209-69-8

Basic information

• Product Name: 1H-Cyclopent[cd]indene
• Synonyms: 1H-Cyclopent[cd]indene
• CAS NO: 209-69-8
• Molecular Formula: C₁₁H₈
• Molecular Weight: 140.18
• Mol File: 209-69-8.mol
• Article Data: 3

Chemical Properties

• Appearance: /
• CAS DataBase Reference: 1H-Cyclopent[cd]indene(CAS DataBase Reference)
• NIST Chemistry Reference: 1H-Cyclopent[cd]indene(209-69-8)
• EPA Substance Registry System: 1H-Cyclopent[cd]indene(209-69-8)

Safety Data

• Hazardous Substances Data: 209-69-8(Hazardous Substances Data)

Upstream product

• 74588-68-4 sodium salt of 1-naphtaldehyde tosylhydrazone 
• 111013-08-2 8-methyl-1,2-dihydrocyclobutanaphthalene-1,2-dione 

Downstream Products

• 34935-94-9 1-Benzhydryliden-cyclopentinden 

Relevant articles and documents

Azulenylcarbene and Naphthylcarbene Isomerizations. Falling Solid Flash Vacuum Pyrolysis

1-Azulenylcarbene 18 has been generated from 5-(1-azulenyl)tetrazole and the sodium salt of azulene-1-carbaldehyde tosylhydrazone using the falling solid flash vacuum pyrolysis (FS-FVP) method. The principal products, which are also formed from both 1- and 2-naphthylcarbenes, cyclobuta[de]naphthalene 6, cyclopenta[cd]indene 16, and benzofulvenallene 17, are explained in terms of two reaction paths, (a) a rearrangement to benzofulvenyl-7-carbene 13 and (b) a rearrangement to 1-naphthylcarbene 1. Moreover, 16 is also formed from 2-azulenylcarbene 30, thereby indicating the occurrence of a 2-azulenylcarbene-1-azulenylcarbene rearrangement. The reaction mechanisms are supported by density functional theory calculations at the B3LYP/6-31G?? level, which indicate that all the rearrangements have activation barriers of 35 kcal/mol, thus making them readily achievable under FVP conditions. Chemical Presented.

FORCE FIELD-SCF CALCULATIONS ON CYCLOPROPENE INTERMEDIATES IN CARBENE REARRANGEMENTS. COMPARISON WITH EXPERIMENT

Heats of formation and geometries of benzocyclopropene, cyclopropa(b)naphthalene, bicyclo(4.1.0)hepta-2,4,7-triene, and benzannelated derivatives have been calculated with a combined force field-SCF progrsm.The bicycloheptatrienes are stabilized relative to the isomeric arylcarbenes by benzannelation, and destabilized by loss of aromaticity and/or increased strain. 1-Naphthylcarbene, 2-naphthylcarbene, 9-phenanthrylcarbene and 9-anthrylcarbene were generated by gas-phase pyrolysis of the corresponding arene aldehyde tosylhydrazone sodium salts, diazomethanes, or 5-aryltetrazoles, and rearranged to cyclobutanaphthalene(21), cyclobutaphenanthrene(33), and cyclobutaanthracene(38), respectively. 10,11-Dihydrodibenzocyclohepten-5-ylidene (15), similarly generated from 5-diazo-10,11-dihydro-5H-dibenzocycloheptene (39), rearranged to 5a,9b-dihydro-5H-benzocyclobutindene(40), 5H-dibenzocycloheptene(41), and 8,9-dihydro-4H-cyclopentaphenanthrene(40). 40 rearranged thermally to 41.The mechanisms of the rearrangements are discussed.