Assembling discrete D4R zeolite SBUs through noncovalent interactions. 3.(1) Mediation by butanols and 1,2-bis(dimethylamino)ethane

Abstract

The use of tetrameric zinc phosphate [Zn(dipp)(CH₃OH)]₄ (1; dipp = diisopropylphenylphosphate dianion) as a suitable building block for realizing new noncovalently linked extended structures, via facile replacement of coordinated methanol molecules by other alcohols, is reported herein. Compounds [Zn(dipp)(sec-butanol)]₄·4H₂O (2) and [Zn(dipp)(tert-butanol)]₄·4H₂O (3) have been synthesized by the addition of sec- or tert-butanol to 1 at room temperature. The reaction of zinc acetate or zinc sulfate with dippH₂ in the presence of N,N,N',N'-tetramethylethylenediamine (tmeda) under similar reaction conditions results in the formation of [H₂tmeda][Zn₄(dipp)₄(MeOH)₂(OAc)₂]·(CH₃OH) (4) or [H₂tmeda][Zn₃(dipp)₃(dippH)₂(CH₃OH)]·(CH₃OH)₃ (5), respectively. Analytically pure compounds 2-5 have been isolated in the form of single crystals directly from the respective reaction mixtures in very good yields and characterized with the aid of analytical and spectroscopic studies. Single-crystal X-ray diffraction studies reveal that compounds 2 and 3 are neutral tetranuclear zinc phosphates. Compound 4 is also a tetrameric phosphate but is anionic. The core structures of compounds 2-4 resemble the double-4-ring secondary building unit (D4R SBU) in zeolites. Compound 5 is a trinuclear ionic zinc phosphate built from three fused S4R SBUs. Compounds 4 and 5 represent the first examples of discrete anionic zinc organophosphates. The presence of coordinated sec- or tert-butanol molecules and a planar water tetramer cluster in 2 and 3, and the H₂tmeda cations and methanol solvents in 4 and 5, leads to the formation of zigzag chainlike supramolecular assemblies in the solid state.