Single crystals were grown by slow diffusion followed by slow
evaporation technique. The intensity data were collected using a
Bruker SMART APEX-II CCD diffractometer, equipped with a fine
focus 1.75 kW sealed tube MoKa radiation (l = 0.71073 Å) at 273
(3) K, with increasing w (width of 0.3 per frame) at a scan speed
of 3 s/frame. The SMART software was used for data acquisition. Data
integration and reduction were undertaken with SAINT and XPREP
software. Structures were solved by direct methods using
SHELXS-97 and refined with full-matrix least squares on F2 using
SHELXL-97. All non-hydrogen atoms were refined anisotropically.
Structural illustrations have been drawn with ORTEP-3 for Windows.