16216-91-4

Basic information

• Product Name: bicyclo[3.2.2]nona-2,6,8-triene
• Synonyms: Bicyclo(3.2.2)nona-2,6,8-triene; Bicyclo[3.2.2]nona-2,6,8-triene
• CAS NO: 16216-91-4
• Molecular Formula: C₉H₁₀
• Molecular Weight: 118.1757
• Mol File: 16216-91-4.mol
• Article Data: 4

Chemical Properties

• Boiling Point: 186.4°C at 760 mmHg
• Flash Point: 42.7°C
• Density: 0.98g/cm³
• Vapor Pressure: 0.914mmHg at 25°C
• Refractive Index: 1.549
• CAS DataBase Reference: bicyclo[3.2.2]nona-2,6,8-triene(CAS DataBase Reference)
• NIST Chemistry Reference: bicyclo[3.2.2]nona-2,6,8-triene(16216-91-4)
• EPA Substance Registry System: bicyclo[3.2.2]nona-2,6,8-triene(16216-91-4)

Safety Data

• Hazardous Substances Data: 16216-91-4(Hazardous Substances Data)

Upstream product

• 17684-76-3 Bicyclo<3.2.2>nona-2,6,8-trien-4-ol 
• 544-25-2 Cyclohepta-1,3,5-triene 
• 944-41-2 (3aα,4β,4aα,5aα,6β,6aα)-4,4a,5,5a,6,6a-hexahydro-4,6-etheno-1H-cycloprop[f]isobenzofuran-1,3(3aH)-dione 
• 21899-14-9 4-Methoxy-bicyclo<3.2.2>nona-2,6,8-trien 
• 56581-52-3 9-bromobarbaralane 

Downstream Products

• 283-19-2 Bicyclo<3.2.2>nonan 

Relevant articles and documents

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Structural Fluxionality in the Tricyclo2,8>nona-3,6-dienyl and Bicyclonona-2,6,8-trienyl Radicals

E.s.r observation of radicals derived from 9-bromtricyclo2,8>nona-3,6-diene, and related compounds, showed that they rearrange by β-scission to bicyclonona-2,6,8-trienyl radicals extremly rapidly; the latter radicals have hyperfine splittings similar to those of allyl radicals. 9-Deuterio- and 2-deuterio-9-bromotricyclo2,8>nona-3,6-diene were reduced with tributyltin hydride.The pattern of deuterium scrambling in the bicyclonona-2,6,8-triene and tricyclo2,8>nona-3,6-diene products showed that the intermediate radicals take part in a degenerate rearrangement sequence which makes them fully fluxional in three dimensions.The two radicals are in equilibrium at ca. 375 K, but the bicyclotrienyl species is more important by a factor of ca. 102.Neither the experimental results nor MNDO semiempirical calculations provided any evidence of additional thermodynamic stabilisation in the radical pair beyond that expected for allyl delocalisation.

Bicyclo nonatrienyl-lithium and -potassium and their Degenerate Rearrangements studied by Multiple Labelling with 13C and 2H, 13C Nuclear Magnetic Resonance Spectroscopy, 13C-13C Coupling Constants, and Isotopic Perturbation

Bicyclononatrienyl-potassium (8) and -lithium (9) in -1,2-dimethoxyethane have been investigated by 13C nuclear magnetic resonance spectroscopy.The absence of an observable isotopic perturbation effect on 13C chemical shifts indicates a symmetric structure of this (CH)91- anion in solution, rather than rapidly equilibrating unsymmetrical homoaromatic ions.One-bond 13C-13C coupling constants obtained from the -labelled ion (10), 1JC1C2 38, 1JC1C7 40.0, and 1JC2C3 62.5 Hz, were compared with those of the corresponding hydrocarbon bicyclonona-2,6,8-triene (11).The couplings indicate no significant structural change in the bridgehead region and support a symmetrical delocalized structure for the bicyclononatrienyl anion.It is proposed that the controversial stabilization of carbanions is not caused by delocalization and homoaromaticity but is rather due to a previously ignored important interaction with the metal ion.The observed scrambling of 13C labels in (8) and (9), from C(3) to C(6)-C(9) and subsequently to C(2), C(4) and C(1), C(5), is consistent with a degenerate rearrangement via the 9-barbaralyl anion.Further support for this mechanism was obtained from the scrambling of two 13C labels from C(3) and C(2), C(4) which is three times faster to C(6)-C(9) than to C(1), C(5) in ion (10).