CH3CH2+\mathrm{CH}_{3} \mathrm{CH}_{2}^{+}CH3CH2+
CH2+\mathrm{CH}_{2}^{+}CH2+
(CH3)2CH+\left(\mathrm{CH}_{3}\right)_{2} \mathrm{CH}^{+}(CH3)2CH+
(CH3)3C+\left(\mathrm{CH}_{3}\right)_{3} \mathrm{C}^{+}(CH3)3C+