The first bis(arylnitrenes) linked by heterocyclic pseudoaromatic rings were generated in a glassy, 77 K 2-methyltetrahydrofuran matrix by photolysis at wavelengths >300 nm : 2,5-bis(3-nitrenophenyl)furan (1); 2,5-bis(3-nitrenophenyl)thiophene (2); 2,5-bis(3-nitrenophenyl)pyrrole (3); 2,5-bis(4-nitrenophenyl)furan (4); 2,5-bis(4-nitrenophenyl) thiophene (5); 2,5-bis(4-nitrenophenyl)pyrrole (6). Systems 1-3 gave quintet ESR spectra with D/hc approximate to 0.16 cm(-1) having thermal peak intensity variations consistent with each system being a pseudodisjoint ground state singlet dinitrene and a thermally populated excited quintet state, similar to behavior exhibited by structurally related bis(arylnitrenes) (Murata, S.; Iwamura, H. J. Am. Chem. Soc. 1991, 113, 5547). On the basis of Curie law ESR spectral peak intensity behavior, multiple conformations of 1 and 3 were deduced as having different values of Delta E-(singlet-->quintet) : for 1, we found peaks with Delta E = 60 and 100 cal/mol; for 3, we found peaks with Delta E = 18 and 110 cal/mol. The major quintet peak of 2 has thermal behavior consistent with Delta E = 88 cal/mol. Systems 4-6 gave triplet biradical ESR spectra consistent with quinonoidal biradical structures having zero field splitting values of D/hc = 0.137 cm(-1) (E/hc = 0.616 cm(-1)), D/hc = 0.190 cm(-1) (E/hc = 0.006 cm(-1)), and D/hc = 0.183 cm(-1) (E/hc = 0.012 cm(-1)), respectively. The biradical ESR spectral intensities for 4-6 decrease with decreasing temperature, showing these to be ground state singlet biradicals.