Unprecedented formation of an N-benzamidobisthiourea derivative and its role in the formation of a new CT state specific towards fluoride ionRanganathan Koteeswari, Pichandi Ashokkumar, Vayalakkavoor T. Ramakrishnan, E. J. Padma Malar, Perumal Ramamurthy
- Chemical Communications, January 2010, Royal Society of Chemistry
- DOI: 10.1039/b926320a
Unprecedented formation of an N-benzamidobisthiourea derivative
What is it about?
N-amidothioureas serve as a new generation of thiourea based anion receptors.In this study a novel N-benzamidobisthiourea derivative with two thiourea groups attached to a single N-atom is reported.This has been utilized as a new class of anion receptor. Tuning of its emission from the locally excited (LE) state to the charge transfer (CT) state was observed specifically for fluoride ion.
Why is it important?
Formation of N-benzamidobisthiourea derivative with two thiourea groups attached to a single N-atom is unprecedented. The presence of a bisthiourea group can be expected to enhance the electron donating ability during anion binding as compared to amidothiourea itself. When 1 adds to fluoride anion, a new emission state was formed which was confirmed by 3D contour spectral studies. The unusual absorption and emission maxima of 1, and the novel spectral response with F addition were rationalized by Density Functional Theory (DFT) computations at B3LYP/6-31+G* level.