Polyynes

Safran vines umbel ( Oenanthe crocata ) contains a polyinoic

Polyines are organic compounds with several carbon-carbon triple bonds , analogous to the polyenes with several C = C double bonds . In the narrower sense, it refers to aliphatic, unbranched hydrocarbons with several triple bonds.

In the atmosphere of Saturn's moon Titan , polyynes are formed that shield ultraviolet radiation .

In plants, polyines occur particularly in the daisy and umbelliferous families . Well over 1000 naturally occurring polyynes isolated from plants, cultures of higher fungi, bacteria, sea sponges and corals are known.

The simplest representative of the polyynes is diacetylene (butadiyne). Also hexatriyne and Octatetrain are representatives of the group of polyines. Molecules with up to about 12 ethyne units are stable; if the ends of the molecule are complexed, polyynes with 14 ethyne units can also be isolated.

Diynes are synthetically accessible by means of a Glaser coupling :

Individual evidence

1. ↑ SPIEGEL ONLINE: Saturn moon Titan: Researchers unravel the secret of UV protection
2. ↑ Annabelle LK Shi Shun, Rik R. Tykwinski: Synthesis of Polyyne Natural Products, Angew. Chem. , 118 (2006) pp. 1050-1073 ( doi : 10.1002 / anie.200502071 ).