In the negative mode, the three distinct peaks are present at m/z = 90.6, 114.6 and 166.5 in the spectra for both TCNE and TCNE-Melamine. The negative ion mode generates peaks for molecules with a higher electron affinity or that readily accept electrons. No peaks corresponding to anions of TCNE, molecular formula C 2 (CN) 4 , i.e. radical anion [TCNE] •-(a molecular mass of 128.09 g/mol), are observed. The largest peak at m/z = 166.5 can be attributed to 1,1,2,3,3,-pentacyanopropenide [C 3 (CN) 5 ] -(a molecular mass of 166.12 g/mol) . The molecular structure is illustrated on the bottom right in Fig. . The peak at m/z = 114.6 indicates the formation of [C 3 (CN) 3 ] -(a molecular mass of 114.087 g/mol) . The peak at m/z = 90.6 can be attributed to tricyanomethanide [C(CN) 3 ] -(a molecular mass of 90.065 g/mol) .