Mixed-ligand CoII and CdII complexes with 4-aminoantipyrine

Abstract

Self-assembly of 4-aminoantipyrine (AAP) and 5-nitroisophthalic acid (H2NIP) with Co(CH3COO)2 or Cd(NO3)2 in CH3OH–H2O at room temperature generated {[Co2(AAP)(NIP)(H2O)8][Co(AAP)(NIP)2(H2O)2](H2O)4.5} (1) and {[Cd(AAP)(NIP)(H2O)](H2O)} n (2), which were further characterized by X-ray diffraction, IR spectra, elemental analysis and solid-state fluorescence spectra. The structure analysis indicates that 1 contains two individual fragments, one NIP-bridged six-coordinate binuclear CoII cation and a mononuclear CoII dianion. The binuclear units are connected into 1-D chains via O–H ··· O hydrogen bond interactions, which were further assembled into a 2-D supramolecular layer bridged by the mononuclear CoII unit. Complex 2 is a linear NIP bridged seven-coordinate CdII polymeric chain with the terminal AAP ligands as decorations, and are further extended into 2-D network by classic hydrogen bonds and π ··· π stacking interactions. Both solid complexes exhibit emission spectra from intraligand electron transfer at room temperature.