Syntheses, molecular structures, and thermal decomposition of cyclopentadienyldicarbonylmanganese chalcogenide derivatives

Abstract

Transmetallation of the dichalcogenide complexes [CpMn(CO)2]2(μ-X2) (X = S or Se) with M(CO)5(thf) (M = Cr or W) afforded new heterometallic complexes CpMn(CO)2(μ-Se2)Cr(CO)5, CpMn(CO)2(μ-Se2)[Cr(CO)5]2, CpMn(CO)2(μ-X2)[W(CO)5]2 (X = S or Se), and CpMn(CO)2(μ-Se2)[Cr(CO)5][W(CO)5]. According to the X-ray diffraction data, their molecular structures contain the cyclic MnX2 fragments coordinated by one or two M(CO)5 groups via the X atoms. Study of thermal decomposition of the manganese complexes with different Mn : M : X ratios (M = Cr, W; X = S, Se, Te) by differential scanning calorimetry (DSC) and thermogravimetry demonstrated that this process took place at rather low temperatures (100—400 °C) and was accompanied by complete elimination of the CO groups followed by elimination of the Cp groups. At any metal to chalcogen ratio, the resulting inorganic chalcogenides contained no impurities of metal oxides and carbides.