On the Interaction Between Deprotonated Cytosine (C-H) and Ba2+: Infrared Multiphoton Spectroscopy and Dynamics

A. CRUZ ORTIZ; M. I. TACCONE; P. MAITRE; M. ROSSA; G. A. PINO *

Chemphyschem

WILEY-V C H VERLAG GMBH

Lugar: Weinheim; Año: 2020 vol. 21 p. 1 - 13

1439-4235

Gas-phase interactions between Ba2+ and deprotonated cytosine (C(-H)) were studied in [C(-H)Ba]+ and [C(-H)BaC]+ complexes by IRMPD spectroscopy coupled to tandem mass-spectrometry in combination with DFT calculations. For the [C(-H)BaC]+ complex only one [C(-H)KAN1O-Ba-Canti]+ isomer was found, although the presence of another structure cannot be neglected. This isomer features a central tetracoordinated Ba2+ that simultaneously interacts with keto-amino [C(-H)]- deprotonated on N1 and neutral keto-amino C. Both moieties are in different planes as a consequence of an additional NH●●●O=C hydrogen bond between C and [C(-H)]-. A sequential IRMPD dynamics is observed in this complex. For the [C(-H)Ba]+ complex produced by electrospray ionization two isomers ([C(-H)KAN1OBa]+ and [C(-H)KAN3OBa]+) were identified, in which Ba2+ interacts simultaneously with the C=O group and the N1 or N3 atom of the keto-amino [C(-H)]-, respectively. A comparison with the related [C(-H)Pb]+ complex (J-Y. Salpin et al., Chem. Phys. Chem. 2014, 15, 2959?2971) is also presented.