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Fusè M, Longhi G, Mazzeo G, Stranges S, Leonelli F, Aquila G, Bodo E, Brunetti B, Bicchi C, Cagliero C, Bloino J, Abbate S. Anharmonic Aspects in Vibrational Circular Dichroism Spectra from 900 to 9000 cm -1 for Methyloxirane and Methylthiirane. J Phys Chem A 2022; 126:6719-6733. [PMID: 36126273 PMCID: PMC9527749 DOI: 10.1021/acs.jpca.2c05332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
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Vibrational circular dichroism (VCD) spectra and the
corresponding
IR spectra of the chiral isomers of methyloxirane and of methylthiirane
have been reinvestigated, both experimentally and theoretically, with
particular attention to accounting for anharmonic corrections, as
calculated by the GVPT2 approach. De novo recorded VCD spectra in
the near IR (NIR) range regarding CH-stretching overtone transitions,
together with the corresponding NIR absorption spectra, were also
considered and accounted for, both with the GVPT2 and with the local
mode approaches. Comparison of the two methods has permitted us to
better describe the nature of active “anharmonic” modes
in the two molecules and the role of mechanical and electrical anharmonicity
in determining the intensities of VCD and IR/NIR data. Finally, two
nonstandard IR/NIR regions have been investigated: the first one about
≈2000 cm–1, involving mostly two-quanta bending
mode transitions, the second one between 7000 and 7500 cm–1 involving three-quanta transitions containing CH-stretching overtones
and HCC/HCH bending modes.
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Affiliation(s)
- Marco Fusè
- Dipartimento di Medicina Molecolare e Traslazionale, Università di Brescia, Viale Europa 11, 25123 Brescia, Italy
| | - Giovanna Longhi
- Dipartimento di Medicina Molecolare e Traslazionale, Università di Brescia, Viale Europa 11, 25123 Brescia, Italy.,Istituto Nazionale di Ottica (INO), CNR, Research Unit of Brescia, c/o CSMT, VIA Branze 45, 25123 Brescia, Italy
| | - Giuseppe Mazzeo
- Dipartimento di Medicina Molecolare e Traslazionale, Università di Brescia, Viale Europa 11, 25123 Brescia, Italy
| | - Stefano Stranges
- Dipartimento di Chimica e Tecnologia del Farmaco, Università"La Sapienza", P.le A. Moro 5, 00185 Roma, Italy.,IOM-CNR, Laboratorio TASC, Basovizza, 34149 Trieste, Italy
| | - Francesca Leonelli
- Dipartimento di Chimica, Università"La Sapienza", P.le A. Moro 5, 00185 Roma, Italy
| | - Giorgia Aquila
- Dipartimento di Chimica, Università"La Sapienza", P.le A. Moro 5, 00185 Roma, Italy
| | - Enrico Bodo
- Dipartimento di Chimica, Università"La Sapienza", P.le A. Moro 5, 00185 Roma, Italy
| | - Bruno Brunetti
- ISMN-CNR, Università La Sapienza, P.le A. Moro 5, 00185 Roma, Italy
| | - Carlo Bicchi
- Dipartimento di Scienza e Tecnologia del Farmaco, Università degli Studi di Torino, Via Pietro Giuria 9,00124 Torino, Italy
| | - Cecilia Cagliero
- Dipartimento di Scienza e Tecnologia del Farmaco, Università degli Studi di Torino, Via Pietro Giuria 9,00124 Torino, Italy
| | - Julien Bloino
- Scuola Normale Superiore, Piazza dei Cavalieri, 56125, Pisa, Italy
| | - Sergio Abbate
- Dipartimento di Medicina Molecolare e Traslazionale, Università di Brescia, Viale Europa 11, 25123 Brescia, Italy.,Istituto Nazionale di Ottica (INO), CNR, Research Unit of Brescia, c/o CSMT, VIA Branze 45, 25123 Brescia, Italy
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Górecki M, Enamullah M, Islam MA, Islam MK, Höfert SP, Woschko D, Janiak C, Pescitelli G. Synthesis and Characterization of Bis[( R or S)- N-1-(X-C 6H 4)ethyl-2-oxo-1-naphthaldiminato-κ 2N, O]-Λ/Δ-cobalt(II) (X = H, p-CH 3O, p-Br) with Symmetry- and Distance-Dependent Vibrational Circular Dichroism Enhancement and Sign Inversion. Inorg Chem 2021; 60:14116-14131. [PMID: 34477372 PMCID: PMC8456410 DOI: 10.1021/acs.inorgchem.1c01503] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
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The enantiopure Schiff
bases (R or S)-N-1-(X-C6H4)ethyl-2-hydroxy-1-naphthaldimine
{X = H [(R or S)-HL1], p-CH3O [(R or S)-HL2],
and p-Br [(R- or S)-HL3]} react with cobalt(II) acetate to give bis[(R or S)-N-1-(X-C6H4)ethyl-2-oxo-1-naphthaldiminato-κ2N,O]-Λ/Δ-cobalt(II) {X = H
[Λ/Δ-Co-(R or S)-L1], p-CH3O [Λ/Δ-Co-(R or S)-L2], and p-Br [Λ/Δ-Co-(R or S)-L3]} (1–3), respectively. Induced Λ and Δ chirality originates
at the metal center of the C2-symmetric
molecule in pseudotetrahedral geometry. Differential scanning calorimetry
analyses explored the thermal stability of the complexes, which undergo
reversible phase transformation from crystalline solid to isotropic
liquid phase for 1 and 3 but irreversible
phase transformation for 2. Like other cobalt(II) complexes,
compounds 1–3 exhibit a continuous
ensemble of absorption and circular dichroism bands, which span from
the UV to IR region and can be collected into a superspectrum. Infrared
vibrational circular dichroism (IR-VCD) spectra witness the coupling
between Co2+-centered low-lying electronic states and ligand-centered
vibrations. The coupling produces enhanced and almost monosignate
VCD spectra, with both effects being mode-dependent in terms of the A or B symmetry (in the C2 point group) and distance from the Co2+ core. Chiroptical superspectra of naphthaldiminatocobalt(II)
complexes 1−3 exhibit a continuous
ensemble of absorption
and circular dichroism bands from the UV to IR region, including peculiar
and almost monosignate vibrational circular dichroism (VCD) spectra
dominated by the coupling between Co2+-centered low-lying
electronic states and ligand-centered vibrations, which depend on
the normal-mode symmetry and distance from the Co2+ core
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Affiliation(s)
- Marcin Górecki
- Department of Chemistry and Industrial Chemistry, University of Pisa, Pisa 56126, Italy.,Institute of Organic Chemistry, Polish Academy of Sciences, Warsaw 01-224, Poland
| | - Mohammed Enamullah
- Department of Chemistry, Jahangirnagar University, Dhaka 1342, Bangladesh
| | | | | | - Simon-Patrick Höfert
- Institute of Inorganic Chemistry and Structural Chemistry, Heinrich-Heine-University of Düsseldorf, Düsseldorf 40225, Germany
| | - Dennis Woschko
- Institute of Inorganic Chemistry and Structural Chemistry, Heinrich-Heine-University of Düsseldorf, Düsseldorf 40225, Germany
| | - Christoph Janiak
- Institute of Inorganic Chemistry and Structural Chemistry, Heinrich-Heine-University of Düsseldorf, Düsseldorf 40225, Germany
| | - Gennaro Pescitelli
- Department of Chemistry and Industrial Chemistry, University of Pisa, Pisa 56126, Italy
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Yang Q, Fusè M, Bloino J, Barone V. Interplay of stereo-electronic, vibronic and environmental effects in tuning the chiroptical properties of an Ir(III) cyclometalated N-heterocyclic carbene. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2021; 254:119631. [PMID: 33761386 DOI: 10.1016/j.saa.2021.119631] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 02/11/2021] [Accepted: 02/14/2021] [Indexed: 06/12/2023]
Abstract
Chiroptical spectra are among the most suitable techniques for investigating the ground and excited electronic states of chiral systems, but their interpretation is not straightforward and strongly benefits from quantum chemical simulations, provided that the employed computational model is sufficiently accurate and deals properly with stereo-electronic, vibrational averaging and environmental effects. Since the synergy among all these effects is only rarely accounted for, especially for large and flexible organometallic systems, the main aim of this contribution is to illustrate the latest developments of computational approaches rooted into the density functional theory for describing stereo-electronic effects and complemented by effective techniques to deal with vibrational modulation effects and solvatochromic shifts. In this connection, chiral iridium complexes offer an especially suitable case study in view of their bright phosphorescence, which is particularly significant for building effective light emitting diodes (OLEDs) and biomarkers and can be finely tuned by the nature of the metal ligands. For instance, a recently synthesized family of cycloiridiated complexes, KC and KD, bearing a pentahelicenic N-heterocyclic carbene (KB), has shown an enhanced long-lasting, bright phosphorescence. Deeper insights into the still unclear nature and origin of the enhancement could be gained by the interpretation of the chiroptical spectra, which is quite challenging in view of the presence of two sources of chirality, the chiral center on Ir and the chiral axis related to the helicene ligand, in addition to the relativistic effects related to the presence of the Ir center. At the same time, the large dimensions of KC and KD hamper the use of the most sophisticated (but prohibitively expensive) computational models, so that more approximate approaches must be validated on a suitable model compound. To this end, after optimizing the computational scheme on a model system devoid of the helicene moiety (KA), we have performed a comprehensive investigation of the KC and KD spectra, whose interpretation is further aided by novel graphical tools. The discussion and analysis of the results will not be focused on the theoretical background, but, rather, on practical details (specific functional, basis set, vibronic model, solvent regime) with the aim of providing general guidelines for the use of last-generation computational spectroscopy tools also by non-specialists.
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Affiliation(s)
- Qin Yang
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy
| | - Marco Fusè
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy
| | - Julien Bloino
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy
| | - Vincenzo Barone
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy.
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Barone V, Alessandrini S, Biczysko M, Cheeseman JR, Clary DC, McCoy AB, DiRisio RJ, Neese F, Melosso M, Puzzarini C. Computational molecular spectroscopy. ACTA ACUST UNITED AC 2021. [DOI: 10.1038/s43586-021-00034-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Yang Q, Fusè M, Bloino J. Theoretical Investigation of the Circularly Polarized Luminescence of a Chiral Boron Dipyrromethene (BODIPY) Dye. Front Chem 2020; 8:801. [PMID: 33102435 PMCID: PMC7522172 DOI: 10.3389/fchem.2020.00801] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 07/30/2020] [Indexed: 01/11/2023] Open
Abstract
Over the last decade, molecules capable of emitting circularly polarized light have attracted growing attention for potential technological and biological applications. The efficiency of such devices depend on multiple parameters, in particular the magnitude and wavelength of the peak of emitted light, and also on the dissymmetry factor for chiral applications. In light of these considerations, molecular systems with tunable optical properties, preferably in the visible spectral region, are particularly appealing. This is the case of boron dipyrromethene (BODIPY) dyes, which exhibit large molecular absorption coefficients, have high fluorescence yields, are very stable, both thermally and photochemically, and can be easily functionalized. The latter property has been extensively exploited in the literature to produce chromophores with a wide range of optical properties. Nevertheless, only a few chiral BODIPYs have been synthetized and investigated so far. Using a recently reported axially chiral BODIPY derivative where an axially chiral BINOL unit has been attached to the chromophore unit, we present a comprehensive computational protocol to predict and interpret the one-photon absorption and emission spectra, together with their chiroptical counterparts. From the physico-chemical properties of this molecule, it will be possible to understand the origin of the circularly polarized luminescence better, thus helping to fine-tune the properties of interest. The sensitivity of such processes require accurate results, which can be achieved through a proper account of the vibrational structure in optical spectra. Methodologies to compute vibrationally-resolved electronic spectra can now be applied on relatively large chromophores, such as BODIPYs, but require more extensive computational protocols. For this reason, particular attention is paid in the description of the different steps of the protocol, and the potential pitfalls. Finally, we show how, by means of appropriate tools and approaches, data from intermediate steps of the simulation of the final spectra can be used to obtain further insights into the properties of the molecular system under investigation and the origin of the visible bands.
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Affiliation(s)
- Qin Yang
- Scuola Normale Superiore, Pisa, Italy
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Keiderling TA. Structure of Condensed Phase Peptides: Insights from Vibrational Circular Dichroism and Raman Optical Activity Techniques. Chem Rev 2020; 120:3381-3419. [DOI: 10.1021/acs.chemrev.9b00636] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Timothy A. Keiderling
- Department of Chemistry, University of Illinois at Chicago 845 West Taylor Street m/c 111, Chicago, Illinois 60607-7061, United States
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Nafie LA. Vibrational optical activity: From discovery and development to future challenges. Chirality 2020; 32:667-692. [DOI: 10.1002/chir.23191] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 01/21/2020] [Accepted: 01/23/2020] [Indexed: 12/13/2022]
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Polavarapu PL, Santoro E. Vibrational optical activity for structural characterization of natural products. Nat Prod Rep 2020; 37:1661-1699. [DOI: 10.1039/d0np00025f] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This review presents the recent progress towards elucidating the structures of chiral natural products and applications using vibrational optical activity (VOA) spectroscopy.
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Evaluation of Molecular Polarizability and of Intensity Carrying Modes Contributions in Circular Dichroism Spectroscopies. APPLIED SCIENCES-BASEL 2019. [DOI: 10.3390/app9214691] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We re-examine the theory of electronic and vibrational circular dichroism spectroscopy in terms of the formalism of frequency-dependent molecular polarizabilities. We show the link between Fermi’s gold rule in circular dichroism and the trace of the complex electric dipole–magnetic dipole polarizability. We introduce the C++ code polar to compute the molecular polarizability complex tensors from quantum chemistry outputs, thus simulating straightforwardly UV-visible absorption (UV-Vis)/electronic circular dichroism (ECD) spectra, and infrared (IR)/vibrational circular dichroism (VCD) spectra. We validate the theory and the code by referring to literature data of a large group of chiral molecules, showing the remarkable accuracy of density functional theory (DFT) methods. We anticipate the application of this methodology to the interpretation of vibrational spectra in various measurement conditions, even in presence of metal surfaces with plasmonic properties. Our theoretical developments aim, in the long run, at embedding the quantum-mechanical details of the chiroptical spectroscopic response of a molecule into the simulation of the electromagnetic field distribution at the surface of plasmonic devices. Such simulations are also instrumental to the interpretation of the experimental spectra measured from devices designed to enhance chiroptical interactions by the surface plasmon resonance of metal nanostructures.
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Chandramouli B, Del Galdo S, Fusè M, Barone V, Mancini G. Two-level stochastic search of low-energy conformers for molecular spectroscopy: implementation and validation of MM and QM models. Phys Chem Chem Phys 2019; 21:19921-19934. [DOI: 10.1039/c9cp03557e] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The search for stationary points in the molecular potential energy surfaces (PES) is a problem of increasing relevance in molecular sciences especially for large, flexible systems featuring several large-amplitude internal motions.
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Affiliation(s)
| | | | | | - Vincenzo Barone
- Scuola Normale Superiore
- 56126 Pisa
- Italy
- Istituto Nazionale di Fisica Nucleare (INFN)
- Sezione di Pisa
| | - Giordano Mancini
- Scuola Normale Superiore
- 56126 Pisa
- Italy
- Istituto Nazionale di Fisica Nucleare (INFN)
- Sezione di Pisa
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