142617-53-6Relevant articles and documents
Study of bismuth alkoxides as possible precursors for ALD
Hatanpaeae, Timo,Vehkamaeki, Marko,Ritala, Mikko,Leskelae, Markku
, p. 3219 - 3226 (2010/06/20)
While searching for bismuth precursors for thin film preparation by atomic layer deposition (ALD) three bismuth alkoxides Bi(OtBu)3 (1), Bi(OCMe2iPr)3 (2), Bi(OC iPr3)3 (3), bismuth β-diketonate, Bi(thd)3 (4), and bismuth carboxylate, Bi(O2C tBu)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 [Bi2O(OCMe2iPr)4] 2 (6). Compound 4 has dimeric structure and compound 5 forms loose tetramers as reported earlier. The structure of toluene solvated crystal [Bi(O2CtBu)3]4·2MeC 6H5 (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 Bi2O3. It exhibited a clear improvement over Bi precursors studied earlier. The Royal Society of Chemistry 2010.
Synthesis, X-ray structure and bonding of tris(2,2-6,6-tetramethylheptane-3,5-dionato) bismuth(III)
Armelao,Bandoli,Casarin,Depaoli,Tondello,Vittadini
, p. 340 - 348 (2008/10/08)
The title compound [Bi(dpm)3] has been synthesized and its molecular structure determined by single-crystal X-ray diffraction. Two different crystalline forms have been found: [(Bi(dpm)3] · H2O (1) and [(Bi(dpm)3] · 3H2O (2). 1 crystallizes in the space group P21/n with a=12.426(5), b=19.565(11), c=15.820(9) A?, β=94.31(4)°, V=3835(2) A?3, Z=4. 2 crystallizes in the space group Pbcn with a=20.953(5), b=19.619(6), c=19.475(3) A?, V=8006(3) A?3, Z=8. The coordination around the Bi atom consists of a distorted pentagonal pyramid with two ligands approximately lying in the basal plane while the third one is in a vertical mirror plane. Molecules are associated in dimer units because of the presence of weak interactions in the crystal lattices. The bonding of the monomer compound has been investigated by means of quasi-relativistic quantum-mechanical calculations on the simpler acetylacetonate complex. The metal-ligand interaction is found to be dominated by ionic interactions with a significant repulsion between the Bi 6s lone pair and the symmetric n+ ligand based combination of the oxygen lone pairs. Such electronic repulsion is reduced, but not eliminated, by relativistic effects. Optimized geometrical parameters obtained by carrying out calculations in the Cs symmetry point group are in good agreement with experiment. Interestingly, however, the pseudo-octahedral D3 structure is found to be lower in energy, suggesting that the observed pyramidal molecular structure cannot be explained on the basis of simple stereochemical arguments.