[formula: see text] Hexamethylbipyrazine-N,N',N",N"'-tetraoxide (1) is synthesized in racemic form and cocrystallized with tetracyanoethylene to give a donor-acceptor (DA) networked lattice. The resulting DA2 cocrystal contains homochiral 2-D DA arrays (layers) cohered by 2.7 A NO...C=C DA bonds with periplanar O p-orbital/C=C orientations. Layer formation is stereoselective, while interlayer relations yield a racemic lattice.

2-Thioxoethen-I-one (8) can thus be generated in a photochemically induced addition of CS to CO. This reaction is reversible. C,OS, which probably possesses a triplet ground state, is stable under matrix conditions. Our results are in accordance with the findings of Schwarz et al., who by neutralization reionization mass spectrometry identified C,0Sr"] but not C202[121 as a viable species in the gas phase.

Leitern bzw. Netze liegen in den beiden polymorphen Formen der durch unterschiedlich rasches Kristallwachstum erhaltenen Kristalle von (TMPDO)2TCNE vor. In kinetisch bevorzugten, purpurfarbenen Kristallen sind die Donor‐ und Acceptorbausteine über N+O− … C(Alken)‐Wechselwirkungen zu Leitern organisiert (siehe unten).