Synthesis, Structure, and Electrochemistry of Acetylide and Oxo Incorporated Mixed Fe/Mo and Fe/W Chalcogen-Bridged Clusters

Abstract

Thermolysis of a benzene solution containing [Fe2Mo(CO)10(μ3-Se)2] (1) and [(η5-C5Me5)W(CO)3C⋮CPh] (2) under an optimum concentration of oxygen in the reaction medium yields the cluster [(η5-C5Me5)MoWFe2(O)(μ3-Se)(μ4-Se)(CO)8(CCPh)] (3), containing a monooxygenated metal center. Under an argon atmosphere, thermolysis of [Fe2Mo(CO)10(μ3-S)2] (4) with [(η5-C5Me5)W(CO)3C⋮CPh] (2) in benzene leads to an oxygen-free mixed metal cluster [(η5-C5Me5)MoWFe4(μ3-S)3(μ4-S)(CO)14(CCPh)] (9). Interestingly, on reacting a benzene solution of 4 with 2 and [(η5-C5Me5)Mo(CO)3C⋮CPh] (5) under an increased concentration of oxygen in the reaction medium gave way to clusters [(η5-C5Me5)WMo2(μ-O)2(μ-S)(μ3-CCPh){Fe2(CO)6(μ3-S)2}2] (6), [(η5-C5Me5)WMo(O)2(μ-O)(μ-CCPh){Fe2(CO)6(μ3-S)2}] (7), and [(η5-C5Me5)Mo3(μ-O)2(μ-S)(μ3-CCPh){Fe2(CO)6(μ3-S)2}2] (8) with higher oxygen content. The structures of the newly formed clusters 3, 6, 7, 8, and 9 were established crystallographically and the oxo-containing Mo and W clusters investigated electrochemically.

Synthesis and Characterization of Ferrocenylchalcogenopropargyl Complexes [Fe(η5-C5H4EICH2C⋮CH)2] (EI = Se, S) and Their Reactions To Form Unusual Ferrocenyl-Containing Metal Clusters with Eclipsed Cp Rings and New Five-Membered FeEICHCCH2 Ring Ligand System

“…In the past we have reported on the reactions of different types of chalcogen-bridged metal carbonyl clusters with mononuclear acetylide complexes. Several new mixed-metal clusters stabilized by bridging chalcogens and acetylide ligands have been obtained by this method, and in many cases coupling of acetylide ligands is observed, with the type of acetylide coupling being strongly influenced by the nature of chalcogens present in the starting complex and by the reaction conditions adopted. − Substituted ferrocenes have attracted considerable interest in the past few years as possible synthons for polyferrocenylenes and related compounds, for useful properties such as electrical conductivity and in the preparation of metal-containing polymers. − Use of bulky ferrocenylacetylene adds an additional variant to the type of product obtainable from reactions carried out in the presence of free acetylenes. Recently we reported on the photochemical reaction of ferrocenylacetylene with iron pentacarbonyl to form 2,5- and 2,6-diferrocenylquinone .…”

Insertion of CS2 into a metal acetylide bond and conversion of the bonding mode of S2CCCPh from η2 to η3

“…5). Absence of bands in the carbonyl region, and a band at 975 cm (1 (6) or 973 cm (1 (7) assignable to a MoÄ/O group are the notable features in their IR spectra [28,29]. Presence of (h 5 -C 5 H 5 ), (h 5 -C 5 Me 5 ) and phenyl groups were confirmed by 1 H-NMR spectra.…”

“…Various modes of coupling reactions were observed and these were found to be dependent on the nature of chalcogen bridges as well as the reaction conditions used [23 Á/27]. Under oxidising conditions we were able to isolate some novel oxo*/containing mixed */metal clusters with chalcogen and acetylide bridges [28,29]. Here we report another facet to the reactions of metal acetylide complexes, namely the photolytic reaction of molybdenum acetylide complexes with CS 2 under aerobic and anaerobic reaction conditions.…”

Synthesis, Structure, and Bonding Nature of Ethynediyl-Bridged Bis(silylene) Dinuclear Complexes of Tungsten and Molybdenum

“…These values are larger than the corresponding angle (348.3°) in 3b and close to the expected value (360°) for sp 2 hybridization. The W–C(ethynediyl) bond distances (W1–C1  2.089(5) Å, W2–C2  2.068(4) Å) are in the range of W–C(alkynyl) bond distances (2.05–2.09 Å) in di- and polynuclear complexes containing a Cp*(CO) 2 W(μ-η 1 :η 2 -CCR) fragment , and are somewhat longer than the W–CC t Bu bond distance (2.050(7) Å) in 3b . Notably, the C1–C2 bond distance of 1.343(6) Å is significantly elongated from the C–C triple-bond distance of 1.208(5) Å in Ph 2 HSiCCSiHPh 2 to a typical C–C double-bond distance.…”