The chalcogen bond is a nonclassical σ-hole-based noncovalent interaction with emerging applications in medicinal chemistry and material science. It is found in organic compounds, including 2D aromatics, but has so far never been observed in 3D aromatic inorganic boron hydrides. Thiaboranes, harboring a sulfur heteroatom in the icosahedral cage, are candidates for the formation of chalcogen bonds. The phenyl-substituted thiaborane, synthesized and crystalized in this study, forms sulfur⋅⋅⋅π type chalcogen bonds. Quantum chemical analysis revealed that these interactions are considerably stronger than both in their organic counterparts and in the known halogen bond. The reason is the existence of a highly positive σ-hole on the positively charged sulfur atom. This discovery expands the possibilities of applying substituted boron clusters in crystal engineering and drug design.

Twelve novel D-p-A chromophores with the N,N 0-dibutylbarbituric acid acceptor, the N,N-dimethylamino donor and a systematically extended p-linker were synthesized. The extent of intramolecular charge-transfer, structure-property relationships and nonlinear optical properties were further investigated by X-ray analysis, electrochemistry, UV/Vis absorption spectra, calculations and EFISH experiments.

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Reactions of lithiated cobalt bis(1,2-dicarbollide)(1(-)) anion (1(-)) in presence of paraformaldehyde, ethylene oxide or trimethylene oxide led to the substitution of 1(-) at the C-atoms resulting in the high yield formation of monosubstituted alkylhydroxy derivatives [(1-HO(CH(2))(n)-1,2-C(2)B(9)H(10))(1',2'-C(2)B(9)H(11))-3,3'-Co(III)](-) (n = 1-3) isolated as caesium salts (Cs2, Cs3, Cs4) along with disubstituted products of general formulation [(HO(CH(2))(n)-1,2-C(2)B(9)H(10))(2)-3,3'-Co(III)](-) (n = 1-3) (Cs5, Cs6 and Cs7). Disubstituted compounds are in fact a mixture of diastereoisomers denoted as 1,1'-anti(rac-), 1,2'-syn- and in case of Cs6 and Cs7 also 1,2-vicinal-isomer, from which only the anti-isomer could be isolated in pure form in case of shorter chain compounds Cs5 and Cs6. All these alkylhydroxy derivatives can serve as versatile precursors for the generation of a variety of functional molecules. Thus, reaction of Me(3)NH4 with NaH and one equivalent of POCl(3) provided after hydrolysis the phosphorylated [(1-(HO)(2)P(O)OC(3)H(6)-1,2-C(2)B(9)H(10))(1',2'-C(2)B(9)H(11))-3,3'-Co(III)](-) derivative, isolated in the form of trimethylammonium salt, Me(3)NH8 as the main product whereas reaction with half of the equivalent produces a high yield of phosphoric acid diester (Me(3)NH)(2)9 comprising in its structure two cages connected via propyl spacers to the central part. The calcium salt Ca(10)(2) of bridged ion [μ-(HOP(O)(OC(3)H(6))(2))-(1,2-C(2)B(9)H(10))(2)-3,3'-Co(III)](-) resulted from reaction of Me(3)NH7 with NaH and one equivalent of POCl(3) followed by hydrolysis and addition of CaCl(2). All new compounds were characterized by multinuclear NMR spectroscopy and mass spectrometry and the structure of Me(3)NH3 and that of the respective salts of the pure anti-stereoisomer of dialkylhydroxy derivatives Cs5 and Me(3)NH6 were established by X-ray crystallography.

Ten optically pure substituted 2-(pyridin-2-yl)imidazolidin-4-ones, 1a-d, 2a-4a, and 2b-4b, were prepared and characterized. The absolute configurations of individual ligands were determined by X-ray analysis or NOESY experiments. The Cu(II) complexes of the respective ligands were studied as enantioselective catalysts of the nitroaldol (Henry) reaction of aldehydes with nitromethane, giving the corresponding substituted 2-nitroalkanols. In the case of an anti arrangement of the imidazolidin-4-one ring, the obtained result was 91-96% ee, whereas in the case of syn arrangement, a significant drop to 25-27% ee was observed.