Raman spectroscopy along with Principal Component Analysis for the confirmation of Silver(I)-N-heterocyclic carbene complex formation

Saqib Ali; Ayesha Riaz; Muhammad Irfan Majeed; Muhammad Adnan Iqbal; Haq Nawaz Bhatti; Nosheen Rashid; Muhammad Kashif; Muhammad Tahir; Saira Nasir; Saifullah; Sidra Farooq; Ammara Naseem; Haq Nawaz

doi:10.1016/j.saa.2019.117851

Raman spectroscopy along with Principal Component Analysis for the confirmation of Silver(I)-N-heterocyclic carbene complex formation

Spectrochim Acta A Mol Biomol Spectrosc. 2020 Mar 5:228:117851. doi: 10.1016/j.saa.2019.117851. Epub 2019 Nov 23.

Authors

Affiliations

¹ Department of Chemistry, University of Agriculture Faisalabad, 38040, Pakistan.
² Department of Chemistry, University of Agriculture Faisalabad, 38040, Pakistan. Electronic address: irfanmajeed2003@gmail.com.
³ Department of Chemistry, University of Agriculture Faisalabad, 38040, Pakistan. Electronic address: adnan.iqbal@uaf.edu.pk.
⁴ Department of Chemistry, University of Central Punjab, Faisalabad Campus, Faisalabad, Pakistan.
⁵ Department of Chemistry, University of Agriculture Faisalabad, 38040, Pakistan. Electronic address: haqchemist@yahoo.com.

PMID: 31786050
DOI: 10.1016/j.saa.2019.117851

Abstract

In this study Raman spectroscopy is employed for the characterization of two different ligands called as S1 and S2 and their respective co-ordinate complexes called C1 and C2. Specific Raman spectral signatures are observed for each of these Silver(I)-N-heterocyclic carbene complexes Ag(I)-(NHCs), which can be associated with the imidazolium ring, part of both of the ligands, indicating the formation of new coordinate covalent bond. For the detailed analysis, Raman spectral data of these ligands and complexes is analyzed by multivariate data analysis technique, Principal Component Analysis (PCA) which is found very helpful to differentiate two ligands and complexes from each other. The significant Raman peaks with higher intensities in the complexes as compared to the respective ligands are associated with imidazole ring which can be attributed to the enhanced polarizability of this ring on complex formation. Moreover, the spectral features associated with (AgC) bond are observed with higher intensity at 360 in (C1) and 383 in (C2). This study indicates the potential of Raman spectroscopy for the characterization and confirmation of formation of organometallic complexes and other chemical products.

Keywords: Organometallic compounds; Principal component analysis; Raman spectroscopy; Silver(I)-N-heterocyclic carbene complexes.