Azimine. III . Kristallstruktur von (1 E , 2 Z )‐ und (1 Z , 2 E )‐2, 3‐Dimethyl‐1‐phthalimido‐azimin ,

Azimines. III. Teilweise vorgetragen in Bern an der Jahresversammlung der Schweizerischen Gesellschaft für Kristallographie, 7.Oktober 1977, und als Autoreferat veröffentlicht [2]. Crystal structure of (1 E ,2 Z )‐ and (1 Z ,2 E )‐2,3‐dimethyl‐1‐phthalimido‐azimine Teilweise aus der Diplomarbeit von R. M. , ETH Zürich 1977. The structures of two diastereoisomeric 2,3‐dimethyl‐1‐phthalimido‐azimines, obtained by addition of phthalimido‐nitrene to ( E )‐azomethane, have been determined by X‐ray analysis. The major adduct 2a forms rhombic (space group Cmc2 1 ), the minor one 2b triclinic crystals (space group P l ). The molecular structures of 2a and 2b in the crystal exhibit several interesting features: (1) The azimines 2a and 2b are true dipolar systems with a coplanar skeleton and with bond angles of about 120°. Thus both azimine N,N bonds are potentially stereogenic centers; (2) 2a and 2b differ in configuration at both of these centers: 2a has