TY  - GEN
AV  - public
TI  - Experimental and Theoretical Study of the Polynuclear Bismuth Compounds : Dimers, Clusters, Molecular Self-Assemblies and Polyhedral Cage Molecules
Y1  - 2010///
ID  - heidok10832
KW  - Struktur 
KW  -  AromatizitätBismuth 
KW  -  Silyl 
KW  -  Iron 
KW  -  Cyclopentadienyl 
KW  -  DFT
A1  - Monakhov, Kirill
UR  - https://archiv.ub.uni-heidelberg.de/volltextserver/10832/
N2  - In the framework of this thesis, the polynuclear bismuth chemistry has been investigated from different perspectives with the main focus on four types of the chemical bonding. Thus, the section of bismuth?bismuth bonding affects redox/metathesis reactions of BiBr3 with bulky lithium silanide Li(thf)3SiPh2tBu in three different ratios, leading to the formation of a Bi?Bi bonded compound, (tBuPh2Si)4Bi2 as one of the reaction products. The quantum chemical study has been mainly performed to shed light on the processes of oligomerisation of R2Bi radicals and bismuth dimers. That is a major challenge in the context of ''thermochromicity'' and ''closed-shell interactions'' in inorganic chemistry of organobismuth compounds with homonuclear Bi?Bi bonds. The section of bismuth?transition-metal bonding gives a deep insight into the structures, the chemical bonding and the electronic behavior of heteronuclear bulky Bi?Fe cage-like clusters, cubic [Bi4Fe8(CO)28]4? and seven-vertex [Bi4Fe3(CO)9], on the experimental and theoretical level. The section of bonding in bismuth?cyclopentadienyl compounds represents a detailed theoretical and experimental study of molecular systems based on cyclopentadienyl bismuth units such as (C5R5)Bi2+, [(C5R5)Bi]n and (C5R5)BiX2 (R = H, Me; X = F, Cl, Br, I; n = 1-4) in order to develop an effective adjustment of their electronic and bonding behavior and then, to be able to manipulate highly fluxional Bi?C5R5 bonds. The experimental part of this section emphasizes the theoretical results by observation of the unprecedented nanoscopic supramolecular architecture [{(C5Me5)5Bi5Br9}{(CH2Cl2)(BiBr4)}]2, cationic molecule [(C5Me5)5Bi6Cl12]+ and zig-zag polymer chains [(C5Me5)BiX2] (X = Br, I). The section of icosahedral and macroicosahedral bismuthanediide oligomers is a conceptual approach to understand the structures and the electronic properties of highly symmetric molecules such as [RnBinM2n?4]4? (n = 12, 32, ?) on the theoretical level. The obtained results open the way to their endohedral chemistry. To sum up, unique structural and bonding features of the molecular assemblies based on C5Me5-substituted bismuth halides, as well as the observed Bi?arene pi-complexations and inverted sandwich behavior found in the crystal cell of a Bi?Fe cluster, are an important step in the development of supramolecular chemistry and crystal engineering of the compounds of the heavy group 15 elements. Furthermore, the bismuth cage and cluster chemistry has taken one step forward. The largest cluster of the bismuth?iron family (Bi4Fe8) and the spherical aromaticity of seven-vertex Bi4Fe3 structure have been observed. The new examples of a Bi4 tetrahedron, stabilized by transition-metal groups, as well as bismuth?s square pyramidal (Bi5) nido-polyhedron-like and octahedral (Bi6) deltahedron-like cages, stabilized by C5Me5 and halo ligands, have been discovered. A new chapter in the theoretical chemistry of highly symmetric bismuth cage molecules (Bi12, Bi32) has been opened.
ER  -