Cyclobutene Derivatives as Bridges

A situation similar to 42qx is depicted in 43qx in which the bond angles of the vinylene bridge are less distorted than in 42qx Thus hybridisation in 43 is more 

2 Four Step Electron Transfer Between a [4] Radialene and a Cyclobutadiene  

The formal combination of the levels RED and OX of general type A, n = 1, will produce the dicationic four-membered ring 44 which actually exists as a completely 

3 Electron Transfer Betweena 1,3-Bismethylene Cyclobutane and a [1.1.0]-Bicyclobutane  

If one connects the two double bonded end groups X in form RED of general structure /I (n = 1) with two methylene bridges instead of the usual a-bond, then 4(5red should result. With well adapted X-groups this cyclobutane derivative 6red may 

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