Triaziridine , c-N3H3, and Its Conjugate Acid. Ions

CycLotriazane (Triaziridine), C-N3H3, and Its Conjugate Acid. Ions 

CAS Registry Numbers C-N3H3 [6572-31-2], C/S-C-N3H3 [108739-42-0], trans-c-t s [108691-97-0], c-N3Hi- [73870-52-7] 

An MBPT calculation of the vibrational spectrum of frans-triaziridine predicted a most intense vibration at 1118 cm and two strong, similar ones at 1287 and 1295 cm The strongest vibration of the cis isomer can be expected at 1561 cm [5]. Complete sets of fundamentals of both isomers, but without intensities, were also obtained at the SCF level [37]. An MP2 calculation yielded rotational constants and microwave frequencies that can be used for the identification of C-N3H3 in interstellar space [38]. 

A calculation using the semiempirical SIND01 method yields ring current indices of 1.14 for C-N3H3 and 1.01 for c-NaHa which indicate the antiaromatic character of these nonplanar systems. The nonplanar c-NaHa was found to be unstable [39]. The stabilization of C-N3H3 caused by arranging the H substituents out of the N3 plane was used to qualify the nonaromatic character of the molecule [40]. 

A crystallographic investigation of 1-methoxycarbonyl-2,3-(cyclopenta-1,3-diyl)triaziri-dine revealed a tetrahedral configuration of the nitrogens with angles NNC of 107 3.5°. The interatomic distances are r(Ni-N2) = 1.479 db 0.002, r(N,-N3) = 1.458 0.002, and 

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