| Title
| - Synthesis and Characterization of Quasi-Two-CoordinateTransition Metal Dithiolates M(SAr*)2 (M = Cr, Mn, Fe, Co, Ni,Zn; Ar* = C6H3-2,6(C6H2-2,4,6-Pri3)2
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| Abstract
| - A sequence of first row transition metal(II) dithiolates M(SAr*)2 (M = Cr(1), Mn(2), Fe(3), Co(4),Ni(5) and Zn(6); Ar* = C6H3-2,6-(C6H2-2,4,6-Pri3)2) has been synthesized and characterized. Compounds1−5 were obtained by the reaction of two equiv of LiSAr* with a metal dihalide, whereas 6 was obtainedby treatment of ZnMe2 with 2 equiv of HSAr*. They were characterized by spectroscopy, magneticmeasurements, and X-ray crystallography. The dithiolates 1, 2, and 4−6 possess linear or nearly linearSMS units with further interactions between M and two ipso carbons from C6H2-2,4,6-Pri3 rings. The ironspecies 3, however, has a bent geometry, two different Fe−S distances, and an interaction between ironand one ipso carbon of a flanking ring. The secondary M−C interactions vary in strength in the sequenceCr2+ ≈ Fe2+> Co2+ ≈ Ni2+> Mn2+ ≈ Zn2+ such that the manganese and zinc compounds have essentiallytwo coordination but the chromium and iron complexes are quasi four and three coordinate, respectively.The geometric distortions in the iron species 3 suggested that the structure represents the initial stage ofa rearrangement into a sandwich structure involving metal-aryl ring coordination. The bent structure of 3probably also precludes the observation of free ion magnetism of Fe2+ recently reported for Fe{C(SiMe3)3}2.DFT calculations on the model compounds M(SPh)2 (M = Cr−Ni) support the higher tendency of the ironspecies to distort its geometry.
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