Reaction of Tl plus with corannulene: Experimental and theoretical study

The interaction of Tl + cation with corannulene was investigated by using electrospray ionization mass spectrometry (ESI-MS). It was found that the thallium cation Tl + forms with corannulene (C 20 H 10 ) two cationic complexes [Tl(C 20 H 10 )] + and [Tl(C 20 H 10 ) 2 ] + . Quantum chemical calculations proceed by density functional theory with two different functionals (B3LYP and M06-D3) provided the most probable structures of these complexes. In the energetically most favored conformation of [Tl(C 20 H 10 )] + complex, the Tl + cation lies on the apex of pyramid which base is formed by the central pentagon of the convexly oriented corannulene molecule. In the [Tl(C 20 H 10 ) 2 ] + complex the "central " cation Tl + is situated between two molecules of the corannulene ligand. Both ligand molecules are convex to the Tl + cation. The interaction energies, E (int), of the considered cation- pi complexes [Tl(C 20 H 10 )] + and [Tl(C 20 H 10 ) 2 ] + were calculated to be -121.75 and -176.98 kJ/mol, respectively.