Exceptionally Long (> or =2.9 A) CC bonding interactions in pi-[TCNE]2(2-) dimers: two-electron four-center cation-mediated CC bonding interactions involving pi* electrons

Exceptionally Long (> or =2.9 A) CC bonding interactions in pi-[TCNE]2(2-) dimers: two-electron four-center cation-mediated CC bonding interactions involving pi* electrons