Question

The^1H NMR spectrum below corresponds to an unknown compound with the molecular formula C_7H_12. There are IR bands at around 2120 and 3330 cm^-1. Deduce and draw the structure of the molecule that corresponds to the data.

Answer 1

From the IR data = 2120 cm^-1 for c = c stretching and 3330 cm^-1 for C = C-H SP(C-H) sp hybridized carbon and hydrogen stretching From the H'-NMR data 3H 0.8-09 for alkane CH_3 is connected to CH_2 group NH = 3, 2 + 1 = 3,3 = 3, Then N = number surrounding hydrogen NH & 1.2-1.5 for 2CH_2 groups are overlapped 2H & 1.5-1.6 for CH_2 attached 2CH_3 group 1H & 1.9 for C + C-H hydrogen, 2H & 2.3 for CH_2 group The expected structure is for C_7H_g is