... (M+-CH 3 · 3, 0. 53% ), 37 7 [M+-OSi(CH 3 ) 3 , 0.64%], 36 3 [M+-Si(CH 3 ) 3 -CH 3 · 2, 4.8%], 299 (M+-C6F5, 65.1%),195 ([C6F5N2]+, 8.7%), 147 {[(CH 3 )2¼O-OSi(CH 3 ) 3 ]+, 24 .3% }, ... 73 {[Si(CH 3 ) 3 ]+, 98.4%}V: 2,5-pyridine-dicarboxylic acidb 31 1 (M+, 30 .6%), 296 (M+-CH 3 , 100%), 266 (M+-CH 3 · 3, 39 .3% ), 238 [M+-Si(CH 3 ) 3 , 11.7%],222 [M+, Si(CH 3 ) 3 -O, ... Si(CH 3 ) 3 -O, 62.7%], 194 [M+-COOSi(CH 3 ) 3 , 39 .3% ], 147 {[(CH 3 )2¼O-OSi(CH 3 ) 3 }+,100%), 77 [M+-COOSi(CH 3 ) 3 -COOSi(CH 3 ) 3 , 90.9%], 73 {[Si(CH 3 ) 3 ]+, 100%}aPentafluorophenylhydrazine...