Synthesis, structural, thermal, photophysical and vibrational spectroscopic studies of potassium-polynitrile based 3D coordination polymer.

Abstract

Among various interactions (such as H-bonding, π-π stacking interaction) which are responsible for the fascinating metallo-architectures, cation - π interaction has emerged as a significantly important force. Moreover, it has now been observed that this interaction is found to be presented ubiquitous across several fields of contemporary interest, such as chemistry, material science, and biology. In this work, we have focused on the design and synthesis of a pentacyano organic anion and potassium cation based 3D coordination polymer (5CNP). The single-crystal XRD structure revealed fascinating structural arrangements due to the existence of several intra and interionic interaction. To the best of our knowledge, such polycyano aromatic system based 3D coordination polymer is not reported. In addition to single crystal X-ray diffraction (SCXRD), we have employed confocal Raman microscopic techniques to understand the structural aspects, particularly the pentacyano functional groups which are Raman active. Considering the prospect of 5CNP as a material, thermal stability, and structyral properties have been studied, in addition to detailed photophysical aspects. The photophysical responses in solid and in solution have been studied by steady and time-resolved fluorescence spectroscopy. Interesting photophysical observation is noted when studied in a binary mixture of THF-toluene. Scanning electron microscopy (SEM) studies have also been done for comprehensive understanding. In the end, cytotoxicity studies have been undertaken to evaluate the toxicity of 5CNP in our cells.