Synthesis of Novel Heterocyclic Clefts Derived from Tetracyclo[6.3.0.04,11.05,9]undecane-3,6-dione and Tricyclo[6.3.0.02,6]ubdecane-3,11,dione

New molecular clefts dipyridazinotricycloundecane derivatives (6a-6c), (9a), and (9b) have been prepared via base promoted reactions of 3,6-di -aryl-1,2,4,5-tetrazines with tetracyclo[6.3.0.0 4,11 .0 5,9 ]unde- cane-3,6-dione (1) and with tricyclo [6.3.0.0 2,6 ]undecane-3,11-dione (10), respectively. Compounds of this type are of interest as a poten- tial new class of host molecules for use in host-guest complexation studies (i.e., inclusion phenomena and molecular recognition). The re- sults obtained via studies of the solution electrochemistry of systems (6a-6c), (9a), and (9b) afforded no evidence for the existence of any significant electronic interaction between opposing «arms» in these molecular clefts