Bruker APEXII CCD diffractometer	3772 independent reflections
Radiation source: fine-focus sealed tube	2737 reflections with I > 2σ(I)
graphite	Rint = 0.072
φ and ω scans	θmax = 24.7°, θmin = 1.9°
Absorption correction: multi-scan (SADABS; Bruker, 1997)	h = −11→11
Tmin = 0.957, Tmax = 0.993	k = −12→12
20692 measured reflections	l = −25→24