Design and syntheses of two novel supermolecular frameworks through weak interactions

Abstract

Abstract Two novel supermolecular frameworks constructed by 2,2′-biquinoline-4,4′-dicarboxylic acid (H 2 bqdc) were synthesized and their crystal structures were characterized by single crystal X-ray diffraction. Complex [Cu(C 12 H 30 N 6 )](NaOH)(bqdc)·2H 2 O ( 1 ) crystallizes in the triclinic space group P -1, with a =7.181(7), b =8.869(9), c =14.105(14) A, α =101.315(8), β =100.487(6), γ =97.282(14)° and Z =1. It exhibits a 2-D framework constructed through hydrogen bonds. The macrocyclic-Cu(II) units decorate to the sheet also through H-bondings. Complex [Ni(en) 2 (H 2 O) 2 ](bqdc)·2H 2 O ( 2 ) crystallizes in the triclinic space group P -1, with a =6.86030(10), b =7.2061(2), c =13.7801(4) A, α =92.756(2), β =101.2050(10), γ =101.7210(10)° and Z =2. This complex exhibits a 3-D frameworks constructed also through weak interactions, especially H-bonding and π–π stacking. Interestingly, a hexa-oxygen ring was found in this structure formed by four water molecules and two carboxyl groups through hydrogen bonds. Thermography analyses of the two complexes were also tested.