20380-30-7

Basic information

• Product Name: tricyclo[4.2.0.0~2,5~]octa-3,7-diene
• CAS NO: 20380-30-7
• Molecular Formula: C₈H₈
• Molecular Weight: 104.1491
• Mol File: 20380-30-7.mol
• Article Data: 3

Chemical Properties

• Boiling Point: 150.5°C at 760 mmHg
• Flash Point: 22.8°C
• Density: 1.15g/cm³
• Vapor Pressure: 4.87mmHg at 25°C
• Refractive Index: 1.629
• CAS DataBase Reference: tricyclo[4.2.0.0~2,5~]octa-3,7-diene(CAS DataBase Reference)
• NIST Chemistry Reference: tricyclo[4.2.0.0~2,5~]octa-3,7-diene(20380-30-7)
• EPA Substance Registry System: tricyclo[4.2.0.0~2,5~]octa-3,7-diene(20380-30-7)

Safety Data

• Hazardous Substances Data: 20380-30-7(Hazardous Substances Data)

Upstream product

• 277-10-1 cubane 
• 110-00-9 furan 
• 998-40-3 tributylphosphine 
• 114068-57-4 3,4-Diaza-tricyclo[3.1.0.0^2,6]hex-3-ene 

Downstream Products

• 629-20-9 1,3,5,7-cyclooctatetraene 

Relevant articles and documents

The rearrangement of the cubane radical cation in solution

The rearrangement of the cubane radical cation (1.+) was examined both experimentally (anodic as well as (photo)chemical oxidation of cubane 1 in acetonitrile) and computationally at coupled cluster, DFT, and MP2 [BCCD(T)/cc-pVDZ//B3LYP/6-31G* + ZPVE as well as BCCD(T)/cc-pVDZ//MP2/6-31G* + ZPVE] levels of theory. The interconversion of the twelve C2v degenerate structures of 1.+ is associated with a sizable activation energy of 1.6 kcal mol-1. The barriers for the isomerization of 1.+ to the cuneane radical cation (2.+) and for the C-C bond fragmentation to the secocubane-4,7-diyl radical cation (10.+) are virtually identical (ΔH0? = 7.8 and 7.9 kcal mol-1, respectively). The low-barrier rearrangement of 10.+ to the more stable syn-tricyclooctadiene radical cation 3.+ favors the fragmentation pathway that terminates with the cyclooctatetraene radical cation 6.+. Experimental single-electron transfer (SET) oxidation of cubane in acetonitrile with photoexcited 1,2,4,5-tetracyanobenzene, in combination with back electron transfer to the transient radical cation, also shows that 1.+ preferentially follows a multistep rearrangement to 6.+ through 10.+ and 3.+ rather than through 2.+. This was confirmed by the oxidation of syn-tricyclooctadiene (3), which, like 1, also forms 6 in the SET oxidation/rearrangement/electron-recapture process. In contrast, cuneane (2) is oxidized exclusively to semibullvalene (9) under analogous conditions. The rearrangement of 1.+ to 6.+ via 3.+, which was recently observed spectroscopically upon ionization in a hydrocarbon glass matrix, is also favored in solution.

3,4-DIAZABENZVALENE, THE AZOALKANE PRECURSOR TO TETRAHEDRANE. SYNTHESIS AND REACTIVITY.

The title diazene 1 has been synthesized and shown to decompose thermally to cyclobutadiene over a surprisingly small barrier.