Alfred Werner’s Coordination Chemistry: New Insights from Old Samples

Abstract

Save your samples! The original compound [Co(en)2(NO2)2]Br prepared by Alfred Werner's student Edith Humphrey around 1900 did not crystallize as a conglomerate, but rather formed twinned crystals of both enantiomorphs. These findings, together with similar results for further samples from the Werner laboratory, provide new insight to the claim that Werner could have proved his coordination theory ten years earlier.