Cubane and step-form structures of dilithium bis(aryloxy)phosphines

The lithium complexes RP(3,5-(Bu2C6H2OLi)-Bu-t)(2)(THF)(4), where R = Ph or Pr-i, ((R)[OPO]Li-2)(2)(THF)(4), synthesized by reaction of the 2-bromo-4,6-di-tert-butylphenol with BuLi and the appropriate dichlorophosphine, possess solid state structures composed of lithium oxide tetragons arranged in a step-form or face sharing half-cubane arrangements. Incorporation of excess lithium aryloxide results in the formation of complexes that display an extended step-form structure, [(Ph)[OPO]Li-2(ArOLi)](2), or a distorted cubane arrangement of tetragons, [(iPr)[OPO]Li3Cl(ArOLi)](THF)(3).