( 1. 昆明贵金属研究所 国家贵金属材料工程技术研究中心,
昆明 650221;
2. 云南瑞升科技有限公司, 昆明 650106)
摘 要: 合成了乙酰丙酮铑, 并采用紫外、 红外、 核磁和质谱等手段研究了乙酰丙酮铑(Ⅲ)的化学结构特征。 结果表明: 乙酰丙酮铑属于低自旋的惰性配合物; 由于配合物中离域π键的形成, 配体羰基已不具备典型的羰基特征; 在快原子的轰击下, 乙酰丙酮铑的配位键逐一断裂, 释放出游离的乙酰丙酮, 最后形成103Rh+, 同时伴随共价键的断裂与重排; 在磁场中, 由于Rh3+的强吸电子效应以及螯合环的环电子流效应, H核化学位移向低场移动。 通过TG-DTA和GC-MS分析并探讨了乙酰丙酮铑的热分解行为, 为其应用提供了热学依据和理论参考, 并建议以300 ℃作为以乙酰丙酮铑为前驱体的CVD铑沉积工艺的沉积温度。
关键字: 乙酰丙酮铑; 结构特征; 热分解; 化学气相沉积
( 1. National Engineering Research Center of Precious Metal,
Kunming Institute of Precious Metals, Kunming 650221, China;
2. Yunnan Reascend Science and Technology Co. LTD, Kunming 650221, China)
Abstract: Rhodium(Ⅲ) acetylacetonate [Rh(acac)3], a precursor for preparing Rh layers by CVD technique, was prepared. Its spectroscopic properties were investigated via UV-vis, IR, 1HNMR and MS and its thermal decomposition behavior via TG-DTA and GC-MS. The results show that,
Rh(acac)3 is a low spinning and inert coordination compound, the characteristics of carbonyls in the ligand disappear due to the formation of conjugate π bonds in
Rh3+—acac- chelating ring, after bombarded by fast atoms, the coordination bonds break and the organic covalent bonds are splited with the formation of 103Rh+, chemical shifts of H nuclei go downward to low field because of electron-attraction of Rh3+ and electron-cyclic effect in the chelating rings, and it sublimates and decomposes at 247 ℃ and 245 ℃ in air and argon, respectively. Series of new complexes, different with the temperatures, appear in the course of the decomposition, according to which it is suggested that a better deposit temperature should be 300 ℃ when plating Rh layers via CVD technique with Rh(acac)3 as the precursor.
Key words: rhodium(Ⅲ) acetylacetonate; chemical structure; thermal properties; CVD