December 2009 issue
Cover illustration: The mixed-valent iron compound [Fe2(C2H5S)3(C12H21Si)2] contains an unusual Fe2S3 core with a short Fe-Fe distance of 2.7842 (5) Å which is clear evidence of an intermetallic bond. The Fe atoms are coordinated by two substituted cyclopentadienyl ligands with their C5 planes nearly perpendicular to the Fe-Fe vector and are bridged by three thiolate ligands. Such a diiron-sulfur compound might act as a model structure of active sites in some metalloproteins. See Jing Li [Acta Cryst. (2009). E65, m1542].