26
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Matulaitis T, dos Santos PL, Tsuchiya Y, Cordes DB, Slawin AMZ, Adachi C, Samuel IDW, Zysman‐Colman E. Donor Influence on the Optoelectronic Properties of N‐Substituted Tetraphenylimidazole Derivatives. ChemistrySelect 2023. [DOI: 10.1002/slct.202300274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
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27
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Halford-McGuff JM, Slawin AMZ, Watson AJB. Steric Parameterization Delivers a Reciprocally Predictive Model for Substrate Reactivity and Catalyst Turnover in Rh-Catalyzed Diyne-Alkyne [2 + 2 + 2] Cycloadditions. ACS Catal 2023. [DOI: 10.1021/acscatal.2c06300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
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28
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Liu H, Hafeez H, Cordes DB, Slawin AMZ, Peters G, Lee SL, Samuel IDW, Morrison FD. Enhanced Photoluminescence and Reduced Dimensionality via Vacancy Ordering in a 10H Halide Perovskite. Inorg Chem 2023; 62:3629-3636. [PMID: 36780272 PMCID: PMC9976281 DOI: 10.1021/acs.inorgchem.2c04433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Vacancy-ordered halide perovskites have received great interest in optoelectronic applications. In this work, we report the novel inorganic halide Cs10MnSb6Cl30 with a distinctive 10H (10-layer hexagonal) perovskite polytype structure with (hcccc)2 stacking. Cs10MnSb6Cl30 has 30% B-site vacancies ordered at both corner- and face-sharing sites, resulting in [MnSb6Cl30]10-n columns, i.e., a reduction of octahedral connectivity to 1D. This results in enhanced photoluminescence in comparison to the previously reported 25% vacancy-ordered 3C polytype Cs4MnSb2Cl12 with 2D connectivity. This demonstrates not only the existence of the 10H perovskite structure in halides but also demonstrates the degree of B-site deficiency and stacking sequence variation as a direction to tune the optical properties of perovskite polytypes via vacancy rearrangements.
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29
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Madayanad Suresh S, Zhang L, Hall D, Si C, Ricci G, Matulaitis T, Slawin AMZ, Warriner S, Olivier Y, Samuel IDW, Zysman-Colman E. A Deep-Blue-Emitting Heteroatom-Doped MR-TADF Nonacene for High-Performance Organic Light-Emitting Diodes. Angew Chem Int Ed Engl 2023; 62:e202215522. [PMID: 36480790 PMCID: PMC10107802 DOI: 10.1002/anie.202215522] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 12/07/2022] [Accepted: 12/08/2022] [Indexed: 12/13/2022]
Abstract
We present a p- and n-doped nonacene compound, NOBNacene, that represents a rare example of a linearly extended ladder-type multiresonant thermally activated delayed fluorescence (MR-TADF) emitter. This compound shows efficient narrow deep blue emission, with a λPL of 410 nm, full width at half maximum, FWHM, of 38 nm, photoluminescence quantum yield, ΦPL of 71 %, and a delayed lifetime, τd of 1.18 ms in 1.5 wt % TSPO1 thin film. The organic light-emitting diode (OLED) using this compound as the emitter shows a comparable electroluminescence spectrum peaked at 409 nm (FWHM=37 nm) and a maximum external quantum efficiency (EQEmax ) of 8.5 % at Commission Internationale de l'Éclairage (CIE) coordinates of (0.173, 0.055). The EQEmax values were increased to 11.2 % at 3 wt % doping of the emitter within the emissive layer of the device. At this concentration, the electroluminescence spectrum broadened slightly, leading to CIE coordinates of (0.176, 0.068).
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30
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Aragoni MC, Podda E, Caria V, Carta SA, Cherchi MF, Lippolis V, Murgia S, Orrù G, Pippia G, Scano A, Slawin AMZ, Woollins JD, Pintus A, Arca M. [Au III(N^N)Br 2](PF 6): A Class of Antibacterial and Antibiofilm Complexes (N^N = 2,2'-Bipyridine and 1,10-Phenanthroline Derivatives). Inorg Chem 2023; 62:2924-2933. [PMID: 36728360 PMCID: PMC9930124 DOI: 10.1021/acs.inorgchem.2c04410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A series of new complexes of general formula [AuIII(N^N)Br2](PF6) (N^N = 2,2'-bipyridine and 1,10-phenanthroline derivatives) were prepared and characterized by spectroscopic, electrochemical, and diffractometric techniques and tested against Gram-positive and Gram-negative bacterial strains (Staphylococcus aureus, Streptococcus intermedius, Pseudomonas aeruginosa, and Escherichia coli), showing promising antibacterial and antibiofilm properties.
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31
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Abdul Rashid FNA, Bacho MZ, Hamali MA, Slawin AMZ, Mohammat MF, Shamsujunaidi R, Abdul Manan MAF. rac-Ethyl rel-(2 R,3 R,4 S)-4-hy-droxy-1,2-dimethyl-5-oxopyrrolidine-3-carboxyl-ate. IUCRDATA 2023; 8:x230075. [PMID: 36911075 PMCID: PMC9993899 DOI: 10.1107/s2414314623000755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 01/28/2023] [Indexed: 02/11/2023] Open
Abstract
The asymmetric unit of the title compound, C9H15NO4, consists of a functionalized pyrrolidine ring having an envelope conformation, synthesized as an ethyl ester. The mol-ecule has three chiral centres and crystallized as a racemic mixture. In the crystal, mol-ecules are linked by pairwise O-H⋯O bonds, generating dimers with twofold rotational symmetry.
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32
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Wang T, Gupta AK, Wu S, Slawin AMZ, Zysman-Colman E. Conjugation-Modulated Excitonic Coupling Brightens Multiple Triplet Excited States. J Am Chem Soc 2023; 145:1945-1954. [PMID: 36638828 PMCID: PMC9880999 DOI: 10.1021/jacs.2c12320] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The design and regulation of multiple room-temperature phosphorescence (RTP) processes are formidably challenging due to the restrictions imposed by Kasha's rule. Here, we report a general design principle for materials that show multiple RTP processes, which is informed by our study of four compounds where there is modulation of the linker hybridization between donor (D) and acceptor (A) groups. Theoretical modeling and photophysical experiments demonstrate that multiple RTP processes can be achieved in sp3 C-linked D-A compounds due to the arrest of intramolecular electronic communication between two triplet states (T1H and T1L) localized on the donor and acceptor or between two triplet states, one localized on the donor and one delocalized across aggregated acceptors. However, for the sp2 C-linked D-A counterparts, RTP from one locally excited T1 state is observed because of enhanced excitonic coupling between the two triplet states of molecular subunits. Single-crystal and reduced density gradient analyses reveal the influence of molecular packing on the coincident phosphorescence processes and the origin of the observed aggregate phosphorescence. These findings provide insights into higher-lying triplet excited-state dynamics and into a fundamental design principle for designing compounds that show multiple RTP.
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33
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Giannoulis A, Ackermann K, Bogdanov A, Cordes DB, Higgins C, Ward J, Slawin AMZ, Taylor JE, Bode BE. Synthesis of mono-nitroxides and of bis-nitroxides with varying electronic through-bond communication. Org Biomol Chem 2023; 21:375-385. [PMID: 36524609 PMCID: PMC9811921 DOI: 10.1039/d2ob01863b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Nitroxides are a unique class of persistent radicals finding a wide range of applications, from spin probes to polarizing agents, and recently bis-nitroxides have been used as proof-of-concept molecules for quantum information processing. Here we present the syntheses of pyrroline-based nitroxide (NO) radicals and give a comparision of two possible synthetic routes to form two key intermediates, namely 2,2,5,5-tetramethylpyrroline-1-oxyl-3-acetylene (TPA) and 1-oxyl-2,2,5,5-tetramethylpyrroline-3-carboxylic acid (TPC). TPC and TPA were then used as precursors for the synthesis of three model compounds featuring two distant NO groups with a variable degree of conjugation and thus electronic communication between them. Using relatively facile synthetic routes, we produced a number of mono- and bis-nitroxides with the structures of multiple compounds unambiguously characterized by X-ray crystallography, while Continuous Wave Electron Paramagnetic Resonance (CW-EPR) allowed us to quantify the electronic communication in the bis-nitroxides. Our study expands the repertoire of mono- and bis-nitroxides with possibilities of exploiting them for studying quantum coherence effects and as polarizing agents.
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34
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Wu S, Kumar Gupta A, Yoshida K, Gong J, Hall D, Cordes DB, Slawin AMZ, Samuel IDW, Zysman‐Colman E. Highly Efficient Green and Red Narrowband Emissive Organic Light-Emitting Diodes Employing Multi-Resonant Thermally Activated Delayed Fluorescence Emitters. Angew Chem Int Ed Engl 2022; 61:e202213697. [PMID: 36300809 PMCID: PMC10100094 DOI: 10.1002/anie.202213697] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Indexed: 11/05/2022]
Abstract
Herein, we demonstrate how judicious selection of the donor decorating a central multi-resonant thermally activated delayed fluorescence (MR-TADF) core based on DiKTa can lead to very high-performance OLEDs. By decorating the DiKTa core with triphenylamine (TPA) and diphenylamine (DPA), 3TPA-DiKTa and 3DPA-DiKTa exhibit bright, narrowband green and red emission in doped films, respectively. The OLEDs based on these emitters showed record-high performance for this family of emitters with maximum external quantum efficiencies (EQEmax ) of 30.8 % for 3TPA-DiKTa at λEL of 551 nm and 16.7 % for 3DPA-DiKTa at λEL =613 nm. The efficiency roll-off in the OLEDs was improved significantly by using 4CzIPN as an assistant dopant in hyperfluorescence (HF) devices. The outstanding device performance has been attributed to preferential horizontal orientation of the transition dipole moments of 3TPA-DiKTa and 3DPA-DiKTa.
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35
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Duan Z, Young CM, Zhu J, Slawin AMZ, O'Donoghue AC, Smith AD. Rate and equilibrium constants for the addition of triazolium salt derived N-heterocyclic carbenes to heteroaromatic aldehydes. Chem Sci 2022; 14:162-170. [PMID: 36605738 PMCID: PMC9769090 DOI: 10.1039/d2sc05704b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 11/13/2022] [Indexed: 11/16/2022] Open
Abstract
Heteroaromatic aldehydes are often used preferentially or exclusively in a range of NHC-catalysed processes that proceed through the generation of a reactive diaminoenol or Breslow Intermediate (BI), with the reason for their unique reactivity currently underexplored. This manuscript reports measurement of rate and equilibrium constants for the reaction between N-aryl triazolium NHCs and heteroaromatic aldehydes, providing insight into the effect of the NHC and heteroaromatic aldehyde structure up to formation of the BI. Variation in NHC catalyst and heteroaromatic aldehyde structure markedly affect the observed kinetic parameters of adduct formation, decay to starting materials and onward reaction to BI. In particular, large effects are observed with both 3-halogen (Br, F) and 3-methyl substituted pyridine-2-carboxaldehyde derivatives which substantially favour formation of the tetrahedral intermediate relative to benzaldehyde derivatives. Key observations indicate that increased steric hindrance leads to a reduction in both k 2 and k -1 for large (2,6-disubstituted)-N-Ar groups within the triazolium scaffold, and sterically demanding aldehyde substituents in the 3-position, but not in the 6-position of the pyridine-2-carboxaldehyde derivatives. As part of this study, the isolation and characterisation of twenty tetrahedral adducts formed upon addition of N-aryl triazolium derived NHCs into heteroaromatic aldehydes are described. These adducts are key intermediates in NHC-catalysed umpolung addition of heteroaromatic aldehydes and are BI precursors.
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36
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Abdul Rashid FNA, Bacho MZ, Slawin AMZ, Abdul Manan MAF, Johari SA, Mohammat MF. Crystal structure of ethyl 1-(2-hydroxyethyl)-4-((4-methoxyphenyl)amino)-5-oxo-2,5-dihydro-1 H-pyrrole-3-carboxylate, C 16H 20N 2O 5. Z KRIST-NEW CRYST ST 2022. [DOI: 10.1515/ncrs-2022-0497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Abstract
C16H20N2O5, triclinic,
P
1
‾
$P\overline{1}$
(no. 2), a = 7.9179(7) Å, b = 10.1982(9) Å, c = 10.4144(8) Å, α = 76.184(7)°, β = 87.090 (7)°, γ = 73.500(8)°, V = 782.86(12) Å3, Z = 2, R
gt
(F) = 0.0458, wR
ref
(F
2) = 0.1333, T = 93 K.
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37
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Madayanad Suresh S, Zhang L, Hall D, Si C, Ricci G, Matulaitis T, Slawin AMZ, Warriner S, Olivier Y, Samuel ID, Zysman-Colman E. A Deep‐Blue‐Emitting Heteroatom‐Doped MR‐TADF Nonacene for High‐Performance Organic Light‐Emitting Diodes. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202215522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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38
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Cain D, Anderson NA, Cordes DB, Slawin AMZ, Watson AJB. Total Synthesis of (±)-Aspidospermidine, (±)-Aspidofractinine, (±)-Limaspermidine, and (±)-Vincadifformine via a Cascade and Common Intermediate Strategy. J Org Chem 2022; 87:15559-15563. [PMID: 36259765 PMCID: PMC9680024 DOI: 10.1021/acs.joc.2c02099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A concise strategy for the total synthesis of several Aspidosperma alkaloids is reported. A Suzuki-Miyaura cross-coupling provides access to a 2-vinyl indole that undergoes a Diels-Alder cascade reaction with butyn-2-one to deliver a pyrroloindoline intermediate. This undergoes cascade amidation, reduction, skeletal rearrangement, and intramolecular Michael addition to provide a common intermediate containing the full framework of the Aspidosperma alkaloids. The utility of this intermediate is shown in the synthesis of four different natural products.
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39
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Wu S, Gupta AK, Yoshida K, Gong J, Hall D, Cordes DB, Slawin AMZ, Samuel IDW, Zysman-Colman E. Highly Efficient Green & Red Narrowband Emissive Organic Light‐Emitting Diodes Employing Multi‐Resonant Thermally Activated Delayed Fluorescence Emitters. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202213697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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40
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Aragoni MC, Cherchi MF, Lippolis V, Pintus A, Podda E, Slawin AMZ, Woollins JD, Arca M. Self-Assembly of Supramolecular Architectures Driven by σ-Hole Interactions: A Halogen-Bonded 2D Network Based on a Diiminedibromido Gold(III) Complex and Tribromide Building Blocks. Molecules 2022; 27:molecules27196289. [PMID: 36234826 PMCID: PMC9571214 DOI: 10.3390/molecules27196289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 09/15/2022] [Accepted: 09/19/2022] [Indexed: 11/16/2022] Open
Abstract
The reaction of the complex [Au(phen)Br2](PF6) (phen = 1,10-phenanthroline) with molecular dibromine afforded {[Au(phen)Br2](Br3)}∞ (1). Single crystal diffraction analysis showed that the [Au(phen)Br2]+ complex cations were bridged by asymmetric tribromide anions to form infinite zig-zag chains featuring the motif ···Au–Br···Br–Br–Br···Au–Br···Br–Br–Br···. The complex cation played an unprecedented halogen bonding (XB) donor role engaging type-I and type-II XB noncovalent interactions of comparable strength with symmetry related [Br3]− anions. A network of hydrogen bonds connects parallel chains in an infinite 2D network, contributing to the layered supramolecular architecture. DFT calculations allowed clarification of the nature of the XB interactions, showing the interplay between orbital mixing, analyzed at the NBO level, and electrostatic contribution, explored based on the molecular potential energy (MEP) maps of the interacting synthons.
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41
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Wang Y, Young CM, Liu H, Hartley WC, Wienhold M, Cordes DB, Slawin AMZ, Smith AD. A Desilylative Approach to Alkyl Substituted C(1)‐Ammonium Enolates: Application in Enantioselective [2+2] Cycloadditions. Angew Chem Int Ed Engl 2022; 61:e202208800. [PMID: 35833471 PMCID: PMC9543305 DOI: 10.1002/anie.202208800] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Indexed: 11/22/2022]
Abstract
The catalytic generation of C(1)‐ammonium enolates from the corresponding α‐silyl‐α‐alkyl substituted carboxylic acids using the isothiourea HyperBTM is reported. This desilylative approach grants access to α‐unsubstituted and α‐alkyl substituted C(1)‐ammonium enolates, which are typically difficult to access through traditional methods reliant upon deprotonation. The scope and limitations of this process is established in enantioselective [2+2]‐cycloaddition processes with perfluoroalkylketones (31 examples, up to 96 % yield and >99 : 1 er), as well as selective [2+2]‐cycloaddition with trifluoromethyl enones (4 examples, up to 75 % yield and >99 : 1 er). Preliminary mechanistic studies indicate this process proceeds through an initial kinetic resolution of an in situ prepared (±)‐α‐silyl‐α‐alkyl substituted anhydride, while the reaction process exhibits overall pseudo zero‐order kinetics.
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42
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Burnett S, Bourne C, Slawin AMZ, van Mourik T, Stasch A. Umpolung of an Aliphatic Ketone to a Magnesium Ketone‐1,2‐diide Complex with Vicinal Dianionic Charge. Angew Chem Int Ed Engl 2022; 61:e202204472. [PMID: 35762819 PMCID: PMC9541192 DOI: 10.1002/anie.202204472] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Indexed: 12/05/2022]
Abstract
The new β‐diketimine iPrDipnacnacH, HC(iPrCNDip)2H, Dip=2,6‐iPr2‐C6H3, was converted to the magnesium(I) complex [{(iPrDipnacnac)Mg}2] and reaction with 2‐adamantanone (OAd) afforded the ketone‐1,2‐diide complex [{(iPrDipnacnac)Mg}2(μ‐OAd)]. The complex contains the first stable dianion of an aliphatic ketone with an electropositive metal and shows an OAd2− unit with long C−O bond and pyramidal carbon centre. DFT studies reveal an anionic charge on both neighbouring C and O atoms. Reductions of aliphatic ketones with magnesium(I) complexes show that these likely proceed via highly reactive dianions and afforded a 1 : 1 mixture of an alkoxide and an enolate when an enolisable ketone was used, and rapid CH activations reactions, e.g., of stabilising ligand moieties, when non‐enolisable ketones were employed.
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43
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Burnett S, de Vere-Tucker M, Davitt M, Cordes DB, Slawin AMZ, Ferns R, van Mourik T, Stasch A. Magnesium Complexes with Isomeric Pyrazol‐4‐ylidene and Imidazol‐2‐ylidene Ligands. Z Anorg Allg Chem 2022. [DOI: 10.1002/zaac.202200207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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44
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Abdelhamid Y, Kasten K, Dunne J, Hartley WC, Young CM, Cordes DB, Slawin AMZ, Ng S, Smith AD. Isothiourea-Catalyzed [2 + 2] Cycloaddition of C(1)-Ammonium Enolates and N-Alkyl Isatins. Org Lett 2022; 24:5444-5449. [PMID: 35848722 PMCID: PMC9490795 DOI: 10.1021/acs.orglett.2c02170] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
Enantioselective [2 + 2] cycloaddition of C(1)-ammonium
enolates
generated catalytically using the isothiourea HyperBTM with N-alkyl isatins gives spirocyclic β-lactones. In situ ring opening with an amine nucleophile generates
isolable highly enantioenriched products in up to 92:8 dr and in >99:1
er.
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Smith AD, Wang Y, Young CM, Liu H, Hartley WC, Wienhold M, Cordes DB, Slawin AMZ. A Desilylative Approach to Alkyl Substituted C(1)‐Ammonium Enolates: Application in Enantioselective [2+2] Cycloadditions. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202208800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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46
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Burnett S, Bourne C, Slawin AMZ, van Mourik T, Stasch A. Umpolung of an Aliphatic Ketone to a Magnesium Ketone‐1,2‐diide Complex with Vicinal Dianionic Charge. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202204472] [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]
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47
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Poskin TJ, Piscelli BA, Yoshida K, Cordes DB, Slawin AMZ, Cormanich RA, Yamada S, O'Hagan D. Janus faced fluorocyclohexanes for supramolecular assembly: synthesis and solid state structures of equatorial mono-, di- and tri alkylated cyclohexanes and with tri-axial C-F bonds to impart polarity. Chem Commun (Camb) 2022; 58:7968-7971. [PMID: 35758098 DOI: 10.1039/d2cc03010a] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Concise and general synthesis protocols are reported to generate all-syn mono-, di- and tri-alkylated cyclohexanes where a single fluorine is located on the remaining carbons of the ring. The alkyl groups are positioned to lie equatorially and to have triaxial C-F bonds imparting polarity to these ring systems. Intermolecular electrostatic interactions in the solid-state structure of the trialkylated systems are explored and the resultant supramolecular order opens up prospects for design in soft materials.
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48
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Abazari R, Amani-Ghadim AR, Slawin AMZ, Carpenter-Warren CL, Kirillov AM. Non-Calcined Layer-Pillared Mn 0.5Zn 0.5 Bimetallic-Organic Framework as a Promising Electrocatalyst for Oxygen Evolution Reaction. Inorg Chem 2022; 61:9514-9522. [PMID: 35699592 PMCID: PMC9775468 DOI: 10.1021/acs.inorgchem.2c00542] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Electrocatalytic generation of oxygen is of great significance for sustainable, clean, and efficient energy production. Multiple electron transfer in oxygen evolution reaction (OER) and its slow kinetics represent a serious hedge for efficient water splitting, requiring the design and development of advanced electrocatalysts with porous structures, high surface areas, abundant electroactive sites, and low overpotentials. These requisites are common for metal-organic frameworks (MOFs) and derived materials that are promising electrocatalysts for OER. The present work reports on the synthesis and full characterization of a heteroleptic 3D MOF, [Zn2(μ4-odba)2(μ-bpdh)]n·nDMF (Zn-MUM-1), assembled from 4,4'-oxydibenzoic acid and 2,5-bis(4-pyridyl)-3,4-diaza-2,4-hexadiene (bpdh). Besides, a series of heterometallic MnZn-MUM-1 frameworks (abbreviated as Mn0.5Zn0.5-MUM-1, Mn0.66Zn0.33-MUM-1, and Mn0.33Zn0.66-MUM-1) was also prepared, characterized, and used for the fabrication of working electrodes based on Ni foam (NF), followed by their exploration in OER. These noble-metal-free and robust electrocatalysts are stable and do not require pyrolysis or calcination while exhibiting better electrocatalytic performance than the parent Zn-MUM-1/NF electrode. The experimental results show that the Mn0.5Zn0.5-MUM-1/NF electrocatalyst features the best OER activity with a low overpotential (253 mV at 10 mA cm-2) and Tafel slope (73 mV dec-1) as well as significant stability after 72 h or 6000 cycles. These excellent results are explained by a synergic effect of two different metals present in the Mn-Zn MOF as well as improved charge and ion transfer, conductivity, and stability characteristics. The present study thus widens the application of heterometallic MOFs as prospective and highly efficient electrocatalysts for OER.
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49
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Ibrahim ABM, Mahmoud GA, Cordes DB, Slawin AMZ. Pb (II) and Hg (II) Thiosemicarbazones for Inhibiting the Broad‐Spectrum Pathogen
Cladosporium sphaerospermum
ASU18 (MK387875) and Altering Its Antioxidant System. Appl Organomet Chem 2022. [DOI: 10.1002/aoc.6798] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Bitai J, Nimmo AJ, Slawin AMZ, Smith AD. Cooperative Palladium/Isothiourea Catalyzed Enantioselective Formal (3+2) Cycloaddition of Vinylcyclopropanes and α,β-Unsaturated Esters. Angew Chem Int Ed Engl 2022; 61:e202202621. [PMID: 35389553 PMCID: PMC9324207 DOI: 10.1002/anie.202202621] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Indexed: 12/15/2022]
Abstract
A protocol for the enantioselective synthesis of substituted vinylcyclopentanes has been realised using cooperative palladium and isothiourea catalysis. Treatment of vinylcyclopropanes with Pd(PPh3 )4 generates a zwitterionic π-allyl palladium intermediate that intercepts a catalytically generated α,β-unsaturated acyl ammonium species prepared from the corresponding α,β-unsaturated para-nitrophenyl ester and the isothiourea (R)-BTM. Intermolecular formal (3+2) cycloaddition between these reactive intermediates generates functionalised cyclopentanes in generally good yields and excellent diastereo- and enantiocontrol (up to >95 : 5 dr, 97 : 3 er), with the use of LiCl as an additive proving essential for optimal stereocontrol. To the best of our knowledge a dual transition metal/organocatalytic process involving α,β-unsaturated acyl ammonium intermediates has not been demonstrated previously.
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