Remskar et al. Nanoscale Res Lett 2011, 6:26 http://www.nanoscalereslett.com/content/6/1/26 Page 3 of 6 Figure 1 The Mo6S4I6 nanowires: a A SEM image of hedgehog-like self-assemblies of identical nanowires grown up to 10 μm in length; b A TEM image revealing rigid nanocrystals with dome terminations; c A HRTEM image with rows of Mo6 clusters surrounded by sulfur and iodine atoms. A stacking fault in otherwise regular order is marked with a stepped line and associated with a disordered structure; d TED pattern of a single Mo6S4I6 nanowire in the [010] zone assigned in accordance with the proposed space group P63/m and lattice parameters of a hexagonal structure with: a = 1.88(5) nm and c = 1.18 nm. exhibit a tendency for easy splitting. A stacking fault marked in Figure 1c with the component of the Burger’s vector perpendicular to the nanowires axis can contri- bute to the resistance of the needles against longitudinal cleavage and decreases a strong anisotropy of these quasi one-dimensional cluster compounds. The electron diffraction pattern of a single Mo6S4I6 nanowire (Figure 1d) is assigned in accordance with the proposed space group P63/m and estimated lattice para- meters of a hexagonal structure with: a = 1.88(5) nm and c = 1.18 nm. The nanowires grow with the [001] axis along their longitudinal direction. Besides Mo6S4I6 nanowires, X-ray investigation of the starting material (Figure 2a-A) reveals the presence of the Mo6S2I8 and traces of MoS2. The (002) MoS2 peak is shown by an asterisk in spectrum (a), while other MoS2 peaks cannot be resolved. Due to nearly identical skeletal structures, most of the diffraction peaks of Mo6S4I6 and Mo6S2I8 nearly match, leading to a broadening of the peaks in addition to the size effect broadening. As an example, the peak at ~.817 nm is composed of two peaks situated at 0.816(1) nm and at 0.825(8) nm. The last one can be associated with the Mo6S2I8 (110) planes, while the first one was used for the approximation of the unknown unit cell of Mo6S4I6 nanowires. The symmetry of the TED pattern (Figure 1d) was utilized for assignation of the peak to the (200) planes of the Mo6S4I6. The peak positioned at 0.197 nm was associated with the (006) planes. Complete determination of the Mo6S4I6 structure needs further studies. Transformation of the Mo6S4I6 Nanowires into MoS2 Nanotubes The X-ray powder diffraction of the product after the transformation (Figure 2a-B) reveals the iodine-free MoS2 compound. The spectrum is assigned according to the MoS2 (JCPDS-No. 77-1716). The Raman spectra of Mo6S4I6 nanowires are shown in Figure 2b-B and is almost identical with that of the pure Mo6S2I8