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  1. Article ; Online: Concerted versus stepwise proton transfer reactions in the [2, 2'-bipyridyl]-3-3'-diol molecule: A static and dynamic ab-initio investigation.

    Briccolani-Bandini, Lorenzo / Brémond, Eric / Pagliai, Marco / Cardini, Gianni / Ciofini, Ilaria / Adamo, Carlo

    Journal of computational chemistry

    2023  Volume 44, Issue 30, Page(s) 2308–2318

    Abstract: The double proton transfer (PT) reaction has been investigated in the [2,2'-bipyridyl]-3-3'-diol, a complex molecule where the proton movements is coupled to significant rearrangement of the electronic structure. Moreover, the reaction could be concerted, ...

    Abstract The double proton transfer (PT) reaction has been investigated in the [2,2'-bipyridyl]-3-3'-diol, a complex molecule where the proton movements is coupled to significant rearrangement of the electronic structure. Moreover, the reaction could be concerted, that is the two protons are exchanged simultaneously, or stepwise, where the two protons are transferred sequentially. To this end, a static exploration of the potential energy surface (PES) was carried together with the analysis of the free-energy surface (FES), both surfaces being evaluated at density functional theory level and different exchange-correlation functionals. While the concerted mechanism has been clearly discharged, the characteristics of the stepwise PT significantly depends on the chosen functionals, some suggesting a clear stepwise mechanism characterized by a stable reaction intermediates and two transitions states, whereas other approaches propend for a asynchronous PT, with a single TS. These features appear on both PES and FES, albeit some differences appears due to their different nature.
    Language English
    Publishing date 2023-08-16
    Publishing country United States
    Document type Journal Article
    ZDB-ID 1479181-X
    ISSN 1096-987X ; 0192-8651
    ISSN (online) 1096-987X
    ISSN 0192-8651
    DOI 10.1002/jcc.27198
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article: Exploring the effect of Mg2+ substitution on amorphous calcium phosphate nanoparticles

    Gelli, Rita / Briccolani-Bandini, Lorenzo / Pagliai, Marco / Cardini, Gianni / Ridi, Francesca / Baglioni, Piero

    Journal of colloid and interface science. 2022 Jan. 15, v. 606

    2022  

    Abstract: The study of Amorphous Calcium Phosphate (ACP) has become a hot topic due to its relevance in living organisms and as a material for biomedical applications. The preparation and characterization of Mg-substituted ACP nanoparticles (AMCP) with tunable Ca/ ... ...

    Abstract The study of Amorphous Calcium Phosphate (ACP) has become a hot topic due to its relevance in living organisms and as a material for biomedical applications. The preparation and characterization of Mg-substituted ACP nanoparticles (AMCP) with tunable Ca/Mg ratio is reported in the present study to address the effect of Mg²⁺ on their structure and stability.AMCPs particles were synthesized by precipitation of the precursors from aqueous solutions. The particles were analyzed in terms of morphology, crystallinity, and thermal stability, to get a complete overview of their physico-chemical characteristics. Computational methods were also employed to simulate the structure of ACP clusters at different levels of Mg²⁺ substitution.Our results demonstrate that AMCP particles with tunable composition and crystallinity can be obtained. The analysis of the heat-induced crystallization of AMCP shows that particles’ stability depends on the degree of Mg²⁺ substitution in the cluster, as confirmed by computational analyses. The presented results shed light on the effect of Mg²⁺ on ACP features at different structural levels and may be useful guidelines for the preparation and design of AMCP particles with a specific Ca/Mg ratio.
    Keywords calcium phosphates ; crystal structure ; crystallization ; thermal stability
    Language English
    Dates of publication 2022-0115
    Size p. 444-453.
    Publishing place Elsevier Inc.
    Document type Article
    ZDB-ID 241597-5
    ISSN 1095-7103 ; 0021-9797
    ISSN (online) 1095-7103
    ISSN 0021-9797
    DOI 10.1016/j.jcis.2021.08.033
    Database NAL-Catalogue (AGRICOLA)

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    In stock of ZB MED Bonn / Germany

    Z 71/707: Show issues

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  3. Article ; Online: "Cyclopropylidene Effect" in the 1,3-Dipolar Cycloaddition of Nitrones to Alkylidene Cyclopropanes: A Computational Rationalization.

    Briccolani-Bandini, Lorenzo / Pagliai, Marco / Cordero, Franca M / Brandi, Alberto / Cardini, Gianni

    The journal of physical chemistry. A

    2021  Volume 125, Issue 18, Page(s) 3892–3899

    Abstract: The regioselectivity in the 1,3-dipolar cycloaddition (1,3-DC) between five-membered cyclic nitrone and methylenecyclopropane (MCP) has been studied through density functional theory (DFT) calculations. The computational study of 1,3-DC with different 1- ... ...

    Abstract The regioselectivity in the 1,3-dipolar cycloaddition (1,3-DC) between five-membered cyclic nitrone and methylenecyclopropane (MCP) has been studied through density functional theory (DFT) calculations. The computational study of 1,3-DC with different 1-alkyl- (or 1,1-dialkyl)-substituted alkenes and the comparison with MCP have evidenced that the electrostatic interaction has a central role in the regioselectivity of the reactions. It has been observed that the electronic effect of the substituent (donor or attractor groups) determines the polarization of the alkene double bond and the reaction mechanism, consequently determining the interaction with nitrones and favoring an orientation between this moiety and the dipolarophile.
    Language English
    Publishing date 2021-04-30
    Publishing country United States
    Document type Journal Article
    ISSN 1520-5215
    ISSN (online) 1520-5215
    DOI 10.1021/acs.jpca.1c02204
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  4. Article ; Online: Exploring the effect of Mg

    Gelli, Rita / Briccolani-Bandini, Lorenzo / Pagliai, Marco / Cardini, Gianni / Ridi, Francesca / Baglioni, Piero

    Journal of colloid and interface science

    2021  Volume 606, Issue Pt 1, Page(s) 444–453

    Abstract: Hypothesis: The study of Amorphous Calcium Phosphate (ACP) has become a hot topic due to its relevance in living organisms and as a material for biomedical applications. The preparation and characterization of Mg-substituted ACP nanoparticles (AMCP) ... ...

    Abstract Hypothesis: The study of Amorphous Calcium Phosphate (ACP) has become a hot topic due to its relevance in living organisms and as a material for biomedical applications. The preparation and characterization of Mg-substituted ACP nanoparticles (AMCP) with tunable Ca/Mg ratio is reported in the present study to address the effect of Mg
    Experiments: AMCPs particles were synthesized by precipitation of the precursors from aqueous solutions. The particles were analyzed in terms of morphology, crystallinity, and thermal stability, to get a complete overview of their physico-chemical characteristics. Computational methods were also employed to simulate the structure of ACP clusters at different levels of Mg
    Findings: Our results demonstrate that AMCP particles with tunable composition and crystallinity can be obtained. The analysis of the heat-induced crystallization of AMCP shows that particles' stability depends on the degree of Mg
    MeSH term(s) Calcium Phosphates ; Crystallization ; Nanoparticles
    Chemical Substances Calcium Phosphates ; amorphous calcium phosphate
    Language English
    Publishing date 2021-08-09
    Publishing country United States
    Document type Journal Article
    ZDB-ID 241597-5
    ISSN 1095-7103 ; 0021-9797
    ISSN (online) 1095-7103
    ISSN 0021-9797
    DOI 10.1016/j.jcis.2021.08.033
    Database MEDical Literature Analysis and Retrieval System OnLINE

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    In stock of ZB MED Bonn / Germany

    Z 71/707: Show issues

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  5. Article: Computational Investigation of the Selective Cleavage of Diastereotopic Cyclopropane Bonds in 5-Spirocyclopropane Isoxazolidines Rearrangement

    Briccolani-Bandini, Lorenzo / Brandi, Alberto / Cardini, Gianni / Chelli, Riccardo / Cordero, Franca M / Gellini, Cristina / Pagliai, Marco

    Journal of organic chemistry. 2019 May 01, v. 84, no. 11

    2019  

    Abstract: The complete path of the Brandi–Guarna rearrangement of 5-spirocyclopropane isoxazolidines has been investigated by means of density functional theory calculations to rationalize the competing formation of tetrahydropyridones and enaminones by the ... ...

    Abstract The complete path of the Brandi–Guarna rearrangement of 5-spirocyclopropane isoxazolidines has been investigated by means of density functional theory calculations to rationalize the competing formation of tetrahydropyridones and enaminones by the determination of the minimum energy reaction paths. Our calculations confirm that the rearrangement is triggered by the homolysis of the isoxazolidine N–O bond followed by cleavage of one of the two C–CH2 cyclopropane bonds as previously proposed by the Fabian group [Eur. J. Org. Chem. 2001, 2001, 4223]. In addition, the results of this work suggest that in the presence of a stereogenic center at isoxazolidine C-4′, the formation of a piperidinone or an enaminone as the final product depends on which of the two diastereotopic C–CH2 bonds of cyclopropane is cleaved in the second step of the process. The result can be of great interest for the understanding of other processes involving the opening of a cyclopropane ring.
    Keywords chemical bonding ; chemical reactions ; chemical structure ; density functional theory ; energy ; homolytic cleavage ; organic chemistry ; organic compounds
    Language English
    Dates of publication 2019-0501
    Size p. 6757-6764.
    Publishing place American Chemical Society
    Document type Article
    ZDB-ID 123490-0
    ISSN 1520-6904 ; 0022-3263
    ISSN (online) 1520-6904
    ISSN 0022-3263
    DOI 10.1021/acs.joc.9b00499
    Database NAL-Catalogue (AGRICOLA)

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    In stock of ZB MED Bonn / Germany

    Z 4' 49/42: Show issues
    Z 7.1: Show issues

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  6. Article ; Online: Computational Investigation of the Selective Cleavage of Diastereotopic Cyclopropane Bonds in 5-Spirocyclopropane Isoxazolidines Rearrangement.

    Briccolani-Bandini, Lorenzo / Brandi, Alberto / Cardini, Gianni / Chelli, Riccardo / Cordero, Franca M / Gellini, Cristina / Pagliai, Marco

    The Journal of organic chemistry

    2019  Volume 84, Issue 11, Page(s) 6757–6764

    Abstract: The complete path of the Brandi-Guarna rearrangement of 5-spirocyclopropane isoxazolidines has been investigated by means of density functional theory calculations to rationalize the competing formation of tetrahydropyridones and enaminones by the ... ...

    Abstract The complete path of the Brandi-Guarna rearrangement of 5-spirocyclopropane isoxazolidines has been investigated by means of density functional theory calculations to rationalize the competing formation of tetrahydropyridones and enaminones by the determination of the minimum energy reaction paths. Our calculations confirm that the rearrangement is triggered by the homolysis of the isoxazolidine N-O bond followed by cleavage of one of the two C-CH
    Language English
    Publishing date 2019-05-10
    Publishing country United States
    Document type Journal Article
    ZDB-ID 123490-0
    ISSN 1520-6904 ; 0022-3263
    ISSN (online) 1520-6904
    ISSN 0022-3263
    DOI 10.1021/acs.joc.9b00499
    Database MEDical Literature Analysis and Retrieval System OnLINE

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    In stock of ZB MED Cologne/Königswinter

    Zs.A 4473: Show issues Location:
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