Crystal Structure of η3-lithio-1,3,3-triphenylpropyne-(diethyl ether)2 and [1-lithio-1-(2-methoxyphenyl)-3,3-diphenylallene–diethyl ether]2: Propargyl- versus allenyl-type structures

✍ Scribed by Dem'yanov, Piotr ;Boche, Gernot ;Marsch, Michael ;Harms, Klaus ;Fyodorova, Galina ;Petrosyan, Valery

• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Weight: 476 KB
• Volume: 1995
• Category: Article
• ISSN: 0947-3440
• DOI: 10.1002/jlac.199519950361

✦ Synopsis

Abstract

Crystal structure investigations reveal that η^3^‐lithio‐1,3,3‐triphenylpropyne‐(diethyl ether)~2~ [6 · (OEt~2~)~2~] is of the propargyl structural type while [1‐lithio‐1‐(2‐methoxyphenyl)‐3,3‐diphenylallene‐(diethyl ether)]~2~ {[7 · OEt~2~]~2~} is of the allenyl type. The assignment of the different structural types is mainly based on a comparison of the bond lengths C1‐C2 and C2‐C3 as well as of the difference ΔCC of these two bond lengths with the corresponding values of theoretical models of the propargyl and allenyl type. This leads also to a correction of an earlier assigned structural type.