Solvothermal Synthesis and Conformation Probe of Novel Europium Complex of Brønsted Acidic Ionic Liquid: 1,3‐ Bis (1‐carboxylatoethyl)imidazolium Bromide

Abstract A novel europium complex [Eu 2 (C 9 N 2 O 4 H 11 ) 3 (OH) 2 ]Br ⋅ H 2 O derived from 1,3‐ bis (1‐carboxylatoethyl)imidazolium bromide ([H 2 bcei]Br, C 9 N 2 O 4 H 11 =bcei 2− ) was synthesized by solvothermal method. [Eu 2 (C 9 N 2 O 4 H 11 ) 3 (OH) 2 ]Br ⋅ H 2 O possesses 3D structure constructed by Eu−O coordination bonds. In this complex, there are two coordinated environments around Eu 3+ , and Eu1 and Eu2 are eight‐ and seven‐ coordinated chemical sphere, respectively. The hydrogen bonds and electrostatic interactions between H 2 O molecules, Br − ions and the 3D framework with positive charges enhance its thermostability. So above the temperature of 290 °C, the 3D framework of [Eu 2 (C 9 N 2 O 4 H 11 ) 3 (OH) 2 ]Br ⋅ H 2 O begins to decompose. The high‐resolution emission spectrum of the complex had been measured, which is consistent with the results of the X‐ray crystal structure analysis, and luminescence lifetime for the complex is 0.937 ms.