While searching for bismuth precursors for thin film preparation by atomic layer deposition (ALD) three bismuth alkoxides Bi(O~t Bu)_3 (1), Bi(OCMe_2~iPr)_3 (2), Bi(OC'Pr_3)_3 (3), bismuth β-diketonate, Bi(thd)_3 (4), and bismuth carboxylate, Bi(O_2C~1Bu)_3 (5), were synthesized and evaluated. The compounds were characterized by CHN, NMR, MS, and TGA/SDTA. Earlier unknown crystal structures of compounds 1 and 3 were solved. Compound 1 forms dimeric and loose polymeric structures in the solid state while 3 is strictly monomeric. For compound 2 crystals suitable for complete structure solution could not be grown. Crystallization trials of 2 from hexane and toluene resulted in oxygen bridged tetramer [Bi_2O(OCMeO2~iPr)_4]_2 (6). Compound 4 has dimeric structure and compound 5 forms loose tetramers as reported earlier. The structure of toluene solvated crystal [Bi(O_ 2C~tBu)_3]_4 .2MeC_6H_5 (7) was solved. All compounds studied showed relatively good volatility and thermal stability. They were all tested in ALD deposition experiments, in which compound 2 was found to be the most suitable for ALD growth of Bi_2O_3. It exhibited a clear improvement over Bi precursors studied earlier.
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