Structural controls of 2D sheet copper(i) ethylene and carbonyl coordination polymers directed by anions and solvents

Abstract

The reactions of Cu(I) ion with {BF₄⁻, ClO₄⁻, or PF₆⁻} anions and 6,6′-dimethyl-4,4′-bipyrimidine (Me₂bpm) under C₂H₄ or CO in MeOH preferentially afforded three 2D sheet Cu(I)–Me₂bpm/{C₂H₄, CO} adducts [Cu₄(Me₂bpm)₃(C₂H₄)₃(MeCN)](BF₄)₄·0.33MeOH}_n (2), {[Cu₄(Me₂bpm)₃-(C₂H₄)₃(MeOH)_0.33](ClO₄)₄}_n (3), and {[Cu₄(Me₂bpm)₃(CO)₃(MeCN)](PF₆)₄·0.33MeCN}_n (4), whereas the similar reaction of Cu(I) ion with a BF₄⁻ anion and Me₂bpm under CO in MeOH gave the metallamacrocyclic tetranuclear Cu(I)–Me₂bpm/CO adduct [Cu₄(Me₂bpm)₄(CO)₄]-(BF₄)₄·4MeOH (5). In Cu(I)–Me₂bpm/{C₂H₄, CO} adducts 2–4, it should be noted that the metallacalix[3]arene structures of the [Cu₃(Me₂bpm)₃]³⁺ framework are linked through another Cu atom with MeCN (2 and 4) or MeOH (3) to produce a chiral 2D sheet structure with small Cu₃ and large Cu₉ cavities. In the small triangular Cu₃ cavities, one MeOH (2) or MeCN (4) molecule is encapsulated in complexes 2 and 4, whereas these Cu₃ cavities are empty in complex 3. In the large Cu₉ cavities, one anion (X = BF₄⁻ (2), ClO₄⁻ (3) or PF₆⁻ (4)) is surrounding by six Me groups of three Me₂bpm on the upside and three anions (X) are functionally accommodated on the downside for complexes 2–4, respectively. In the Cu(I)–Me₂bpm/CO adduct 5, two of the four BF₄⁻ anions are accommodated in the upper and lower cavities of the [Cu₄(Me₂bpm)₄] framework. We demonstrated that the metallamacrocyclic and polymeric 2D sheet Cu(I)–Me₂bpm/{C₂H₄, CO} adducts can be reasonably self-assembled under the direction of anions and solvents.