Chemistry Department, University of St. Andrews, St. Andrews, Fife KY 16 9ST Gt. Britain
Abstract:
Molecular geometries and heats of formation have been calculated, using MINDO/3, for mass spectral fragment pairs (A+ + B) derived from formamide. There are five stable isomeric forms of the molecular ion: [H2NC(OH)]+, (H3NCO)+, [HNC(OH2)]+, [NCH(OH2)]+, and (NCOH3)+ (in order of increasing , but no isomer (H2NCHO)+. There are three isomeric forms of (M—H)+: (H2NCO)+ (HNCOH)+, and (NCOH2)+: the only stable form of (M—2H)+ is (NCOH)+. Other (A/B)+ fragment pairs calculated are (CO/NH3)+, (HCO/NH2)+, (H2O/HCN)+, (H2O/HNC)+ [HO. + (HCNH)+], and [HO. + (H2NC)+]. The structure of the doubly charged ion M2+ is also reported.