formation and stability of partially and completely substituted cellulose nitrite esters in dipolar aprotic solvents containing N2O4

As some contradictions still exist concerning the mechanism of cellulose dissolution in N2O4-N,N,-dimethylformamide and N2O4-dimethyl sulfoxide systems, the problem of the existence and stability of cellulose trinitrite in these systems has been investigated using 13C NMR spectroscopy. Cellulose trinitrite is definitely formed as a rather stable compound provided a very low level of water (0.01-0.02%) is maintained in the system. Upon addition of protic liquids (H2O or MeOH), decomposition of the nitrite groups takes place in the order of stability C-2 < C-3 C-2 > C-3 was observed. The homogeneous nitrosation of cellulose dissolved in LiCl-N,N-dimethylacetamide indicated a reactivity of OH groups in the order C-6 > C-3 greater than or equal to C-2.