Lim Booyong S, Rahtu Antti, Park Jin-Seong, Gordon Roy G
Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
Inorg Chem. 2003 Dec 1;42(24):7951-8. doi: 10.1021/ic0345424.
A series of homoleptic metal amidinates of the general type M(R-R'AMD)(n) (R = (i)Pr, (t)Bu, R' = Me, (t)Bu) has been prepared and structurally characterized for the transition metals Ti, V, Mn, Fe, Co, Ni, Cu, Ag, and La. In oxidation state 3, monomeric structures were found for the metals Ti(III), V(III), and La(III). Bridging structures were observed for the metals in oxidation state 1. Cu(I) and Ag(I) are held in bridged dimers, and Ag(I) also formed a trimer that cocrystallized with the dimer. Metals in oxidation state 2 occurred in either monomeric or dimeric form. Metals with smaller ionic radii (Co, Ni) were monomeric. Larger metals (Fe, Mn) gave monomeric structures only with the bulkier tert-butyl-substituted amidinates, while the less bulky isopropyl-substituted amidinates formed dimers. The new compounds were found to have properties well-suited for use as precursors for atomic layer deposition (ALD) of thin films. They have high volatility, high thermal stability, and high and properly self-limited reactivity with molecular hydrogen, depositing pure metals, or water vapor, depositing metal oxides.
已制备出一系列通式为M(R-R'AMD)(n)（R = 异丙基，叔丁基，R' = 甲基，叔丁基）的均配型金属脒基配合物，并对过渡金属钛、钒、锰、铁、钴、镍、铜、银和镧进行了结构表征。在氧化态为3时，发现金属钛(III)、钒(III)和镧(III)为单体结构。氧化态为1的金属观察到桥连结构。铜(I)和银(I)以桥连二聚体形式存在，并且银(I)还形成了与二聚体共结晶的三聚体。氧化态为2的金属以单体或二聚体形式出现。离子半径较小的金属（钴、镍）为单体。较大的金属（铁、锰）仅与体积较大的叔丁基取代脒基形成单体结构，而体积较小的异丙基取代脒基则形成二聚体。发现这些新化合物具有非常适合用作薄膜原子层沉积（ALD）前驱体的性质。它们具有高挥发性、高热稳定性，并且与分子氢反应性高且具有适当的自限性，可沉积纯金属，或与水蒸气反应，可沉积金属氧化物。
