51
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Bühringer MU, Padberg K, Phleps MD, Maid H, Placht C, Neiss C, Ferguson MJ, Görling A, Tykwinski RR. Double Bonds? Studies on the Barrier to Rotation about the Cumulenic C=C Bonds of Tetraaryl[
n
]cumulenes (
n=
3, 5, 7, 9). Angew Chem Int Ed Engl 2018; 57:8321-8325. [DOI: 10.1002/anie.201802137] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Indexed: 11/08/2022]
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52
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Hetzer C, Guldi DM, Tykwinski RR. Frontispiece: Pentacene Dimers as a Critical Tool for the Investigation of Intramolecular Singlet Fission. Chemistry 2018. [DOI: 10.1002/chem.201883361] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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53
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Kunzmann A, Gruber M, Casillas R, Tykwinski RR, Costa RD, Guldi DM. Tuning pentacene based dye-sensitized solar cells. NANOSCALE 2018; 10:8515-8525. [PMID: 29693096 DOI: 10.1039/c8nr01502c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We report on the synthesis, as well as photophysical and electrochemical characterization of a new family of pentacene derivatives, which are applied in n-type dye-sensitized solar cells (DSSCs). As far as the molecular structure of the pentacene is concerned, the synthetic design focuses on cyano acrylic tethered at the 13-position of the pentacene chromophore. The electrolyte composition features increasing amounts of Li+ ions as an additive. In general, the increase of Li+ concentrations extrinsically reduces the quasi Fermi level of the photoanode and as such facilitates the electron injection process. We demonstrate that pentacene derivatives give rise to a unique charge injection process, which is controlled by the positioning of the quasi Fermi level energies as a function of the Li+ concentration. As a result of the enhanced charge injection, device efficiencies as high as 1.5% are achieved, representing a 3-fold increase from previously reported efficiencies in pentacene-based DSSCs. These findings are supported by device analysis in combination with transient absorption and electrochemical impedance spectroscopy assays.
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54
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Basel BS, Zirzlmeier J, Hetzer C, Reddy SR, Phelan BT, Krzyaniak MD, Volland MK, Coto PB, Young RM, Clark T, Thoss M, Tykwinski RR, Wasielewski MR, Guldi DM. Evidence for Charge-Transfer Mediation in the Primary Events of Singlet Fission in a Weakly Coupled Pentacene Dimer. Chem 2018. [DOI: 10.1016/j.chempr.2018.04.006] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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55
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Hetzer C, Guldi DM, Tykwinski RR. Pentacene Dimers as a Critical Tool for the Investigation of Intramolecular Singlet Fission. Chemistry 2018; 24:8245-8257. [DOI: 10.1002/chem.201705355] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Indexed: 11/09/2022]
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56
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Neugebauer TS, Franz M, Frankenberger S, Tykwinski RR, Drewello T. Laser desorption vs. electrospray of polyyne-threaded rotaxanes: Preventing covalent cross-linking and promoting noncovalent aggregation. J Chem Phys 2018; 148:064308. [PMID: 29448797 DOI: 10.1063/1.5013123] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Laser-induced cross-linking of polyynes is successfully hindered when the polyyne is encapsulated as part of a rotaxane and therefore protected by a surrounding macrocycle. When the rotaxane is electrosprayed, however, noncovalent aggregate ions are efficiently formed. Aggregates of considerable size (including more than 50 rotaxane molecules with masses beyond 100k Da) and charge states (up to 13 charges and beyond) have been observed. Either protons or sodium cations act as the charge carriers. These aggregates are not formed when the individual components of the rotaxane, i.e., the macrocycle or the polyyne, are separately electrosprayed. This underlines the structural importance of the rotaxane for the aggregate formation. Straightforward force field calculations indicate that the polyyne thread hinders the folding of the macrocycles, which facilitates the bonding interaction between the two components.
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57
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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]
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58
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Gruber M, Bauer W, Maid H, Schöll K, Tykwinski RR. Synthetic and NMR studies on hexaphenylcarbodiphosphorane (Ph3P C PPh3). Inorganica Chim Acta 2017. [DOI: 10.1016/j.ica.2017.04.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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59
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Garoni E, Zirzlmeier J, Basel BS, Hetzer C, Kamada K, Guldi DM, Tykwinski RR. Two-Photon Absorption in Pentacene Dimers: The Importance of the Spacer Using Upconversion as an Indirect Route to Singlet Fission. J Am Chem Soc 2017; 139:14017-14020. [DOI: 10.1021/jacs.7b08287] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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60
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Marshall JL, Lehnherr D, Lindner BD, Tykwinski RR. Reductive Aromatization/Dearomatization and Elimination Reactions to Access Conjugated Polycyclic Hydrocarbons, Heteroacenes, and Cumulenes. Chempluschem 2017; 82:967-1001. [PMID: 31961601 DOI: 10.1002/cplu.201700168] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 05/18/2017] [Indexed: 11/12/2022]
Abstract
Acenes, heteroacenes, conjugated polycyclic hydrocarbons, and polycyclic aromatic hydrocarbons (collectively referred to in this review as conjugated polycyclic molecules, CPMs) have fascinated chemists since they were first isolated and synthesized in the mid 19th century. Most recently, these compounds have shown significant promise as the active components in organic devices (e.g., solar cells, thin-film transistors, light-emitting diodes, etc.), and, since 2001, a plethora of publications detail synthetic strategies to produce CPMs. In this review, we discuss reductive aromatization, reductive dearomatization, and elimination/extrusion reactions used to form CPMs. After a brief discussion on early methods to synthesize CPMs, we detail the use of reagents used for the reductive (de)aromatization of precursors containing 1,4-diols/diethers, including SnCl2 and iodide (I- ). Extension of these methods to carbomers and cumulenes is briefly discussed. We then describe low-valent metal species used to reduce endoxides to CPMs, and discuss the methods to directly reduce acenediones and acenones to the respective acene. In the final section, we describe methods used to affect aromatization to the desired CPM via extrusion of small, volatile molecules.
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61
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Wendinger D, Tykwinski RR. Odd [n]Cumulenes (n = 3, 5, 7, 9): Synthesis, Characterization, and Reactivity. Acc Chem Res 2017; 50:1468-1479. [PMID: 28561581 DOI: 10.1021/acs.accounts.7b00164] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
In comparison to the omnipresent two- and three-dimensional allotropes of carbon, namely, graphite and diamond (as well as recent entries graphene, carbon nanotubes, and fullerenes), a detailed understanding of the one-dimensional carbon allotrope carbyne is not well established, and even the existence of carbyne has been a matter of controversy over the past decades. Composed of sp-hybridized carbon, carbyne could potentially exist in two forms, either as a polyyne (alternating single and triple bonds, expected to show a semiconducting behavior) or as a cumulene (all carbon atoms are connected via double bonds, predicted to show metallic behavior). Although a number of publications are available on the hypothetical structure and properties of carbyne, specific knowledge about its physical and spectroscopic characteristics is still unclear. In order to predict the properties of carbyne, the synthesis and study of model compounds, namely, polyynes and cumulenes, has been a promising avenue. The synthesis of polyynes has been extensively explored in the last decades, culminating with the isolation of a polyyne with 22 acetylene units, which allows extrapolation to the properties of carbyne. Extended cumulenes, on the other hand, have remained much less well-known, and specific studies of properties versus molecular length are quite limited. A limiting factor to the study of [n]cumulenes has been their dramatically increased reactivity, especially in comparison to polyynes of comparable length. For example, most known [7]cumulenes can only be handled in solution, while the polyynes of equivalent length (i.e., a triyne with three acetylene units) are quite stable. [9]Cumulenes are the longest derivatives studied to date. In this Account, we describe our efforts to design and synthesize odd [n]cumulenes (i.e., n = 3, 5, 7, 9) that are sufficiently persistent under ambient conditions to allow in depth characterization of physical and spectral properties. This goal has been achieved through modification of the end-capping groups by increasing the steric bulk and thereby shielding the reactive cumulene framework to provide stable [7]- and [9]cumulenes. An alternative route to stabilization is accomplished via encapsulation of the cumulene skeleton in a macrocycle, that is, formation of cumulene rotaxanes. The new sterically encumbered cumulenic products are reasonably stable under normal laboratory conditions, although some readily undergo cycloaddition reactions to give interesting products. We have explored preliminary trends for the reactivity of long [n]cumulenes. Finally, trends in the series of [n]cumulene model compounds are now discernible, including a thorough consideration of bond length alternation (BLA) in long [n]cumulenes using X-ray crystallographic analyses, as well as electronic properties via UV-vis spectroscopy and cyclic voltammetry.
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62
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Lehnherr D, Adam M, Murray AH, McDonald R, Hampel F, Tykwinski RR. Synthesis, physical properties, and chemistry of donor–acceptor-substituted pentacenes. CAN J CHEM 2017. [DOI: 10.1139/cjc-2016-0450] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Pentacenes bearing electron-donating and (or) -withdrawing groups, namely methoxy-, dialkylamino-, and nitroaryl moieties, are synthesized to afford polarized pentacenes. The optical, electrochemical, and chemical properties of these derivatives are explored. The cycloaddition reaction of selected derivatives with tetracyanoethylene (TCNE) is explored, and the experimental results are rationalized on the basis calculations using density functional theory (DFT). X-ray crystallographic data provides insight into the molecular structure and intermolecular interactions present in the solid state.
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63
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Prenzel D, Sander T, Gebhardt J, Soni H, Hampel F, Görling A, Maier S, Tykwinski RR. Triethynylmethanol Derivatives: Stable Acetylenic Building Blocks for Surface Chemistry. Chemistry 2017; 23:1846-1852. [DOI: 10.1002/chem.201604404] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Indexed: 11/11/2022]
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64
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Milan DC, Krempe M, Ismael AK, Movsisyan LD, Franz M, Grace I, Brooke RJ, Schwarzacher W, Higgins SJ, Anderson HL, Lambert CJ, Tykwinski RR, Nichols RJ. The single-molecule electrical conductance of a rotaxane-hexayne supramolecular assembly. NANOSCALE 2017; 9:355-361. [PMID: 27924336 DOI: 10.1039/c6nr06355a] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Oligoynes are archetypical molecular wires due to their 1-D chain of conjugated carbon atoms and ability to transmit charge over long distances by coherent tunneling. However, the stability of the oligoyne can be an issue. Here we address this problem by two stabilization methods, namely sterically shielding endgroups, and rotaxination to produce an insulated molecular wire. We demonstrate the threading of a hexayne within a macrocycle to form a rotaxane and report measurements of the electrical conductance of this single supramolecular assembly within an STM break junction. The macrocycle is retained around the hexayne through the use of 3,5-diphenylpyridine stoppers at both ends of the molecular wire, which also serve as chemisorption contacts to the gold electrodes of the junction. Molecular conductance was measured for both the supramolecular assembly and also for the molecular wire in the absence of the macrocycle. The threaded macrocycle, which at room temperature is mobile along the length of the hexayne between the stoppers, has only a minimal impact on the conductance. However, the probability of molecular junction formation in a given break junction formation cycle is notably lower with the rotaxane. In seeking to understand the conductance behavior, the electronic properties of these molecular assemblies and the electrical behavior of the junctions have been investigated by using DFT-based computational methods.
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65
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Prenzel D, Kirschbaum RW, Chalifoux WA, McDonald R, Ferguson MJ, Drewello T, Tykwinski RR. Polymerization of acetylene: polyynes, but not carbyne. Org Chem Front 2017. [DOI: 10.1039/c6qo00648e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Polymerization of acetylene in the presence of sterically-hindered endgroups leads to polyynes, but with lengths shorter than by stepwise syntheses.
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66
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Garcia‐Borràs M, Konishi A, Waterloo A, Liang Y, Cao Y, Hetzer C, Lehnherr D, Hampel F, Houk KN, Tykwinski RR. Tautomerization and Dimerization of 6,13‐Disubstituted Derivatives of Pentacene. Chemistry 2016; 23:6111-6117. [DOI: 10.1002/chem.201604099] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Indexed: 11/11/2022]
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67
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Krempe M, Lippert R, Hampel F, Ivanović-Burmazović I, Jux N, Tykwinski RR. Pyridyl-Endcapped Polyynes: Stabilized Wire-like Molecules. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201608633] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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68
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Krempe M, Lippert R, Hampel F, Ivanović‐Burmazović I, Jux N, Tykwinski RR. Pyridyl‐Endcapped Polyynes: Stabilized Wire‐like Molecules. Angew Chem Int Ed Engl 2016; 55:14802-14806. [DOI: 10.1002/anie.201608633] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Indexed: 11/08/2022]
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69
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Etschel SH, Tykwinski RR, Halik M. Enhancing the Dispersibility of TiO 2 Nanorods and Gaining Control over Region-Selective Layer Formation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:10604-10609. [PMID: 27668509 DOI: 10.1021/acs.langmuir.6b02480] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We demonstrate that the dispersibility and reactivity of core-shell TiO2 nanorods (NRs) can be controlled significantly through functionalization with a combination of ligands based on phosphonic acid derivatives (PAs). Specifically, a glycol based PA allows dispersion of the NRs in methanol (MeOH). On the other hand, incorporating an alkyne terminated PA in the ligand shell of the NRs allows for a copper-catalyzed alkyne-azide cycloaddition (CuAAC) reaction with an azide-patterned aluminum oxide (AlOx) substrate and forms a region-selectively deposited film of NRs. We clearly demonstrate that the quality of the NR films correlates strongly with the stability of the NR dispersions in the reaction medium. In particular, tuning the concentration of alkyne PA in the ligand shell inhibits aggregation of the NRs on the substrate, while reactivity for the CuAAC reaction is maintained. The surface coverage with NRs fits the Langmuir model. This study illustrates that surface functionalization of AlOx substrates can be effectively and conveniently controlled through enhancing the dispersibility of the NRs using mixed ligand shells.
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70
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Spörler S, Müller L, Waterloo AR, Tykwinski RR, Burzlaff N. Carbon-rich dinuclear ruthenium bisallenylidene complexes. J Organomet Chem 2016. [DOI: 10.1016/j.jorganchem.2016.06.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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71
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Reus C, Lechner MP, Schulze M, Lungerich D, Diner C, Gruber M, Stryker JM, Hampel F, Jux N, Tykwinski RR. Unexpected Michael Additions on the Way to 2.3,8.9-Dibenzanthanthrenes with Interesting Structural Properties. Chemistry 2016; 22:9097-101. [DOI: 10.1002/chem.201601435] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2016] [Indexed: 11/06/2022]
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72
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Zirzlmeier J, Casillas R, Reddy SR, Coto PB, Lehnherr D, Chernick ET, Papadopoulos I, Thoss M, Tykwinski RR, Guldi DM. Solution-based intramolecular singlet fission in cross-conjugated pentacene dimers. NANOSCALE 2016; 8:10113-23. [PMID: 27122097 DOI: 10.1039/c6nr02493a] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
We show unambiguous and compelling evidence by means of pump-probe experiments, which are complemented by calculations using ab initio multireference perturbation theory, for intramolecular singlet fission (SF) within two synthetically tailored pentacene dimers with cross-conjugation, namely XC1 and XC2. The two pentacene dimers differ in terms of electronic interactions as evidenced by perturbation of the ground state absorption spectra stemming from stronger through-bond contributions in XC1 as confirmed by theory. Multiwavelength analysis, on one hand, and global analysis, on the other hand, confirm that the rapid singlet excited state decay and triplet excited state growth relate to SF. SF rate constants and quantum yields increase with solvent polarity. For example, XC2 reveals triplet quantum yields and rate constants as high as 162 ± 10% and (0.7 ± 0.1) × 10(12) s(-1), respectively, in room temperature solutions.
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73
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Sale AC, Murray AH, Prenzel D, Hampel F, De Luca L, Tykwinski RR. Diels-Alder Cycloaddition of Tetraphenylcyclopentadienone and 1,3,5-Hexatriynes. European J Org Chem 2016. [DOI: 10.1002/ejoc.201600116] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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74
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Casari CS, Tommasini M, Tykwinski RR, Milani A. Carbon-atom wires: 1-D systems with tunable properties. NANOSCALE 2016; 8:4414-35. [PMID: 26847474 DOI: 10.1039/c5nr06175j] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
This review provides a discussion of the current state of research on linear carbon structures and related materials based on sp-hybridization of carbon atoms (polyynes and cumulenes). We show that such systems have widely tunable properties and thus represent an intriguing and mostly unexplored field for both fundamental and applied sciences. We discuss the rich interplay between the structural, vibrational, and electronic properties focusing on recent advances and the future perspectives of carbon-atom wires and novel hybrid sp-sp(2)-carbon architectures.
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75
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Schulze M, Scherer A, Hampel F, Stryker JM, Tykwinski RR. Synthesis and Aggregation Behavior of Chiral Naphthoquinoline Petroporphyrin Asphaltene Model Compounds. Chemistry 2016; 22:3378-3386. [DOI: 10.1002/chem.201504683] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Indexed: 11/09/2022]
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76
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Movsisyan LD, Franz M, Hampel F, Thompson AL, Tykwinski RR, Anderson HL. Polyyne Rotaxanes: Stabilization by Encapsulation. J Am Chem Soc 2016; 138:1366-76. [PMID: 26752712 PMCID: PMC4772075 DOI: 10.1021/jacs.5b12049] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
![]()
Active metal template Glaser coupling
has been used to synthesize
a series of rotaxanes consisting of a polyyne, with up to 24 contiguous sp-hybridized carbon atoms, threaded through a variety of
macrocycles. Cadiot–Chodkiewicz cross-coupling affords higher
yields of rotaxanes than homocoupling. This methodology has been used
to prepare [3]rotaxanes with two polyyne chains locked through the
same macrocycle. The crystal structure of one of these [3]rotaxanes
shows that there is extremely close contact between the central carbon
atoms of the threaded hexayne chains (C···C distance
3.29 Å vs 3.4 Å for the sum of van der Waals radii) and
that the bond-length-alternation is perturbed in the vicinity of this
contact. However, despite the close interaction between the hexayne
chains, the [3]rotaxane is remarkably stable under ambient conditions,
probably because the two polyynes adopt a crossed geometry. In the
solid state, the angle between the two polyyne chains is 74°,
and this crossed geometry appears to be dictated by the bulk of the
“supertrityl” end groups. Several rotaxanes have been
synthesized to explore gem-dibromoethene moieties as “masked”
polyynes. However, the reductive Fritsch–Buttenberg–Wiechell
rearrangement to form the desired polyyne rotaxanes has not yet been
achieved. X-ray crystallographic analysis on six [2]rotaxanes and
two [3]rotaxanes provides insight into the noncovalent interactions
in these systems. Differential scanning calorimetry (DSC) reveals
that the longer polyyne rotaxanes (C16, C18, and C24) decompose at
higher temperatures than the corresponding unthreaded polyyne axles.
The stability enhancement increases as the polyyne becomes longer,
reaching 60 °C in the C24 rotaxane.
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77
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Spörler S, Strinitz F, Rodehutskors P, Müller L, Waterloo AR, Dürr M, Hübner E, Ivanović-Burmazović I, Tykwinski RR, Burzlaff N. Carbon-rich cyclopentadienyl ruthenium allenylidene complexes. NEW J CHEM 2016. [DOI: 10.1039/c5nj03556b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ruthenium allenylidene complexes based on carbon-rich polyaromatic moieties have been synthesized with interesting intermolecular π-interactions.
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78
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Schulze M, Scott DE, Scherer A, Hampel F, Hamilton RJ, Gray MR, Tykwinski RR, Stryker JM. Steroid-Derived Naphthoquinoline Asphaltene Model Compounds: Hydriodic Acid Is the Active Catalyst in I2-Promoted Multicomponent Cyclocondensation Reactions. Org Lett 2015; 17:5930-3. [PMID: 26584791 DOI: 10.1021/acs.orglett.5b03193] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A multicomponent cyclocondensation reaction between 2-aminoanthracene, aromatic aldehydes, and 5-α-cholestan-3-one has been used to synthesize model asphaltene compounds. The active catalyst for this reaction has been identified as hydriodic acid, which is formed in situ from the reaction of iodine with water, while iodine is not a catalyst under anhydrous conditions. The products, which contain a tetrahydro[4]helicene moiety, are optically active, and the stereochemical characteristics have been examined by VT-NMR and VT-CD spectroscopies, as well as X-ray crystallography.
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79
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Portilla L, Etschel SH, Tykwinski RR, Halik M. Green processing of metal oxide core-shell nanoparticles as low-temperature dielectrics in organic thin-film transistors. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2015; 27:5950-5954. [PMID: 26308740 DOI: 10.1002/adma.201502792] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 07/08/2015] [Indexed: 06/04/2023]
Abstract
TiO2 , Fe3 O4, AlOx , ITO (indium tin oxide), and CeO2 nanoparticles are tailored to exhibit excellent dispersability in deionized water and alcohols. The latter provides an ecofriendly solution for processing metal oxide nanoparticles at a neutral pH. Water-processed dielectrics from the metal oxide nanoparticles are incorporated into organic thin-film transistors fabricated on rigid and flexible substrates.
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80
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Abstract
For the last 60+ years, the synthesis and study of cumulenes and polyynes have been the focus of a small, but dedicated, group of researchers. Many of the remarkable electronic, optical, and structural properties of cumulenes and polyynes had already been identified in the earliest reports. The molecular lengths achievable by the initial syntheses were, unfortunately, somewhat limited by synthetic methods available. For the past 15 years, we have worked toward expanding on the synthesis of cumulenes and polyynes through the development of new methods and stabilization motifs. As new compounds have become available, homologous series of cumulenes and polyynes have then been examined as a function of molecular length. While we are not yet there, we would like to eventually provide a general description of the sp-carbon allotrope carbyne, and this account presents some of our efforts toward this goal.
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81
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Waterloo AR, Lippert R, Jux N, Tykwinski RR. Axial coordination of pyridyl-containing pentacenes to porphyrins. J COORD CHEM 2015. [DOI: 10.1080/00958972.2015.1057711] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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82
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Etschel SH, Portilla L, Kirschner J, Drost M, Tu F, Marbach H, Tykwinski RR, Halik M. Region-Selective Deposition of Core-Shell Nanoparticles for 3 D Hierarchical Assemblies by the Huisgen 1,3-Dipolar Cycloaddition. Angew Chem Int Ed Engl 2015; 54:9235-8. [DOI: 10.1002/anie.201501957] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Revised: 04/27/2015] [Indexed: 01/03/2023]
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83
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Etschel SH, Portilla L, Kirschner J, Drost M, Tu F, Marbach H, Tykwinski RR, Halik M. Region-Selective Deposition of Core-Shell Nanoparticles for 3 D Hierarchical Assemblies by the Huisgen 1,3-Dipolar Cycloaddition. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201501957] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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84
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Franz M, Januszewski JA, Wendinger D, Neiss C, Movsisyan LD, Hampel F, Anderson HL, Görling A, Tykwinski RR. Innentitelbild: Cumulen-Rotaxane: Stabilisierung und Charakterisierung von [9]Cumulenen (Angew. Chem. 22/2015). Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201503956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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85
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Franz M, Januszewski JA, Wendinger D, Neiss C, Movsisyan LD, Hampel F, Anderson HL, Görling A, Tykwinski RR. Inside Cover: Cumulene Rotaxanes: Stabilization and Study of [9]Cumulenes (Angew. Chem. Int. Ed. 22/2015). Angew Chem Int Ed Engl 2015. [DOI: 10.1002/anie.201503956] [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]
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86
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Zirzlmeier J, Lehnherr D, Coto PB, Chernick ET, Casillas R, Basel BS, Thoss M, Tykwinski RR, Guldi DM. Singlet fission in pentacene dimers. Proc Natl Acad Sci U S A 2015; 112:5325-30. [PMID: 25858954 PMCID: PMC4418859 DOI: 10.1073/pnas.1422436112] [Citation(s) in RCA: 274] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Singlet fission (SF) has the potential to supersede the traditional solar energy conversion scheme by means of boosting the photon-to-current conversion efficiencies beyond the 30% Shockley-Queisser limit. Here, we show unambiguous and compelling evidence for unprecedented intramolecular SF within regioisomeric pentacene dimers in room-temperature solutions, with observed triplet quantum yields reaching as high as 156 ± 5%. Whereas previous studies have shown that the collision of a photoexcited chromophore with a ground-state chromophore can give rise to SF, here we demonstrate that the proximity and sufficient coupling through bond or space in pentacene dimers is enough to induce intramolecular SF where two triplets are generated on one molecule.
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87
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Franz M, Januszewski JA, Wendinger D, Neiss C, Movsisyan LD, Hampel F, Anderson HL, Görling A, Tykwinski RR. Cumulen-Rotaxane: Stabilisierung und Charakterisierung von [9]Cumulenen. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201501810] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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88
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Franz M, Januszewski JA, Wendinger D, Neiss C, Movsisyan LD, Hampel F, Anderson HL, Görling A, Tykwinski RR. Cumulene Rotaxanes: Stabilization and Study of [9]Cumulenes. Angew Chem Int Ed Engl 2015; 54:6645-9. [DOI: 10.1002/anie.201501810] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Indexed: 11/10/2022]
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89
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Diner C, Scott DE, Tykwinski RR, Gray MR, Stryker JM. Scalable, Chromatography-Free Synthesis of Alkyl-Tethered Pyrene-Based Materials. Application to First-Generation “Archipelago Model” Asphaltene Compounds. J Org Chem 2015; 80:1719-26. [DOI: 10.1021/jo502650m] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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90
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Chernick ET, Casillas R, Zirzlmeier J, Gardner DM, Gruber M, Kropp H, Meyer K, Wasielewski MR, Guldi DM, Tykwinski RR. Pentacene Appended to a TEMPO Stable Free Radical: The Effect of Magnetic Exchange Coupling on Photoexcited Pentacene. J Am Chem Soc 2015; 137:857-63. [DOI: 10.1021/ja510958k] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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91
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Wendinger D, Januszewski JA, Hampel F, Tykwinski RR. Thermal dimerization of [n]cumulenes (n = 5, 7, 9). Chem Commun (Camb) 2015; 51:14877-80. [DOI: 10.1039/c5cc05679a] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The dimerization of tetraaryl[n]cumulenes gives a radialene (n = 5) and expanded radialenes (n = 7 or 9).
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92
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Schulze M, Lechner MP, Stryker JM, Tykwinski RR. Aggregation of asphaltene model compounds using a porphyrin tethered to a carboxylic acid. Org Biomol Chem 2015; 13:6984-91. [DOI: 10.1039/c5ob00836k] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Two model compounds are used in NMR spectroscopic studies to probe aggregation toward unraveling the mysteries of intermolecular interactions in asphaltenes, which are the heaviest portions of petroleum.
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93
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Ramsaywack S, Karaca S, Gholami M, Murray AH, Hampel F, McDonald R, Elmaci N, Lüthi HP, Tykwinski RR. Donor- and/or Acceptor-Substituted Expanded Radialenes: Theory, Synthesis, and Properties. J Org Chem 2014; 79:10013-29. [DOI: 10.1021/jo5016085] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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94
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Strinitz F, Tucher J, Januszewski JA, Waterloo AR, Stegner P, Förtsch S, Hübner E, Tykwinski RR, Burzlaff N. Carbon-Rich Ruthenium Allenylidene Complexes Bearing Heteroscorpionate Ligands. Organometallics 2014. [DOI: 10.1021/om5002777] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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95
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Waterloo AR, Sale AC, Lehnherr D, Hampel F, Tykwinski RR. Aryl substitution of pentacenes. Beilstein J Org Chem 2014; 10:1692-705. [PMID: 25161729 PMCID: PMC4142869 DOI: 10.3762/bjoc.10.178] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 06/25/2014] [Indexed: 01/02/2023] Open
Abstract
A series of 11 new pentacene derivatives has been synthesized, with unsymmetrical substitution based on a trialkylsilylethynyl group at the 6-position and various aryl groups appended to the 13-position. The electronic and physical properties of the new pentacene chromophores have been analyzed by UV–vis spectroscopy (solution and thin films), thermoanalytical methods (DSC and TGA), cyclic voltammetry, as well as X-ray crystallography (for 8 derivatives). X-ray crystallography has been specifically used to study the influence of unsymmetrical substitution on the solid-state packing of the pentacene derivatives. The obtained results add to our ability to better predict substitution patterns that might be helpful for designing new semiconductors for use in solid-state devices.
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96
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Januszewski JA, Hampel F, Neiss C, Görling A, Tykwinski RR. Unerwartete Bildung eines [4]Radialens und mehrerer Dendralene bei der Addition von Tetracyanoethylen an ein Tetraaryl[5]cumulen. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201309355] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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97
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Januszewski JA, Hampel F, Neiss C, Görling A, Tykwinski RR. Unexpected Formation of a [4]Radialene and Dendralenes by Addition of Tetracyanoethylene to a Tetraaryl[5]cumulene. Angew Chem Int Ed Engl 2014; 53:3743-7. [DOI: 10.1002/anie.201309355] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2013] [Indexed: 11/10/2022]
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98
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Chernick ET, Börzsönyi G, Steiner C, Ammon M, Gessner D, Frühbeißer S, Gröhn F, Maier S, Tykwinski RR. Optisch reine, monodisperse cis-Oligodiacetylene: Chiralitätsverstärkung durch Aggregation. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201307904] [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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99
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Januszewski JA, Tykwinski RR. Synthesis and properties of long [n]cumulenes (n ≥ 5). Chem Soc Rev 2014; 43:3184-203. [DOI: 10.1039/c4cs00022f] [Citation(s) in RCA: 124] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This review highlights the synthesis and reactivity of longer [n]cumulenes (n ≥ 5) and summarizes their electronic and structural properties.
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100
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Chernick ET, Börzsönyi G, Steiner C, Ammon M, Gessner D, Frühbeisser S, Gröhn F, Maier S, Tykwinski RR. Optically Pure, Monodispersecis-Oligodiacetylenes: Aggregation-Induced Chirality Enhancement. Angew Chem Int Ed Engl 2013; 53:310-4. [PMID: 24288289 DOI: 10.1002/anie.201307904] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2013] [Indexed: 11/09/2022]
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