The Gaussian-based multiconfiguration time-dependent Hartree (G-MCTDH) method is applied to calculate the S(2)(pipi( *)) absorption spectrum of pyrazine molecule, whose diffuse structure results from ultrafast nonadiabatic dynamics at S(2)-S(1) conical intersection. 24-mode second-order vibronic-coupling model Raab et al. [J. Chem. Phys. 110, 936 (1999)] employed, along with 4-mode and 10-mode reduced-dimensional variants this model. G-MCTDH can be used either as an all-Gaussian approach or...

The interactions between substituted 5-<italic>R</italic>-3-(pyridyl-2)-1,2,4-triazines with <italic>in situ</italic> generated aryne intermediates have been studied.

A convenient approach towards 5-(aryl/alkyl)amino-1,2,4-triazines and α-arylamino-2,2′-bipyridines was developed following <italic>ipso</italic>-substitution of a cyano-group by amino groups and, finally, aza-Diels-Alder reaction with 1-morpholynocyclopentene.

Herein, a highly efficient palladium-catalyzed tandem approach for the synthesis of 1,2,3-triazolo-azepine-fused benzosuberenes (TAABS) has been developed first time with vinyl bromide and internal alkynes as starting precursors. The given reaction proceeded under ligand- additive-free conditions via sequential carbopalladation, followed by intramolecular electrophilic substitution. Also, protocol good functional group tolerance, wherein range sterically hindered TAABS analogues synthesized...

The molecular anion <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:msup><a:mrow><a:msub><a:mi mathvariant="normal">C</a:mi><a:mn>2</a:mn></a:msub></a:mrow><a:mo>−</a:mo></a:msup></a:math> has been of interest in the past few years as a candidate for laser cooling due to its electronic structure and favorable branching ratios ground vibrational states. Molecular hydrogen used by Wester group at Innsbruck buffer gas cool molecule's internal rovibrational motion. In present work we...

An efficient metal-free single-step protocol has been developed for the direct synthesis of flavones from 2-hydroxyacetophenone and substituted benzaldehydes.

Herein, a heterogeneous Pd/C-catalyzed direct one-step four-component double carbonylative approach for cascade synthesis of 2-aryl quinazolinones has been reported the first time starting from 2-iodoaniline derivatives and aryl iodides. The given reaction involves simultaneous implementation two different gaseous surrogates

Extended cavity pyrene-based iptycenes were synthesized for the turn-off fluorescence detection of RDX and common nitro-aromatic explosives.

We report for the first time an accurate ab initio potential energy surface HeH+-H2 system in four dimensions (4D) treating both diatomic species as rigid rotors. The computed point values are fitted using artificial neural network method and used quantum close coupling calculations different initial states of rotors, their ground electronic states, over a range collision energies. state-to-state cross section results to compute rate coefficients temperatures relevant interstellar...

Full-dimensional quantum mechanical computations are carried out to investigate the photodissociation dynamics of à state NH(3) and ND(3) using multiconfiguration time-dependent Hartree (MCTDH) method with recently developed coupled ab initio potential energy surfaces (PESs) [Z. H. Li, R. Valero, D. G. Truhlar, Theor. Chim. Acc. 118, 9 (2007)]. To use MCTDH efficiently PESs represented as based on high-dimensional model representation. The ← X̃ absorption spectra for both isotopomers were...

The stereo- and regioselective formation of chiral molecules is an interesting important topic in organic synthesis due to its wide applicability intricacy during synthesis. Herein, we disclose a method for the selective functionalization glycal dienes synthesizing different glycosides branched sugars regioselectively. methodology broad regarding substrate scope which various nucleophiles glycals were explored. Furthermore, delve into converting synthesized products naphthalene-fused pyran...

New micelle-forming fluorescence molecular sensors are reported based on 1-hydroxypyrene designed exclusively for the detection of nitro-aliphatic explosives/taggants.

ABSTRACT The anion C5N− is one of the largest linear (C,N)-bearing chains detected in interstellar medium. Here we present and discuss general features new ab initio potential energy surfaces describing interaction this with He H2. We employ a Legendre Polynomials expansion representation for former an artificial neural network fit latter. then carry out quantum scattering calculations to yield rotationally inelastic cross-sections collisions H2, using relative translational values range...

The ground-state properties of the monomer and dimer formic acid, acetic benzoic acid have been investigated using Hartree−Fock (HF) density functional theory (DFT) methods 6-311++G(d,p) basis set. Some low-lying excited states studied time-dependent (TDDFT) with LDA B3LYP functionals also employing complete-active-space-self-consistent-field (CASSCF) multireference configuration interaction (MRCI) methodologies. DFT calculations predict geometries in quantitative agreement available...

In a kinematically complete experiment on the dissociative double ionization of CO2 by electron impact, spontaneous and metastable decay have been observed via channel CO2(2+) --> CO+ + O+. The shows lifetime 5.8 +/- 1.5 micros. measured kinetic energy release spectrum dissociation one broad peak. To understand features, ab initio potential surface (PES) for ground electronic state was computed using multireference configuration interaction method correlation-consistent polarized-valence...

Two different ab initio potential energy surfaces are employed to investigate the efficiency of rotational excitation channels for polar molecular ion HeH+ interacting with He atoms. We further use them quantum dynamics both proton-exchange reaction and purely inelastic collisions over a broad range temperatures. In current modeling studies, this cation is considered be one possible cooling sources under early universe conditions after recombination era has recently been found exist in...

We present the results of a time-dependent quantum mechanical investigation using centrifugal sudden approximation in form reaction probability as function collision energy (E(trans)) range 0.3-3.0 eV for total angular momentum (J) values and excitation sigma(E(trans)) exchange H(-) + H(2) (v = 0, j 0) --> its isotopic variants three dimensions on an accurate ab initio potential surface published recently (J. Chem. Phys. 2004, 121, 9343). The are shown to be excellent agreement with those...

Herein, a first-ever heterogeneous Pd/C-catalyzed single-step tandem approach for the synthesis of 2-carboxamidocyclohexane-1,3-diones via direct carbonylative C–H amidation cyclohexane-1,3-diones is reported. The reaction progressed under base-, oxidant-, and ligand-free conditions employing oxalic acid as CO surrogate sodium azide nitrogen precursor in double-layer vial system.

The collision-induced process He + H(2)(+)(v = 0-2; j 0-3) → H H(+) has been investigated using a time-dependent quantum mechanical wave packet approach, within the centrifugal sudden approximation. exchange reaction H(2)(+) HeH(+) H, which lower threshold, dominates over dissociation entire energy range considered in this study. cross section for both and channels branching ratio between two have computed on McLaughlin-Thompson-Joseph-Sathyamurthy potential-energy surface compared with...

Abstract A Pot, Atom, Step Economic (PASE) approach is reported towards [1, 2,4]triazolo[1, 5‐d][1, 2,4]triazines, substituted with the azole ring pharmacophore residues, such as 1‐adamantyl or 2‐furanyl moieties, naproxen well aliphatic and (het)aromatic substituents, starting from easily available 1,2,4‐triazine‐5‐carbonitriles carboxylic acids hydrazides. This involves a sequence of two solvent‐free reactions accompanied by Dimroth rearrangement on last step. The structures final products...

Abstract We report new results from quantum calculations of energy-transfer processes taking place in interstellar environments and involving two newly observed molecular species: C 5 N − 7 collision with He atoms p–H 2 molecules. These species are part the anionic chains labeled as cyanopolyynes, which have been over years molecule-rich circumstellar envelopes clouds. In present work, we first carry out ab initio for interaction potential then obtain state-to-state rotationally inelastic...

Time-independent quantum mechanical (TIQM) approach (helicity basis truncated at k = 2) has been used for computing differential and integral cross sections the exchange reaction H- + D2 (v 0, j 0-4) --> HD D- H2 0-3) in three dimensions on an accurate ab initio potential energy surface. It is shown that j-weighted section values are good agreement with experimental results reported by Zimmer Linder four different relative translational energies (Etrans 0.55, 0.93, 1.16 1.48 eV) (H-, D2) one...