Bruker APEXII CCD diffractometer	3083 independent reflections
Radiation source: fine-focus sealed tube	2207 reflections with I > 2σ(I)
graphite	Rint = 0.022
φ and ω scans	θmax = 25.5°, θmin = 2.4°
Absorption correction: multi-scan (SADABS; Bruker, 2004)	h = −8→8
Tmin = 0.936, Tmax = 0.948	k = −9→9
5579 measured reflections	l = −20→17