SUBSTITUENT EFFECT ON CARBODITHIOATE LIGAND FIELD STRENGTH IN IRON(III) CARBODITHIOATES: SYNTHESIS AND CHARACTERIZATION

摘要

New iron(III) carbodithioate complexes ofthe general formulae Fe(Lcdt)_3 f(where L is the anionof an heterocyclic amine and Lcdt are the followinganions: 4-methylpiperazine- 1-carbodithioate (4-MPipzcdt), 4-phenylpiperazine- 1-carbodithioate (4-PPipzcdt), piperidinecarbodithioate (Pipdcdt), 2-methylpiperidine-carbodithioate (2-MPipdcdt), 4-methylpiperidnie carbodithioate (4-MPipdcdt),morpholinecarbodithioate (Morphcdt), 2,6-dirnethyhnorpholinecarbodithioate (2,6-M_2Morphcdt),2,5-ditnethylpyrrolecarbodithioate (2,5-M_2Pyrrcdt)]and Fe_2[2-MPipz(cdt)_2]_3 [(2-MPipz(cdt)_2 = 2-methylpiperazine- 1, 4-dicarbodithioate dianion)Jhave been synthesized. These compounds have beencharacterized by elemental analyses, infrared spectraland magnetic susceptibility measurements and m somecases by electron paramagnetic resonance studies. Theroom temperature magnetic moments of the complexes areindicative of a trigonally distorted octahedralgeometry around iron(III) observing a ~6A_1reversible ~2T_2 spin croosover phenomenon. The EPRstudies give the g_av values 4.4960-4.9962.