Challenges in spectroscopy: accuracy versus interpretation from isolated molecules to condensed phases
This themed issue includes a collection of articles on Challenges in spectroscopy: accuracy versus interpretation from isolated molecules to condensed phases.
Quantum approaches to vibrational dynamics and spectroscopy: is ease of interpretation sacrificed as rigor increases?
The subject of this Perspective is quantum approaches, beyond the harmonic approximation, to vibrational dynamics and IR spectroscopy.
On the prediction of core level binding energies in molecules, surfaces and solids
Core level binding energies, measured by X-ray photoelectron spectroscopy providing unique information regarding the chemical environment of atoms in a system, can be estimated by a diversity of state-of-the-art accurate methods here detailed.
New insights about the monomer and homodimer structures of the human AOX1
We conducted MD simulations to provide a comprehensive study on the human aldehyde oxidase and on the impact that the allosteric inhibitor thioridazine and malonate ions have on its structure, particularly on the catalytic tunnel.
N2+(2Σg) and Rb(2S) in a hybrid trap: modeling ion losses from radiative association paths
N2+ + Rb → (N2Rb)+(v) + ħω radiative association: partial vibronic cross-sections corresponding to the R8 transition as a function of the emitted photon energies and wavelengths in the ultraviolet region.
The role of dispersion and anharmonic corrections in conformational analysis of flexible molecules: the allyl group rotamerization of matrix isolated safrole
Conformational changes of the monomeric safrole isolated in low temperature xenon matrices, induced thermally or using narrow-band UV radiation, represent challenging example for the theoretical structural, spectroscopic and energetic analysis.
Accurate empirical rovibrational energies and transitions of H216O
Several significant improvements are proposed to the computational molecular spectroscopy protocol MARVEL (Measured Active Rotational–Vibrational Energy Levels), facilitating the inversion of a large set of measured rovibrational transitions to energy levels.
Non covalent interactions stabilizing the chiral dimer of CH2ClF: a rotational study
Two C–H⋯Cl–C and one C–H⋯F–C bonds stabilize (by 5.9 kJ mol−1) the dimer of chlorofluoromethane observed by rotational spectroscopy in the gas phase. The spectral analysis is complicated by the quadrupolar effects of the two nonequivalent Cl nuclei.
Algebraic diagrammatic construction for the polarisation propagator in combination with effective fragment potentials
The effective fragment potential (EFP) method for the efficient inclusion of solvation effects is combined with the algebraic diagrammatic construction (ADC) scheme for the second- and third-order polarisation propagator.
The Gigahertz and Terahertz spectrum of monodeutero-oxirane (c-C2H3DO)
The rotational spectrum of monodeutero-oxirane was analysed as measured using the Zurich Gigahertz (GHz) spectrometer and our highest resolution Fourier Transform Infrared (FTIR) spectrometer system coupled to synchrotron radiation at the Swiss Light Source (SLS).
Rovibrational quantum dynamics of the vinyl radical and its deuterated isotopologues
Rotational–vibrational states up to 3200 cm−1, beyond the highest-lying stretching fundamental, are computed variationally for the vinyl radical (VR), H2CβCαH, and the following deuterated isotopologues of VR: CH2CD, CHDCH, and CD2CD.
Internal dynamics of cyclohexanol and the cyclohexanol–water adduct
Two for a tango: the rotational spectrum of a cyclohexanol–water dimer evidences a concerted motion of the water molecule and the hydroxyl group of the ring.
Evaluating rotation diffusion properties of molecules from short trajectories
An efficient approach is reported to estimate the rotational diffusion tensor of molecules from the global angular momentum autocorrelation functions obtained from short molecular dynamics trajectories.
The HKrCCH⋯CO2 complex: an ab initio and matrix-isolation study
Structure of the HKrCCH⋯CO2 complex prepared in a low-temperature krypton matrix.
A combined experimental and theoretical study of optical rotatory dispersion for (R)-glycidyl methyl ether in aqueous solution
We present a theoretical-experimental study of the optical rotation of (R)-glycidylmethylether using a mixed quantum-classical model for solvent effects.
Elucidating DNA binding of dithienylethenes from molecular dynamics and dichroism spectra
DNA intercalation and groove binding of two photoswitching dithienylethene derivatives have been studied and characterized by means of molecular dynamics and electronic circular dichroism.
Far-IR and UV spectral signatures of controlled complexation and microhydration of the polycyclic aromatic hydrocarbon acenaphthene
UV and IR spectroscopic study of the controlled complexation and microhydration of a polycyclic aromatic hydrocarbon under isolated conditions using free electron laser FELIX.
4s to 5s and 4p photoexcitation dynamics of K atoms from the surface of helium nanodroplets: a theoretical study
We study the photodissociation of the potassium atom from a superfluid helium nanodroplet upon 5s 2S or 4p 2P excitation using the time-dependent helium density functional method (He-TDDFT). The results show possible K spin–orbit relaxation.
Unveiling anharmonic coupling by means of excited state ab initio dynamics: application to diarylethene photoreactivity
We adopted excited state ab initio dynamics and a new time resolved vibrational analysis to unveil coupling between modes promoting photorelaxation.
Molecular synthons for accurate structural determinations: the equilibrium geometry of 1-chloro-1-fluoroethene
The equilibrium structure for 1-chloro-1-fluoroethene is obtained by high-level quantum chemical calculations and the semi-experimental approach.
Large amplitude vibrations of acetyl isocyanate, methyl cyanoformate, and acetyl cyanate
The far infrared region of three detectable molecules sharing the empirical formula C3H3O2N, acetyl isocyanate CH3CONCO (AISO), methyl cyanoformate NC–COOCH3 (MCN) and acetyl cyanate CH3COOCN (ACN), is explored using explicitly correlated coupled cluster ab initio methods and a variational procedure designed for non-rigid species and large amplitude motions.
Aggregation of lactic acid in cold rare-gas matrices and the link to solution: a matrix isolation-vibrational circular dichroism study
Crucial insight into lactic acid self-aggregation in solution is obtained by following its unique VCD spectral features in cold matrices.
The rotational spectrum of 15ND. Isotopic-independent Dunham-type analysis of the imidogen radical
First observation of the THz spectrum of 15ND. Global analysis of the imidogen radical spectra and derivation of the Born–Oppenheimer equilibrium bond length.
Pd doping, conformational, and charge effects on the dichroic response of a monolayer protected Au38(SR)24 nanocluster
TDDFT simulations of the absorption and CD spectra of a Pd2Au36(SC2H4Ph)24 monolayer-protected cluster (MPC) are carried out with the aim of investigating the effects of doping, conformational degrees of freedom of the thiolates’ end-groups, and charge states on its chiro-optical response.
EPR sensing of metal and organic cations using a novel spin-labelled dibenzo-24-crown-8-ether
Novel dibenzo-24-crown ether substituted nitroxides and their use as spin probes for the detection of cation guests by EPR are reported.
Quantum tunneling dynamical behaviour on weakly bound complexes: the case of a CO2–N2 dimer
The dynamics induced by quantum tunneling is found to be closely connected to the shape of the potentials for weakly bound complexes.
Theoretical insight into joint photodynamic action of a gold(I) complex and a BODIPY chromophore for singlet oxygen generation
Inclusion of a heavy gold atom in a peripheral position of BODIPY is enough to promote ISC.
Double resonance rotational spectroscopy of He–HCO+
The ground state of He–HCO+ is investigated using a recently developed double resonance technique, consisting of a rotational transition followed by a vibrational transition into a dissociative state.
Interactions between azines and alcohols: a rotational study of pyridine–tert-butyl alcohol
The observed spectrum identifies a Cs symmetry σ-type complex, with the two subunits held together by coplanar “classical” O–H⋯N and weak C–H⋯π intermolecular hydrogen bonds. The O⋯N distance decreases by 4 mÅ upon deuteration of the hydroxyl group (reverse Ubbelohde effect).
Computing vibration–rotation-tunnelling levels of HOD dimer
Using an accurate 6D water dimer potential energy surface, we compute vibration–rotation-tunnelling levels of HOD dimer, by assuming that the two monomers are rigid.
Evaluation of the aggregation process in a mixture of propofol and benzocaine
Aggregation of propofol and benzocaine was explored using mass-resolved laser spectroscopy and DFT calculations.
State-of-the-art computation of the rotational and IR spectra of the methyl-cyclopropyl cation: hints on its detection in space
A route toward the detection of the methyl-cyclopropenyl cation in space: a spectroscopic characterization by state-of-the-art computational approaches.
Spectroscopy of a rotating hydrogen molecule in carbon nanotubes
Computing the energy levels of molecular hydrogen rotating in carbon nanotubes of increasing size.
On the simulation of vibrationally resolved electronic spectra of medium-size molecules: the case of styryl substituted BODIPYs
Vibronic spectra of two BODIPY derivatives were computed using both Time-Independent (TI) and Time-Dependent (TD) formalisms including solvent and temperature effects with several DFT functionals.
How to treat C–F stretching vibrations? A vibrational CD study on chiral fluorinated molecules
Due to the poor prediction of harmonic frequencies, vibrational modes containing C–F stretching motions are often strongly misplaced by common hybrid functionals. Herein we show that M06-2X functional performs exceptionally good in these cases.
The rotation–vibration spectrum of methyl fluoride from first principles
State-of-the-art theoretical methods are used to investigate the rotation–vibration spectrum of methyl fluoride.
About this collection
The special issue will be devoted to the latest research outcomes in the modelling of spectroscopic properties of chemical systems spanning from isolated molecules to condensed phases, with particular focus on accuracy and interpretative capabilities of computational methodologies and the interplay of experiment and theory. Indeed, in the last few years the interplay of quantum chemistry and experimental spectroscopy has strongly increased the dimension of systems amenable to an accurate characterization, thus extending to building blocks of biomolecules, condensed phases and flexible systems.
Guest Edited by Cristina Puzzarini (Università di Bologna), Maria J. Ramos (Universidade do Porto) and Maria Pilar de Lara-Castells (CSIC Madrid).