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Warrington S, Montanaro S, Elsegood MRJ, Nichol GS, Wright IA. Structure-Property Relationships for Potential Inversion From Electron Acceptors Based on Thiophene-Fused Triptycene Quinones, 1,4-Diketones and Their Malononitrile Adducts. Chemistry 2024; 30:e202400782. [PMID: 38517200 DOI: 10.1002/chem.202400782] [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: 02/27/2024] [Revised: 03/20/2024] [Accepted: 03/21/2024] [Indexed: 03/23/2024]
Abstract
The synthesis and properties of a series of 11,11,12,12-tetracyano-9,10-anthraquinodimethane (TCAQ) inspired electron acceptors based on thiophene-fused quinone and triptycene motifs is presented. This has yielded insights into structure-property relationships for establishing and modulating simultaneous two-electron reduction processes in TCAQ analogues. These new compounds were synthesised using a Friedel-Crafts acylation between triptycene and thiophene-3,4-dicarbonyl chloride. Isomeric para-quinones featuring a [c]-fused thiophene on one side and a β,β- or α,β-fused triptycene on the other were isolated alongside a thiophene-3,4-diketone which bears two triptycene fragments. Knoevenagel condensation of these products with malononitrile produced a quinoidal bis(dicyanomethylene), an oxo-dicyanomethylene and an acyclic bis(dicyanomethylene). This series of new electron accepting molecules has been studied using X-ray crystallography and the implications of their 3D structures on NMR and UV/vis absorbance spectroscopy and cyclic voltammetry results have been ascertained with conclusions underpinned by computational methods.
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Affiliation(s)
- Stefan Warrington
- School of Chemistry, University of Edinburgh Joseph Black Building, David Brewster Road, Edinburgh, EH16 5PL, United Kingdom
- Department of Chemistry, Loughborough University, Epinal Way, Loughborough, Leicestershire, LE11 3TU, United Kingdom
| | - Stephanie Montanaro
- Department of Chemistry, Loughborough University, Epinal Way, Loughborough, Leicestershire, LE11 3TU, United Kingdom
| | - Mark R J Elsegood
- Department of Chemistry, Loughborough University, Epinal Way, Loughborough, Leicestershire, LE11 3TU, United Kingdom
| | - Gary S Nichol
- School of Chemistry, University of Edinburgh Joseph Black Building, David Brewster Road, Edinburgh, EH16 5PL, United Kingdom
| | - Iain A Wright
- School of Chemistry, University of Edinburgh Joseph Black Building, David Brewster Road, Edinburgh, EH16 5PL, United Kingdom
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2
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Vicent DJ, Pérez-Escribano M, Cárdenas-Valdivia A, Barragán A, Calbo J, Urgel JI, Écija D, Santos J, Casado J, Ortí E, Martín N. Dimeric tetrabromo- p-quinodimethanes: synthesis and structural/electronic properties. Chem Sci 2023; 14:10112-10120. [PMID: 37772123 PMCID: PMC10530488 DOI: 10.1039/d3sc01615c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 08/09/2023] [Indexed: 09/30/2023] Open
Abstract
Despite their great potential as molecular building blocks for organic synthesis, tetrabromo-p-quinodimethanes (TBQs) are a relatively unknown family of compounds. Herein, we showcase a series of five derivatives incorporating two tetrabromo-anthraquinodimethane (TBAQ) units linked by π-conjugated spacers of different nature and length. The resulting dimers TBQ1-5 are fully characterised by means of thorough spectroscopic measurements and theoretical calculations. Interestingly, owing to the steric hindrance imposed by the four bulky bromine atoms, the TBAQ fragments adopt a characteristically warped geometry, somehow resemblant of a butterfly, and the novel dimers show a complex NMR pattern with signal splittings. To ascertain whether dynamic processes regarding fluxional inversion of the butterfly configurations are involved, first-principles calculations assessing the interconversion energy barriers are performed. Three possible stereoisomers are predicted involving two diastereomers, thus accounting for the observed NMR spectra. The rotational freedom of the TBAQ units around the π-conjugated linker influences the structural and electronic properties of TBQ1-5 and modulates the electronic communication between the terminal TBAQ moieties. The role of the linker on the electronic properties is investigated by Raman and UV-vis spectroscopies, theoretical calculations and UV-vis measurements at low temperature. TBQ1-5 are of interest as less-explored structural building precursors for a variety of scientific areas. Finally, the sublimation, self-assembly and reactivity on Au(111) of TBQ3 is assessed.
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Affiliation(s)
- Diego J Vicent
- Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Complutense de Madrid 28040 Madrid Spain
| | | | | | - Ana Barragán
- IMDEA-Nanociencia C/ Faraday, 9, Campus de Cantoblanco 28049 Madrid Spain
| | - Joaquín Calbo
- Instituto de Ciencia Molecular, Universidad de Valencia 46980 Paterna Spain
| | - José I Urgel
- IMDEA-Nanociencia C/ Faraday, 9, Campus de Cantoblanco 28049 Madrid Spain
| | - David Écija
- IMDEA-Nanociencia C/ Faraday, 9, Campus de Cantoblanco 28049 Madrid Spain
| | - José Santos
- Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Complutense de Madrid 28040 Madrid Spain
| | - Juan Casado
- Departamento de Química Física, Universidad de Málaga 229071 Malaga Spain
| | - Enrique Ortí
- Instituto de Ciencia Molecular, Universidad de Valencia 46980 Paterna Spain
| | - Nazario Martín
- Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Complutense de Madrid 28040 Madrid Spain
- IMDEA-Nanociencia C/ Faraday, 9, Campus de Cantoblanco 28049 Madrid Spain
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Gruber M, Padberg K, Min J, Waterloo AR, Hampel F, Maid H, Ameri T, Brabec CJ, Tykwinski RR. Acenequinocumulenes: Lateral and Vertical π-Extended Analogues of Tetracyanoquinodimethane (TCNQ). Chemistry 2017; 23:17829-17835. [DOI: 10.1002/chem.201704314] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Indexed: 11/06/2022]
Affiliation(s)
- Marco Gruber
- Department für Chemie und Pharmazie; Interdisciplinary Center for Molecular Materials (ICMM); Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU); Henkestrasse 42 91054 Erlangen Germany
| | - Kevin Padberg
- Department für Chemie und Pharmazie; Interdisciplinary Center for Molecular Materials (ICMM); Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU); Henkestrasse 42 91054 Erlangen Germany
| | - Jie Min
- Materials for Electronics and Energy Technology (i-MEET); Friedrich Alexander Universität Erlangen-Nürnberg (FAU); Martensstrasse 7 91058 Erlangen Germany
| | - Andreas R. Waterloo
- Department für Chemie und Pharmazie; Interdisciplinary Center for Molecular Materials (ICMM); Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU); Henkestrasse 42 91054 Erlangen Germany
| | - Frank Hampel
- Department für Chemie und Pharmazie; Interdisciplinary Center for Molecular Materials (ICMM); Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU); Henkestrasse 42 91054 Erlangen Germany
| | - Harald Maid
- Department für Chemie und Pharmazie; Interdisciplinary Center for Molecular Materials (ICMM); Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU); Henkestrasse 42 91054 Erlangen Germany
| | - Tayebeh Ameri
- Materials for Electronics and Energy Technology (i-MEET); Friedrich Alexander Universität Erlangen-Nürnberg (FAU); Martensstrasse 7 91058 Erlangen Germany
| | - Christoph J. Brabec
- Materials for Electronics and Energy Technology (i-MEET); Friedrich Alexander Universität Erlangen-Nürnberg (FAU); Martensstrasse 7 91058 Erlangen Germany
| | - Rik R. Tykwinski
- Department für Chemie und Pharmazie; Interdisciplinary Center for Molecular Materials (ICMM); Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU); Henkestrasse 42 91054 Erlangen Germany
- Current address: Department of Chemistry; University of Alberta; Edmonton AB T6G 2G2 Canada
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Gómez R, Seoane C, Segura JL. The first two decades of a versatile electron acceptor building block: 11,11,12,12-tetracyano-9,10-anthraquinodimethane (TCAQ). Chem Soc Rev 2007; 36:1305-22. [PMID: 17619690 DOI: 10.1039/b605735g] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This critical review surveys the development of the structural and electrochemical knowledge of the TCAQ moiety since its discovery, nearly two decades ago, until the present. Additionally, recent advances in the chemistry and functionalization of this versatile building block are highlighted, with special emphasis on the strategies devoted to the preparation of donor-acceptor molecular and polymeric materials. The applications of TCAQ-based materials in materials science as electrical conductors, molecular rectifiers, in photoinduced electron transfer processes, optoelectronic devices and as electrochiroptical materials are also reviewed (89 references).
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Affiliation(s)
- Rafael Gómez
- Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Madrid, Spain
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Godbert N, Batsanov AS, Bryce MR, Howard JA. Molecular saddles. 4. Redox-active cyclophanes by bridging the 9,10-bis(1,3-dithiol-2-ylidene)-9,10-dihydroanthracene system: synthesis, electrochemistry, and X-ray crystal structures of neutral species and a dication salt. J Org Chem 2001; 66:713-9. [PMID: 11430087 DOI: 10.1021/jo001014q] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report the synthesis of a new series of cyclophanes 11a-d by ester-forming macrocyclization reactions of diol 9 with the dicarbonyl chloride derivatives of benzene, thiophene, ferrocene, and diphenyl ether, 10a-d, respectively. Compounds 11a-d display a two-electron, quasireversible oxidation wave in the cyclic voltammogram to yield the dication species at Eoxpa = 0.70-0.72 V (for 11a-c) and 0.47 V (for 11d) (vs Ag/AgCl in acetonitrile). The raised oxidation potentials for 11a-c reflect the reduced stability of the twisted dication structure within the steric constraints of the smaller cyclophanes. Consistent with this, the value of delta E (defined as Eoxpa - Eoxpc) decreases (i.e., reversibility of the oxidation process increases) in the sequence 11d > 11c > 11a > 11b as the bridging chain becomes shorter. X-ray crystal structures are reported for compounds 11a-d and the dication salt 11d2+(I3-)2.(CH2Cl2)2.25. For 11a-d the typical saddle-shaped conformation of the 9,10-bis(1,3-dithiol-2-ylidene)-9,10-dihydroanthracene moiety is observed, with the strain imposed by the cyclophane ring being accommodated in the structure of the bridging unit. In the dication 11d2+ both dithiolium rings are planar and the anthracene unit is essentially aromatic, with the conformation of the bridge basically the same as in neutral 11d.
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Affiliation(s)
- N Godbert
- Department of Chemistry, University of Durham, Durham DH1 3LE, United Kingdom
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New chiral binaphthyl building blocks: synthesis of the first optically active tetrathiafulvalene and 11,11,12,12-tetracyano-9, 10-anthraquinodimethane dimers. J Org Chem 2000; 65:7566-74. [PMID: 11076616 DOI: 10.1021/jo0009649] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
New enantiomerically pure binaphthyl derivatives bearing triphenylphosphine or phosphonate groups have been synthesized and used as building blocks to prepare the first optically active TTF and TCAQ dimers. Due to the restricted rotation of the two naphthalene rings, binaphthyl derivatives are ideal candidates to be used as nonplanar spacers between electroactive units in the search for materials with enhanced dimensionality. The electronic absorption spectra of dimers in which the electroactive unit is in conjugation with the naphthalene fragment reveal the presence of intramolecular photoinduced electron-transfer process from the TTF to the naphthalene unit in 5 and 6 and from the naphthalene moiety to the TCAQ unit in 7. Electrochemical studies on the new dimers show the redox potentials of TTF and TCAQ units as well as the oxidation wave for the naphthalene moiety and reveal no significant electronic interaction between the two electroactive units, which is in agreement with the results obtained from theoretical calculations at the PM-3 level which indicate that the angle between rings in the binaphthyl systems ranges from 75 to 80 degrees.
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[60]Fullerene adducts with improved electron acceptor properties [In Process Citation]. J Org Chem 2000; 65:5986-95. [PMID: 10987931 DOI: 10.1021/jo0003753] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The synthesis of C(60)-based dyads in which the C(60) core is covalently attached to a strong electron acceptor moiety such as quinones, TCNQ or DCNQI derivatives, has been carried out by 1, 3-dipolar cycloaddition of "in situ" generated azomethyne ylides or nitrile oxides to C(60). As expected, the obtained pyrrolidino[3', 4':1,2][60]fullerenes exhibit reduction potentials of the C(60) framework which are cathodically shifted in comparison with the parent C(60). In contrast, isoxazolo[4',5':1,2][60]fullerenes show reduction waves for the fullerene core that are anodically shifted in comparison with the parent C(60), which indicates that they are remarkably stronger acceptors than C(60).The electron acceptor organic addend also undergoes an anodic shift due to the electronic interaction with the C(60) moiety. The molecular geometry of pyrrolidinofullerenes has been calculated at the semiempirical PM3 level and reveals a highly distorted geometry for the acceptor moiety in compound 13, and a most stable conformation in which both dicyanomethylene units are far away from the C(60) surface.
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Martín N, Sánchez L, Seoane C, Ortí E, Viruela PM, Viruela R. Synthesis, Properties, and Theoretical Characterization of Largely π-Extended Tetrathiafulvalene Derivatives with Quinonoid Structures. J Org Chem 1998. [DOI: 10.1021/jo9719416] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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9
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Martín N, Segura JL, Seoane C, Ortí E, Viruela PM, Viruela R, Albert A, Cano FH, Vidal-Gancedo J, Rovira C, Veciana J. Synthesis, Characterization, and Theoretical Study of Sulfur-Containing Donor-Acceptor DCNQI Derivatives with Photoinduced Intramolecular Electron Transfer. J Org Chem 1996; 61:3041-3054. [PMID: 11667166 DOI: 10.1021/jo952274o] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The donor-acceptor compounds N,N'-dicyanobenzo[b]naphtho[2,3-e][1,4]dithiin-6,11-quinonediimine (9a) and N,N'-dicyanobenzo[b]naphtho[2,3-e][1,4]oxathiin-6,11-quinonediimine (10a) and their methyl-substituted derivatives (9b and 10b-d, respectively) have been prepared, and their structural and electronic properties have been characterized by both experimental techniques and quantum-chemical calculations. The (1)H-NMR spectra evidence the existence of a syn/anti isomerism in solution. Both experimental and theoretical data suggest that the preferred configuration of the N-CN groups corresponds to a syn isomer for 9 and to an anti isomer for 10. The X-ray analysis performed for 9b reveals that molecules are not planar and pack in vertical stacks showing an overlap between donor and acceptor moieties of adjacent molecules. In agreement with X-ray data, theoretical calculations predict that both for 9 and 10 the acceptor DCNQI moiety is folded and adopts a butterfly-type structure and the donor moiety is bent along the line passing through the heteroatoms. The energy difference between planar and butterfly structures is calculated to be < 3 kcal/mol at the ab initio 6-31G level. The UV-vis spectra present a broad absorption in the visible which corresponds to a photoinduced intramolecular electron transfer from the high-energy HOMO furnished by the donor moiety to the low-energy LUMO located on the DCNQI fragment. Cyclic voltammetry displays one oxidation peak to the cation and two one-electron reduction waves to the anion and dianion. Theoretical calculations show the planarization of the acceptor/donor moiety induced by reduction/oxidation. The formation of stable radical anions is corroborated by the intense EPR signals recorded for reduced 9. The assignment of the hyperfine coupling constants of the EPR spectra is consistent with the existence of a preferred syn configuration.
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Affiliation(s)
- Nazario Martín
- Institut de Ciència de Materials de Barcelona (CSIC), Campus U.A.B., E-08193 Bellaterra, Spain
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