Organotetrelchalkogenidcluster mit Heteroadamantanstruktur

In the framework of this dissertation, the three sub-projects presented in the objective were investigated. In the first sub-project, the white light generation (WLG) first observed on [(StySn)4S6] for organotetrel chalcogenide clusters with an adamantane-type structure was investigated in more detail. For this purpose, the substance library was significantly extended, in particular in order to analyze necessary prerequisites for the white-light emission. By systematic variation of both the core composition and the organic substituents the understanding of the underlying mechanism was improved, and possible ways to selectively modify the emission spectra were found. In a first study, it could be shown by varying the tetrel element and the substituents that the amorphicity of the compounds is a basic requirement for the WLG, since otherwise emission occurs in phase as second harmonic generation (SHG). By further variation of the organic substituents and replacement of the sulfur atoms in the inorganic core by selenium atoms, it was further found that - opposing the initial hypothesis - no pi electron system, but only a cyclic organic substituent is required, and that the emission seems to be limited by the HOMO-LUMO gap of the compound. By this it can be ruled out that the WLG is caused by an excitation into real electronic states. Instead, the observed effect is to be understood as an excitation into extremely short-lived virtual states that lie within the gap. In the second part of the project, the reactivity of [(PhSn)4S6] towards transition metal complexes was investigated, whereby different ternary clusters were obtained. In reactions with coinage metal complexes with sterically less demanding phosphine ligands, clusters were synthesized in which the inorganic core of the starting material is retained and one of the phenyl substituents is replaced with a coinage metal complex fragment. The resulting clusters have the composition [f(R3P)3MSngfPhSng3S6] (M/R = Cu/Me, Ag/Et, Au/Me). However, by use of the more bulky phosphine ligand PPh3 the organotin sulfide cluster is decomposed and subsequently rearranged to a larger ternary cluster with the composition [(CuPPh3)4(PhSn)18Cu6S31Cl2], which is the first cluster with ternary inorganic core which was obtained without an additional source of sulfide. Either by oxidation of this reaction solution or by deliberate use of [Cu(PPh3)2Cl2], the first Cu/Sn/S cluster with copper atoms in the +II oxidation state was obtained. Transferring the ligand-exchange reactions carried out with coinage metal complexes to Group 6 complexes allowed for the preparation of clusters with the composition [f(PhSn)3SnS6gf(CpM)3S4g] (M = Mo, W) in which an adamantane-type organotinsul- fide cluster is substituted with a thiotungstate or thiomolybdate cage. The thiometalate cages correspond to sections of a MoS2 or WS2 layer, which allows the compounds to be considered as molecular model systems for the adsorption of organotin sulfide clusters on corresponding surfaces. The binding situation in the molecules was rationalized by DFT calculations, which revealed a mixed-valence situation and an unusual two-electron-fourcenter bond connecting the two subunits of the molecules. In addition to these ternary clusters, whose syntheses always proceeded from [(PhSn)4S6], the reactivity of the already intensely studied clusters [(R1Sn)3S4Cl] and [(R1Sn)4S6] towards various zinc compounds was investigated. It was not possible to isolate any ternary cluster with zinc, but various salts of the defect-heterocubane-type [(RSn)3S4]+ cations were obtained with chlorostannate and chlorozincate anions. In addition, hydrolysis of [(R2Sn)4S6] with [ZnCl2(H2O)2] generated in situ resulted in the first mixed oxide/sulfide cluster with adamantane-type structure, [(R2Sn)4S5O]. In the third sub-project, reactions of the organogermanium trichloride R1GeCl3 with the bis(trimethylsilyl)chalcogenides gave the dinuclear [(R1GeCl)2E2] (E = S, Se, Te) complexes, which were already known for the heavy homologue tin. It was shown by NMR titration experiments that the intermediates in the reaction cascade known for the tin compounds [((R1GeCl2)2E] and [(R1Ge)3E4Cl] are not formed in the case of germanium.