Gold in its Divalent Form (IMAGE) Johannes Gutenberg Universitaet Mainz Caption Gold in its divalent form is stable in the center of porphyrins. Credit Ill./©: Katja Heinze, JGU Usage Restrictions This image may only be used in connection with the press release "Mainz-based researchers stabilized gold in very rare oxidation state +II", issued by Johannes Gutenberg University Mainz on August 8, 2017. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.