Polyynylcontaining

Polyynyl-containing compounds are chemical species that include at least one polyyne substituent, a chain of carbon atoms linked by consecutive triple bonds separated by single bonds. The polyyne fragment is typically described as -(C≡C)n- with n ≥ 2, so diynes and longer chains are common. Such groups can be attached to aromatic rings, alkyl backbones, or incorporated into larger molecular frameworks.

Structurally, polyynyl chains are linear and feature sp-hybridized carbon along their length. The multiple C≡C units impart high unsaturation and distinctive electronic characteristics, which influence reactivity, stability, and optical properties. In many cases, longer polyyne chains are more reactive toward oxidation and radical species, and their stability can depend strongly on substitution and environmental conditions. The extended conjugation in polyyne-containing systems can shift electronic absorption, sometimes producing color in longer chains.

Synthesis of polyyne-containing compounds employs various carbon–carbon coupling and elongation strategies. Methods include Sonogashira-type couplings to assemble diynes, Glaser oxidative coupling to extend chains, and iterative or modular coupling approaches to build longer polyyne fragments. Polyyne motifs also occur in certain natural products and are studied in astrochemistry and combustion science as reactive intermediates and precursors to carbon-rich materials.

Applications of polyynyl-containing motifs span materials science and molecular electronics. They are used as building blocks for conjugated systems, dyes, and nonlinear optical materials, and serve as precursors to carbon-rich architectures such as graphdiyne. Safe handling requires awareness of potential sensitivity to air, heat, and light, with storage typically under inert conditions for longer polyyne chains.

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