Miquel Moreno | Universitat Autònoma de Barcelona (original) (raw)

Uploads

Papers by Miquel Moreno

Research paper thumbnail of The measurement of covalency in tetragonal complexes

Journal of Physics C: Solid State Physics

Research paper thumbnail of Is an Extremely Low-Field Proton Signal in the NMR Spectrum Conclusive Evidence for a Low-Barrier Hydrogen Bond?

The Journal of Physical Chemistry a, Nov 12, 1997

Research paper thumbnail of Bidimensional tunneling splitting in the A� 1B2 and X� 1A1 states of tropolone

Research paper thumbnail of First Examples of a Modulated Bridging μ 2 -1:2κ N -Triazine in Double Helical Silver Compounds. Experimental and Theoretical Evidence

Inorg Chem, 2010

The synthesis of several silver double helices containing bis(3,5dimethylpyrazolyl)-6-(R)-s-triaz... more The synthesis of several silver double helices containing bis(3,5dimethylpyrazolyl)-6-(R)-s-triazine ligands is described. The structure of two of them has been determined by X-ray difraction. Both derivatives represent the first reported examples of a new interaction mode for a triazine ring that involves a triazine N atom bridging two metal centers. Argentophilic contacts are also present. The Ag-N and Ag-Ag interactions have been demonstrated by theoretical studies, which also showed the clear influence of weak interactions with the counteranion and the effect of the symmetry of the triazine substituent. The different donor characters of these substituents allows a modulation of the strength of the bridging Ag-N(triazine) interaction. Double pi-pi stacking, anion-pi interactions, hydrogen bonds, and hydrophobic effects are observed in an unusual highly symmetrical interpenetrated three-dimensional superstructure.

Research paper thumbnail of Bidimensional tunneling splitting in the A-tilde 1B2 and X-tilde 1A1 states of tropolone

Research paper thumbnail of H-Atom Transfer and Rotational Processes in the Ground and First Singlet Excited Electronic States of 2-(2‘-Hydroxyphenyl)oxazole Derivatives: Experimental and Theoretical Studies †

The Journal of Physical Chemistry, 1996

Research paper thumbnail of Intramolecular hydrogen bonding in ribonucleoside sugar hydroxyls. An ab initio study

Research paper thumbnail of Comparison between intramolecular proton transfers involving the carboxylate and alkoxide groups

Chemical Physics, Nov 1, 1990

Research paper thumbnail of Chromophore Interactions Leading to Different Absorption Spectra in mNeptune1 and mCardinal Red Fluorescent Proteins

Phys. Chem. Chem. Phys., 2016

Differences in the absorption spectra of two recently synthesized red fluorescent proteins are tr... more Differences in the absorption spectra of two recently synthesized red fluorescent proteins are traced to the different interactions of their chromophore.

Research paper thumbnail of On the tautomerization reaction 2-pyridone 2-hydroxypyridine: an ab initio study

Chemical Physics Letters, Aug 1, 1990

Research paper thumbnail of A discrete variable representation study of the dynamics of the double proton transfer in bicyclic oxalamidines

Chemical Physics Letters, Jun 8, 2001

DFT electronic calculations are performed for the double proton transfer in bicyclic oxalamidines... more DFT electronic calculations are performed for the double proton transfer in bicyclic oxalamidines 2,2 ′ -bis-(3,4,5,6-tetrahydro-1,3-diazine) (OA6) and 2,2 ′ -bis-(4,5,6,7-tetrahydro-1,3-diazepine ) (OA7). Bidimensional potential energy surfaces retaining the characteristics of the ...

Research paper thumbnail of Tunnelling paths for proton transfer reactions in solution. A discussion over a simplified model

Journal of Molecular Structure Theochem, Nov 18, 1996

Research paper thumbnail of Theoretical Study on the Excited-State Intramolecular Proton Transfer in the Aromatic Schiff Base Salicylidene Methylamine: an Electronic Structure and Quantum Dynamical Approach

The Journal of Physical Chemistry a, May 1, 2006

Research paper thumbnail of Quantum mechanical phenomena in dihydrogen and polyhydride transition metal systems

Research paper thumbnail of Reactions of singlet and triplet methylene with a C-H bond of ethylene. An ab initio study

The Journal of Physical Chemistry, 1988

Research paper thumbnail of Direct observation of breaking of the intramolecular H-bond, and slowing down of the proton motion and tuning its mechanism in an HBO derivative

Physical chemistry chemical physics : PCCP, Jan 27, 2015

We report on spectroscopic and photodynamical behaviours of 5-amino-2-(2'-hydroxyphenyl)benzo... more We report on spectroscopic and photodynamical behaviours of 5-amino-2-(2'-hydroxyphenyl)benzoxazole (5A-HBO) in different solutions. The dye undergoes an ultrafast ICT reaction (<50 fs) (comparable to that observed for its methylated derivative, 5A-MBO), in agreement with the results of TD-DFT theoretical calculations (gas phase). Depending on the used solvent, the ICT reaction can be followed by a reversible/irreversible excited-state intramolecular proton transfer (ESIPT) reaction or by breaking of the intramolecular hydrogen bond (IHB). 5A-HBO in n-heptane solution exhibits an irreversible and slow (20 ps) ESIPT reaction, while that of the parent compound, HBO, takes place in less than 150 fs. Compared to excited HBO behaviour, theoretical calculations on 5A-HBO suggest a higher energy barrier (∼4 kcal mol(-1)) between the relaxed enol and keto tautomers, in addition to a less stabilization of the latter, which is in agreement with experiments in n-heptane. On the other ha...

Research paper thumbnail of Quantum Mechanics and Molecular Mechanics Studies of Host-Guest Stabilization and Reactivity in Cyclodextrin Nanocavities

Cyclodextrin Materials Photochemistry, Photophysics and Photobiology, 2006

Research paper thumbnail of Transient low-barrier hydrogen bond in the photoactive state of green fluorescent protein

Phys. Chem. Chem. Phys., 2015

A transient low-barrier hydrogen bond has been found directly after photoexcitation using quantum... more A transient low-barrier hydrogen bond has been found directly after photoexcitation using quantum dynamics to study the excited-state process in GFP.

Research paper thumbnail of H-Atom Transfer and Rotational Processes in the Ground and First Singlet Excited Electronic States of 2-(2‘-Hydroxyphenyl)oxazole Derivatives:  Experimental and Theoretical Studies †

The Journal of Physical Chemistry, 1996

Research paper thumbnail of On the unexpected isotope effect on the exchange coupling constant in partially deuterated transition-metal trihydride complexes

Berichte der Bunsengesellschaft für physikalische Chemie, 1998

In this paper we attempt to explain the unusual isotope effect displayed by the 'H-NMR scalar H-H... more In this paper we attempt to explain the unusual isotope effect displayed by the 'H-NMR scalar H-H coupling of the hydrides in complexes [c~lrL(H)~]+ (L=various phosphine and phosphite ligands) when one of the equivalent protons is turned into a deuteron @.

Research paper thumbnail of The measurement of covalency in tetragonal complexes

Journal of Physics C: Solid State Physics

Research paper thumbnail of Is an Extremely Low-Field Proton Signal in the NMR Spectrum Conclusive Evidence for a Low-Barrier Hydrogen Bond?

The Journal of Physical Chemistry a, Nov 12, 1997

Research paper thumbnail of Bidimensional tunneling splitting in the A� 1B2 and X� 1A1 states of tropolone

Research paper thumbnail of First Examples of a Modulated Bridging μ 2 -1:2κ N -Triazine in Double Helical Silver Compounds. Experimental and Theoretical Evidence

Inorg Chem, 2010

The synthesis of several silver double helices containing bis(3,5dimethylpyrazolyl)-6-(R)-s-triaz... more The synthesis of several silver double helices containing bis(3,5dimethylpyrazolyl)-6-(R)-s-triazine ligands is described. The structure of two of them has been determined by X-ray difraction. Both derivatives represent the first reported examples of a new interaction mode for a triazine ring that involves a triazine N atom bridging two metal centers. Argentophilic contacts are also present. The Ag-N and Ag-Ag interactions have been demonstrated by theoretical studies, which also showed the clear influence of weak interactions with the counteranion and the effect of the symmetry of the triazine substituent. The different donor characters of these substituents allows a modulation of the strength of the bridging Ag-N(triazine) interaction. Double pi-pi stacking, anion-pi interactions, hydrogen bonds, and hydrophobic effects are observed in an unusual highly symmetrical interpenetrated three-dimensional superstructure.

Research paper thumbnail of Bidimensional tunneling splitting in the A-tilde 1B2 and X-tilde 1A1 states of tropolone

Research paper thumbnail of H-Atom Transfer and Rotational Processes in the Ground and First Singlet Excited Electronic States of 2-(2‘-Hydroxyphenyl)oxazole Derivatives: Experimental and Theoretical Studies †

The Journal of Physical Chemistry, 1996

Research paper thumbnail of Intramolecular hydrogen bonding in ribonucleoside sugar hydroxyls. An ab initio study

Research paper thumbnail of Comparison between intramolecular proton transfers involving the carboxylate and alkoxide groups

Chemical Physics, Nov 1, 1990

Research paper thumbnail of Chromophore Interactions Leading to Different Absorption Spectra in mNeptune1 and mCardinal Red Fluorescent Proteins

Phys. Chem. Chem. Phys., 2016

Differences in the absorption spectra of two recently synthesized red fluorescent proteins are tr... more Differences in the absorption spectra of two recently synthesized red fluorescent proteins are traced to the different interactions of their chromophore.

Research paper thumbnail of On the tautomerization reaction 2-pyridone 2-hydroxypyridine: an ab initio study

Chemical Physics Letters, Aug 1, 1990

Research paper thumbnail of A discrete variable representation study of the dynamics of the double proton transfer in bicyclic oxalamidines

Chemical Physics Letters, Jun 8, 2001

DFT electronic calculations are performed for the double proton transfer in bicyclic oxalamidines... more DFT electronic calculations are performed for the double proton transfer in bicyclic oxalamidines 2,2 ′ -bis-(3,4,5,6-tetrahydro-1,3-diazine) (OA6) and 2,2 ′ -bis-(4,5,6,7-tetrahydro-1,3-diazepine ) (OA7). Bidimensional potential energy surfaces retaining the characteristics of the ...

Research paper thumbnail of Tunnelling paths for proton transfer reactions in solution. A discussion over a simplified model

Journal of Molecular Structure Theochem, Nov 18, 1996

Research paper thumbnail of Theoretical Study on the Excited-State Intramolecular Proton Transfer in the Aromatic Schiff Base Salicylidene Methylamine: an Electronic Structure and Quantum Dynamical Approach

The Journal of Physical Chemistry a, May 1, 2006

Research paper thumbnail of Quantum mechanical phenomena in dihydrogen and polyhydride transition metal systems

Research paper thumbnail of Reactions of singlet and triplet methylene with a C-H bond of ethylene. An ab initio study

The Journal of Physical Chemistry, 1988

Research paper thumbnail of Direct observation of breaking of the intramolecular H-bond, and slowing down of the proton motion and tuning its mechanism in an HBO derivative

Physical chemistry chemical physics : PCCP, Jan 27, 2015

We report on spectroscopic and photodynamical behaviours of 5-amino-2-(2'-hydroxyphenyl)benzo... more We report on spectroscopic and photodynamical behaviours of 5-amino-2-(2'-hydroxyphenyl)benzoxazole (5A-HBO) in different solutions. The dye undergoes an ultrafast ICT reaction (<50 fs) (comparable to that observed for its methylated derivative, 5A-MBO), in agreement with the results of TD-DFT theoretical calculations (gas phase). Depending on the used solvent, the ICT reaction can be followed by a reversible/irreversible excited-state intramolecular proton transfer (ESIPT) reaction or by breaking of the intramolecular hydrogen bond (IHB). 5A-HBO in n-heptane solution exhibits an irreversible and slow (20 ps) ESIPT reaction, while that of the parent compound, HBO, takes place in less than 150 fs. Compared to excited HBO behaviour, theoretical calculations on 5A-HBO suggest a higher energy barrier (∼4 kcal mol(-1)) between the relaxed enol and keto tautomers, in addition to a less stabilization of the latter, which is in agreement with experiments in n-heptane. On the other ha...

Research paper thumbnail of Quantum Mechanics and Molecular Mechanics Studies of Host-Guest Stabilization and Reactivity in Cyclodextrin Nanocavities

Cyclodextrin Materials Photochemistry, Photophysics and Photobiology, 2006

Research paper thumbnail of Transient low-barrier hydrogen bond in the photoactive state of green fluorescent protein

Phys. Chem. Chem. Phys., 2015

A transient low-barrier hydrogen bond has been found directly after photoexcitation using quantum... more A transient low-barrier hydrogen bond has been found directly after photoexcitation using quantum dynamics to study the excited-state process in GFP.

Research paper thumbnail of H-Atom Transfer and Rotational Processes in the Ground and First Singlet Excited Electronic States of 2-(2‘-Hydroxyphenyl)oxazole Derivatives:  Experimental and Theoretical Studies †

The Journal of Physical Chemistry, 1996

Research paper thumbnail of On the unexpected isotope effect on the exchange coupling constant in partially deuterated transition-metal trihydride complexes

Berichte der Bunsengesellschaft für physikalische Chemie, 1998

In this paper we attempt to explain the unusual isotope effect displayed by the 'H-NMR scalar H-H... more In this paper we attempt to explain the unusual isotope effect displayed by the 'H-NMR scalar H-H coupling of the hydrides in complexes [c~lrL(H)~]+ (L=various phosphine and phosphite ligands) when one of the equivalent protons is turned into a deuteron @.

Log In