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Type of Document Dissertation Author Todorov, Iliya Author's Email Address itodorov@nd.edu URN etd-07132006-110653 Title Aromatic, conjugated and polymeric species of Sn in the solid state. Degree Doctor of Philosophy Department Chemistry and Biochemistry Advisory Committee
Advisor Name Title Dr. Kenneth Henderson Committee Chair Dr. Graham Lappin Committee Member Dr. Marya Lieberman Committee Member Keywords
- intermatallics
- X-ray
- Zintl phases
Date of Defense 2006-06-28 Availability unrestricted Abstract Recent advances in tetrel chemistry (Tt = Si, Ge, Sn, Pb), stimulated the search for other Zintl phases with novel anionic structures. For that reason, we began thorough and systematic studies over the pseudobinary A–AE–Tt systems (A = alkali metal; AE = alkaline-earth). After exploring a great deal of compositions within the pseudo-binary systems with mixed A/AE metals, we have embarked on exploring analogous systemswith the help of mixed of alkali and rare-earth metals (RE). The major part of the work presented in this dissertation deals with the synthesis
and structural characterization of a variety of novel intermetallic compounds. A few noteworthy examples are: 1) Na8BaSn6 and Na8BaPb6 with aromatic pentagonal rings of Sn56- and Pb56-, respectively, that are isostructural and isoelectronic with the cyclpentadienyl anion, C5H5
-; 2) Li9-xEuSn6+x, Li5Ca7Sn11, L i6Eu5Sn9 with trimers, hexamers and infinite conjugated chains of Sn, in addition to aromatic pentagonal rings;
3) LiMgEu2Sn3 and LiMgSr2Sn3 with infinite conjugated chains of Sn and single atom
anions; 4) Na4CaSn6 with channels built of cyclohexane-like units of Sn6
6-; 5)Li2Ln5Sn7 (Ln = Ce, Pr, Sm, Eu) with branched polymeric 1D chains.
Another part of this dissertation concentrates on our attempts to synthesize
heteroatomic rings isoelectronic with those of group 14 by a combination of elements
from groups 13 (Tr) and 15 (Pn), respectively. However all probed reactions produced
novel compounds with extended structures based on TrPn4-tetrahedra. All of the above-mentioned compounds nicely illustrate the delicate balance
between packing efficiency and electronic requirements, which explains the stabilization
of these novel tetrel clusters, which are inaccessible in pure binary systems.
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