Preparation of long-chain polyynes of C24H2 and C26H2 by liquid-phase laser ablation in decalin

The longest-chain polyyne that has ever been synthesized is C24H2 by Estmond et al. using the complicated acetylene coupling method. On the other hand, in simple liquid-phase laser ablation method, we have recently obtained the longest-chain polyyne of C22H2. In the present study, we report the synthesis of long-chain polyynes of C24H2 and C26H2 from graphite pellets in solvent of decalin by liquid-phase laser ablation. It is believed that the termination reaction on both ends of these polyyne molecules hardly occurs in decalin with relatively less number of hydrogen atoms and these long-chain polyynes could be synthesized.