kallene

Kallene is a term that does not have a single, widely accepted definition in standard reference works. In many cases it appears as a misspelling or variant of allene, the class of organic compounds featuring a cumulated diene structure.

In chemistry, allene refers to compounds with the formula R2C=C=CR2 (propadiene being the simplest example, CH2=C=CH2). The central carbon is sp-hybridized, and the terminal substituents on the two ends lie in perpendicular planes. Substituted allenes can exhibit axial chirality when each terminus carries two different substituents. Allene chemistry encompasses reactions such as cycloadditions and various additions to the cumulated double bonds. The term "kallene" is not standard in contemporary English-language texts; when encountered, it typically indicates either a transliteration variant, an OCR error, or regional usage.

Outside chemistry, "Kallene" may also appear as a personal surname or as a place name in obscure or fictional contexts, but there is no widely recognized geographic or biographical entry under this spelling in major reference works.

Because of these ambiguities, contexts should be consulted to determine the intended meaning. If the reference is chemical, the correct term is usually "allene."