Publications by authors named "Morgante P"

This work explores an efficient and numerically accurate procedure to obtain the Fukui function from fractional orbital occupation calculations. The energy- and density-linearity conditions are investigated in the context of using optimally tuned range-separated hybrid functionals for the calculation of the Fukui function. The methodology is then used to study the reactivity of organic radicals exhibiting energetic inversion between the singly occupied molecular orbital (SOMO) and the highest occupied molecular orbital (HOMO), that is, SOMO-HOMO inversion (SHI).

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This study confirms the hypothesis that [MnCl(OPPh)] () and acetonitrile-solvated MnCl (i.e., [MnCl(MeCN)]) can be used as synthons to prepare Mn(III) chloride complexes with facially coordinating ligands.

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Density-corrected (DC) density functional theory (DFT) has been proposed to overcome difficulties related to the self-interaction error. The procedure uses the Hartree-Fock electron density (matrix) non-self-consistently in conjunction with an approximate functional. DC-DFT has so far mainly been tested for total energy differences, whereas other types of molecular properties have not been evaluated systematically.

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This work analyzes the performance of 250 electronic structure theory methods (including 240 density functional approximations) for the description of spin states and the binding properties of iron, manganese, and cobalt porphyrins. The assessment employs the Por21 database of high-level computational data (CASPT2 reference energies taken from the literature). Results show that current approximations fail to achieve the "chemical accuracy" target of 1.

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The experimental measurement of the photophysical and chiroptical properties of helicene-based π-conjugated emitters with electron-accepting (-CN, -py, -NO) or donating (TMS, NMe, NH) moieties is reported at low temperature (77 K). The samples exhibit strong circularly polarized phosphorescence in frozen solution of 2-MeTHF, with a luminescence dissymmetry factor reaching 1.6 × 10 and a lifetime of over 0.

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Allylation reactions of aldehydes are chemical transformations of fundamental interest, as they give direct access to chiral homoallylic alcohols. In this work, we focus on the full computational characterization of the catalytic activity of substituted biisoquinoline-N,N'-dioxides for the allylation of 2-naphthaldehyde. We characterized the structure of all transition states as well as identified the π stacking interactions that are responsible for their relative energies.

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This work details the synthesis, characterization, and catalytic activity of reactive low-coordinate organozinc complexes. The complexes activate hydrogen and they appear to be more active in hydrogenation of ketones and imines than their tridentate pincer analogs. This is thought, in part, to be due to the lack of trailing third phosphorus arm present in previous work.

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A new database, VROA36, is introduced to investigate the performance of computational approaches for vibrational Raman optical activity (VROA) calculations. The database is composed of 36 molecules with known experimental VROA spectra. It includes 93 conformers.

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Two series of zinc salts, [EtZn][A] and Zn[A], with weakly coordinating anions [A] as counterions have been prepared, and their activities as catalysts for hydrosilylation reactions of 1-hexene, benzophenone, and acetophenone have been investigated. The counterions and per- and partially chlorinated 1-ammonio--dodecaborate anions [MeNBCl] [], [PrNBHCl] [], [BuNBHCl] [], and [HexNBHCl] [] were chosen as potential and more readily available alternatives to carborate anions such as [CHBCl] and [HexCBCl]. The basicity of anion [] was determined as being close to that of the triflimide anion [N(SOCF)], and the fluoride ion affinities (FIAs) of compounds [EtZn][] and Zn[] are lower than those of the Lewis acids B(CF) and Zn[HexCBCl].

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This article summarizes technical advances contained in the fifth major release of the Q-Chem quantum chemistry program package, covering developments since 2015. A comprehensive library of exchange-correlation functionals, along with a suite of correlated many-body methods, continues to be a hallmark of the Q-Chem software. The many-body methods include novel variants of both coupled-cluster and configuration-interaction approaches along with methods based on the algebraic diagrammatic construction and variational reduced density-matrix methods.

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Article Synopsis
  • The 7-nitroindolinyl family of caging chromophores has been studied for two decades, but their uncaging mechanism is still not fully understood.
  • State-of-the-art density functional theory calculations revealed that two uncaging pathways—classical cyclization and acyl migration—compete, with the latter showing characteristics of a unique mechanism combining Norrish types I and II.
  • The study explains improved quantum yields in certain chromophores by their better triplet excited state dynamics, potentially leading to more effective designs for these caging molecules.
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The aim of the present work was the biophysical characterization of the Amynthas gracilis hemoglobin (HbAg). The oxy-HbAg optical absorption data, with Soret and Q bands centered at 415, 540 and 575 nm, were stable and unchanged at pH 7.0.

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Plants are continuously exposed to agents that can generate DNA lesions. Nucleotide Excision Repair (NER) is one of the repair pathways employed by plants to protect their genome, including from sunlight. The Xeroderma Pigmentosum type B (XPB) protein is a DNA helicase shown to be involved in NER and is also an essential subunitof the Transcription Factor IIH (TFIIH) complex.

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The amount of data and number of databases for the assessment and parameterization of density functional theory methods has grown substantially in the past two decades. In this work, we introduce a novel cluster analysis technique for density functional theory calculations of the electronic structure of atoms and molecules with the goal of creating new statistically significant databases with broad chemical scope, and a manageable number of data-points. By analyzing without a priori chemical assumptions a population of almost 350k data-points, we create a new database called ASCDB containing only 200 data-points.

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The generation of an iminium from amines is a way to functionalize the α carbon by coupling reactions. The reaction mechanism of the conversion of tertiary amines to iminium with CuCl(HO) as catalyst in aerobic conditions has been computationally and experimentally studied in this work. This process is initiated by the oxidation of the amine to a radical cation dichlorocuprate through the reduction of Cu to Cu.

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The importance of databases of reliable and accurate data in chemistry has substantially increased in the past two decades. Their main usage is to parametrize electronic structure theory methods, and to assess their capabilities and accuracy for a broad set of chemical problems. The collection we present here-ACCDB-includes data from 16 different research groups, for a total of 44,931 unique reference data points, all at a level of theory significantly higher than density functional theory, and covering most of the periodic table.

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The design, synthesis, and evaluation of axial-chiral biisoquinolines bearing polar aromatic C-H bonds as Lewis base catalysts are reported. Lewis bases containing the 3,5-bis(trifluoromethyl)phenyl group were found to be significantly more enantioselective for a wider range of substrates than those bearing aromatic residues that are not strongly electron-deficient in the allylation of aldehydes with allyltrichlorosilane. Also, optically pure 3,3'-dibromo-1,1'-biisoquinoline N, N'-dioxide that has not been previously reported was synthesized as a common catalyst precursor to facilitate the study.

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Premise Of The Study: We developed the first set of microsatellite markers for Pimenta pseudocaryophyllus to support further studies on genetic diversity and to inform conservation strategies.

Methods And Results: The microsatellite-enriched library approach was used to isolate and characterize 12 new molecular markers. It was possible to detect 11 polymorphic microsatellite loci and one monomorphic locus.

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The xeroderma pigmentosum complementation group B (XPB) protein is involved in both DNA repair and transcription in human cells. It is a component of the transcription factor IIH (TFIIH) and is responsible for DNA helicase activity during nucleotide (nt) excision repair (NER). Its high evolutionary conservation has allowed identification of homologous proteins in different organisms, including plants.

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Nucleotide excision repair in Arabidopsis thaliana differs from other eukaryotes as it contains two paralogous copies of the corresponding XPB/RAD25 gene. In this work, the functional characterization of one copy, AtXPB1, is presented. The plant gene was able to partially complement the UV sensitivity of a yeast rad25 mutant strain, thus confirming its involvement in nucleotide excision repair.

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Background: The compositional nature of the pigment of melanosis coli is essentially unknown. Previous histochemical studies suggested that this pigment has certain similarities with lipofuscin (i.e.

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The recent recovery of Mycobacterium paratuberculosis from tissues of patients with Crohn's disease has highlighted the possible etiologic role of this microorganism in the disease. However, the immunological evidence generated by various groups supporting this hypothesis is as yet inconclusive. A specific antibody response might be masked in these patients by the wide antigenic homologies prevailing within the genus Mycobacterium.

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