Copper(II) ethylene glycol carboxylates were investigated as precursors for inkjet printing of conductive copper patterns. The compounds with the general formula Cu[O2CCRR'(OC2H4)(2)OCH3](2) (R = R' = H: 2a; R = H, R' = Me: 2b; R = R' = Me: 2c; R = H, R' = Ph: 2d, R/R' = O: 2e) show a high solubility in water and many organic solvents. By thermal decomposition the compounds yield pure copper as the only non-volatile product, as confirmed by X-ray powder diffraction and energy-dispersive X-ray spectroscopy. Depending on the substituents R and R' the decomposition temperature varies between 175 and 220 degrees C. The mechanism of the thermal degradation was studied by thermogravimetry-mass spectrometry coupling experiments. For complex 2a, an aqueous 1.5 M solution (7.7 wt.% copper) exhibits rheological properties that are well-suited for inkjet printing. Thermal conversion of the as-printed structures under inert conditions yielded copper layers with only minor residues of carbon and oxygen. Electrical conductivities of 1.5 . 10(6) S.m(-1) on polyimide and 8.1 . 10(6) S.m(-1) on glass were found, which correspond to 2.6 and 14% of the bulk copper conductivity, respectively. (C) 2014 Elsevier B. V. All rights reserved.