). Recrystallisation of Ba(OdbP)(2) from THF gave a good yield of the crystalline dimer [Ra(Odbp)(2)(THF)](2) (.) 2THF. Attempted recrystallisation of Sr(Odbp)(2) from THF mostly yielded microcrystalline material characterized as [Sr(OdbP)(2)](n) but on one occasion gave a small crop of crystalline [Sr-9(Odbp)(8)(O2SiMe2)(4)(OH)(2)(THF)(6)(OH2)(2)] (.) 6THF derived from the adventitious reaction of Sr(OdbP)(2) with dimethylsilicone grease ( OSiMe2 (infinity))- In the solid-state [Ba(Odbp)(2)(THF)](2) (.) 2THF displays significant intramolecular Ba... pi-arene interactions with the pendant benzyl substituents. [Sr-9(Odbp)(8)(O2SiMe2)(4)-(OH)(2)(THF)(6)(OH2)(2)] (.) 6THF features a square prismatic [Sr(O2SiMe2)(4)](6-) core capped by two inverse crown-like square [Sr-4(Odbp)(4)-(OH)(L)(4)](3+)units, where L = OH2 or THF, that are staggered with respect to the cuboidal core. (c) 2006 Elsevier Ltd. All rights reserved.