Reactions of Tetrakis(dimethylamide)-Titanium, -Zirconium and -Hafnium with Silanes: Synthesis of Unusual Amide Hydride Complexes and Mechanistic Studies of Titanium-Silicon-Nitride (Ti-Si-N) Formatio
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- 作者：Xiaozhan Liu ; Zhongzhi Wu ; Hu Cai ; Yihui Yang ; Tianniu Chen ; Catherine E. Vallet ; Ray A. Zuhr ; David B. Beach ; Zhi-Hui Peng ; Yun-Dong Wu ; Thomas E. Concolino ; Arnold L. Rheingold ; and Ziling Xue
- 刊名：Journal of the American Chemical Society
- 出版年：2001
- 出版时间：August 22, 2001
- 年：2001
- 卷：123
- 期：33
- 页码：8011 - 8021
- 全文大小：173K
- 年卷期：v.123,no.33(August 22, 2001)
- ISSN：1520-5126
文摘
M(NMe2)4 (M = Ti, Zr, Hf) were found to react with H2SiR'Ph (R' = H, Me, Ph) to yield H2,aminosilanes, and black solids. Unusual amide hydride complexes [(Me2N)3M(
-H)(-NMe2)2]2M (M = Zr,1; Hf, 2) were observed to be intermediates and characterized by single-crystal X-ray diffraction. [(Me2N)3M(-D)(-NMe2)2]2M (1-d2, 2-d2) were prepared through reactions of M(NMe2)4 with D2SiPh2. Reactions of(Me2N)3ZrSi(SiMe3)3 (5) with H2SiR'Ph were found to give aminosilanes and (Me2N)2Zr(H)Si(SiMe3)3 (6).These reactions are reversible through unusual equilibria such as (Me2N)3ZrSi(SiMe3)3 (5) + H2SiPh2 
(Me2N)2Zr(H)Si(SiMe3)3 (6) + HSi(NMe2)Ph2. The deuteride ligand in (Me2N)2Zr(D)Si(SiMe3)3 (6-d1)undergoes H-D exchange with H2SiR'Ph (R' = Me, H) to give 6 and HDSiR'Ph. The reaction of Ti(NMe2)4with SiH4 in chemical vapor deposition at 450 
C yielded thin Ti-Si-N ternary films containing TiN andSi3N4. Ti(NMe2)4 reacts with SiH4 at 23 C to give H2, HSi(NMe2)3, and a black solid. HNMe2 was notdetected in this reaction. The reaction mixture, upon heating, gave TiN and Si3N4 powders. Analyses andreactivities of the black solid revealed that it contained -H and unreacted -NMe2 ligands but no silicon-containing ligand. Ab initio quantum chemical calculations of the reactions of Ti(NR2)4 (R = Me, H) withSiH4 indicated that the formation of aminosilanes and HTi(NR2)3 was favored. These calculations also showedthat HTi(NH2)3 (3b) reacted with SiH4 or H3Si-NH2 in the following step to give H2Ti(NH2)2 (4b) andaminosilanes. The results in the current studies indicated that the role of SiH4 in its reaction with Ti(NMe2)4was mainly to remove amide ligands as HSi(NMe2)3. The removal of amide ligands is incomplete, and thereaction thus yielded "=Ti(H)(NMe2)" as the black solid. Subsequent heating of the black solid and HSi(NMe2)3 may then yield TiN and Si3N4, respectively, as the Ti-Si-N materials.
-H)(-NMe2)2]2M (M = Zr,1; Hf, 2) were observed to be intermediates and characterized by single-crystal X-ray diffraction. [(Me2N)3M(-D)(-NMe2)2]2M (1-d2, 2-d2) were prepared through reactions of M(NMe2)4 with D2SiPh2. Reactions of(Me2N)3ZrSi(SiMe3)3 (5) with H2SiR'Ph were found to give aminosilanes and (Me2N)2Zr(H)Si(SiMe3)3 (6).These reactions are reversible through unusual equilibria such as (Me2N)3ZrSi(SiMe3)3 (5) + H2SiPh2 (Me2N)2Zr(H)Si(SiMe3)3 (6) + HSi(NMe2)Ph2. The deuteride ligand in (Me2N)2Zr(D)Si(SiMe3)3 (6-d1)undergoes H-D exchange with H2SiR'Ph (R' = Me, H) to give 6 and HDSiR'Ph. The reaction of Ti(NMe2)4with SiH4 in chemical vapor deposition at 450 C yielded thin Ti-Si-N ternary films containing TiN andSi3N4. Ti(NMe2)4 reacts with SiH4 at 23 C to give H2, HSi(NMe2)3, and a black solid. HNMe2 was notdetected in this reaction. The reaction mixture, upon heating, gave TiN and Si3N4 powders. Analyses andreactivities of the black solid revealed that it contained -H and unreacted -NMe2 ligands but no silicon-containing ligand. Ab initio quantum chemical calculations of the reactions of Ti(NR2)4 (R = Me, H) withSiH4 indicated that the formation of aminosilanes and HTi(NR2)3 was favored. These calculations also showedthat HTi(NH2)3 (3b) reacted with SiH4 or H3Si-NH2 in the following step to give H2Ti(NH2)2 (4b) andaminosilanes. The results in the current studies indicated that the role of SiH4 in its reaction with Ti(NMe2)4was mainly to remove amide ligands as HSi(NMe2)3. The removal of amide ligands is incomplete, and thereaction thus yielded "=Ti(H)(NMe2)" as the black solid. Subsequent heating of the black solid and HSi(NMe2)3 may then yield TiN and Si3N4, respectively, as the Ti-Si-N materials.