CuICuII and AgIp-isocyanobenzoates as novel 1D semiconducting coordination oligomers

Abstract

Two novel semiconducting coordination oligomers with 1D chain structures, namely [H_0.07 Cu^I_0.65Cu^II_0.14(μ-p-CNC₆H₄CO₂)·0.9H₂O]_n and [Ag(μ-p-CNC₆H₄CO₂)]_n, were obtained and characterized by XRD powder patterns, and XPS, EPR, UV-vis-NIR, IR and Raman spectroscopy. According to XRD analysis, Cu^ICu^II–ICNBA is an amorphous solid, while Ag^I–ICNBA crystalizes with a monoclinic unit cell in the C2/c space group (Z = 4). The composition and further information of Cu^ICu^II–ICNBA were obtained from the spectroscopic data. In correspondence with the quantification of terminal groups from high-resolution XPS spectra, Cu^ICu^II–ICNBA and Ag^I–ICNBA are composed of an average of 9 and 7 monomer units, respectively, resulting in 1D-oligomers. The spectroscopic evidence indicates that Cu^ICu^II–ICNBA is better described as a non-stoichiometric coordination oligomer (where non-integer ratios of metal ions can be accommodated), while Ag^I–ICNBA is stoichiometric. In both materials, each metal center is linked by two μ-η¹:η¹-p-isocyanobenzoate ligands forming microfibers of around 120 nm (Cu^ICu^II-material) and 310 nm (Ag^I-material) in average diameters with optical band gaps of 2.60 eV and 2.17 eV, respectively.