He asked for the bp of the nitroalkanes not the nitroalkenes
But I think he was a little confused.
Most of the nitrostyrenes can actually be distilled, but there will be losses due to decomposition. If purification or beautification is desired EtOAC (ethyl acetate) is the best solvent. The crystals are so beautiful. The best option beside recrystallisation is high-vacuum sublimation. This is very efficient for nitrostyrenes.
The nitroalkanes can be distilled, and with regular high vacuum the boiling points are between 140-180°C. If they survive that why shouldn't they survive a measly 110°C when distilling off toluene at STP? In
Post 352950
(Barium: "Get that double bond without borohydride", Novel Discourse) the authors recommend distillation at large scale production. The PBI reduction takes place in refluxing n-BuOH (bp 117-118°C) and the yields are good to excellent. No harm from that temp there either.