title: Cyclopropenylidenes: from interstellar space to an isolated derivative in the laboratory.
abstract: Like many of the molecular species that have been detected in the interstellar medium, the singlet carbene cyclopropenylidene (C3H2) has been presumed to be too unstable to isolate in the laboratory. However, by appending pi-electron-donating amino groups to the triangular skeleton, we prepared a cyclopropenylidene derivative that is stable at room temperature. In contrast to previously isolated carbenes, this compound does not require a heteroatom adjacent to the electron-deficient carbon to confer stability. Despite the presence of amino groups, the geometric parameters of the cyclic skeleton, revealed by x-ray crystallography, are only slightly perturbed relative to those of the calculated structure of unsubstituted cyclopropenylidene. Stable cyclopropenylidene derivatives might thus serve as models for a better understanding of the formation of carbon-bearing molecules in the interstellar medium.
authors.affiliation: University of California, Riverside-CNRS Joint Research Chemistry Laboratory (Unité Mixte Internationale 2957), Department of Chemistry, University of California, Riverside, CA 92521-0403, USA.
authors.forename: Vincent
authors.initials: V
authors.lastname: Lavallo
authors.forename: Yves
authors.initials: Y
authors.lastname: Canac
authors.forename: Bruno
authors.initials: B
authors.lastname: Donnadieu
authors.forename: Wolfgang W
authors.initials: WW
authors.lastname: Schoeller
authors.forename: Guy
authors.initials: G
authors.lastname: Bertrand
mesh_terms: D018360:Crystallography, X-Ray; D003521:Cyclopropanes / Q000737:chemistry / Q000302:isolation & purification*; D005118:Extraterrestrial Environment; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D013696:Temperature; D013816:Thermodynamics
chemical_list: D003521:Cyclopropanes