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Laconsay CJ, Tantillo DJ. Modulating Escape Channels of Cycloheptatrienyl Rhodium Carbenes To Form Semibullvalene. J Org Chem 2023. [PMID: 37335974 DOI: 10.1021/acs.joc.3c00735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/21/2023]
Abstract
We describe the various escape channels available to dirhodium carbene intermediates from cycloheptatrienyl diazo compounds located with density functional theory. An intramolecular cyclopropanation would, in principle, provide a new route to semibullvalenes (SBVs). A detailed exploration of the potential energy surface reveals that methylating carbon-7 suppresses a competing β-hydride migration pathway to heptafulvene products, giving SBV formation a reasonable chance. During our explorations, we additionally discovered unusual spirononatriene, spironorcaradiene, and metal-stabilized 9-barbaralyl cation structures as local minima.
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Affiliation(s)
- Croix J Laconsay
- Department of Chemistry, University of California─Davis, Davis, California 95616, United States
| | - Dean J Tantillo
- Department of Chemistry, University of California─Davis, Davis, California 95616, United States
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Shapeshifting radicals. Chem Phys 2022. [DOI: 10.1016/j.chemphys.2021.111373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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3
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Coordination Properties of Non-Rigid Phosphinoyldithioformate Complexes of the [Mo2O2(µ-S)2]2+ Cation in Catalytic Sulfur Transfer Reactions with Thiiranes. Catalysts 2021. [DOI: 10.3390/catal11050593] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Two “Mo2O2S2”-based complexes with phosphinoyldithioformate ligands were synthesized from the metathesis reaction of [R2P(O)CS2]− with (Me4N)2[Mo2O2(µ-S)2(Cl)4] to give [Mo2O2(µ-S)2{R2P(O)CS2}2] (1; R = Ph, 2; R = Bn). The complexes were fully characterized, including the X-ray crystal structure for 1. Variable temperatures 31P NMR of 1 and 2 exhibit non-rigid behavior in solution where three and two coordination isomers were present, respectively. The organic substituent on the P atom greatly impacts the complex non-rigid properties and behavior. The catalytic activity of 1 and 2 towards sulfur atom transfer (SAT) using propylene sulfide and cyclohexene sulfide was explored, employing homogeneous reaction conditions at an ambient temperature on the NMR scale. The complexes showed distinctly different properties along with high conversions in short reaction times. A catalytic cycle consistent with the results is proposed.
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Theoretical Study on Epoxide Ring-opening in CO2/Epoxide Copolymerization Catalyzed by Bifunctional Salen-Type Cobalt(III) Complexes: Influence of Stereoelectronic Factors. Catalysts 2021. [DOI: 10.3390/catal11030328] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Propylene oxide (PO) binding and ring-opening reaction with the bifunctional CO2/epoxide copolymerization catalyst, based on the Co(III)-salcy complex including two quaternary ammonium salts with n-butyl substituents (N+-chains) were investigated by Density Functional Theory (DFT) calculations and compared with the model systems without the N+-chains. The importance of the different possible stereoisomers and the stereoselectivity of these processes for (S)- and (R)-enantiomers of PO were considered. To explore the conformational space for the real catalyst, a complex approach, developed previously was applied. The calculations for the model systems directly demonstrate that PO-ring opening proceeds preferentially in trans catalysts’ configuration and no participation of cis-β isomers is viable; nucleophilic attack at the methylene-carbon atom is preferred over that at methine-carbon atom. For the real bifunctional catalyst, with the (S,S)-configuration of cyclohexane, the results indicate a preference of (R)-PO ring-opening over (S)-PO ring-opening (ca. 6:5). Concerning stereoisomers resulting from the orientation of N+-chains in the real catalyst, different groups of structures participate in the ring-opening reaction for (R)-PO, and different for (S)-PO. The high population of nonreactive complexes of (R)-PO may be the key factor responsible for decreasing the activity of the analyzed catalyst in the epoxide ring-opening reaction.
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Cope rearrangements in shapeshifting molecules re-examined by means of high-level CCSDT(Q) composite ab initio methods. Chem Phys Lett 2020. [DOI: 10.1016/j.cplett.2020.138018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Zou W, Tao Y, Kraka E. Describing Polytopal Rearrangements of Fluxional Molecules with Curvilinear Coordinates Derived from Normal Vibrational Modes: A Conceptual Extension of Cremer-Pople Puckering Coordinates. J Chem Theory Comput 2020; 16:3162-3193. [PMID: 32208729 DOI: 10.1021/acs.jctc.9b01274] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
In this work a new curvilinear coordinate system is presented for the comprehensive description of polytopal rearrangements of N-coordinate compounds (N = 4-7) and systems containing an N-coordinate subunit. It is based on normal vibrational modes and a natural extension of the Cremer-Pople puckering coordinates ( J. Am. Chem. Soc. 1975, 97, 1354) together with the Zou-Izotov-Cremer deformation coordinates ( J. Phys. Chem. A 2011, 115, 8731) for ring structures to N-coordinate systems. We demonstrate that the new curvilinear coordinates are ideal reaction coordinates describing fluxional rearrangement pathways by revisiting the Berry pseudorotation and the lever mechanism in sulfur tetrafluoride, the Berry pseudorotation and two Muetterties' mechanisms in pentavalent compounds, the chimeric pseudorotation in iodine pentafluoride, Bailar and Ray-Dutt twists in hexacoordinate tris-chelates as well as the Bartell mechanism in iodine heptafluoride. The results of our study reveal that this dedicated curvilinear coordinate system can be applied to most coordination compounds opening new ways for the systematic modeling of fluxional processes.
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Affiliation(s)
- Wenli Zou
- Institute of Modern Physics, Northwest University, and Shaanxi Key Laboratory for Theoretical Physics Frontiers, Xi'an, Shaanxi 710127, P. R. China.,Department of Chemistry, Southern Methodist University, 3215 Daniel Avenue, Dallas, Texas 75275-0314, United States
| | - Yunwen Tao
- Department of Chemistry, Southern Methodist University, 3215 Daniel Avenue, Dallas, Texas 75275-0314, United States
| | - Elfi Kraka
- Department of Chemistry, Southern Methodist University, 3215 Daniel Avenue, Dallas, Texas 75275-0314, United States
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Udovenko AA, Slobodyuk AB, Emelina TB, Laptash NM. Fluxional seven-coordinated fluorido- and oxofluoridotantalates. ACTA CRYSTALLOGRAPHICA SECTION B, STRUCTURAL SCIENCE, CRYSTAL ENGINEERING AND MATERIALS 2019; 75:1115-1125. [PMID: 32830691 DOI: 10.1107/s2052520619013465] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 10/01/2019] [Indexed: 06/11/2023]
Abstract
Seven-coordinated (NH4)2TaF7, Rb2TaF7 and Rb3TaOF6 were synthesized in single-crystal form and their structures were determined. A monocapped trigonal prism (CTP) or a pentagonal bipyramid (PB) of the TaF72- anion are stereochemically nonrigid and coexist in the first two compounds as a result of strong intraspheric dynamics. Upon cooling, tetragonal Rb2TaF7 undergoes a first-order phase transition at 145 K and the seven-coordinated polyhedron transforms into a regular CTP. The seven-coordinated polyhedron in (NH4)2TaF7 approaches the PB configuration as the temperature decreases. Cubic elpasolite-like Rb3TaOF6 is characterized by the simultaneous two-state coexistence of TaOF63- of the PB shape as rigidly reoriented and as fluxional. In the former case, the central atom is disordered over the octahedron in the unit cell, allowing the determination of the short Ta-O distance, whereas in the latter case, tantalum remains in the polyhedron center, resulting in synchronous Ta-O and Ta-F stretching vibrations appearing as the infrared band at 723 cm-1.
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Affiliation(s)
- Anatoly A Udovenko
- Institute of Chemistry Far Eastern Branch of RAS, 159 Pr. Stoletiya Vladivostoka, Vladivostok 690022, Russian Federation
| | - Arseny B Slobodyuk
- Institute of Chemistry Far Eastern Branch of RAS, 159 Pr. Stoletiya Vladivostoka, Vladivostok 690022, Russian Federation
| | - Tatiana B Emelina
- Institute of Chemistry Far Eastern Branch of RAS, 159 Pr. Stoletiya Vladivostoka, Vladivostok 690022, Russian Federation
| | - Natalia M Laptash
- Institute of Chemistry Far Eastern Branch of RAS, 159 Pr. Stoletiya Vladivostoka, Vladivostok 690022, Russian Federation
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Császár AG, Fábri C, Sarka J. Quasistructural molecules. WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE 2019. [DOI: 10.1002/wcms.1432] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Attila G. Császár
- Laboratory of Molecular Structure and Dynamics, Institute of Chemistry ELTE Eötvös Loránd University Budapest Hungary
- MTA‐ELTE Complex Chemical Systems Research Group Budapest Hungary
| | - Csaba Fábri
- Laboratory of Molecular Structure and Dynamics, Institute of Chemistry ELTE Eötvös Loránd University Budapest Hungary
- MTA‐ELTE Complex Chemical Systems Research Group Budapest Hungary
| | - János Sarka
- Department of Chemistry and Biochemistry Texas Tech University Lubbock Texas USA
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Wang X, Shyshov O, Hanževački M, Jäger CM, von Delius M. Ammonium Complexes of Orthoester Cryptands Are Inherently Dynamic and Adaptive. J Am Chem Soc 2019; 141:8868-8876. [DOI: 10.1021/jacs.9b01350] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Xiang Wang
- Institute of Organic Chemistry and Advanced Materials, University of Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Oleksandr Shyshov
- Institute of Organic Chemistry and Advanced Materials, University of Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Marko Hanževački
- Department of Chemical and Environmental Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
- Rudjer Boskovic Institute, Bijenicka 54, 10000 Zagreb, Croatia
| | - Christof M. Jäger
- Department of Chemical and Environmental Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Max von Delius
- Institute of Organic Chemistry and Advanced Materials, University of Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany
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11
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Wagner JP, McDonald DC, Duncan MA. Spectroscopy of Proton Coordination with Ethylenediamine. J Phys Chem A 2018; 122:5168-5176. [PMID: 29771517 DOI: 10.1021/acs.jpca.8b03592] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Protonated ethylenediamine monomer, dimer, and trimer were produced in the gas phase by an electrical discharge/supersonic expansion of argon seeded with ethylenediamine (C2H8N2, en) vapor. Infrared spectra of these ions were measured in the region from 1000 to 4000 cm-1 using laser photodissociation and argon tagging. Computations at the CBS-QB3 level were performed to explore possible isomers and understand the infrared spectra. The protonated monomer exhibits a gauche conformation and an intramolecular hydrogen bond. Its parallel shared proton vibration occurs as a broad band around 2785 cm-1, despite the formally equivalent proton affinities of the two amino groups involved, which usually leads to low frequency bands. The barrier to intramolecular proton transfer is 2.2 kcal mol-1 and does not vanish upon addition of the zero-point energy, unlike the related protonated ammonia dimer. The structure of the dimer is formed by chelation of the monomer's NH3+ group, thereby localizing the excess proton and increasing the frequency of the intramolecular shared proton vibration to 3157 cm-1. Other highly fluxional dimer structures with facile intermolecular proton transfer and concomitant structural reorganization were computed to lie within 2 kcal mol-1 of the experimentally observed structure. The spectrum of the trimer is rather diffuse, and a clear assignment is not possible. However, an isomer with an intramolecular proton transfer like that of the monomer is most consistent with the experimental spectrum.
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Affiliation(s)
- J Philipp Wagner
- Department of Chemistry , University of Georgia , 140 Cedar Street , Athens , Georgia 30602 , United States
| | - David C McDonald
- Department of Chemistry , University of Georgia , 140 Cedar Street , Athens , Georgia 30602 , United States
| | - Michael A Duncan
- Department of Chemistry , University of Georgia , 140 Cedar Street , Athens , Georgia 30602 , United States
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Malischewski M, Seppelt K. Isolation and Characterization of a Non-Rigid Hexamethylbenzene-SO 2+ Complex. Angew Chem Int Ed Engl 2017; 56:16495-16497. [PMID: 29084371 DOI: 10.1002/anie.201708552] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2017] [Revised: 10/11/2017] [Indexed: 11/06/2022]
Abstract
During our studies towards the preparation of the pentagonal-pyramidal hexamethylbenzene dication C6 (CH3 )62+ , we isolated the unprecedented dicationic species C6 (CH3 )6 SO2+ (AsF6- )2 from the reaction of hexamethylbenzene with a mixture of anhydrous HF, AsF5 , and liquid SO2 . This compound can be understood as a complex of unknown SO2+ with hexamethylbenzene. Herein, we report on its synthesis, molecular structure, and spectroscopic characterization.
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Affiliation(s)
- Moritz Malischewski
- Freie Universität Berlin, Institut für Chemie und Biochemie-Anorganische Chemie, Fabeckstraße 34-36, 14195, Berlin, Germany.,Université Pierre et Marie Curie Paris 6, Institut Parisien de Chimie Moléculaire, 4 Place Jussieu, 75252, Paris cedex 5, France
| | - Konrad Seppelt
- Freie Universität Berlin, Institut für Chemie und Biochemie-Anorganische Chemie, Fabeckstraße 34-36, 14195, Berlin, Germany
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Grimme S, Schreiner PR. Computerchemie: das Schicksal aktueller Methoden und zukünftige Herausforderungen. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201709943] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Stefan Grimme
- Mulliken Center for Theoretical Chemistry; Universität Bonn; Beringstraße 4 53115 Bonn Deutschland
| | - Peter R. Schreiner
- Institut für Organische Chemie; Justus-Liebig-Universität; Heinrich-Buff-Ring 17 35392 Gießen Deutschland
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Grimme S, Schreiner PR. Computational Chemistry: The Fate of Current Methods and Future Challenges. Angew Chem Int Ed Engl 2017; 57:4170-4176. [PMID: 29105929 DOI: 10.1002/anie.201709943] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Indexed: 11/12/2022]
Abstract
"Where do we go from here?" is the underlying question regarding the future (perhaps foreseeable) developments in computational chemistry. Although this young discipline has already permeated practically all of chemistry, it is likely to become even more powerful with the rapid development of computational hard- and software.
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Affiliation(s)
- Stefan Grimme
- Mulliken Center for Theoretical Chemistry, University of Bonn, Beringstr. 4, 53115, Bonn, Germany
| | - Peter R Schreiner
- Institute of Organic Chemistry, Justus-Liebig University, Heinrich-Buff-Ring 17, 35392, Giessen, Germany
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Malischewski M, Seppelt K. Isolierung und Charakterisierung eines nicht-starren Hexamethylbenzol-SO2+
-Komplexes. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201708552] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Moritz Malischewski
- Freie Universität Berlin; Institut für Chemie und Biochemie - Anorganische Chemie; Fabeckstraße 34-36 14195 Berlin Deutschland
- Université Pierre et Marie Curie Paris 6; Institut Parisien de Chimie Moléculaire; 4 Place Jussieu 75252 Paris cedex 5 Frankreich
| | - Konrad Seppelt
- Freie Universität Berlin; Institut für Chemie und Biochemie - Anorganische Chemie; Fabeckstraße 34-36 14195 Berlin Deutschland
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Schmidt M, Reinscheid F, Sun H, Abromeit H, Scriba GKE, Sönnichsen FD, John M, Reinscheid UM. Hidden Flexibility of Strychnine. European J Org Chem 2014. [DOI: 10.1002/ejoc.201301760] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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