Bismuth tris(N,N′-di-tert-butylacetamidinate) dimer [Bi(tBu-AMD)3]2 was synthesized in following way: bismuth trichloride, BiCl3 (1 eq.) combined with 3 eq. of Li(N,N′-di-tert-butylacetamidinate) (obtained by reaction of methyllithium with 1,3-di-tert-butylcarbodiimide) were refluxed overnight in THF. After THF evaporation, extraction in dry hexanes, filtration and hexanes evaporation from the filtrate, the crude product was isolated.
Pure [Bi(tBu-AMD)3]2 was obtained by sublimation (70° C/ 80 mTorr), it is solid with meltim point 95° C. [Bi(tBu-AMD)3]2 was shown to be dimeric, according to cryoscopy in p-xylene solution.
Bismuth tris(N,N’-di-tert-butylacetamidinate) [Bi(tBu-AMD)3]2 was successfully applied for the growth of films of bismuth oxide
Bi2O3 by ALD, at substrate temperature 200°C. [Bi(tBu-AMD)3]2 was evaporated in a vapor source at 85°C temperature. The growth rate of Bi2O3 layers using [Bi(tBu-AMD)3]2 was ~0.03 nanometers per cycle.[i]
[i] R.G. Gordon, B.S. Lim, US Patent US7737290B2, «Atomic layer deposition using metal amidinates » , https://patents.google.com/patent/US7737290B2/en , https://patentimages.storage.googleapis.com/99/5e/7f/e20606f8f5f3ad/US7737290.pdf