annulynes

Annulynes are a class of hypothetical organic compounds that are cyclic and contain alternating single and triple bonds. The general formula for an annulynne is C2n. They are considered highly strained molecules due to the presence of the triple bonds within a ring structure. The smallest possible annulynne would be cyclooctatriyne, C8. The extreme strain in these molecules makes their synthesis and isolation very challenging.

Theoretical studies have investigated the electronic structure and properties of annulynes. Due to the sp hybridization of the carbon atoms in the triple bonds, annulynes would exhibit significant deviation from planarity in smaller rings. This deviation from planarity would further contribute to their inherent instability. In larger rings, the strain might be less pronounced, potentially allowing for more stable structures.

The concept of annulynes is closely related to annulenes, which are cyclic hydrocarbons with alternating single and double bonds. While annulenes have been synthesized and studied extensively, annulynes remain largely theoretical entities. The high reactivity expected from the strained triple bonds would likely lead to rapid decomposition or polymerization under normal conditions. Research into annulynes continues to be primarily theoretical, exploring the limits of chemical structure and stability.