Rotational spectra of the symmetric-top complexes N-14(2)center dot center dot center dot ICF3 and N-15(2)center dot center dot center dot ICF3 were observed and analysed to give rotational constants B-0, centrifugal distortion constants D-J and D-JK, and nuclear quadrupole coupling constants chi(aa)(X). Significantly different values of chi(aa)(Ni-14) and chi(aa)(No-14) establish chemical inequivalence of the two N-14 nuclei and an average zero-point oscillation angle of 19.8(5)degrees for the N-2 subunit. A distance r(N center dot center dot center dot I) = 3.443(1) angstrom only slightly shorter than the sum of the N and I van der Waals radii, a small intermolecular stretching force constant k(sigma) = 2.94 N m(-1) and negligible charge redistribution on complex formation demonstrate the presence of a weak halogen bond. (C) 2015 Elsevier B.V. All rights reserved.