Suitable crystals for X-ray diffraction were mounted on a loop with protective oil, and X-ray data was collected on a Bruker APEX II CCD detector diffractometer using graphite monochromated MoKα radiation (λ = 0.71073 Å) and operated in a φ and ω scans mode. A semi empirical absorption correction was carried out using SADABS (Sheldrick, G. M. SADABS, Bruker AXS Inc., Madison, Wisconsin, USA, 2004). Data collection, cell refinement and data reduction were done with the SMART and SAINT programs (SMART and SAINT, Bruker AXS Inc., Madison, Wisconsin, USA, 2004).
The structures were solved by direct methods using SIR97 [35] (link) and refined by fullmatrix least-squares methods using the program SHELXL97 [36] using the winGX software package [37] (link). Non-hydrogen atoms were refined with anisotropic thermal parameters, except in cases of disorder where these specific atoms were refined as isotropic, whereas H-atoms were placed in idealized positions and allowed to refine riding on the parent C atom. Molecular graphics were prepared using ORTEP [38] (link).
The structures were solved by direct methods using SIR97 [35] (link) and refined by fullmatrix least-squares methods using the program SHELXL97 [36] using the winGX software package [37] (link). Non-hydrogen atoms were refined with anisotropic thermal parameters, except in cases of disorder where these specific atoms were refined as isotropic, whereas H-atoms were placed in idealized positions and allowed to refine riding on the parent C atom. Molecular graphics were prepared using ORTEP [38] (link).