Question: Compare between the boiling points of isobutane and 1-butyne
The answer to this question is given as 1-butyne has higher boiling point than isobutane.
My approach: I have been taught a few concepts (which I learnt for granted), in my organic chemistry class:
- The carbon with a longer chain has a higher boiling point than its isomer with more branching or a shorter hydrocarbon chain. (Kindly correct me if I am wrong here and provide an explanation)
From here I decided that butyne will have a greater boiling point (though I made an incorrect assumption), and luckily my answer came out to be correct, but I am not convinced about the reason for it. Please help with the correct explanation for this question.
I have a proposition that since the electronegativity of $\mathrm{sp}$ hybridisation carbon is very high (only a little bit less than nitrogen), will it show hydrogen bonding? This justifies the given answer.
If it does not show hydrogen bonding, why so? All conditions are fulfilled, a highly electron deficient hydrogen is present and electrons are present in the $\pi$ bond between the carbons. Please help.