AN UNUSUAL IRON-OXO TETRANUCLEAR SPECIES - LI-2(HDPHF)(2)FE4O4(DPHF)(6)CENTER-DOT-4TOLUENE - A UBIQUITOUS SIDE PRODUCT IN THE CHEMISTRY OF IRON FORMAMIDINE COMPOUNDS/

structural characterization of a tetranuclear iron(III)-oxo species, L i-2(HDPhF)(2)Fe4O4(DPhF)(6) . 4toluene (1), (DPhF = N,N'-diphenylforma midinato; HDPhF = N,N'-diphenylformamidine) is presented. The crystal structure reveals a centrosymmetric eight-membered ring of alternating iron and oxygen atoms in which the two crystallographically independe nt iron atoms are bridged by amidinato groups. Additional amidinato li nkages are formed between iron and lithium atoms. The coordination env ironment of each iron center, two of the bridging oxo anions and each of the Li+ cations in the molecule is tetrahedral. Crystal data for th e compound are as follows: triclinic, P (1) over bar, a = 15.310(4), b =15.341(3), c=14.171(3) Angstrom, alpha=92.80(3), beta=113.25(3), gamm a=74.65(2)degrees, Z=1.