Hans-Werner Wanzlick (1917-1988) was a German chemist. A Professor of chemistry at Technische Universität Berlin he is notable for work on persistent carbenes and for proposing the Wanzlick equilibrium between saturated imidazolin-2-ylidenes and their dimers â which he called "das doppelte Lottchen", after a 1949 novel by Erich Kästner about a pair of mischievous twins.