Directed self-assembly of mono and dinuclear copper(ii) isophthalates into 1D polymeric structures. Design and an unusual cocrystallization

Abstract

New examples of 1D coordination polymers containing mononuclear and dinuclear copper(II) complexes with a series of isophthalates have been designed, synthesized and characterized by single-crystal X-ray diffraction. The reaction between the aqua-complex [Cu(tmen)(H₂O)_x][ClO₄]₂ (tmen = N,N,N′,N′-tetramethylethylenediamine) and isophthalate 5-Xip (substituted in position 5, X = –H, –NO₂) results in infinite chains with stoichiometry [Cu(tmen)(5-Xip)(H₂O)]_n. A charge-assisted hydrogen bond of type Cu–OH₂⋯O organizes the 1D chains into 2D layers. On the other hand, the self-assembly of the complex [Cu(tmen)(H₂O)_x][ClO₄]₂ with a series of isophthalates 5-Xip dianion (X = –H, –NO₂, –NH₂, –OMe) in presence of 0.5 equiv. of KOH results in 1D chains with dinuclear complexes [Cu₂(tmen)₂(μ-OH)]⁺³ as building blocks. The absence of a water molecule coordinated to Cu(II) atom in the dinuclear chains generates different patterns into 2D. The reaction of the aqua-complex of Cu(II) with tetrafluoroisophthalate (TFip) gave a new Janus complex [Cu₂(tmen)₂(H₂O)₂(TFip)₂]·[Cu(tmen)(TF-ip)]_n·3(H₂O), where two different supramolecular arrangements are present in the same single crystal (a dimeric structure and 1D polymeric structure).