1
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Quintano M, Moura RT, Kraka E. Exploring Jahn-Teller distortions: a local vibrational mode perspective. J Mol Model 2024; 30:102. [PMID: 38478107 DOI: 10.1007/s00894-024-05882-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Accepted: 02/20/2024] [Indexed: 04/06/2024]
Abstract
The characterization of normal mode (CNM) procedure coupled with an adiabatic connection scheme (ACS) between local and normal vibrational modes, both being a part of the Local Vibrational Mode theory developed in our group, can identify spectral changes as structural fingerprints that monitor symmetry alterations, such as those caused by Jahn-Teller (JT) distortions. Employing the PBE0/Def2-TZVP level of theory, we investigated in this proof-of-concept study the hexaaquachromium cation case,[ Cr ( OH 2 ) 6 ] 3 + /[ Cr ( OH 2 ) 6 ] 2 + , as a commonly known example for a JT distortion, followed by the more difficult ferrous and ferric hexacyanide anion case,[ Fe ( CN ) 6 ] 4 - /[ Fe ( CN ) 6 ] 3 - . We found that in both cases CNM of the characteristic normal vibrational modes reflects delocalization consistent with high symmetry and ACS confirms symmetry breaking, as evidenced by the separation of axial and equatorial group frequencies. As underlined by the Cremer-Kraka criterion for covalent bonding, from[ Cr ( OH 2 ) 6 ] 3 + to[ Cr ( OH 2 ) 6 ] 2 + there is an increase in axial covalency whereas the equatorial bonds shift toward electrostatic character. From[ Fe ( CN ) 6 ] 4 - to[ Fe ( CN ) 6 ] 3 - we observed an increase in covalency without altering the bond nature. Distinct π back-donation disparity could be confirmed by comparison with the isolated CN- system. In summary, our study positions the CNM/ACS protocol as a robust tool for investigating less-explored JT distortions, paving the way for future applications.
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Affiliation(s)
- Mateus Quintano
- Computational and Theoretical Chemistry Group (CATCO), Department of Chemistry, Southern Methodist University, 3215 Daniel Ave, Dallas, TX, 75275-0314, USA
| | - Renaldo T Moura
- Computational and Theoretical Chemistry Group (CATCO), Department of Chemistry, Southern Methodist University, 3215 Daniel Ave, Dallas, TX, 75275-0314, USA
- Department of Chemistry and Physics, Center of Agrarian Sciences, Federal University of Paraiba, Areia, PB, 58397-000, Brazil
| | - Elfi Kraka
- Computational and Theoretical Chemistry Group (CATCO), Department of Chemistry, Southern Methodist University, 3215 Daniel Ave, Dallas, TX, 75275-0314, USA.
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2
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Talewar SK, Pardo LC, Headen TF, Halukeerthi SO, Chikani B, Rosu-Finsen A, Salzmann CG. Hydrophobic hydration of the hydrocarbon adamantane in amorphous ice. Faraday Discuss 2024; 249:69-83. [PMID: 37794776 PMCID: PMC10845010 DOI: 10.1039/d3fd00102d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 06/19/2023] [Indexed: 10/06/2023]
Abstract
Hydrophobic molecules are by definition difficult to hydrate. Previous studies in the area of hydrophobic hydration have therefore often relied on using amphiphilic molecules where the hydrophilic part of a molecule enabled the solubility in liquid water. Here, we show that the hydrophobic adamantane (C10H16) molecule can be fully hydrated through vapour codeposition with water onto a cryogenic substrate at 80 K resulting in the matrix isolation of adamantane in amorphous ice. Using neutron diffraction in combination with the isotopic substitution method and the empirical potential structure refinement technique, we find that the first hydration shell of adamantane is well structured consisting of a hydrogen-bonded cage of 28 water molecules that is also found in cubic structure II clathrate hydrates. The four hexagonal faces of the 51264 cage are situated above the four methine (CH) groups of adamantane whereas the methylene (CH2) groups are positioned below the edges of two adjoining pentagonal faces. The oxygen atoms of the 28 water molecules can be categorised on the basis of symmetry equivalences as twelve A, twelve B and four C oxygens. The water molecules of the first hydration shell display orientations consistent with those expected for a clathrate-hydrate-type cage, but also unfavourable ones with respect to the hydrogen bonding between the water molecules. Annealing the samples at 140 K, which is just below the crystallisation temperature of the matrix, removes the unfavourable orientations and leads to a slight increase in the structural order of the first hydration shell. The very closest water molecules display a tendency for their dipole moments to point towards the adamantane which is attributed to steric effects. Other than this, no significant polarisation effects are observed which is consistent with weak interactions between adamantane and the amorphous ice matrix. FT-IR spectroscopy shows that the incorporation of adamantane into amorphous ice leads to a weakening of the hydrogen bonds. In summary, the matrix-isolation of the highly symmetric adamantane in amorphous ice provides an interesting test case for hydrophobic hydration. Studying the structure and spectroscopic properties of water at the interface with hydrophobic hydrocarbons is also relevant for astrophysical environments, such as comets or the interstellar medium, where amorphous ice and hydrocarbons have been shown to coexist in large quantities.
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Affiliation(s)
- Sukhpreet K Talewar
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK.
| | - Luis Carlos Pardo
- Grup de Caracterització de Materials, Departament de Física, EEBE, Universitat Politècnica de Catalunya, and Barcelona Research Center in Multiscale Science and Engineering, C/Eduard Maristany 10, E-08019 Barcelona, Spain
| | - Thomas F Headen
- ISIS Pulsed Neutron and Muon Source, STFC Rutherford Appleton Laboratory, Harwell Campus, OX11 0QX, UK
| | - Siriney O Halukeerthi
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK.
| | - Bharvi Chikani
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK.
| | - Alexander Rosu-Finsen
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK.
| | - Christoph G Salzmann
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK.
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Miyazaki M, Ono M, Otsuka R, Dopfer O, Fujii M. Electronic and vibrational spectroscopies of aromatic clusters with He in a supersonic jet: The case of neutral and cationic phenol-Hen (n = 1 and 2). J Chem Phys 2023; 159:134303. [PMID: 37787127 DOI: 10.1063/5.0169716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 09/15/2023] [Indexed: 10/04/2023] Open
Abstract
Van der Waals clusters composed of He and aromatic molecules provide fundamental information about intermolecular interactions in weakly bound systems. In this study, phenol-helium clusters (PhOH-Hen with n ≤ 2) are characterized for the first time by UV and IR spectroscopies. The S1 ← S0 origin and ionization energy both show small but additive shifts, suggesting π-bound structures of these clusters, a conclusion supported by rotational contour analyses of the S1 origin bands. The OH stretching vibrations of the PhOH moiety in the clusters match with those of bare PhOH in both the S0 and D0 states, illustrating the negligible perturbation of the He atoms on the molecular vibration. Matrix shifts induced by He attachment are discussed based on the observed band positions with the help of complementary quantum chemical calculations. For comparison, the UV and ionization spectra of PhOH-Ne are reported as well.
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Affiliation(s)
- Mitsuhiko Miyazaki
- Natural Science Division, Faculty of Core Research, Ochanomizu University, 2-1-1 Ohtsuka, Bunkyo-ku, Tokyo 112-8610, Japan
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Megumi Ono
- School of Life Science and Technology, Tokyo Institute of Technology, 4259, Nagatsuta-cho, Midori-ku, Yokohama 226-8503, Japan
| | - Remina Otsuka
- School of Life Science and Technology, Tokyo Institute of Technology, 4259, Nagatsuta-cho, Midori-ku, Yokohama 226-8503, Japan
| | - Otto Dopfer
- Institut für Optik und Atomare Physik, Technische Universität Berlin, 10623 Berlin, Germany
- International Research Frontiers Initiative (IRFI), Institute of Innovation Research, Tokyo Institute of Technology, 4259, Nagatsuta-cho, Midori-ku, Yokohama 226-8503, Japan
| | - Masaaki Fujii
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan
- School of Life Science and Technology, Tokyo Institute of Technology, 4259, Nagatsuta-cho, Midori-ku, Yokohama 226-8503, Japan
- International Research Frontiers Initiative (IRFI), Institute of Innovation Research, Tokyo Institute of Technology, 4259, Nagatsuta-cho, Midori-ku, Yokohama 226-8503, Japan
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4
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Rubli PT, Dopfer O. Infrared spectrum of the 1-cyanoadamantane cation: evidence of hydrogen transfer and cage-opening upon ionization. Phys Chem Chem Phys 2023; 25:22734-22743. [PMID: 37584199 DOI: 10.1039/d3cp03417h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/17/2023]
Abstract
The radical cations of diamondoids are important intermediates in their functionalization reactions and are also candidates as carriers for astronomical absorption and emission features. Although neutral diamondoids have been studied extensively, information regarding their radical cations is largely lacking, particularly for functionalized diamondoid derivatives. Herein, we characterize the structure of the 1-cyanoadamantane radical cation (C10H15CN+, AdCN+) using infrared photodissociation (IRPD) spectroscopy of mass selected AdCN+N2 clusters in the XH stretch range (2400-3500 cm-1) and dispersion-corrected density functional theory calculations (B3LYP-D3BJ/cc-pVTZ). A group of three distinct CH stretch bands are observed in the 2800-3000 cm-1 range, in addition to a highly redshifted absorption at 2580 cm-1 attributed to the acidic CH proton predicted by calculations. An unexpected broad absorption peaking at 3320 cm-1 is also detected and assigned to an NH stretch mode based on its width and frequency. Calculations indicate that hydrogen atom transfer (HAT) from the adamantyl cage (C10H15, Ady) to the N atom of the CN group yields lower energy structures, with an open-cage isomer exhibiting such hydrogen transfer being the global minimum on the potential energy surface. The energy barriers involved in the formation of this open-cage isomer are also lower than those calculated for generation of the analogous open-cage 1-amantadine cation isomer which has previously been identified by IRPD. The combined consideration of IRPD spectra and calculations indicates a major population of the nascent canonical closed-cage isomer and a smaller population of the global minimum isomer featuring both cage-opening and hydrogen transfer.
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Affiliation(s)
- Peter Theodore Rubli
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany.
| | - Otto Dopfer
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany.
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5
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George MAR, Dopfer O. Microhydration of the adamantane cation: intracluster proton transfer to solvent in [Ad(H 2O) n=1-5] + for n ≥ 3. Phys Chem Chem Phys 2023; 25:13593-13610. [PMID: 37144298 DOI: 10.1039/d3cp01514a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Radical cations of diamondoids are important intermediates in their functionalization reactions in polar solvents. To explore the role of the solvent at the molecular level, we characterize herein microhydrated radical cation clusters of the parent molecule of the diamondoid family, adamantane (C10H16, Ad), by infrared photodissociation (IRPD) spectroscopy of mass-selected [Ad(H2O)n=1-5]+ clusters. IRPD spectra of the cation ground electronic state recorded in the CH/OH stretch and fingerprint ranges reveal the first steps of this fundamental H-substitution reaction at the molecular level. Analysis of size-dependent frequency shifts with dispersion-corrected density functional theory calculations (B3LYP-D3/cc-pVTZ) provides detailed information about the acidity of the proton of Ad+ as a function of the degree of hydration, the structure of the hydration shell, and the strengths of the CH⋯O and OH⋯O hydrogen bonds (H-bonds) of the hydration network. For n = 1, H2O strongly activates the acidic C-H bond of Ad+ by acting as a proton acceptor in a strong CH⋯O ionic H-bond with cation-dipole configuration. For n = 2, the proton is almost equally shared between the adamantyl radical (C10H15, Ady) and the (H2O)2 dimer in a strong C⋯H⋯O ionic H-bond. For n ≥ 3, the proton is completely transferred to the H-bonded hydration network. The threshold for this size-dependent intracluster proton transfer to solvent is consistent with the proton affinities of Ady and (H2O)n and confirmed by collision-induced dissociation experiments. Comparison with other related microhydrated cations reveals that the acidity of the CH proton of Ad+ is in the range of strongly acidic phenol+ but lower than for cationic linear alkanes such as pentane+. Significantly, the presented IRPD spectra of microhydrated Ad+ provide the first spectroscopic molecular-level insight of the chemical reactivity and reaction mechanism of the important class of transient diamondoid radical cations in aqueous solution.
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Affiliation(s)
| | - Otto Dopfer
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany.
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6
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George MAR, Dopfer O. Microhydrated clusters of a pharmaceutical drug: infrared spectra and structures of amantadineH +(H 2O) n. Phys Chem Chem Phys 2023; 25:5529-5549. [PMID: 36723361 DOI: 10.1039/d2cp04556g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Solvation of pharmaceutical drugs has an important effect on their structure and function. Analysis of infrared photodissociation spectra of amantadineH+(H2O)n=1-4 clusters in the sensitive OH, NH, and CH stretch range by quantum chemical calculations (B3LYP-D3/cc-pVTZ) provides a first impression of the interaction of this pharmaceutically active cation with water at the molecular level. The size-dependent frequency shifts reveal detailed information about the acidity of the protons of the NH3+ group of N-protonated amantadineH+ (AmaH+) and the strength of the NH⋯O and OH⋯O hydrogen bonds (H-bonds) of the hydration network. The preferred cluster growth begins with sequential hydration of the NH3+ group by NH⋯O ionic H-bonds (n = 1-3), followed by the extension of the solvent network through OH⋯O H-bonds. However, smaller populations of cluster isomers with an H-bonded solvent network and free N-H bonds are already observed for n ≥ 2, indicating the subtle competition between noncooperative ion hydration and cooperative H-bonding. Interestingly, cyclic water ring structures are identified for n ≥ 3, each with two NH⋯O and two OH⋯O H-bonds. Despite the increasing destabilization of the N-H proton donor bonds upon gradual hydration, no proton transfer to the (H2O)n solvent cluster is observed up to n = 4. In addition to ammonium cluster ions, a small population of microhydrated iminium isomers is also detected, which is substantially lower for the hydrophilic H2O than for the hydrophobic Ar environment.
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Affiliation(s)
| | - Otto Dopfer
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany.
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7
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Kappe M, Schiller A, Krasnokutski SA, Ončák M, Scheier P, Cunningham EM. Electronic spectroscopy of cationic adamantane clusters and dehydrogenated adamantane in helium droplets. Phys Chem Chem Phys 2022; 24:23142-23151. [PMID: 36148794 PMCID: PMC9533311 DOI: 10.1039/d2cp03523e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report the first helium-tagged electronic spectra of cationic adamantane clusters, along with its singly, doubly, and triply dehydrogenated analogues embedded in helium droplets. Absorption spectra were measured by recording the evaporation of helium atoms as a function of laser wavelength in the range of 300-2150 nm. Experimental spectra are coupled with simulated spectra obtained from quantum chemical calculations. The spectrum of cationic adamantane agrees with the electronic photodissociation spectrum measured previously, with an additional low-energy absorption at around 1000 nm. The spectra of the dehydrogenated molecules present broad absorptions exclusively in the high-energy region (300-600 nm). For the higher order adamantane dimer and trimer ions, strong absorptions are observed in the low-energy region (900-2150 nm), rationalised by transitions delocalised over two adamantane units.
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Affiliation(s)
- Miriam Kappe
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020, Innsbruck, Austria.
| | - Arne Schiller
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020, Innsbruck, Austria.
| | - Serge A Krasnokutski
- Laboratory Astrophysics Group of the MPI for Astronomy at the University of Jena, Helmholtzweg 3, D-07743, Jena, Germany
| | - Milan Ončák
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020, Innsbruck, Austria.
| | - Paul Scheier
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020, Innsbruck, Austria.
| | - Ethan M Cunningham
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020, Innsbruck, Austria.
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8
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George MAR, Dopfer O. Infrared spectra and structures of protonated amantadine isomers: detection of ammonium and open-cage iminium ions. Phys Chem Chem Phys 2022; 24:16101-16111. [PMID: 35748364 DOI: 10.1039/d2cp01947g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The protonated form of amantadine (1-C10H15NH2, Ama), the amino derivative of adamantane (C10H16, Ada), is a wide-spread antiviral and anti-Parkinsonian drug and plays a key role in many pharmaceutical processes. Recent studies reveal that the adamantyl cage (C10H15) of Ama can open upon ionization leading to distonic bicyclic iminium isomers, in addition to the canonical nascent Ama+ isomer. Herein, we study protonation of Ama using infrared photodissociation spectroscopy (IRPD) of Ar-tagged ions and density functional theory calculations to characterize cage and open-cage isomers of AmaH+ and the influence of the electron-donating NH2 group on the cage-opening reaction potential. In addition to the canonical ammonium isomer (AmaH+(I)) with an intact adamantyl cage, we identify at least one slightly less stable protonated bicyclic iminium ion (AmaH+(II)). While the ammonium ion is generated by protonation of the basic NH2 group, AmaH+(II) is formally formed by H addition to a distonic bicyclic iminium ion produced upon ionization of Ama and subsequent cage opening.
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Affiliation(s)
| | - Otto Dopfer
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany.
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9
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George MAR, Dopfer O. Opening of the Diamondoid Cage upon Ionization Probed by Infrared Spectra of the Amantadine Cation Solvated by Ar, N 2 , and H 2 O. Chemistry 2022; 28:e202200577. [PMID: 35611807 PMCID: PMC9400954 DOI: 10.1002/chem.202200577] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Indexed: 01/18/2023]
Abstract
Radical cations of diamondoids, a fundamental class of very stable cyclic hydrocarbon molecules, play an important role in their functionalization reactions and the chemistry of the interstellar medium. Herein, we characterize the structure, energy, and intermolecular interaction of clusters of the amantadine radical cation (Ama+, 1‐aminoadamantane) with solvent molecules of different interaction strength by infrared photodissociation (IRPD) spectroscopy of mass‐selected Ama+Ln clusters, with L=Ar (n≤3) and L=N2 and H2O (n=1), and dispersion‐corrected density functional theory calculations (B3LYP−D3/cc‐pVTZ). Three isomers of Ama+ generated by electron ionization are identified by the vibrational properties of their rather different NH2 groups. The ligands bind preferentially to the acidic NH2 protons, and the strength of the NH…L ionic H‐bonds are probed by the solvation‐induced red‐shifts in the NH stretch modes. The three Ama+ isomers include the most abundant canonical cage isomer (I) produced by vertical ionization, which is separated by appreciable barriers from two bicyclic distonic iminium ions obtained from cage‐opening (primary radical II) and subsequent 1,2 H‐shift (tertiary radical III), the latter of which is the global minimum on the Ama+ potential energy surface. The effect of solvation on the energetics of the potential energy profile revealed by the calculations is consistent with the observed relative abundance of the three isomers. Comparison to the adamantane cation indicates that substitution of H by the electron‐donating NH2 group substantially lowers the barriers for the isomerization reaction.
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Affiliation(s)
| | - Otto Dopfer
- Institut für Optik und Atomare PhysikTechnische Universität BerlinHardenbergstr. 3610623BerlinGermany
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10
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Müller D, Dopfer O. Microsolvation of H 2O +, H 3O +, and CH 3OH 2+ by He in a cryogenic ion trap: structure of solvation shells. Phys Chem Chem Phys 2022; 24:11222-11233. [PMID: 35481676 DOI: 10.1039/d2cp01192a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Due to the weak interactions of He atoms with neutral molecules and ions, the preparation of size-selected clusters for the spectroscopic characterization of their structures, energies, and large amplitude motions is a challenging task. Herein, we generate H2O+Hen (n ≤ 9) and H3O+Hen (n ≤ 5) clusters by stepwise addition of He atoms to mass-selected ions stored in a cryogenic 22-pole ion trap held at 5 K. The population of the clusters as a function of n provides insight into the structure of the first He solvation shell around these ions given by the anisotropy of the cation-He interaction potential. To rationalize the observed cluster size distributions, the structural, energetic, and vibrational properties of the clusters are characterized by ab initio calculations up to the CCSD(T)/aug-cc-pVTZ level. The cluster growth around both the open-shell H2O+ and closed-shell H3O+ ions begins by forming nearly linear and equivalent OH⋯He hydrogen bonds (H-bonds) leading to symmetric structures. The strength of these H-bonds decreases slightly with n due to noncooperative three-body induction forces and is weaker for H3O+ than for H2O+ due to both enhanced charge delocalization and reduced acidity of the OH protons. After filling all available H-bonded sites, addition of further He ligands around H2O+ (n = 3-4) occurs at the electrophilic singly occupied 2pz orbital of O leading to O⋯He p-bonds stabilized by induction and small charge transfer from H2O+ to He. As this orbital is filled for H3O+, He atoms occupy in the n = 4-6 clusters positions between the H-bonded He atoms, leading to a slightly distorted regular hexagon ring for n = 6. Comparison between H3O+Hen and CH3OH2+Hen illustrates that CH3 substitution substantially reduces the acidity of the OH protons, so that only clusters up to n = 2 can be observed. The structure of the solvation sub-shells is visible in both the binding energies and the predicted vibrational OH stretch and bend frequencies.
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Affiliation(s)
- David Müller
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany.
| | - Otto Dopfer
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany.
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11
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Robert George MA, Dopfer O. Infrared Spectrum of the Amantadine Cation: Opening of the Diamondoid Cage upon Ionization. J Phys Chem Lett 2022; 13:449-454. [PMID: 34990124 DOI: 10.1021/acs.jpclett.1c03948] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Radical cations of diamondoids, a fundamental class of highly stable cycloalkanes, are intermediates in functionalization reactions and possibly present in the interstellar medium. Herein, we characterize the structure of the radical cation of 1-amantadine (1-C10H15NH2+, Ama+), the amino derivative of the parent adamantane (C10H16+, Ada+), by infrared spectroscopy and density functional theory calculations. The structural isomers of Ama+ produced by electron ionization are probed by infrared photodissociation of cold Ar-tagged ions. In addition to the canonical nascent Ama+ isomer with an intact C10H15 cage, we identify two distonic bicyclic iminium isomers in which the adamantyl cage opens upon ionization, one of which is lower in energy than the cage isomer. The reaction profile with barriers and intermediates for this cage-opening reaction are determined. Comparison with Ada+ suggests that this type of ionization-induced cage-opening may be a common feature for diamondoids and important for their reactivity.
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Affiliation(s)
- Martin Andreas Robert George
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstrsase 36, 10623 Berlin, Germany
| | - Otto Dopfer
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstrsase 36, 10623 Berlin, Germany
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12
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Asvany O, Schlemmer S. Rotational action spectroscopy of trapped molecular ions. Phys Chem Chem Phys 2021; 23:26602-26622. [PMID: 34817492 DOI: 10.1039/d1cp03975j] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Rotational action spectroscopy is an experimental method in which rotational spectra of molecules, typically in the microwave to sub-mm-wave domain of the electromagnetic spectrum (∼1-1000 GHz), are recorded by action spectroscopy. Action spectroscopy means that the spectrum is recorded not by detecting the absorption of light by the molecules, but by the action of the light on the molecules, e.g., photon-induced dissociation of a chemical bond, a photon-triggered reaction, or photodetachment of an electron. Typically, such experiments are performed on molecular ions, which can be well controlled and mass-selected by guiding and storage techniques. Though coming with many advantages, the application of action schemes to rotational spectroscopy was hampered for a long time by the small energy content of a corresponding photon. Therefore, the first rotational action spectroscopic methods emerged only about one decade ago. Today, there exists a toolbox full of different rotational action spectroscopic schemes which are summarized in this review.
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Affiliation(s)
- Oskar Asvany
- I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany.
| | - Stephan Schlemmer
- I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany.
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13
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George MAR, Buttenberg F, Förstel M, Dopfer O. Microhydration of substituted diamondoid radical cations of biological relevance: infrared spectra of amantadine +-(H 2O) n = 1-3 clusters. Phys Chem Chem Phys 2020; 22:28123-28139. [PMID: 33290468 DOI: 10.1039/d0cp05299j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Hydration of biomolecules and pharmaceutical compounds has a strong impact on their structure, reactivity, and function. Herein, we explore the microhydration structure around the radical cation of the widespread pharmaceutical drug amantadine (C16H15NH2, Ama) by infrared photodissociation (IRPD) spectroscopy of mass-selected Ama+Wn = 1-3 clusters (W = H2O) recorded in the NH, CH, and OH stretch range of the cation ground electronic state. Analysis of the size-dependent frequency shifts by dispersion-corrected density functional theory calculations (B3LYP-D3/cc-pVTZ) provides detailed information about the acidity of the protons of the NH2 group of Ama+ and the structure and strength of the NHO and OHO hydrogen bonds (H-bonds) of the hydration network. The preferred sequential cluster growth begins with hydration of the two acidic NH protons of the NH2 group (n = 1-2) and continues with an extension of the H-bonded hydration network by forming an OHO H-bond of the third W to one ligand in the first hydration subshell (n = 3), like in the W2 dimer. For n = 2, a minor population corresponds to Ama+W2 structures with a W2 unit attached to Ama+via a NHW2 H-bond. Although the N-H proton donor bonds are progressively destabilized by gradual microhydration, no proton transfer to the Wn solvent cluster is observed in the investigated size range (n ≤ 3). Besides the microhydration structure, we also obtain a first impression of the structure and IR spectrum of bare Ama+, as well as the effects of both ionization and hydration on the structure of the adamantyl cage. Comparison of Ama+ with aliphatic and aromatic primary amine radical cations reveals differences in the acidity of the NH2 group and the resulting interaction with W caused by substitution of the cycloalkyl cage.
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14
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Chatterjee K, Dopfer O. Spectroscopic identification of fragment ions of DNA/RNA building blocks: the case of pyrimidine. Phys Chem Chem Phys 2020; 22:17275-17290. [PMID: 32685941 DOI: 10.1039/d0cp02919j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Pyrimidine (Pym, 1,3-diazine, 1,3-diazabenzene) is an important N-heterocyclic building block of nucleobases. Understanding the structures of its fragment and precursor ions provides insight into its prebiotic and abiotic synthetic route. The long-standing controversial debate about the structures of the primary fragment ions of the Pym+ cation (C4H4N2+, m/z 80) resulting from loss of HCN, C3H3N+ (m/z 53), is closed herein with the aid of a combined approach utilizing infrared photodissociation (IRPD) spectroscopy in the CH and NH stretch ranges (νCH/NH) and density functional theory (DFT) calculations. IRPD spectra of cold Ar/N2-tagged fragment ions reveal that the C3H3N+ population is dominated by cis-/trans-HCCHNCH+ ions (∼90%) along with a minor contribution of the most stable H2CCCNH+ and cis-/trans-HCCHCNH+ isomers (∼10%). We also spectroscopically confirm that the secondary fragment resulting from further loss of HCN, C2H2+ (m/z 26), is the acetylene cation (HCCH+). The spectroscopic characterization of the identified C3H3N+ isomers and their hydrogen-bonded dimers with Ar and N2 provides insight into the acidity of their CH and NH groups. Finally, the vibrational properties of Pym+ in the 3 μm range are probed by IRPD of Pym+-(N2)1-2 clusters, which shows a high π-binding affinity of Pym+ toward a nonpolar hydrophobic ligand. Its νCH spectrum confirms the different acidity of the three nonequivalent CH groups.
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Affiliation(s)
- Kuntal Chatterjee
- Institut für Optik und Atomare Physik, TU Berlin, Hardenbergstr. 36, 10623 Berlin, Germany.
| | - Otto Dopfer
- Institut für Optik und Atomare Physik, TU Berlin, Hardenbergstr. 36, 10623 Berlin, Germany.
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15
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George MAR, Förstel M, Dopfer O. Infrared Spectrum of the Adamantane
+
–Water Cation: Hydration‐Induced C−H Bond Activation and Free Internal Water Rotation. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202003637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
| | - Marko Förstel
- Institut für Optik und Atomare Physik Technische Universität Berlin Hardenbergstrasse 36 10623 Berlin Germany
| | - Otto Dopfer
- Institut für Optik und Atomare Physik Technische Universität Berlin Hardenbergstrasse 36 10623 Berlin Germany
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16
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George MAR, Förstel M, Dopfer O. Infrared Spectrum of the Adamantane + -Water Cation: Hydration-Induced C-H Bond Activation and Free Internal Water Rotation. Angew Chem Int Ed Engl 2020; 59:12098-12104. [PMID: 32392402 PMCID: PMC7383494 DOI: 10.1002/anie.202003637] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Indexed: 12/21/2022]
Abstract
Diamondoid cations are reactive intermediates in their functionalization reactions in polar solution. Hydration is predicted to strongly activate their C-H bonds in initial proton abstraction reactions. To study the effects of microhydration on the properties of diamondoid cations, we characterize herein the prototypical monohydrated adamantane cation (C10 H16 + -H2 O, Ad+ -W) in its ground electronic state by infrared photodissociation spectroscopy in the CH and OH stretch ranges and dispersion-corrected density functional theory (DFT) calculations. The water (W) ligand binds to the acidic CH group of Jahn-Teller distorted Ad+ via a strong CH⋅⋅⋅O ionic H-bond supported by charge-dipole forces. Although W further enhances the acidity of this CH group along with a proton shift toward the solvent, the proton remains with Ad+ in the monohydrate. We infer essentially free internal W rotation from rotational fine structure of the ν3 band of W, resulting from weak angular anisotropy of the Ad+ -W potential.
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Affiliation(s)
- Martin Andreas Robert George
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstrasse 36, 10623, Berlin, Germany
| | - Marko Förstel
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstrasse 36, 10623, Berlin, Germany
| | - Otto Dopfer
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstrasse 36, 10623, Berlin, Germany
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17
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Chatterjee K, Dopfer O. Microhydration of protonated biomolecular building blocks: protonated pyrimidine. Phys Chem Chem Phys 2020; 22:13092-13107. [PMID: 32490447 DOI: 10.1039/d0cp02110e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Protonation and hydration of biomolecules govern their structure, conformation, and function. Herein, we explore the microhydration structure in mass-selected protonated pyrimidine-water clusters (H+Pym-Wn, n = 1-4) by a combination of infrared photodissociation spectroscopy (IRPD) between 2450 and 3900 cm-1 and density functional theory (DFT) calculations at the dispersion-corrected B3LYP-D3/aug-cc-pVTZ level. We further present the IR spectrum of H+Pym-N2 to evaluate the effect of solvent polarity on the intrinsic molecular parameters of H+Pym. Our combined spectroscopic and computational approach unequivocally shows that protonation of Pym occurs at one of the two equivalent basic ring N atoms and that the ligands in H+Pym-L (L = N2 or W) preferentially form linear H-bonds to the resulting acidic NH group. Successive addition of water ligands results in the formation of a H-bonded solvent network which increasingly weakens the NH group. Despite substantial activation of the N-H bond upon microhydration, no intracluster proton transfer occurs up to n = 4 because of the balance of relative proton affinities of Pym and Wn and the involved solvation energies. Comparison to neutral Pym-Wn clusters reveals the drastic effects of protonation on microhydration with respect to both structure and interaction strength.
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Affiliation(s)
- Kuntal Chatterjee
- Institut für Optik und Atomare Physik, TU Berlin, Hardenbergstr. 36, 10623 Berlin, Germany.
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18
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Xiong T, Saalfrank P. Vibrationally Broadened Optical Spectra of Selected Radicals and Cations Derived from Adamantane: A Time-Dependent Correlation Function Approach. J Phys Chem A 2019; 123:8871-8880. [PMID: 31536349 DOI: 10.1021/acs.jpca.9b03305] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Diamondoids are hydrogen-saturated molecular motifs cut out of diamond, forming a class of materials with tunable optoelectronic properties. In this work, we extend previous work on neutral, closed-shell diamondoids by computing with hybrid density functional theory and time-dependent correlation functions vibrationally broadened absorption spectra of cations and radicals derived from the simplest diamondoid, adamantane, namely, the neutral 1- and 2-adamantyl radicals (C10H15), the 1- and 2-adamantyl cations (C10H15+), and the adamantane radical cation (C10H16+). For selected cases, we also report vibrationally broadened emission, photoelectron, and resonance Raman spectra. Furthermore, the effect of the damping factor on the vibrational fine-structure is studied. The following trends are found: (1) Low-energy absorptions of the adamantyl radicals and cations, and of the adamantane cation, are all strongly red-shifted with respect to adamantane; (2) also, emission spectra are strongly red-shifted, whereas photoelectron spectra are less affected for the cases studied; (3) vibrational fine-structures are reduced compared to those of adamantane; (4) the spectroscopic signals of 1- and 2-adamantyl species are significantly different from each other; and (5) reducing the damping factor has only a limited effect on the vibrational fine-structure in most cases. This suggests that removing hydrogen atoms and/or electrons from adamantane leads to new optoelectronic properties, which should be detectable by vibronic spectroscopy.
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Affiliation(s)
- Tao Xiong
- Institut für Chemie , Universität Potsdam , Karl-Liebknecht-Straße 24-25 , D-14476 Potsdam , Germany
| | - Peter Saalfrank
- Institut für Chemie , Universität Potsdam , Karl-Liebknecht-Straße 24-25 , D-14476 Potsdam , Germany
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19
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Endo T, Matsuda Y, Moriyama S, Fujii A. Infrared Spectroscopic Study on Trimethyl Amine Radical Cation: Correlation between Proton-Donating Ability and Structural Deformation. J Phys Chem A 2019; 123:5945-5950. [DOI: 10.1021/acs.jpca.9b01261] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Tomoya Endo
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3, Aramaki-Aza-Aoba, Aoba-ku, Sendai 980-8578, Miyagi, Japan
| | - Yoshiyuki Matsuda
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3, Aramaki-Aza-Aoba, Aoba-ku, Sendai 980-8578, Miyagi, Japan
| | - Shohei Moriyama
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3, Aramaki-Aza-Aoba, Aoba-ku, Sendai 980-8578, Miyagi, Japan
| | - Asuka Fujii
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3, Aramaki-Aza-Aoba, Aoba-ku, Sendai 980-8578, Miyagi, Japan
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20
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Chatterjee K, Matsumoto Y, Dopfer O. Aromatic Charge Resonance Interaction Probed by Infrared Spectroscopy. Angew Chem Int Ed Engl 2019; 58:3351-3355. [DOI: 10.1002/anie.201811432] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 11/22/2018] [Indexed: 11/09/2022]
Affiliation(s)
- Kuntal Chatterjee
- Institut für Optik und Atomare PhysikTechnische Universität Berlin Hardenbergstr. 36 10623 Berlin Germany
| | - Yoshiteru Matsumoto
- Department of ChemistryFaculty of ScienceShizuoka University 836 Ohya, Suruga Shizuoka 422-8529 Japan
| | - Otto Dopfer
- Institut für Optik und Atomare PhysikTechnische Universität Berlin Hardenbergstr. 36 10623 Berlin Germany
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21
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Schwarz H, Asmis KR. Identification of Active Sites and Structural Characterization of Reactive Ionic Intermediates by Cryogenic Ion Trap Vibrational Spectroscopy. Chemistry 2019; 25:2112-2126. [PMID: 30623993 DOI: 10.1002/chem.201805836] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 01/07/2019] [Indexed: 01/02/2023]
Abstract
Cryogenic ion trap vibrational spectroscopy paired with quantum chemistry currently represents the most generally applicable approach for the structural investigation of gaseous cluster ions that are not amenable to direct absorption spectroscopy. Here, we give an overview of the most popular variants of infrared action spectroscopy and describe the advantages of using cryogenic ion traps in combination with messenger tagging and vibrational predissociation spectroscopy. We then highlight a few recent studies that apply this technique to identify highly reactive ionic intermediates and to characterize their reactive sites. We conclude by commenting on future challenges and potential developments in the field.
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Affiliation(s)
- Helmut Schwarz
- Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 135, 10623, Berlin, Germany
| | - Knut R Asmis
- Wilhelm-Ostwald Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, 04103, Leipzig, Germany
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22
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Chatterjee K, Matsumoto Y, Dopfer O. Aromatic Charge Resonance Interaction Probed by Infrared Spectroscopy. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201811432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Kuntal Chatterjee
- Institut für Optik und Atomare PhysikTechnische Universität Berlin Hardenbergstr. 36 10623 Berlin Germany
| | - Yoshiteru Matsumoto
- Department of ChemistryFaculty of ScienceShizuoka University 836 Ohya, Suruga Shizuoka 422-8529 Japan
| | - Otto Dopfer
- Institut für Optik und Atomare PhysikTechnische Universität Berlin Hardenbergstr. 36 10623 Berlin Germany
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Bouwman J, Horst S, Oomens J. Spectroscopic Characterization of the Product Ions Formed by Electron Ionization of Adamantane. Chemphyschem 2018; 19:3211-3218. [PMID: 30307689 PMCID: PMC6392131 DOI: 10.1002/cphc.201800846] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Indexed: 11/27/2022]
Abstract
A structural characterization of the products formed in the dissociative electron ionization of adamantane (C10 H16 ) is presented. Molecular structures of product ions are suggested based on multiple-photon dissociation spectroscopy using the Free Electron Laser for Infrared eXperiments (FELIX) in combination with quantum-chemical calculations. Product ions are individually isolated in an ion trap tandem mass spectrometer and their action IR spectra are recorded. Atomic hydrogen loss from adamantane yields the 1-adamantyl isomer. The IR spectrum of the C8 H11 + product ion is best reproduced by computed spectra of 2- and 4-protonated meta-xylene and ortho- and para-protonated ethylbenzenes. The spectrum of the product ion at m/z 93 suggests that it is composed of a mixture of ortho-protonated toluene, para-protonated toluene and 1,2-dihydrotropylium, while the spectrum of the m/z 79 ion is consistent with the benzenium ion. This study thus suggests that adamantane is efficiently converted into aromatic species and astrophysical implications for the interstellar medium are highlighted.
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Affiliation(s)
- Jordy Bouwman
- Radboud UniversityInstitute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7NL-6525 EDNijmegenthe Netherlands
- Present address: Sackler Laboratory for Astrophysics, Leiden ObservatoryLeiden UniversityP.O. Box 95132300 RALeidenThe Netherlands
| | - Stefan Horst
- Radboud UniversityInstitute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7NL-6525 EDNijmegenthe Netherlands
| | - Jos Oomens
- Radboud UniversityInstitute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7NL-6525 EDNijmegenthe Netherlands
- van't Hoff Institute for Molecular SciencesUniversity of AmsterdamScience Park 9041098XHAmsterdamThe Netherlands
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24
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George MAR, Truong NX, Savoca M, Dopfer O. IR Spectrum and Structure of Protonated Monosilanol: Dative Bonding between Water and the Silylium Ion. Angew Chem Int Ed Engl 2018; 57:2919-2923. [PMID: 29341408 DOI: 10.1002/anie.201712999] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Indexed: 11/08/2022]
Abstract
We report the spectroscopic characterization of protonated monosilanol (SiH3 OH2+ ) isolated in the gas phase, thus providing the first experimental determination of the structure and bonding of a member of the elusive silanol family. The SiH3 OH2+ ion is generated in a silane/water plasma expansion, and its structure is derived from the IR photodissociation (IRPD) spectrum of its Ar cluster measured in a tandem mass spectrometer. The chemical bonding in SiH3 OH2+ is analyzed by density functional theory (DFT) calculations, providing detailed insight into the nature of the dative H3 Si+ -OH2 bond. Comparison with protonated methanol illustrates the differences in bonding between carbon and silicon, which are mainly related to their different electronegativity and the different energy of the vacant valence pz orbital of SiH3+ and CH3+ .
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Affiliation(s)
| | - Nguyen Xuan Truong
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623, Berlin, Germany
| | - Marco Savoca
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623, Berlin, Germany
| | - Otto Dopfer
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623, Berlin, Germany
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25
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Candian A, Bouwman J, Hemberger P, Bodi A, Tielens AGGM. Dissociative ionisation of adamantane: a combined theoretical and experimental study. Phys Chem Chem Phys 2018; 20:5399-5406. [PMID: 29155909 DOI: 10.1039/c7cp05957d] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Diamond nanoparticles, or nanodiamonds, are intriguing carbon-based materials which, maybe surprisingly, are the most abundant constituent of presolar grains. While the spectroscopic properties of even quite large diamondoids have already been explored, little is known about their unimolecular fragmentation processes. In this paper we characterise the dissociative ionisation of adamantane (C10H16) - the smallest member of the diamondoid family - utilising imaging Photoelectron Photoion Coincidence (iPEPICO) spectroscopy and Density Functional Theory (DFT) calculations. We have found adamantane to dissociatively photoionise via several parallel channels of which H, C3H7 and C4H8 losses are the most important ones. Calculations confirm the existence of a rate-limiting transition state for the multiple C-loss channels, which is located at 10.55 eV with respect to neutral adamantane. In addition, we found dissociation channels leading to small cationic hydrocarbons, which may be relevant in the interstellar medium.
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Affiliation(s)
- Alessandra Candian
- Leiden Observatory, Leiden University, P.O. Box 9513, 2300-RA Leiden, The Netherlands.
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26
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George MAR, Truong NX, Savoca M, Dopfer O. IR Spectrum and Structure of Protonated Monosilanol: Dative Bonding between Water and the Silylium Ion. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201712999] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
| | - Nguyen Xuan Truong
- Institut für Optik und Atomare Physik; Technische Universität Berlin; Hardenbergstr. 36 10623 Berlin Germany
| | - Marco Savoca
- Institut für Optik und Atomare Physik; Technische Universität Berlin; Hardenbergstr. 36 10623 Berlin Germany
| | - Otto Dopfer
- Institut für Optik und Atomare Physik; Technische Universität Berlin; Hardenbergstr. 36 10623 Berlin Germany
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27
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Klyne J, Schmies M, Miyazaki M, Fujii M, Dopfer O. Stepwise microhydration of aromatic amide cations: water solvation networks revealed by the infrared spectra of acetanilide +-(H 2O) n clusters (n ≤ 3). Phys Chem Chem Phys 2018; 20:3148-3164. [PMID: 28913535 DOI: 10.1039/c7cp04659f] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The structure and activity of peptides and proteins strongly rely on their charge state and the interaction with their hydration environment. Here, infrared photodissociation (IRPD) spectra of size-selected microhydrated clusters of cationic acetanilide (AA+, N-phenylacetamide), AA+-(H2O)n with n ≤ 3, are analysed by dispersion-corrected density functional theory calculations at the ωB97X-D/aug-cc-pVTZ level to determine the stepwise microhydration process of this aromatic peptide model. The IRPD spectra are recorded in the informative X-H stretch (νOH, νNH, νCH, amide A, 2800-3800 cm-1) and fingerprint (amide I-II, 1000-1900 cm-1) ranges to probe the preferred hydration motifs and the cluster growth. In the most stable AA+-(H2O)n structures, the H2O ligands solvate the acidic NH proton of the amide by forming a hydrogen-bonded solvent network, which strongly benefits from cooperative effects arising from the excess positive charge. Comparison with neutral AA-H2O reveals the strong impact of ionization on the acidity of the NH proton and the topology of the interaction potential. Comparison with related hydrated formanilide clusters demonstrates the influence of methylation of the amide group (H → CH3) on the shape of the intermolecular potential and the structure of the hydration shell.
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Affiliation(s)
- Johanna Klyne
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany.
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28
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Xiong T, Włodarczyk R, Gallandi L, Körzdörfer T, Saalfrank P. Vibrationally resolved photoelectron spectra of lower diamondoids: A time-dependent approach. J Chem Phys 2018; 148:044310. [PMID: 29390801 DOI: 10.1063/1.5012131] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Tao Xiong
- Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Straße 24-25, D-14476 Potsdam, Golm, Germany
| | - Radosław Włodarczyk
- Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Straße 24-25, D-14476 Potsdam, Golm, Germany
| | - Lukas Gallandi
- Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Straße 24-25, D-14476 Potsdam, Golm, Germany
| | - Thomas Körzdörfer
- Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Straße 24-25, D-14476 Potsdam, Golm, Germany
| | - Peter Saalfrank
- Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Straße 24-25, D-14476 Potsdam, Golm, Germany
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29
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Morini F, Watanabe N, Kojima M, Deleuze MS, Takahashi M. Influence of molecular vibrations on the valence electron momentum distributions of adamantane. J Chem Phys 2017. [DOI: 10.1063/1.4977060] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Filippo Morini
- Center of Molecular and Materials Modelling, Hasselt University, Agoralaan Gebouw D, B-3590 Diepenbeek, Belgium
| | - Noboru Watanabe
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan
| | - Masataka Kojima
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan
| | - Michael Simon Deleuze
- Center of Molecular and Materials Modelling, Hasselt University, Agoralaan Gebouw D, B-3590 Diepenbeek, Belgium
| | - Masahiko Takahashi
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan
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31
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Bouchet A, Klyne J, Ishiuchi SI, Fujii M, Dopfer O. Conformation of protonated glutamic acid at room and cryogenic temperatures. Phys Chem Chem Phys 2017; 19:10767-10776. [DOI: 10.1039/c6cp08553a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Linear infrared spectroscopy of protonated glutamic acid in a cryogenic ion trap allows for the clear-cut and quantitative identification of the two conformers of this fundamental biomolecule.
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Affiliation(s)
- Aude Bouchet
- Institut für Optik und Atomare Physik
- Technische Universität Berlin
- Berlin
- Germany
- Laboratory for Chemistry and Life Science
| | - Johanna Klyne
- Institut für Optik und Atomare Physik
- Technische Universität Berlin
- Berlin
- Germany
| | - Shun-ichi Ishiuchi
- Laboratory for Chemistry and Life Science
- Institute of Innovation Research
- Tokyo Institute of Technology
- Yokohama
- Japan
| | - Masaaki Fujii
- Laboratory for Chemistry and Life Science
- Institute of Innovation Research
- Tokyo Institute of Technology
- Yokohama
- Japan
| | - Otto Dopfer
- Institut für Optik und Atomare Physik
- Technische Universität Berlin
- Berlin
- Germany
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32
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Zhou YH, Liu XW, Chen LQ, Wang SQ, Cheng Y. Synthesis, structure and superoxide dismutase-like activity of two mixed-ligand Cu(II) complexes with N,N′-bis(2-pyridylmethyl)amantadine. Polyhedron 2016. [DOI: 10.1016/j.poly.2016.07.027] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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Affiliation(s)
- Inbal Tuvi-Arad
- Department of Natural Sciences; The Open University of Israel; 1 University Road Raanana 4353701 (Israel)
| | - András Stirling
- Institute of Organic Chemistry; Research Center for Natural Sciences; P.O.B. 286 Budapest 1519 (Hungary)
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Bouchet A, Schütz M, Chiavarino B, Crestoni ME, Fornarini S, Dopfer O. IR spectrum of the protonated neurotransmitter 2-phenylethylamine: dispersion and anharmonicity of the NH3(+)-π interaction. Phys Chem Chem Phys 2016; 17:25742-54. [PMID: 25757357 DOI: 10.1039/c5cp00221d] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The structure and dynamics of the highly flexible side chain of (protonated) phenylethylamino neurotransmitters are essential for their function. The geometric, vibrational, and energetic properties of the protonated neutrotransmitter 2-phenylethylamine (H(+)PEA) are characterized in the N-H stretch range by infrared photodissociation (IRPD) spectroscopy of cold ions using rare gas tagging (Rg = Ne and Ar) and anharmonic calculations at the B3LYP-D3/(aug-)cc-pVTZ level including dispersion corrections. A single folded gauche conformer (G) protonated at the basic amino group and stabilized by an intramolecular NH(+)-π interaction is observed. The dispersion-corrected density functional theory calculations reveal the important effects of dispersion on the cation-π interaction and the large vibrational anharmonicity of the NH3(+) group involved in the NH(+)-π hydrogen bond. They allow for assigning overtone and combination bands and explain anomalous intensities observed in previous IR multiple-photon dissociation spectra. Comparison with neutral PEA reveals the large effects of protonation on the geometric and electronic structure.
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Affiliation(s)
- Aude Bouchet
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstrasse 36, D-10623 Berlin, Germany.
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35
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Dopfer O, Fujii M. Probing Solvation Dynamics around Aromatic and Biological Molecules at the Single-Molecular Level. Chem Rev 2016; 116:5432-63. [DOI: 10.1021/acs.chemrev.5b00610] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Otto Dopfer
- Institut
für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstrasse 36, 10623 Berlin, Germany
| | - Masaaki Fujii
- Laboratory
for Chemistry and Life Science, Tokyo Institute of Technology, Yokohama 226-8503, Japan
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36
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Schütz M, Bouchet A, Dopfer O. Infrared spectrum of the cold ortho-fluorinated protonated neurotransmitter 2-phenylethylamine: competition between NH+⋯π and NH+⋯F interactions. Phys Chem Chem Phys 2016; 18:26980-26989. [DOI: 10.1039/c6cp05915e] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
IR spectra of cold rare-gas tagged ions reveal the switch of the preferred conformation of the highly flexible side chain of a prototypical protonated neurotransmitter induced by site-specific aromatic fluorination.
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Affiliation(s)
- Markus Schütz
- Institut für Optik und Atomare Physik
- Technische Universität Berlin
- D-10623 Berlin
- Germany
| | - Aude Bouchet
- Institut für Optik und Atomare Physik
- Technische Universität Berlin
- D-10623 Berlin
- Germany
| | - Otto Dopfer
- Institut für Optik und Atomare Physik
- Technische Universität Berlin
- D-10623 Berlin
- Germany
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37
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Schütz M, Sakota K, Moritz R, Schmies M, Ikeda T, Sekiya H, Dopfer O. Simultaneous Interaction of Hydrophilic and Hydrophobic Solvents with Ethylamino Neurotransmitter Radical Cations: Infrared Spectra of Tryptamine+-(H2O)m-(N2)n Clusters (m,n ≤ 3). J Phys Chem A 2015; 119:10035-51. [DOI: 10.1021/acs.jpca.5b07408] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Markus Schütz
- Institut
für Optik und Atomare Physik, Technische Universität Berlin, D-10623 Berlin, Germany
| | - Kenji Sakota
- Department
of Chemistry, Faculty of Sciences, and Department of Molecular Chemistry,
Graduate School of Science, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan
| | - Raphael Moritz
- Institut
für Optik und Atomare Physik, Technische Universität Berlin, D-10623 Berlin, Germany
| | - Matthias Schmies
- Institut
für Optik und Atomare Physik, Technische Universität Berlin, D-10623 Berlin, Germany
| | - Takamasa Ikeda
- Department
of Chemistry, Faculty of Sciences, and Department of Molecular Chemistry,
Graduate School of Science, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan
| | - Hiroshi Sekiya
- Department
of Chemistry, Faculty of Sciences, and Department of Molecular Chemistry,
Graduate School of Science, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan
| | - Otto Dopfer
- Institut
für Optik und Atomare Physik, Technische Universität Berlin, D-10623 Berlin, Germany
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38
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Kelleher PJ, Johnson CJ, Fournier JA, Johnson MA, McCoy AB. Persistence of dual free internal rotation in NH4(+)(H2O)·Hen=0-3 ion-molecule complexes: expanding the case for quantum delocalization in He tagging. J Phys Chem A 2015; 119:4170-6. [PMID: 25867931 DOI: 10.1021/acs.jpca.5b03114] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
To explore the extent of the molecular cation perturbation induced by complexation with He atoms required for the application of cryogenic ion vibrational predissociation (CIVP) spectroscopy, we compare the spectra of a bare NH4(+)(H2O) ion (obtained using infrared multiple photon dissociation (IRMPD)) with the one-photon CIVP spectra of the NH4(+)(H2O)·He1-3 clusters. Not only are the vibrational band origins minimally perturbed, but the rotational fine structures on the NH and OH asymmetric stretching vibrations, which arise from the free internal rotation of the -OH2 and -NH3 groups, also remain intact in the adducts. To establish the location and the quantum mechanical delocalization of the He atoms, we carried out diffusion Monte Carlo (DMC) calculations of the vibrational zero point wave function, which indicate that the barriers between the three equivalent minima for the He attachment are so small that the He atom wave function is delocalized over the entire -NH3 rotor, effectively restoring C3 symmetry for the embedded -NH3 group.
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Affiliation(s)
- Patrick J Kelleher
- †Sterling Chemistry Laboratory, Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, United States
| | - Christopher J Johnson
- †Sterling Chemistry Laboratory, Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, United States
| | - Joseph A Fournier
- †Sterling Chemistry Laboratory, Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, United States
| | - Mark A Johnson
- †Sterling Chemistry Laboratory, Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, United States
| | - Anne B McCoy
- ‡Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
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39
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Gunchenko PA, Novikovskii AA, Byk MV, Fokin AA. Structure and transformations of diamantane radical cation: Theory and experiment. RUSSIAN JOURNAL OF ORGANIC CHEMISTRY 2015. [DOI: 10.1134/s1070428014120057] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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40
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Bouchet A, Klyne J, Piani G, Dopfer O, Zehnacker A. Diastereo-specific conformational properties of neutral, protonated and radical cation forms of (1R,2S)-cis- and (1R,2R)-trans-amino-indanol by gas phase spectroscopy. Phys Chem Chem Phys 2015; 17:25809-21. [DOI: 10.1039/c5cp00576k] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The effects of ionisation and protonation on the geometric and electronic structure of a prototypical aromatic amino-alcohol with two chiral centres are revealed by IR and UV spectroscopy.
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Affiliation(s)
- Aude Bouchet
- Institut für Optik und Atomare Physik
- Technische Universität Berlin
- D-10623 Berlin
- Germany
| | - Johanna Klyne
- Institut für Optik und Atomare Physik
- Technische Universität Berlin
- D-10623 Berlin
- Germany
| | - Giovanni Piani
- CNRS
- Institut des Sciences Moléculaires d’Orsay (ISMO/UMR8214) and Univ. Paris Sud
- Orsay
- France
- CLUPS (Centre Laser de l’Université Paris Sud/LUMAT FR 2764)
| | - Otto Dopfer
- Institut für Optik und Atomare Physik
- Technische Universität Berlin
- D-10623 Berlin
- Germany
| | - Anne Zehnacker
- CNRS
- Institut des Sciences Moléculaires d’Orsay (ISMO/UMR8214) and Univ. Paris Sud
- Orsay
- France
- CLUPS (Centre Laser de l’Université Paris Sud/LUMAT FR 2764)
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41
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Schmies M, Miyazaki M, Fujii M, Dopfer O. Microhydrated aromatic cluster cations: Binding motifs of 4-aminobenzonitrile-(H2O)n cluster cations with n ≤ 4. J Chem Phys 2014; 141:214301. [DOI: 10.1063/1.4901893] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Matthias Schmies
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany
| | - Mitsuhiko Miyazaki
- Chemical Resources Laboratory, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Masaaki Fujii
- Chemical Resources Laboratory, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Otto Dopfer
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany
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42
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Patrick CE, Giustino F. Unified theory of electron-phonon renormalization and phonon-assisted optical absorption. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2014; 26:365503. [PMID: 25134725 DOI: 10.1088/0953-8984/26/36/365503] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We present a theory of electronic excitation energies and optical absorption spectra which incorporates energy-level renormalization and phonon-assisted optical absorption within a unified framework. Using time-independent perturbation theory we show how the standard approaches for studying vibronic effects in molecules and those for addressing electron-phonon interactions in solids correspond to slightly different choices for the non-interacting Hamiltonian. Our present approach naturally leads to the Allen-Heine theory of temperature-dependent energy levels, the Franck-Condon principle, the Herzberg-Teller effect and to phonon-assisted optical absorption in indirect band gap materials. In addition, our theory predicts sub-gap phonon-assisted optical absorption in direct gap materials, as well as an exponential edge which we tentatively assign to the Urbach tail. We also consider a semiclassical approach to the calculation of optical absorption spectra which simultaneously captures energy-level renormalization and phonon-assisted transitions and is especially suited to first-principles electronic structure calculations. We demonstrate this approach by calculating the phonon-assisted optical absorption spectrum of bulk silicon.
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43
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Johnson CJ, Wolk AB, Fournier JA, Sullivan EN, Weddle GH, Johnson MA. Communication: He-tagged vibrational spectra of the SarGlyH+ and H+(H2O)2,3 ions: Quantifying tag effects in cryogenic ion vibrational predissociation (CIVP) spectroscopy. J Chem Phys 2014; 140:221101. [DOI: 10.1063/1.4880475] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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44
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Banerjee S, Saalfrank P. Vibrationally resolved absorption, emission and resonance Raman spectra of diamondoids: a study based on time-dependent correlation functions. Phys Chem Chem Phys 2014; 16:144-58. [DOI: 10.1039/c3cp53535e] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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45
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Schmies M, Patzer A, Schütz M, Miyazaki M, Fujii M, Dopfer O. Microsolvation of the acetanilide cation (AA+) in a nonpolar solvent: IR spectra of AA+–Lnclusters (L = He, Ar, N2; n ≤ 10). Phys Chem Chem Phys 2014; 16:7980-95. [DOI: 10.1039/c4cp00401a] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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46
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Richter R, Wolter D, Zimmermann T, Landt L, Knecht A, Heidrich C, Merli A, Dopfer O, Reiß P, Ehresmann A, Petersen J, Dahl JE, Carlson RMK, Bostedt C, Möller T, Mitric R, Rander T. Size and shape dependent photoluminescence and excited state decay rates of diamondoids. Phys Chem Chem Phys 2014; 16:3070-6. [DOI: 10.1039/c3cp54570a] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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47
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George MAR, Savoca M, Dopfer O. Infrared Spectrum of the Si3H8+Cation: Evidence for a Bridged Isomer with an Asymmetric Three-Center Two-Electron SiHSi Bond. Chemistry 2013; 19:15315-28. [DOI: 10.1002/chem.201302189] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2013] [Indexed: 11/09/2022]
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48
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Quantum nuclear dynamics in the photophysics of diamondoids. Nat Commun 2013; 4:2006. [DOI: 10.1038/ncomms3006] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Accepted: 05/14/2013] [Indexed: 11/08/2022] Open
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49
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Stedwell CN, Galindo JF, Roitberg AE, Polfer NC. Structures of biomolecular ions in the gas phase probed by infrared light sources. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2013; 6:267-285. [PMID: 23560933 DOI: 10.1146/annurev-anchem-062012-092700] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Infrared (IR) spectroscopy of biomolecular ions combines mass spectrometry's high sensitivity and ability to analyze complex mixtures with the enhanced structural information available from vibrational spectroscopy. IR spectroscopy is in principle well placed to distinguish isomers and allow chemical classification of unknown molecules. This review gives an outline of current instrumentation, spectroscopic approaches, and potential bottlenecks. We discuss the most promising applications in bioanalytical mass spectrometry in view of recent experimental results, as well as future applications based on bioinformatics.
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Affiliation(s)
- Corey N Stedwell
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, USA.
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50
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Savoca M, George MAR, Langer J, Dopfer O. Infrared spectrum of the disilane cation (Si2H6+) from Ar-tagging spectroscopy. Phys Chem Chem Phys 2013; 15:2774-81. [DOI: 10.1039/c2cp43773b] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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