Related Experiment Video
Updated: Feb 4, 2026

Detection of Nitric Oxide and Superoxide Radical Anion by Electron Paramagnetic Resonance Spectroscopy from Cells using Spin Traps
Published on: August 18, 2012
Isolation of Tetracyano-Naphthalenediimide and Its Stable Planar Radical Anion
Yogendra Kumar1, Sharvan Kumar1, Kalyanashis Mandal1
1Supramolecular and Material Chemistry Lab, School of Physical Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.
Abstract:
Reported herein is the first isolation of tetracyano-naphthalenediimide [NDI(CN)4 ] and its radical anion, and structural elucidation through spectroscopic and X-ray diffraction studies. The radical anion shows remarkable stability and was purified by chromatography, which is unique for planar radical anions. The stability results from multiple hydrogen bonds to the counter ion and through an array of intramolecular noncovalent interactions. The radical anion revealed one of the strongest NDI π-π interactions (3.268 Å). Electrochemical studies of [NDI(CN)4 ] confirm its extraordinarily low-lying LUMO (-5.0 eV), rendering it one of the strongest electron-deficient planar π systems to be isolated. The manifold potential, which remained unknown to date, can now be explored for these open- and closed-shell planar π systems.
Related Concept Videos
Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
Radical Reactivity: Nucleophilic Radicals
Radical Reactivity: Electrophilic Radicals
Radicals
Aromatic Hydrocarbon Anions: Structural Overview
Due to the absence of continuous...
Planar Rigid-Body Motion
Planar motion is typically divided into three distinct categories. The first is rectilinear translation, demonstrated by a subway train that moves along...

