A5080758756- Advanced Chemical Physics Studies
- Molecular Spectroscopy and Structure
- Quantum, superfluid, helium dynamics
- Spectroscopy and Quantum Chemical Studies
- Synthesis and Properties of Aromatic Compounds
- Molecular spectroscopy and chirality
- Inorganic Fluorides and Related Compounds
- Crystallography and molecular interactions
- Nonlinear Optical Materials Research
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Supramolecular Self-Assembly in Materials
- Chemical Thermodynamics and Molecular Structure
- Atmospheric Ozone and Climate
- Synthesis and Biological Evaluation
- Synthesis and Reactions of Organic Compounds
- Photochemistry and Electron Transfer Studies
- Solid-state spectroscopy and crystallography
- Various Chemistry Research Topics
- Crystal structures of chemical compounds
- Structural and Chemical Analysis of Organic and Inorganic Compounds
- Synthesis and biological activity
- Spectroscopy and Laser Applications
- Advanced NMR Techniques and Applications
- Chemical Reaction Mechanisms
Universidade de Santiago de Compostela
2014-2023
Rede de Química e Tecnologia
2017
Centro Singular de Investigación en Química Biológica y Materiales Moleculares
2012-2015
Humboldt-Universität zu Berlin
2013
Kazimierz Wielki University in Bydgoszcz
2012
Utah State University
2007
Fujitsu (United Kingdom)
1998
Aarhus University
1992-1997
Aarhus University Hospital
1995
University of Utah
1993
Dalton is a powerful general-purpose program system for the study of molecular electronic structure at Hartree-Fock, Kohn-Sham, multiconfigurational self-consistent-field, Møller-Plesset, configuration-interaction, and coupled-cluster levels theory. Apart from total energy, wide variety properties may be calculated using these electronic-structure models. Molecular gradients Hessians are available geometry optimizations, dynamics, vibrational studies, whereas magnetic resonance optical...
The secondary structure of a dissymmetric and chiral poly(diphenylacetylene) (PDPA) is elucidated by combining the data from NMR experiments (regioregular head to tail structure), Raman IR studies (E configuration polyene double bonds), high-resolution AFM images (helical pitch, packing angle orientation external helix). As result, an E-transoidal backbone describing three coaxial helices obtained. Theoretical electronic circular dichroism (ECD) show good correspondence between experimental...
Equilibrium dissociation energies De of the benzene–argon van der Waals complex are calculated in ground state S0 and excited S1 using integral-direct coupled cluster methods. The results confirm previous investigations S0, showing that high quality correlation consistent basis sets connected triple excitations imperative for a good description complex. We estimate CCSD(T) energy De=389±2 cm−1 S0. Using CCSD linear response approach frequency shift (redshift) δνe=19 is obtained. Accurate...
The calculated ECD spectrum (time-dependent density functional theory TD-DFT) for small oligomers of polyphenylacetylenes (PPAs) show a very good match with the experimental spectra PPA polymers, particularly first Cotton band associated to helical sense internal polyenic backbone. This has been proven series PPAs representative cis-cisoidal, cis-transoidal, compressed and stretched polyene backbones, identical or opposite internal/external rotational senses allows prediction helix directly...
Abstract A complex aggregation pathway towards two diastereomeric P and M supramolecular helices arises from the of a short, chiral, rigid oligo(phenyleneethynylene) [OPE, ( S )‐ 1 ]. Thus, while Agg I aggregate is obtained when DCM solution diluted with MCH at room temperature, II generated only after slow heating (353 K)/cooling (273 K) process. Interestingly, during formation (mechanism 1), short chain oligomers are produced, which have great tendency to in plane, yielding brick‐like...
Using the time-dependent Lagrangian response approach, recently revived orbital optimized coupled cluster (OCC) model is reformulated using nonorthogonal rotations in a manner that conserves commutativity of excitation operators. The gauge invariance and simple pole structure OCC linear function are retained, while dimension eigenvalue problem reduced by factor 2. Restricting operator to double excitations, we have carried out first implementation invariant theory. Test calculations energy,...
A highly accurate ab initio intermolecular potential energy surface for the benzene–argon van der Waals complex is evaluated using coupled cluster singles and doubles model including connected triple excitations [CCSD(T)] with an augmented correlation consistent polarized valence double zeta basis set extended midbond functions. The vibrational levels obtained by full three-dimensional dynamical calculations are in excellent agreement available experimental data.
Using the coupled cluster singles and doubles including connected triples model augmented correlation consistent polarized valence double zeta basis set extended with a of 3s3p2d1f1g midbond functions, ab initio helium–, neon–, argon–cyclopropane ground state intermolecular potential energies are evaluated fitted to an analytic function up four-body interactions. These first energy surfaces available for these complexes characterized by absolute minimum −73.3 cm−1 at distance on cyclopropane...
Using augmented polarized correlation consistent basis sets extended with midbond functions, we evaluate the ground state interaction potential and induced electric dipole polarizabilities first second hyperpolarizabilities of He–Ar, Ne–Ar He–Ne van der Waals complexes. For calculation resort to coupled cluster singles doubles (CCSD) model corrected for triple excitations, CCSD(T), whereas properties are evaluated CCSD response theory. As a check quality potential, rovibrational spectrum gas...
The potential energy surface involved in the thermal decomposition of 1-propanol radicals was investigated detail using automated codes (tsscds2018 and Q2DTor). From predicted elementary reactions, a relevant reaction network constructed to study at temperatures range 1000–2000 K. Specifically, this comprises 18 conformational channels (CRCs), which general exhibit large wealth conformers reactants transition states. Rate constants for all CRCs were calculated two approaches within...
The role of the main dihedral angles in electronic circular dichroism (ECD) spectra poly(phenylacetylene)s (PPAs) was estimated by using time-dependent density functional theory (TD-DFT) for oligo(phenylacetylene)s (n = 12). These studies reveal that cis–transoidal arrangements, first Cotton effect is dominated excitations involving molecular orbitals (MOs) mainly related to polyene backbone. Hence, this scaffold, ± sign reflects P/M helical sense internal helix polymer. However,...
Supramolecular and covalent polymers share multiple structural effects such as chiral amplification, helical inversion, sergeants soldiers, or majority rules, among others. These features are related to the axial structure found in both types of materials, which responsible for their properties. Herein a novel material combining information characteristics from fields polymers, supramolecular (oligo(p-phenyleneethynylene) (OPE)) (poly(acetylene) (PA)), is presented. To achieve this goal,...
The frequency-dependent interaction induced polarizabilities and second hyperpolarizabilities are calculated for He2 at the coupled cluster singles doubles full configuration levels Ar2 level. frequency-dependence is approximated by a power series to second-order in frequency arguments using Cauchy moments hyperpolarizability dispersion coefficients. Using large correlation consistent basis sets, results close set limit obtained. computed curves (hyper-) tabulated range of internuclear...
The ground- [NO(X(2)Π)] and excited-state [NO(A(2)Σ(+))] intermolecular potential energy surfaces (IPESs) of the NO-Ne NO-Ar van der Waals complexes are evaluated using RCCSD(T) spin-restricted coupled cluster method d-aug-cc-pVQZ basis set extended with a 3s3p2d1f1g midbond functions. These bases selected from results systematic basis-set convergence study carried out for NO(A(2)Σ(+))-Ar state. We fit interaction energies to analytic functions compare those previously available. (NO-Ne)...
A chiral harvesting transmission mechanism is described in poly(acetylene)s bearing oligo(<italic>p</italic>-phenyleneethynylene)s (OPEs) used as rigid achiral spacers and derivatized with pendant groups.
The second dielectric virial coefficients of helium and argon are investigated using a fully quantum statistical approach recent accurate ab initio results for the interatomic potentials interaction-induced polarizabilities. We thereby extend preceding investigation based on semiclassical to include effects. For support findings previous study by Moszynski et al. [J. Chem. Phys. 247, 440 (1995)] that effects substantial temperatures below 10 K, while they practically negligible above 70 K....
It is shown that the isotropic hyperfine coupling constant Aiso associated with Fermi contact interaction can be accurately calculated from conventional multiconfiguration self-consistent-field wave functions if, in addition to expectation value of operator, one also includes terms originating response function. These are nonvanishing only for perturbation operators nonsymmetric spin space. Calculations N and BH2 illustrate importance indicate a good estimate polarization core orbitals may...
The first three-dimensional ab initio intermolecular potential energy surface of the Ar–CO van der Waals complex is calculated using coupled cluster singles and doubles including connected triples model augmented correlation-consistent polarized valence quadruple zeta (aug-cc-pVQZ) basis set extended with a (3s3p2d1f1g) midbond functions. averaged over three lowest vibrational states CO. Rovibrational energies are up to 50 cm−1 above ground state, thus enabling comprehensive comparison...
A detailed analysis of the interaction-induced linear and non-linear axial static electric dipole properties interaction energy model HCHO(HF)(n) (n = 1, 2) complexes is carried out using HF SCF, MP2, CCSD CCSD(T) levels approximation combined with a wide range basis sets, namely correlation-consistent sets Dunning co-workers, polarization-consistent Jensen, recently reported polarized LPol sets. The results this study show that even smallest among LPol-ds LPol-dl yield induced an accuracy...
Preparation of helical structures à la carte by monomer design dynamic polymers such as poly(phenylacetylene)s (PPAs) is a difficult task due to conformational freedom the polyene backbone. Herein, we study monomer/helical polymer scaffold relationship preparation two novel phenylacetylene series substituted at phenyl ring in ortho-, meta-, or para-positions with enantiomers either α-hydroxy-α-phenylacetic acid (1) α-chloro-α-phenylacetic (S-2) linked through an anilide bond. These monomers...
In helical polymers, sense induction is usually commanded by teleinduction mechanism, where the largest substituent of chiral residue directly attached to main chain one that commands sense. this work, different structures with senses are induced in a polymer [poly-(phenylacetylene)] when conformational composition two dihedral angles pendant group more than residues tamed. Thus, while angle at 1 [(R)- or (S)-alanine], backbone, produces an extended bent conformation resulting scaffolds...
The dielectric, refractivity, Kerr, and hyperpolarizability second virial coefficients for the helium argon gases are evaluated a wide range of temperatures using semiclassical approach high quality frequency-dependent interaction induced electric polarizabilities hyperpolarizabilities previous paper. For we obtain satisfactory agreement with most experimental data dielectric refractivity coefficients. Our results confirm that gas Kerr coefficient is very small at beyond 70 K. good recent...
The frequency-dependent interaction induced polarizability and second hyperpolarizability of the argon dimer are computed for a range internuclear distances employing coupled cluster singles doubles response approach. frequency dependence interaction-induced properties is treated through order in arguments using expansions Cauchy moments dispersion coefficients. dielectric, refractivity, Kerr virial coefficients temperatures recent accurate ab initio potential ground state dimer. For most...
The benzene-argon S1 intermolecular potential energy surface is evaluated using coupled-cluster linear response methods and an augmented correlation-consistent polarized valence double-zeta basis set extended with midbond functions. As a result of the S1←S0 excitation, well depth increases equilibrium distance decreased by 0.065 Å. Full three-dimensional vibrational calculations van der Waals levels, ab initio potential, are in good agreement available experimental data.