Buch, Englisch, 252 Seiten, Paperback, Format (B × H): 148 mm x 210 mm, Gewicht: 331 g
Buch, Englisch, 252 Seiten, Paperback, Format (B × H): 148 mm x 210 mm, Gewicht: 331 g
ISBN: 978-3-95404-269-2
Verlag: Cuvillier
The aim of this thesis is to investigate, if ionic liquids can offer a novel kind of metal carbonyl chemistry. The reactivity of metal carbonyls in imidazolium based ionic liquids is analyzed, This has resulted in several novel metal carbonyl compounds, coordination chains and networks: [BMIm]6[S][{Fe(CO)3}4(SnI)6I4]2, [BMIm]2[{Fe(CO)3}4(SnI)6I4], [AIm][FeI(CO)3(SnI3)2] (AIm: EMIm, EHIm, PMIm), Te2Fe(CO)4{Fe(CO)3}2, [BMIm][{Te2}3{Mn(CO)3}2{Mn(CO)4}3], [BMIm][M(OTf)3], (M: Fe, Mn), [AIm][Li(OTf)2] (AIm: BMIm, EMIm), [EMIm][{GeI4}2I], [Co{1,4-(CN)2C6H4}2(NTf2)2][SnI(Co(CO)4)3]2, CoI2{1,3-(CN)2C6H4} and FeI2{1,4-(CN)2C6H4}.
By reaction of Fe(CO)5 with SnI4 in 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([EMIm][NTf2]), [EMIm][FeI(CO)3(SnI3)2] was obtained, containing the novel barbell-shaped [FeI(CO)3(SnI3)2]- cluster anion. According to bond-length considerations, the isolobal concept, as well as based on infrared/Mössbauer spectroscopy and DFT-based Mulliken population analysis, the bonding situation in [FeI(CO)3(SnI3)2]- can be concluded as comparable to Fe(CO)5 and SnI4 with Fe±0 and Sn+III as the formal oxidation states. In addition, by reacting Fe(CO)5 with SnI4 in 1-butyl-3-methylimidazolium bistrifluromethanesulfonimide, the novel adamantane-like cluster anion [{Fe(CO)3}4(SnI)6I4]2- was obtained in [BMIm]2[{Fe(CO)3}4(SnI)6I4]. A similar reaction of Fe(CO)5, SnI4 and NH4I in 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([BMIm][OTf]) resulted in [BMIm]6[S][{Fe(CO)3}4(SnI)6I4]2, containing again the adamantane-like cluster anion [{Fe(CO)3}4(SnI)6I4]2-, in which Fe(CO)3-groups are sited at the (CH) position of adamantane and SnI is positioned instead of (CH2). [{Fe(CO)3}4(SnI)6I4]2- represents the first bimetallic adamantane-analogue structure to date. The valence states of iron and tin in [{Fe(CO)3}4(SnI)6I4]2- were investigated based on bond-lengths considerations, FT-IR and 119Sn-Mössbauer spectroscopy as well as via DFT calculations. These investigations resulted in Fe±0 and Sn+1.33 as the formal oxidation states. The packing of [BMIm]2[{Fe(CO)3}4(SnI)6I4] could be related to the AlB2 structure type via group-subgroup relations.
Te2Fe(CO)4{Fe(CO)3}2 could be obtained by reaction of Fe(CO)5 with TeI4 in the ionic liquid [BMIm][AlCl4]. A novel ufosan-like anion [{Te2}3{Mn(CO)3}2{Mn(CO)4}3]- could be obtained in [BMIm][{Te2}3{Mn(CO)3}2{Mn(CO)4}3]. Here, the distorted cubic frame is defined by three Te2-2 units and two Mn(CO)3 fragments. Three edges of the cubic frame are capped by Mn(CO)4 groups.
In [BMIm][Mn(OTf)3] and [BMIm][Fe(OTf)3], one dimensional coordination chains, 18[M(OTf)3], (M=Mn, Fe) were obtained by reacting Mn2(CO)10 or Fe(CO)5, respectively, with GeI4 in [BMIm][OTf] as the ionic liquid. Both compounds, [BMIm][Mn(OTf)3] and [BMIm][Fe(OTf)3] exhibit strong antiferomagnetic interactions between the metal centers.
Moreover, by employing phenylendinitriles as ligands two novel, infinite, onedimensional coordination chains were obtained in CoI2{1,3-(CN)2C6H4} and FeI2{1,4-(CN)2C6H4}. By reacting SnI4 and Co2(CO)8 with 1,4-(CN)2C6H4 in [EMIm][NTf2], vinous crystals of [Co{1,4-(CN)2C6H4}2(NTf2)2][SnI(Co(CO)4)3]2 were obtained. Here, layers of 28[Co{1,4-(CN)2C6H4}2(NTf2)2] are stacked on top of each other forming cubic voids that are filled with [SnI(Co(CO)4)3] molecules. Soi far, this is the first compound known, which contains a carbonyl cluster embedded in a network structure.
For the synthesis of all these compounds, the ionic liquid played an advantageous role. The high redox stability of ionic liquids, their weakly coordinating properties and their inertness are considered as beneficial aspects. Anionic and purely inorganic (i.e., not stabilized by alkyl/aryl ligands) compounds such as [BMIm]6[S][{Fe(CO)3}4(SnI)6I4]2, [BMIm]2[{Fe(CO)3}4(SnI)6I4] [AIm][FeI(CO)3(SnI3)2] (AIm: EMIm, EHIm, PMIm), Te2Fe(CO)4{Fe(CO)3}2, [BMIm][{Te2}3{Mn(CO)3}2{Mn(CO)4}3] are rare till now and often described as highly sensitive. The weakly coordinating properties of the ionic liquid – or the absence of more strongly coordinating solvents and ligands – encourage the formation of coordination networks with 1,3- and 1,4-dicyanobenzene as the only available linker.
In the short annex of this work, nanoscaled co-doped tin oxide (SnO2:Sc,F and SnO2:Y,F) prepared by a polyol mediated synthesis is presented. The optical and electrical properties of these materials were investigated with regard to an application as transparent conducting oxide.
