The torsional motion of a molecule composed two substituted benzene rings, linked by single bond, is coherently controlled pair strong ($3\ifmmode\times\else\texttimes\fi{}1{0}^{13}\text{ }\text{ }\mathrm{W}\text{ }{\mathrm{cm}}^{\ensuremath{-}2}$), nonresonant (800 nm) 200-fs-long laser pulses---both linearly polarized perpendicular to the single-bond axis. If second pulse sent at time when rings rotate toward (away from) each other amplitude torsion strongly enhanced (reduced). persists...

Rotation of molecules embedded in He nanodroplets is explored by a combination fs laser-induced alignment experiments and angulon quasiparticle theory. We demonstrate that at low fluence the pulse, molecule its solvation shell can be set into coherent collective rotation lasting long enough to form revivals. With increasing fluence, however, revivals disappear -- instead, rotational dynamics as rapid for an isolated observed during first few picoseconds. Classical calculations trace this...

The carbon disulphide (${\mathrm{CS}}_{2}$) dimer is formed inside He nanodroplets and identified using fs laser-induced Coulomb explosion, by observing the ${\mathrm{CS}}_{2}^{+}$ ion recoil velocity. It then shown that a 160 ps moderately intense laser pulse can align in advantageous spatial orientations which allow us to determine cross-shaped structure of analysis correlations between emission angles nascent ${\mathrm{S}}^{+}$ ions, following explosion process. Our method will enable...

Molecules with their axes sharply confined in space, available through laser-induced alignment methods, are essential for many current experiments, including ultrafast molecular imaging. Most of these applications require both that the aligning laser field is turned-off, to avoid undesired perturbations, and molecules remain aligned sufficiently long reactions dynamics can be mapped out. Presently, this only possible small, linear times less than 1 picosecond. Here, we demonstrate strong,...

Alignment of OCS, ${\mathrm{CS}}_{2}$, and ${\mathrm{I}}_{2}$ molecules embedded in helium nanodroplets is measured as a function time following rotational excitation by nonresonant, comparatively weak ps laser pulse. The distinct peaks the power spectra, obtained Fourier analysis, are used to determine rotational, $B$, centrifugal distortion, $D$, constants. For $B$ $D$ match values known from IR spectroscopy. ${\mathrm{CS}}_{2}$ ${\mathrm{I}}_{2}$, they first experimental results reported....

We demonstrate 3D spatial alignment of 3,5-dichloroiodobenzene molecules embedded in helium nanodroplets using nonresonant elliptically polarized 160 ps laser pulses at a 1 kHz repetition rate. Through Coulomb explosion imaging and ion-ion covariance mapping, the is characterized found to be stronger than that isolated molecules. The follows intensity profile pulse almost adiabatically, except for delayed response droplets, which could exploited field-free alignment. Our results pave way...

Dimers and trimers of carbonyl sulfide (OCS) molecules embedded in helium nanodroplets are aligned by a linearly polarized 160 ps long moderately intense laser pulse Coulomb exploded with an 40 fs probe order to determine their structures. For the dimer, recording 2D images OCS$^+$ S$^+$ ions covariance analysis emission directions allow us conclude that structure is slipped-parallel shape similar found for gas phase dimers. trimer, ion corresponding maps reveal presence barrel-shaped (as...

We report a quantitative study of the effect nonaxial recoil during Coulomb explosion laser-aligned molecules and introduce method to remove blurring caused by in fragment-ion angular distributions. Simulations show that affects correlations between emission directions fragment ions differently from imperfect molecular alignment. The method, based on analysis correlation explosion, is used deconvolute experimental deconvolution then applied number data sets correct degree alignment for...

Iodine (I2) molecules embedded in He nanodroplets are aligned by a 160 ps long laser pulse. The highest degree of alignment, occurring at the peak pulse and quantified ⟨cos2휃2D⟩, is measured as function intensity. results well described ⟨cos2휃2D⟩ calculated for gas isolated each with an effective rotational constant 0.6 times gas-phase value temperature 0.4 K. Theoretical analysis using angulon quasiparticle to describe rotating superfluid helium rationalizes why alignment mechanism similar...

A moderately intense 450 fs laser pulse is used to create rotational wave packets in gas phase ${\mathrm{I}}_{2}$ molecules. The ensuing time-dependent alignment, measured by Coulomb explosion imaging with a delayed probe pulse, exhibits the characteristic revival structures expected for but also complex nonperiodic substructure and decreasing mean alignment not observed before. quantum mechanical model attributes phenomena coupling between angular momenta nuclear spins through electric...

Coulomb explosion of 1,4--diiodobenzene molecules, isolated or embedded in helium nanodroplets, is induced by irradiation with an intense femtosecond laser pulse. The recoiling ion fragments are probed time-of-flight measurements and two-dimensional velocity map imaging. Correlation analysis the emission directions ${\mathrm{I}}^{+}$ ions from each end molecules reveals significant deviation axial recoil, i.e., where leave strictly along I-I symmetry axis. For relative angular distribution...

Core–shell particles with water clusters as the core and surrounded by an atomic or molecular shell have been synthesized for first time adding a co-dopant sequentially to helium nanodroplets. The co-dopants chosen investigation were Ar, O2, N2, CO, CO2, NO C6D6. These used investigate effect of outer on ionization material charge transfer in specific aim was determine how identity affects fragmentation cluster ions, i.e. whether it helps stabilize parent ion ((H2O)n+) formation increases...

Electron impact ionization of helium nanodroplets containing a dopant, M, can lead to the detection both M(+) and helium-solvated cations type M(+)·He(n) in gas phase. The observation helium-doped ions, He(n)M(+), has potential provide information on aftermath charge transfer process that leads ion production from droplet. Here we report attachment ions four common diatomic dopants, M = N(2), O(2), CO, NO. For experiments carried out with droplets an average size 7500 atoms, monomer show...

We present an efficient, noise-robust method based on Fourier analysis for reconstructing the three-dimensional measure of alignment degree, ⟨cos2θ⟩, directly from its two-dimensional counterpart, ⟨cos2θ2D⟩. The applies to nonadiabatic linear molecules induced by a linearly polarized, nonresonant laser pulse. Our theoretical shows that transform time-dependent ⟨cos2θ2D⟩ trace over one molecular rotational period contains additional frequency components compared ⟨cos2θ⟩. These can be...

The He(n)(+)/He(2)(+) (n ≥ 3) signal ratios in the mass spectra derived from electron impact ionization of pure helium nanodroplets are shown to increase with droplet size, reaching an asymptotic limit at average size approximately 50,000 atoms. This is explained terms a charge hopping model, where on positive able penetrate more deeply into liquid as increases. deeper point localizes form He(2)(+), greater likelihood collisions surrounding ion begins leave droplet, thus increasing...

Dimers of carbon disulfide (${\mathrm{CS}}_{2}$) molecules embedded in helium nanodroplets are aligned using a moderately intense, 160-ps, nonresonant, circularly polarized laser pulse. It is shown that the intermolecular carbon-carbon (C-C) axis aligns along perpendicular to polarization plane alignment The degree alignment, quantified by $\ensuremath{\langle}{cos}^{2}{\ensuremath{\theta}}_{\text{2D}}\ensuremath{\rangle}$, determined from emission directions recoiling...

A 160-ps near-Gaussian, linearly polarized laser pulse is used to align iodine (${\mathrm{I}}_{2}$) molecules embedded in helium nanodroplets. The rise time of the sufficiently long and smooth that alignment, characterized by $\ensuremath{\langle}{cos}^{2}{\ensuremath{\theta}}_{2\mathrm{D}}\ensuremath{\rangle}$, behaves adiabatically during turnon. However, after has turned off $\ensuremath{\langle}{cos}^{2}{\ensuremath{\theta}}_{2\mathrm{D}}\ensuremath{\rangle}$ stays above 0.50 a...

Optical excitation of toluene to the S1 electronic state in helium nanodroplets is found alter rate production fragment ions C7H7+ and C5H5+ when droplets are subjected subsequent electron ionization. The optical process reduces abundance delivered into gas phase, whereas become more abundant beyond a minimum droplet size. This contrasts with normal depletion spectroscopy, where absorption molecular dopant nanodroplet shrinks droplet, thus, impact cross-sections because dissipation absorbed...

In a recent experiment (H2O)n/Xm binary clusters (where X = Ar, N2, CO, CO2, and several other molecules) were formed in superfluid helium nanodroplets investigated by electron impact mass spectrometry [Liu et al., Phys. Chem. 13, 13920 (2011)10.1039/c1cp20653b]. The addition of dopant was found to affect the branching ratio between H3O+(H2O)n (H2O)+n+2 formation. Specifically, CO increased proportion protonated water cluster ions, whereas dopants such as had opposite effect. this work ab...