Chemical Physics Letters (v.519-520, #C)
Editorial Board (IFC).
Ionization of water in interfacial electric fields: An electrochemical view by Eric M. Stuve (1-17).
Display Omitted► Water ionizes to hydronium H+(H2O) m and hydroxide OH−(H2O) n in fields of ≈0.3 V/Å. ► Ionization fields similar to those at electrode/electrolyte interfaces. ► Dielectric properties, ion cluster size and energetics, and ionization images. ► Ion participation in electrocatalytic reactions: H2 and CO oxidation, O2 reduction. ► Directions for integrated experimental and theoretical research and new techniques.High electric fields promote ionization of water, yet relatively little is known about this topic due to the difficulty of generating such fields. The high field capability of field emitter tips enables study of ionization in water layers. Results from this work include ionization fields, water layer morphology, dielectric properties, coadsorbate interactions, cluster distributions of hydrated hydronium ions H+(H2O) m , and field ionization images. These experimental results, combined with theoretical findings, are interpreted in the context of four examples from electrochemistry; double layer structure, hydrogen oxidation, CO oxidation, and oxygen reduction; to reveal the research frontier in interfacial ionization of water.
Quantum mechanical modeling of electronic excitations in metal oxides: Magnesia as a prototype by Dalal K. Kanan; Sahar Sharifzadeh; Emily A. Carter (18-24).
Display Omitted► Characterizing excitations in metal oxides can provide insight into photocatalysis. ► Comparisons of embedded correlated wavefunction models are given. ► Electrostatic embedding combined with multireference wavefunctions most accurate. ► For delocalized excitations, Green’s function methods superior, though much more expensive. ► Embedded correlated wavefunctions best for local excited states.We compare embedded correlated wavefunction (ECW) approaches for predicting excited states within MgO as a prototypical metal oxide. The crystal is partitioned into a cluster treated with CW methods and a background described by various electrostatic or orbital-free-density-functional-theory (DFT)-based embedding potentials. The excited singlet and triplet states are found to be nearly degenerate and of charge-transfer type, consistent with experiment. Although the prediction of excitation energies by ECW theory with an electrostatic description of the background falls slightly short of more expensive Green’s function methods, it is significantly improved over standard DFT or non-embedded CW methods.
On the kinetics of thermal electron attachment to perfluoroethers by J. Kopyra; J. Wnorowska; W. Barszczewska; S. Karolczak; I. Szamrej (25-28).
The temperature dependence of the thermal electron attachment rate coefficients were obtained by means of swarm technique.Display Omitted► The thermal electron attachment rate coefficients for four perfluoroethers were reported. ► The activation energies for electron attachment to perfluoroethers were obtained. ► The exponential relationship between the rate coefficients obtained at T = 298 K and activation energies was discussed.In this Letter we report the results of the measurements of the rate coefficients for thermal attachment to several perfluoroethers namely perfluorodiglyme (C6F14O3), perfluorotriglyme (C8F18O4), perfluoropolyether (CF3–(OCF(CF3)CF2) n –(OCF2) m –OCF3) and perfluorocrownether ((C2F4O)5). Rate coefficients were obtained under thermal conditions in the temperature range 298–378 K. The increase of the rates with temperature follows the Arrhenius law and the activation energies have been obtained from the slope of the ln(k) vs. 1/T. The respective values of the rate coefficients (at 298 K) and activation energies are as follows: 7.7 ± 1.2 × 10−11 cm3 s−1 (0.18 ± 0.005 eV), 6.7 ± 2.1 × 10−11 cm3 s−1 (0.25 ± 0.004 eV), 2.1 ± 0.2 × 10−10 cm3 s−1 (0.16 ± 0.010 eV), 3.1 × 10−11 cm3 s−1 (0.27 ± 0.003 eV) for C6F14O3, C8F18O4, CF3–(OCF(CF3)CF2)n–(OCF2)m–OCF3 and (C2F4O)5.
Planar tetracoordinate carbon in CE4 2− (E = Al–Tl) clusters by Abril Carolina Castro; Martha Audiffred; Jose M. Mercero; Jesus M. Ugalde; Miguel A. Méndez-Rojas; Gabriel Merino (29-33).
Display Omitted► Planar tetracoordinate carbon atoms in binary clusters. ► Planar tetracoordinate carbons in pentaatomic molecules. ► CE4 2− is a sigma and pi aromatic system. ► Heavier analogues of CAl4 2−.The structures and bonding of the CE4 2−clusters (E = Al, Ga, In, Tl) have been theoretically studied via B3LYP/def2-TZVP computations. Total energies were recalculated at the CCSD(T)/def2-TZVPP//B3LYP/def2-TZVP level in order to corroborate the energy differences. Our computations show that all the CE4 2−and CE4Li−clusters (E = Al, Ga, In,Tl) have a planar tetracoordinate carbon structure. Interestingly, while the most stable form of CAl4Li− and CGa4Li− is planar with coordination of Li+ to an edge of the CE4 2− fragment, for CIn4Li− and CTl4Li− the pyramidal structures with C 4 v symmetry are the lowest-energy structures.
LIF spectroscopy of jet-cooled 1:1 complex between 7-azaindole and 2-pyrrolidinone by Moitrayee Mukherjee; Shreetama Karmakar; Tapas Chakraborty (34-39).
Display Omitted► LIF spectroscopy and photophysics of 7-azaindole⋯2-pyrrolidinone complex. ► The vibronic bands in the fluorescence excitation spectrum show puckering doublets. ► Puckering barrier is predicted ∼260 cm−1 and zero-point splitting 10 cm−1. ► Complex emits tautomer fluorescence in hydrocarbon solution but UV emission in jet. ► High barrier is suggested for inhibition of tautomerization in isolated complex.Laser-induced fluorescence (LIF) spectra of a 1:1 complex between 7-azaindole (7AI) and five-member cyclic amide 2-pyrrolidinone (2-PDN) have been measured in a supersonic free jet expansion. The bands in the excitation spectrum appear doublet, which has been attributed to splitting of the zero-point level in the ground state due to puckering of 2-PDN moiety of the complex in a symmetric double minimum potential. This feature is consistent with low puckering barrier (∼260 cm−1) predicted by electronic structure calculation. The complex emits only UV fluorescence from locally excited state in the jet, but visible tautomer fluorescence is observed in hydrocarbon solution.
Experimental and theoretical investigation of the parabanic acid molecule following VUV excitation and photodissociation by A.F. Lago; J.M. Oliva; J.Z. Dávalos (40-44).
Display Omitted► Experimental and theoretical investigation of parabanic acid molecule. ► Photoelectron photoion coincidence spectra in the 11–21 eV range. ► VUV photoionization and dissociation mechanisms of parabanic acid molecule.Photodissociation experiments have been performed for the parabanic acid (C3H2N2O3) molecule in vapor phase using time-of-flight mass spectrometry and synchrotron radiation in the VUV photon energy range. Electron ion coincidence (PEPICO) spectra and partial ion yields have been recorded as a function of the photon energy covering the 11–21 eV valence range region. The resulting photoionization products as well as proposed fragmentation pathways leading to those species are presented and discussed. Electronic structure computations for the neutral and ionic species were also carried out at the B3LYP/aug-cc-pVTZ level of theory.
Strong surface adsorption of aqueous sodium nitrite as an ion pair by D.E. Otten; R. Onorato; R. Michaels; J. Goodknight; R.J. Saykally (45-48).
Display Omitted► SHG spectra reveal unusually strong surface adsorption. ► Spectra fit best to concerted ion pair adsorption model. ► Nitrite and nitrate behave very differently. ► Resembles ‘Jones–Ray Effect.’We describe the first detailed experimental characterization of surface adsorption of an aqueous ion pair and quantify the unusual surface behavior of sodium nitrite, a ubiquitous component of natural waters. The onset of unusually strong adsorption at concentrations as low as ca. 0.1 M resembles the controversial ‘Jones–Ray Effect,’ wherein 13 salts exhibited surface tension minima in the millimolar region before resuming the normal linear increase with bulk concentrations. Given the compelling analogy recently found between adsorption of ions to the air–water interface, and the Hofmeister Effects of biochemistry, these results have important implications for the mechanism underlying these phenomena.
A theoretical spectroscopy investigation of oxosumanenes by Emilie Cauët; Denis Jacquemin (49-53).
Display Omitted► DFT is used to investigate the properties of bowl-shaped oxosumanenes. ► Agreement between theory and experiment is reached for most properties. ► Significant differences between sumanene and oxosumanenes are predicted.Using Density Functional Theory approaches, we investigate the structure and spectroscopic signatures of sumanene, monooxosumanene and trioxosumanene, three synthesised bowl-shaped compounds. The simulated properties include geometries, charges, polarisabilities, infrared and UV/visible spectra as well as complexation energies. Refined approaches have been considered (anharmonic frequencies, state-specific solvent model, dispersion-corrected DFT…) and a valuable agreement with experimental reference values is reached for most properties. The evolution of the electronic features of sumanene upon oxidation has been rationalised.
Synthesis of highly active visible-light-driven colloidal silver orthophosphate by A. Khan; M. Qamar; M. Muneer (54-58).
Highly uniform and monodisperse Ag3PO4 with size of ∼200 nm was synthesized which showed excellent photocatalytic activity for removal of a variety of water contaminants.Display Omitted► Synthesis of monodisperse and uniform silver orthophosphate. ► Showed much better photocatalytic activity than micron size Ag3PO4, TiO2 and ZnO. ► Catalyzed the removal of a variety of pollutants under sunlight-type excitation.The present study deals with the synthesis of highly uniform and spherical visible-light-driven colloidal silver phosphate (Ag3PO4) with the size of ∼200 nm. These colloidal particles showed excellent photocatalytic activity for the removal of different dyes and pesticide under sunlight-type excitation. The photocatalytic activity of these particles, obtained by colloidal method, was found to be much higher than silver phosphate obtained by precipitation method, or titanium dioxide, or zinc oxide under identical conditions. The effect of catalyst amount and recyclability on the photocatalytic response of Ag3PO4 was also investigated.
Fabrication of magnetically separable palladium–graphene nanocomposite with unique catalytic property of hydrogenation by Sourov Chandra; Sourav Bag; Pradip Das; Dipsikha Bhattacharya; Panchanan Pramanik (59-63).
Display Omitted► A facile route for the synthesis of well water dispersed magnetically separable graphene nanocatalyst. ► Pd2+ assists the formation of Fe3O4 nanoparticles. ► Room temperature hydrogenation of vinyl acetate.One step solvothermal route has been developed to prepare a well dispersed magnetically separable palladium–graphene nanocomposite, which can act as a unique catalyst against hydrogenation due to the uniform decoration of palladium nanoparticles throughout the surface of the magnetite–graphene nanocomposite and hence can be reused for several times. In addition to catalytic activity, palladium nanoparticles also facilitate the formation and homogeneous distribution of magnetite (Fe3O4) nanoparticles onto the graphene surfaces or else an agglomerated product has been obtained after the solvothermal reduction of graphene oxide in presence of Fe3+ alone.
The role of vortices in the process of impurity nanoparticles coalescence in liquid helium by E.B. Gordon; A.V. Karabulin; V.I. Matyushenko; V.D. Sizov; I.I. Khodos (64-68).
Display Omitted► Metal atoms condensation in superfluid helium occurs mainly in quantized vortices. ► The main products are nanowires, beads appeared at large metal content. ► Traces of zigzag-shaped nanowires formed in usual vortices of liquid helium. ► The production of long polymer monochains was shown to be possible in HeII.The process of condensation of metal atoms in superfluid helium was shown to occur mainly in the quantized vortices. Firstly the spherical nanocrystals were grown there. At low metal content in liquid they fused then into long cylindrical nanowires. At higher metal content the spherical microparticles were formed instead with their size terminated by mutual repulsion arisen in vortex core. Small number of zigzag-shaped nanowires was found to be formed in usual vortices of normal liquid helium as well. The production of ideal 1-D structures such as long polymer chains was predicted for non-metallic material condensation in superfluid helium.
Unravelling the enhanced reactivity of bulk CeO2 doped with gallium: A periodic DFT study by Paola Quaino; Olga Syzgantseva; Luca Siffert; Frederik Tielens; Christian Minot; Monica Calatayud (69-72).
Display Omitted► Ceria doped with gallium exhibits outstanding chemical reactivity. ► Gallium induces strong relaxations in the CeO2 host. ► The doped material is more reducible than pure CeO2 or Ga2O3.Doping CeO2 with gallium leads to promising materials with application in hydrogen purification processes for fuel cells. The bulk ceria–gallia is investigated by ab initio calculations. The outstanding reactivity is explained by important relaxations induced by gallium in the ceria host, having a strong impact in the electronic structure. As a result, the mixed oxide is found to be more reducible than the pure oxides in agreement with experimental data. It is thus possible to correlate structure and reactivity of the doped system on the molecular level, representing a step forward to the rational design of materials with selected properties.
Enhanced photoluminescence of water-soluble Mn-doped ZnS quantum dots by thiol ligand exchange by Jinju Zheng; Fengmei Gao; Guodong Wei; Weiyou Yang (73-77).
Display Omitted► We reported the enhanced photoluminescence of Mn:ZnS d-dots by thiol ligand exchange. ► The mechanism for the enhanced PL of thiol-coated Mn:ZnS d-dots has been discussed. ► The quantum yield of the as-synthesized water-soluble dots can reach as high as 50%. ► The efficient and water soluble d-dots are suitable for biomedical applications.Hydrophobic Mn-doped ZnS quantum dots (Mn:ZnS d-dots) were made to be water soluble by coating a monolayer of mercaptopropionic acid (MPA). It is found that the PL efficiency of Mn:ZnS d-dots with various shell thicknesses were all improved after thiol (MPA) ligand exchange. We attribute their PL enhancement to the effective surface passivation induced by the thiol ligand and significantly decrease of holes transfer from d-dots to ligands. The PL QY of as-synthesized thiol-coated d-dots can reach as high as 50%. These efficient, stable, and water soluble d-dots are confirmed to be suitable for biomedical applications.
Synthesis of diameter controlled carbon nanotubes using self-assembled catalyst nanoparticles by Ankur Baliyan; Takahiro Fukuda; Takashi Uchida; Yoshikata Nakajima; Tatsuro Hanajiri; Toru Maekawa (78-82).
Display Omitted► CNTs are grown by the PECVD method using mono-dispersed iron oxide nanoparticles. ► The internal diameter of CNTs is very close to that of nanoparticles. ► The diameter is uniform irrespective of the thickness of the layers of nanoparticles.Vertically-aligned diameter-controlled carbon nanotubes (CNTs) are synthesised by the plasma enhanced chemical vapour deposition (PECVD) method using multi-layers of self-assembled catalytic ligand-coated iron oxide nanoparticles. We find that the mono-dispersed nanoparticles play a vital role for the production of diameter-controlled CNTs. A new growth model is also proposed based on the experimental results. The present results may make a great contribution to the development and design of mechanical, electronic and biomedical devices, in which diameter-controlled CNTs are utilised.
Binding of molecular hydrogen to halide anions: A computational exploration of eco-friendly materials for hydrogen storage by Fabio Pichierri (83-88).
Display Omitted► The interaction of molecular hydrogen with halide anions is investigated with the aid of DFT calculations. ► The bromide anion has the ability to bind up to seven hydrogen molecules. ► QTAIM analyses reveal the presence of closed-shell interactions. ► Eco-friendly and low-cost materials for hydrogen storage are proposed.Using density functional theory calculations, we investigate the structures of the complexes derived from the interaction of molecular hydrogen to halide anions. The bromide anion can bind up to seven hydrogen molecules while both fluoride and chloride anions form stable complexes with up to six hydrogen molecules. According to the results of QTAIM analyses, closed shell interactions are operative in these complexes.
Oscillatory behavior of Rh/YSZ under electropromoted conditions by C. Jiménez-Borja; A. de Lucas-Consuegra; F. Sapountzi; F. Dorado; A. Katsaounis; J.L. Valverde (89-92).
Display Omitted► Electrochemically induced oscillatory phenomena were investigated on Rh films. ► Oscillations period and amplitude were analyzed depending on the polarization. ► Oscillations were related with cyclic oxidation and reduction of the rhodium. ► Amplitude increased linearly with the potential and period remained almost constant. ► Amplitude was strongly dependent on the temperature due to changes in YSZ conductivity.Electrochemical induced oscillations were studied during ethylene oxidation over Rh films deposited on YSZ. Oscillations period and amplitude were for the first time analyzed depending on the applied potential or current, related with cyclic oxidation and reduction reactions and discussed on the basis of the phenomenon of the electrochemical promotion of catalysis.
Properties of oxidized phospholipid monolayers: An atomistic molecular dynamics study by Morteza Khabiri; Martina Roeselova; Lukasz Cwiklik (93-99).
Display Omitted► We model oxidized DOPC monolayers with molecular dynamics and potential of mean force. ► Orientational reversal of oxidized chains toward water phase occurs. ► Accumulation of oxidized lipids in the monolayer is observed, nonanal evaporates. ► Massive oxidation causes loss of the structure and solubilization of oxidized lipids.Non-saturated lipids in the lung surfactant are prone to oxidation by oxidative species present in air. In this Letter, oxidized monolayers of dioleoylphosphatidylcholine (DOPC) were studied by means of both molecular dynamics and potential of mean force calculations. Structural changes of the monolayer following oxidation were revealed, including orientational reversal of oxidized chains. Accumulation of oxidized lipids in the monolayer is observed for moderate oxidation ratios, whereas removal of the short-chain oxidation product is predicted at long timescales. Massive oxidation leads to the loss of the well-ordered monolayer structure and partial solubilization of the oxidized lipids in the aqueous subphase.
The reaction mechanism for dehydration process catalyzed by type I dehydroquinate dehydratase from Gram-negative Salmonella enterica by Yuan Yao; Ze-Sheng Li (100-104).
Display Omitted► The dehydration process catalyzed by type I dehydroquinate dehydratase was studied. ► This reaction undergoes a two-step cis-elimination mechanism. ► The catalytic roles of His143 and the Schiff base were clarified.The fundamental reaction mechanism for the dehydration process catalyzed by type I dehydroquinate dehydratase from Gram-negative Salmonella enterica has been studied by density functional theory calculations. The results indicate that the dehydration process undergoes a two-step cis-elimination mechanism, which is different from the previously proposed one. The catalytic roles of both the highly conserved residue His143 and the Schiff base formed between the substrate and Lys170 have also been elucidated. The structural and mechanistic insight presented here may direct the design of type I dehydroquinate dehydratase enzyme inhibitors as non-toxic antimicrobials, anti-fungals, and herbicides.
Terahertz absorption spectroscopy of protein-containing reverse micellar solution by H. Murakami; Y. Toyota; T. Nishi; S. Nashima (105-109).
Display Omitted► Protein-containing reverse micelles with ∼20 and ∼600 water molecules are studied. ► Derivation of the terahertz absorption spectrum of protein in solution. ► Spectral analysis by use of the structural parameters of the reverse micelle. ► Difference between conditions of water associated with protein and with surfactant.Terahertz time-domain spectroscopy has been carried out for AOT/isooctane reverse micellar solution with myoglobin at the water-to-surfactant molar ratios (w 0) of 0.2 and 4.4. The amplitude of the absorption spectrum increases with increasing the protein concentration at w 0 = 0.2, whereas it decreases at w 0 = 4.4. The molar extinction coefficients of the protein-filled reverse micelle, and the constituents, i.e., myoglobin, water, and AOT, have been derived by use of the structural parameters of the micellar solution. The experimental results are interpreted in terms of hydration onto the protein and surfactant in the reverse micelle.
Manifestation of strong quadrupole light–molecule interaction in the SER and SEHR spectra of pyrazine and phenazine by A.M. Polubotko (110-117).
Display Omitted► Here we estimated and demonstrated strong enhancement of the SER and SEHR cross-sections. ► We bring selection rules for contributions, which form these cross-sections. ► On this base we interpreted successfully the SER and SEHR spectra of pyrazine and phenazine. ► The results explain appearance of forbidden lines in these spectra. ► Coincidence with experimental SER and SEHR spectra of pyrazine and phenazine is excellent.It is demonstrated that explanation of appearance of strong forbidden lines in the SEHR spectra of pyrazine and phenazine, caused by totally symmetric vibrations and also other details of their SER and SEHR spectra can be made on the base of the dipole-quadrupole theory. The main point of this theory is conception of a strong quadrupole light–molecule interaction, arising in surface fields strongly varying in space near a rough metal surface. Existence of the pointed lines is a good corroboration of existence of the strong quadrupole light–molecule interaction.
Angular dependence of the two-electron intex distribution by Adam J. Proud; Jason K. Pearson (118-124).
Display Omitted► New method of looking at electron pairs is introduced in the angular intex density, A ( θ Ru ) . ► Correlation effects on the angular distribution of electrons are analyzed. ► A ( θ Ru ) is employed in the study of the electron correlation hole.The probability density for the angle between the intracular ( u ) and extracular ( R ) coordinate vectors using both Hartree–Fock (HF) and explicitly correlated Kinoshita wave functions is presented. This angular density, A ( θ Ru ) , and the angular-dependent intex density, X ( R , u , θ Ru ) , are explored for the helium isoelectronic series from He to Ne8+ to study how electron pairs are distributed in atomic systems (both HF and exact). We demonstrate that the most probable angle depends significantly on the scalar values of R and u for both the HF and exact treatments. As R and u increase, the favoured angle for these densities approach 0 and π .
Importance of a multiconfigurational description for molecular junctions by Martin Vérot; Serguei A. Borshch; Vincent Robert (125-129).
Display Omitted► We model electron transport through magnetic systems. ► The molecular fragment is described with a multiconfigurational approach. ► The influence of spectroscopic details is analyzed.The importance of the multiconfigurational description of the junction electronic structure is investigated in quantum transport through molecular devices. Using an accurate wavefunction-based description of the low-energy spectroscopy, transport through a 2-electron/2-molecular orbital prototype is evaluated, covering lowly – H2-like – to highly – O2-like – correlated regimes. The contributions arising from the presence of competing singlet and triplet states in magnetic systems are analyzed. It is shown that the electronic conductivity provides a signature of the full multiplet energy spectrum, as well as of the multideterminant structure of wavefunctions.
Extracting decay curves of the correlated fluorescence photons measured in fluorescence correlation spectroscopy by Kunihiko Ishii; Tahei Tahara (130-133).
Display Omitted► Combination of time-correlated single photon counting and FCS (TCSPC-FCS). ► TCSPC-FCS data were analyzed with newly introduced 2D correlation maps. ► Emissive uncorrelated background was successfully subtracted. ► Efficient method to determine reliable fluorescence lifetime in FCS experiments.We have developed a new method to extract the decay curves of the correlated fluorescence photons from the data of fluorescence correlation spectroscopy using time-correlated single photon counting. In this method, a two-dimensional correlation map of photon pairs is generated at an absolute delay time with reference to the excitation-emission delay of each photon. Using a dye-labeled DNA as an example, we have demonstrated that the decay curve of the correlated fluorescence photons is separated from the uncorrelated background signals simply by subtracting a two-dimensional correlation map at sufficiently long delay time without additional prior information.
Does B3LYP correctly describe magnetism of manganese complexes with various oxidation numbers and various structural motifs? by Shusuke Yamanaka; Keita Kanda; Toru Saito; Yasutaka Kitagawa; Takashi Kawakami; Masahiro Ehara; Mitsutaka Okumura; Haruki Nakamura; Kizashi Yamaguchi (134-140).
Display Omitted► A first ab initio benchmark of the manganese complexes with various oxidation states and structural motifs. ► We examined all magnetic interactions of 16 complexes and compared the results with the experimental ones. ► We examined B3LYP functional. ► We proposed a modest and reliable basis set for the purpose.We assessed the applicability and basis set dependency of the B3LYP functional to investigate magnetic interactions of Mn complexes. For the purpose, we constructed a test set consisting of 16 Mn complexes with various oxidation states and structural motifs.The B3LYP results correctly reproduced magnetism and magneto–redox correlation of the standard μ-oxo motifs with superexchange paths, while it does not work for weak magnetic complexes. We also showed that a modest basis set yields results similar to those of triple-zeta plus diffuse-and-polarization functions. This basis set is expected to be a standard basis set for investigating magnetism of manganese complexes.
Two-photon-induced intramolecular excited-state proton transfer process and nonlinear optical properties of HBI in ethanol solution by Feng Wu; Lina Ma; Siwen Zhang; Yaohui Geng; Jiang Lü; Xiaoman Cheng (141-144).
The two-photon-induced excited state intramolecular proton transfer (ESIPT) process of 2-(2′-hydroxyphenyl) benzimidazole (HBI) in ethanol solution has been investigated. We focused on the calculation of TPA coefficient and nonlinear refraction index of HBI, and found that the theoretical calculated results were in good agreement with the experimental ones. By establishing the two-photon-induced ESIPT kinetic model for HBI, the TPA cross section was determined to be 2.09 × 104 GM. For their large TPA cross section, HBI is a promising TPA candidate material for their potential application in many fields.Display Omitted► The optical nonlinearity of HBI was investigated for the first time. ► The nonlinear absorption was confirmed to originate from TPA. ► By establishing ESIPT kinetic model, the TPA cross section was obtained. ► The HBI molecules exhibit much larger TPA cross section than other similar structural ones. ► The high nonlinearities were interpreted on the basis of the nonlinear optical molecular design and their origin.The two-photon-induced excited state intramolecular proton transfer (ESIPT) process of 2-(2′-hydroxyphenyl) benzimidazole (HBI) in ethanol solution has been investigated. We focused on the calculation of TPA coefficient and nonlinear refraction index of HBI, and found that the theoretical calculated results were in good agreement with the experimental ones. By establishing the two-photon-induced ESIPT kinetic model for HBI, the TPA cross section was determined to be 2.09 × 104 GM. For their large TPA cross section, HBI is a promising TPA candidate material for their potential application in many fields.
New range-separated hybrids based on the TCA density functional by Jessica Hermet; Pietro Cortona; Carlo Adamo (145-149).
Display Omitted► New range-separated hybrid functionals have been constructed. ► The Hirao and coworkers’ range-separation procedure was used. ► The new hybrids are based on the TCA functional and its global hybrid TCA0. ► The performances of the new functionals have been assessed on various databases. ► Very good results were obtained, particularly by the range-separated TCA0 functional.We have applied the Hirao and coworkers’ range-separation procedure to the recently proposed (GGA-like) TCA functional and to the global hybrid obtained from it by using the theoretical mixing coefficient a 0 = 0.25. The range-separation parameter ω has been determined by optimizing the performances for some commonly used benchmark databases. Successively, we have applied the resulting functionals to the calculation of some vertical excitation energies. We have found that the range-separation procedure strongly improves the performances of both the TCA functional and its global hybrid. The results are better than those obtained by the corresponding range-separated hybrids based on the PBE functional.