Assisted intramolecular proton transfer in (uracil)2Ca2+ complexes

Why Is the Spontaneous Deprotonation of [Cu(uracil)2]2+ Complexes Accompanied by Enolization of the System?

“…A comparison of the initial structures a(e1)−H and b(e1)−H in the two reactions with the corresponding products (U−H)UCu(O2O4) and (U−H)UCu(O4O4) , respectively, seems to indicate that this second enolization process corresponds in both cases to an intramolecular PT from the NH group to the free carbonyl group nearby. The aim of the present study was to show, by means of the reaction‐force formalism, that the mechanism is more complex, and could be classified as an assisted intramolecular PT similar to that described in the literature for [(uracil) 2 Ca] 2+ complexes, with the difference that in Ca 2+ ‐containing systems the process takes place in the doubly charged complex, because the [Ca(uracil) 2 ] 2+ species are thermochemically stable in the gas phase 5…”

New insights into the gas-phase unimolecular fragmentations of [Cysteine–Ca]2+ complexes

“…The CE2 Coulomb explosion also initiates with the C-NH 3 bond cleavage, followed by the formation of a C-HÁÁÁNH 3 hydrogen bond. The final transfer of this C-H proton toward the ammonia molecule is assisted by the arrival of a second proton coming from the CH 2 group attached to SH, in a kind of assisted proton transfer mechanism [40] (see Scheme 2).…”

Theoretical and computational chemistry in Spain

“…These studies cover the development and application of theoretical methods to study a wide range of relevant topics including chemical bonding [3][4][5][6], molecular structure [7][8][9][10][11][12], molecular properties [13][14][15], molecular interactions [16][17][18], reaction mechanisms [9,[19][20][21][22][23][24][25][26], catalysis [27][28][29], surface science [29][30][31][32], photochemistry [33,34], dynamics [7,[35][36][37][38][39], solvent effects [40], diffusion processes [41], and rational drug design [42], in some cases in tight collaboration with experimental groups. This diversity in covered topics implies ongoing use of almost all computational methods and tools available in the field and has moreover led to ongoing methodological developments, like those devoted to derive localization/delocalization electronic functions and indices to analyze electron correlation, bond formation and aromaticity [3]…”