Polymeric mesoions, 3. Synthesis of polymeric mesoionic 1,3‐diazinium‐olates via polymer analogous modification of a polythiourea from m ‐phenylenediamine and p ‐phenylene diisothiocyanate

Mesoionic poly(1,1′‐(1,3‐phenylene)‐3,3′‐(1,4‐phenylene)‐bis(5‐decyl‐2‐decylthio‐4,6‐dioxo‐1,3‐diazine)) ( 6 ) was prepared by cyclisation of the isothiourea component of poly(1,1′‐(1,3‐phenylene)‐3,3′‐(1,4‐phenylene)‐bis(2‐decylisothiourea)) ( 4 ) with decylmalonic acid (5) by use of dicyclohexylcarbodiimide (DCC). Polymer 4 was obtained by polymer analogous alkylation of poly(1,1′‐(1,3‐phenylene)‐3,3′‐(1,4‐phenylene)‐bisthiourea) ( 3 ). For comparison of spectroscopic data, 5‐butyl‐2‐propylthio‐4,6‐dioxo‐1,3‐diphenyl‐1,3‐diazine ( 9 ) was synthesized as low molecular weight model compound.