PHOTOCHEMISTRY OF THE AZOALKANES 2,3-DIAZABICYCLO[2.2.1]HEPT-2-ENE AND SPIRO[CYCLOPROPANE-1,7'-[2,3]DIAZABICYCLO[2.2.1]HEPT-2-ENE] - ON THE QUESTIONS OF ONE-BOND VS 2-BOND CLEAVAGE DURING THE DENITROGENATION, CYCLIZATION VS REARRANGEMENT OF THE 1,3-DIRADICALS, AND DOUBLE INVERSION