Polyyne-Type Materials - Polyynes: Synthesis, Properties, and Applications - page 198

SCHEME 10.1 General synthetic route of PpPB and PpPE.

FIGURE 10.5 TG/DTA results of PpPE, PpPB, and PpPO under an argon
atmosphere.

having the shortest polyyne unit (m ¼ 1). From the peak area, the heat

H) (in/kJ g 1 ) is estimated to be in the order PpPE<
PpPB<PpPO, but

of reaction (

H (kJ (mol acetylene) 1 ) values are almost
constant at about 40 kJ (mol acetylene) 1 . Since the exothermic reaction is
due to cross-linking reactions between the polyyne chains, the total amount
of heat is approximately estimated by subtracting the bond dissociation
energy of a conjugated C

the

C bond from the sum of the
bonding energies of C-C newly formed by the cross-linking reaction.
However, for example, the experimental value of

C bond to a C ¼

H for PpPB (86 kJ (mol