Dinuclear iron-molybdenum-sulfur complexes containing the FeS2Mo core. Syntheses, ground-state electronic structures and crystal and molecular structures of the [(C6H5)4P]2[(C6H5S)2FeS2MoS2], [(C2H5)4N]2[(C6H5S)2FeS2WS2], and [(C6H5)4P]2[(S5)FeS2MS2] (M = Mo, W) complexes

Abstract

Durch Reaktion der Komplexe (I) mit den Ammoniumsalzen (II) der Tetrathiometallate werden die Komplexe (III) in guten Ausb. erhalten.

Selenium as a Structural Surrogate of Sulfur: Template-Assisted Assembly of Five Types of Tungsten–Iron–Sulfur/Selenium Clusters and the Structural Fate of Chalcogenide Reactants

“…The η 2 binding mode of the WS 3 group has been observed previously with the heavier metals of groups 8–10 . The dimensions of the WS 2 Fe rhombus are nearly the same as in related molecules such as [S 2 WS 2 FeX 2 ] 2– (X = anion) − and [(Me 2 PCH 2 CH 2 S)­W­(S)­S 2 FeCl 2 ] 1– . The product is best considered as W 6+ Fe 2+ , with the isomer shift of 0.52 mm/s relative to an FeS 4 site apparently decreased by some extent of electron delocalization to the fully oxidized tungsten site.…”

“…The η 2 binding mode of the WS 3 group has been previously observed with the heavier Group 8–10 metals. 21 The dimensions of the WS 2 Fe rhomb are nearly the same as in related molecules such as [S 2 WS 2 FeX 2 ] 2− (X = anion) 34–36 and [(Me 2 PCH 2 CH 2 S)W(S)S 2 FeCl 2 ] 1−37 The product is best considered as W 6+ Fe 2+ with the isomer shift of 0.52 mm/s, relative to an FeS 4 site, apparently decreased by some extent of electron delocalization to the fully oxidized tungsten site. Reaction with two equiv each of FeCl 2 and NaSEt produces trinuclear 3 38 (61%) which undergoes ligand substitution reaction 4 to yield isostructural 4 (49%) whose isomer shift of 0.45 mm/s suggests the description W 4+ Fe 3+ Fe 2+ .…”

Photochemistry of the Dinitrosyl Iron Complex [S5Fe(NO)2]- Leading to Reversible Formation of [S5Fe(μ-S)2FeS5]2-: Spectroscopic Characterization of Species Relevant to the Nitric Oxide Modification and Repair of [2Fe−2S] Ferredoxins

“…In contrast to the formation of [(NO) 2 Fe(SH) 2 ] - , the ([Fe 4 S 3 (NO) 7 ] - ) compound observed by Glidewell and co-workers for the reaction of S 8 /S x 2- and [Fe(CO) 3 (NO)] - , , the reaction mixture finally led to the isolation of the THF-soluble dark-brown [PPN][S 5 Fe(NO) 2 ] ( 1 ) and the known red-brown [PPN] 2 [S 5 Fe(μ-S) 2 FeS 5 ] ( 2 ) precipitate identified by IR ν NO and X-ray diffraction analysis. , Complex 1 exhibits two IR ν NO bands (1739 s, 1695 s cm -1 (THF)). The ν NO bands of complex 1 are 5 and 2 cm -1 lower than those of the dinitrosyl iron−chalcogenolate complexes [(NO) 2 Fe(SPh) 2 ] - (1744, 1709 cm -1 (CsI)) and [(NO) 2 Fe(SePh) 2 ] - (1741 s, 1697 s cm -1 (CH 2 Cl 2 )), , respectively. Thus, we propose that the [S 5 ] 2- unit, [SePh] 2 2- , and [SPh] 2 2- have similar electron-donating abilities to the {Fe(NO) 2 } 9 moiety. , This formalism invokes the Enemark−Feltham notation, which stresses the well-known covalency and delocalization in the electronically amorphous Fe(NO) 2 unit without committing to formal oxidation states of Fe and NO, respectively; that is, the assignment could be Fe I- (NO + ) 2 , Fe I ( • NO) 2 , Fe III (NO - ) 2 , or a resonance hybrid of these forms …”

“…The ν NO bands of complex 1 are 5 and 2 cm -1 lower than those of the dinitrosyl iron−chalcogenolate complexes [(NO) 2 Fe(SPh) 2 ] - (1744, 1709 cm -1 (CsI)) and [(NO) 2 Fe(SePh) 2 ] - (1741 s, 1697 s cm -1 (CH 2 Cl 2 )), , respectively. Thus, we propose that the [S 5 ] 2- unit, [SePh] 2 2- , and [SPh] 2 2- have similar electron-donating abilities to the {Fe(NO) 2 } 9 moiety. , This formalism invokes the Enemark−Feltham notation, which stresses the well-known covalency and delocalization in the electronically amorphous Fe(NO) 2 unit without committing to formal oxidation states of Fe and NO, respectively; that is, the assignment could be Fe I- (NO + ) 2 , Fe I ( • NO) 2 , Fe III (NO - ) 2 , or a resonance hybrid of these forms 3 …”

Pentasulfide S52- as the First Tridentate Chelating Ligand in Ru(P(OE)3)3S5(E = Me and Et)

“…Only a few complexes with bidentate S 5 2- ligand are known. The first reported complex was homoleptic optically active [Pt(S 5 ) 3 ]. − The most thoroughly studied polysulfide compound of S 5 2- ion is Cp 2 TiS 5 , and similar compounds for zirconium, hafnium, and vanadium are also reported. − The MS 5 unit has the chair conformation in all known mononuclear complexes such as [Cr(NH 3 ) 2 (S 5 ) 2 ] 2- and [(S 5 )Mn(S 6 )] 2- . , The variation of the “bite” of S 5 2- is wide and the largest one is in [(S 5 )Fe(MoS 4 )] 2- . , In the case of ruthenium there is a striking paucity of polysulfido complexes and that with S 5 2- ion is rare, although there is a number of ruthenium complexes with monodentate and/or polydentate organosulfur ligands coordinated through sulfur . All hitherto reported possible polysulfides occurring in metal complexes act as bidentate chelating ligand, except the tridentate chelating behavior of S 7 2- ion in (PMe 3 ) 3 MS 7 (M = Ru and Os) .…”