Highly air- and moisture-sensitive complexes having sulfonamide ligands, (TsNR)2Ti(NMe2)2 (Ts =
p-MeC6H4SO2), were prepared by treatment of two equivalents of TsNHR with Ti(NMe2)4 at room temperature. One of the compounds, where R =
i-Pr (1), was studied in detail; the crystal structure of 1 revealed that both of the TsNi-Pr ligands were bound to the metal in an η2-coordination mode. Solution dynamics of 1 showed that an η1/η2 interconversion occurred above 60 °C with an activation energy of 15.8 kcal molâ1. Treatment of Ti(NMe2)4 with the sulfonamide TsHN(CH2)2O(CH2)2NHTs (3),
led to the formation of [TsN(CH2)2O(CH2)2NTs]Ti(NMe2)2 (2) in high yield, in which the sulfonamide moiety was coordinated to the titanium center in an η3 (NON) mode. No sign of η1/η2 interconversion of the sulfonamide ligands was seen in solution. Treatment of 2 with Me3SiCl resulted in the formation of [TsN(CH2)2O(CH2)2NTs}Ti(NMe2)Cl]2 (4) and [TsN(CH2)2O(CH2)2NTs}TiCl2]2 (5). An X-ray structure determination of 4 revealed that sulfonyl oxygen bridging resulted in the formation of an eight membered ring.
通过在室温下用 Ti(NMe2)4 处理两当量的 TsNHR,制备出了具有磺酰胺
配体 (TsNR)2Ti(NMe2)2 (Ts = p-MeC6H4SO2)的对空气和湿气高度敏感的配合物。对其中一种 R = i-Pr 的化合物(1)进行了详细研究;1 的晶体结构显示,两种 TsNi-Pr
配体均以δ-2 配位模式与
金属结合。1 的溶液动力学显示,δ-1/δ-2 相互转化发生在 60 °C 以上,活化能为 15.8 kcal molâ1 。用磺酰胺 TsHN(
CH2)2O( )2NHTs(3)处理 Ti(NMe2)4,可生成高产率的 [TsN( )2O( )2NTs]Ti(NMe2)2(2)。磺酰胺
配体在溶液中没有δ-1/δ-2 相互转化的迹象。用 Me3SiCl 处理 2 会生成 [TsN( )2O( )2NTs}Ti(NMe2)Cl]2 (4) 和 [TsN( )2O( )2NTs}TiCl2]2 (5)。4 的 X 射线结构测定显示,磺酰基氧桥接形成了一个八分子环。