Cn1cnc2ncnc(N)c21    mol8261    0_1
Cn1c[nH+]c2ncnc(N)c21    mol8261    1_1
Cn1cnc2nc[nH+]c(N)c21    mol8261    1_2
Cn1cnc2[nH+]cnc(N)c21    mol8261    1_3
Cn1cnc2ncnc([NH3+])c21    mol8261    1_4