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The aging effect on the proton conductivity of graphene oxide (GO) is investigated. Characterizations of oxygenated functional groups and measurement of the proton conductivity have been performed using freshly prepared GO and the same sample after preserving for three years under ambient conditions. Although GO retains its layered structure, a slight deviation in its powder X-ray diffraction (PXRD) pattern and Raman spectra upon aging implies some changes in the interlayer distance and functional groups. Decomposition of epoxy groups on aging has been recognised by X-ray photoelectron spectroscopy (XPS) analysis. The proton conductivity was found to be reduced by 25% after three years of aging. [ABSTRACT FROM AUTHOR]

Cobalt(II) complexes with terpyridine-type ligands, [Co(n-pyterpy)2](ClO4)2 (n=3 (1), 4 (2)), were prepared and characterised. Different positions of the nitrogen atom in the terpyridine ligands influenced their assembly properties in the crystal structures. Complex 1 showed a 2D network structure consisting of 1D chains connected by intermolecular N ⋯HC interactions. On the other hand, complex 2 consisted of two different cobalt ion sites (Co1 and Co2) with slightly different coordination environments. Complex 2 showed 1D chains with no interchain interactions. Such differences are discussed with the cooperativities estimated by their spin crossover behaviours. [ABSTRACT FROM AUTHOR]