Polymerization of 1‐(2‐Propynyl)‐3‐methylimidazolium Bromide using Cyclometalated Pd(II) Catalysts and Study of the Interaction of Ensuing Oligomer with BSA

Abstract

AbstractTwo novel cyclometalated binuclear chloro‐bridged palladium based catalysts, {(PdClL1)2} (1) and {(PdClL2)2} (2) have been synthesized by reacting PdCl2 with 4‐nitro‐(benzylidene‐(4‐tert‐butyl‐phenyl)‐amine (L1) and 4‐methylester‐(benzylidene‐(4‐tert‐butyl‐phenyl)‐amine (L2), respectively. These have been characterized by elemental analyses, spectroscopic studies (IR, 1H, 13C NMR, ESI‐MS), and their structures have been authenticated by X‐ray single crystal analyses. Polymerization of ionic liquid monomer using these catalysts has been investigated. 1 exhibited best catalytic activity and each catalyst afforded both conducting and fluorescent oligomers and high molecular weight polymers. Resulting oligomers and polymers have been characterized by spectroscopic and conductivity, GPC, SEM‐EDAX, PXRD studies. Oligomers are fluorescent and their emission intensity enhances upon interaction with anions. Binding behaviour of oligomers has been examined with BSA. Quenching of the intrinsic fluorescence of BSA in presence of oligomers have been studied by steady state, synchronous, and 3D fluorescence spectroscopy and changes in secondary structure quantified by CD spectroscopy.