1-Nitroindoline

Abstract

In the title compound, C(8)H(8)N(2)O(2), the nitramino group is planar and only slightly twisted with respect to the indoline rings. The bridgehead N--C bond is slightly shorter than in typical secondary aromatic nitramines. The N--N bond has some double-bond character. The molecules are connected by weak C--H...O hydrogen bonds, forming chains parallel to the z direction.

Charge-density analysis of 1-nitroindoline: refinement quality using freeRfactors and restraints

“…The structure of 1-nitroindoline has been previously reported by Zaleski et al (2001). Since the previous experiment was performed at room temperature, some structural differences are observed.…”

“…The 1-nitroindoline structure in space group P " 1 1 was found to be the same as that determined at room temperature (Zaleski et al, 2001). The structure was refined by a full-matrix least-squares method using SHELXL97 (Sheldrick, 2008).…”

“…The bond lengths, angles and torsion angles of the 1-nitroindoline structure at 90 K (after the multipolar refinement) are given in Table 3. Compared with the structure at room temperature (Zaleski et al, 2001) the unit-cell volume is reduced by 3%.…”

“…1-Nitroindoline was prepared following the procedure described by Zaleski et al (2001). Indoline and sodium hydride were heated in boiling toluene for 2 h under a nitrogen atmosphere.…”

“…Significant hydrogen bonding is present in the crystal structure. Based on energy criteria, careful examination of the intermolecular space for additional interactions has been carried out, resulting in three hydrogen bonds (Table 6) compared with the previous structural study (Zaleski et al, 2001). On each bond path between the hydrogen and acceptor atoms, there is a critical point of the type (3,À1) ( Table 6).…”