91-12-3

Basic information

• Product Name: bicyclopentadienylidene
• Synonyms: bicyclopentadienylidene;fulvalene;5-(2,4-Cyclopentadien-1-ylidene)-1,3-cyclopentadiene;Pentafulvalene;Δ1,1'-Bi[2,4-cyclopentadiene];Δ5,5'-Bi[1,3-cyclopentadiene];1,1'-Bi[cyclopenta-2,4-diene];1,1'-Bi[cyclopentane]-2,2',4,4'-tetrene
• CAS NO: 91-12-3
• Molecular Formula: C10H8
• Molecular Weight: 0
• Mol File: 91-12-3.mol
• Article Data: 8

Chemical Properties

• Appearance: /
• CAS DataBase Reference: bicyclopentadienylidene(CAS DataBase Reference)
• NIST Chemistry Reference: bicyclopentadienylidene(91-12-3)
• EPA Substance Registry System: bicyclopentadienylidene(91-12-3)

Safety Data

• Hazardous Substances Data: 91-12-3(Hazardous Substances Data)

Usage

Definition

ChEBI: A cyclic hydrocarbon that consists of two cyclopentane rings connected via a C2C bond between the methylene groups.

Upstream product

• 21423-86-9 9,10-dihydrofulvalene 
• 74-85-1 ethene 
• 1192-27-4 5-diazo-1,3-cyclopentadiene 
• 201230-82-2 carbon monoxide 
• 4729-01-5 cyclopentadienylidene 
• 542-92-7 cyclopenta-1,3-diene 
• 674-82-8 4-methyleneoxetan-2-one 
• 4984-82-1 sodium cyclopentadienylide 
• 4729-01-5 cyclopentadienylidene anion radical 

Relevant articles and documents

Photochemistry of matrix-isolated cyclopentadienylidene revisited

Irradiation of diazocyclopentadiene (1) in a matrix at 10 K with the wavelength λ = 366 nm leads - as already known - to rapid loss of nitrogen and the formation of cyclopentadienylidene (T-2). Upon photoexcitation of cyclopentadienylidene (2) with light of the wavelength λ = 313 nm the (s-E)-(E)-conformer of 2-penten-4-yn-1-ylidene (T-7a) can be detected, which is effectively converted into 3-ethynylcyclopropene (6) by using light with a wavelength of λ = 436 nm. The structural elucidation of T-7a and 6 is based on the comparison of the experimental and calculated IR spectra. Irradiation of cyclopentadienylidene (2), isolated together with the eliminated nitrogen in the same matrix cage, with light of wavelengths longer than 570 nm initiates a partial back-reaction to the starting material, diazocyclopentadiene (1) by recapturing the evolved nitrogen molecule.

DIRECT IR-SPECTROSCOPIC OBSERVATION OF (1+2)-CYCLOADDITION OF CYCLOPENTADIENYLIDENE TO ETHYLENE IN ARGON MATRIX

Cyclopentadienylidene was generated in argon matrix doped with 2percent C2H4 and the direct reaction of the carbene with C2H4 in matrix, when it was annealing from 12 to 40-45 K, was observed.