1
|
Liza N, Coe DJ, Lu Y, Blair EP. Ab initio studies of counterion effects in molecular quantum-dot cellular automata. J Comput Chem 2024; 45:392-404. [PMID: 38014502 DOI: 10.1002/jcc.27247] [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: 03/08/2023] [Revised: 08/08/2023] [Accepted: 10/15/2023] [Indexed: 11/29/2023]
Abstract
Molecular quantum-dot cellular automata (QCA) is a low-power computing paradigm that may offer ultra-high device densities and THz-speed switching at room temperature. A single mixed-valence (MV) molecule acts as an elementary QCA device known as a cell. Cells coupled locally via the electrostatic field form logic circuits. However, previously-synthesized ionic MV molecular cells are affected by randomly-located, nearby neutralizing counterions that can bias device states or change device characteristics, causing incorrect computational results. This ab initio study explores how non-biasing counterions affect individual molecular cells. Additionally, we model two novel neutral, zwitterionic MV QCA molecules designed to avoid biasing and other undesirable counterionic effects. The location of the neutralizing counterion is controlled by integrating one counterion into each cell at a well-defined, non-biasing location. Each zwitterionic QCA candidate molecule presented here has a fixed, integrated counterion, which neutralizes the mobile charges used to encode the device state.
Collapse
Affiliation(s)
- Nishattasnim Liza
- Department of Electrical and Computer Engineering, Baylor University, Waco, Texas, USA
| | - Daniel J Coe
- Department of Electrical and Computer Engineering, Baylor University, Waco, Texas, USA
| | - Yuhui Lu
- Department of Electrical and Computer Engineering, Baylor University, Waco, Texas, USA
| | - Enrique P Blair
- Department of Electrical and Computer Engineering, Baylor University, Waco, Texas, USA
| |
Collapse
|
2
|
Yamamoto T, Yamane H, Yokoshi N, Oka H, Ishihara H, Sugawara Y. Optical Imaging of a Single Molecule with Subnanometer Resolution by Photoinduced Force Microscopy. ACS NANO 2024; 18:1724-1732. [PMID: 38157420 PMCID: PMC10795473 DOI: 10.1021/acsnano.3c10924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2023] [Revised: 12/22/2023] [Accepted: 12/26/2023] [Indexed: 01/03/2024]
Abstract
Visualizing the optical response of individual molecules is a long-standing goal in catalysis, molecular nanotechnology, and biotechnology. The molecular response is dominated not only by the electronic states in their isolated environment but also by neighboring molecules and the substrate. Information about the transfer of energy and charge in real environments is essential for the design of the desired molecular functions. However, visualizing these factors with spatial resolution beyond the molecular scale has been challenging. Here, by combining photoinduced force microscopy and Kelvin probe force microscopy, we have mapped the photoinduced force in a pentacene bilayer with a spatial resolution of 0.6 nm and observed its "multipole excitation". We identified the excitation as the result of energy and charge transfer between the molecules and to the Ag substrate. These findings can be achieved only by combining microscopy techniques to simultaneously visualize the optical response of the molecules and the charge transfer between the neighboring environments. Our approach and findings provide insights into designing molecular functions by considering the optical response at each step of layering molecules.
Collapse
Affiliation(s)
- Tatsuya Yamamoto
- Department
of Applied Physics, Osaka University, Suita, Osaka 565-0871, Japan
| | - Hidemasa Yamane
- Department
of Physics, Kitasato University, Sagamihara, Kanagawa 252-0373, Japan
- Osaka
Research Institute of Industrial Science and Technology, Izumi, Osaka 594-1157, Japan
| | - Nobuhiko Yokoshi
- Department
of Physics and Electronics, Osaka Metropolitan
University, Sakai, Osaka 599-8531, Japan
| | - Hisaki Oka
- Department
of Physics, Kitasato University, Sagamihara, Kanagawa 252-0373, Japan
| | - Hajime Ishihara
- Department
of Materials Engineering Science, Osaka
University, Toyonaka, Osaka 560-8531, Japan
| | - Yasuhiro Sugawara
- Department
of Applied Physics, Osaka University, Suita, Osaka 565-0871, Japan
| |
Collapse
|
3
|
Mallada B, Ondráček M, Lamanec M, Gallardo A, Jiménez-Martín A, de la Torre B, Hobza P, Jelínek P. Visualization of π-hole in molecules by means of Kelvin probe force microscopy. Nat Commun 2023; 14:4954. [PMID: 37587123 PMCID: PMC10432393 DOI: 10.1038/s41467-023-40593-3] [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: 03/31/2023] [Accepted: 07/31/2023] [Indexed: 08/18/2023] Open
Abstract
Submolecular charge distribution significantly affects the physical-chemical properties of molecules and their mutual interaction. One example is the presence of a π-electron-deficient cavity in halogen-substituted polyaromatic hydrocarbon compounds, the so-called π-holes, the existence of which was predicted theoretically, but the direct experimental observation is still missing. Here we present the resolution of the π-hole on a single molecule using the Kelvin probe force microscopy, which supports the theoretical prediction of its existence. In addition, experimental measurements supported by theoretical calculations show the importance of π-holes in the process of adsorption of molecules on solid-state surfaces. This study expands our understanding of the π-hole systems and, at the same time, opens up possibilities for studying the influence of submolecular charge distribution on the chemical properties of molecules and their mutual interaction.
Collapse
Affiliation(s)
- B Mallada
- Institute of Physics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
- Regional Centre of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute (CATRIN), Palacký University Olomouc, 78371, Olomouc, Czech Republic
- Department of Physical Chemistry, Palacký University Olomouc, Tr. 17. listopadu 12, 771 46, Olomouc, Czech Republic
| | - M Ondráček
- Institute of Physics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - M Lamanec
- Department of Physical Chemistry, Palacký University Olomouc, Tr. 17. listopadu 12, 771 46, Olomouc, Czech Republic
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo Námĕstí 542/2, 16000, Prague, Czech Republic
- IT4Innovations, VŠB - Technical University of Ostrava, 17. Listopadu 2172/15, 708 00, Ostrava-Poruba, Czech Republic
| | - A Gallardo
- Institute of Physics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - A Jiménez-Martín
- Institute of Physics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
- Regional Centre of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute (CATRIN), Palacký University Olomouc, 78371, Olomouc, Czech Republic
| | - B de la Torre
- Institute of Physics, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
- Regional Centre of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute (CATRIN), Palacký University Olomouc, 78371, Olomouc, Czech Republic.
| | - P Hobza
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo Námĕstí 542/2, 16000, Prague, Czech Republic.
- IT4Innovations, VŠB - Technical University of Ostrava, 17. Listopadu 2172/15, 708 00, Ostrava-Poruba, Czech Republic.
| | - P Jelínek
- Institute of Physics, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
- Regional Centre of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute (CATRIN), Palacký University Olomouc, 78371, Olomouc, Czech Republic.
| |
Collapse
|
4
|
Li T, Bandari VK, Schmidt OG. Molecular Electronics: Creating and Bridging Molecular Junctions and Promoting Its Commercialization. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2209088. [PMID: 36512432 DOI: 10.1002/adma.202209088] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 11/28/2022] [Indexed: 06/02/2023]
Abstract
Molecular electronics is driven by the dream of expanding Moore's law to the molecular level for next-generation electronics through incorporating individual or ensemble molecules into electronic circuits. For nearly 50 years, numerous efforts have been made to explore the intrinsic properties of molecules and develop diverse fascinating molecular electronic devices with the desired functionalities. The flourishing of molecular electronics is inseparable from the development of various elegant methodologies for creating nanogap electrodes and bridging the nanogap with molecules. This review first focuses on the techniques for making lateral and vertical nanogap electrodes by breaking, narrowing, and fixed modes, and highlights their capabilities, applications, merits, and shortcomings. After summarizing the approaches of growing single molecules or molecular layers on the electrodes, the methods of constructing a complete molecular circuit are comprehensively grouped into three categories: 1) directly bridging one-molecule-electrode component with another electrode, 2) physically bridging two-molecule-electrode components, and 3) chemically bridging two-molecule-electrode components. Finally, the current state of molecular circuit integration and commercialization is discussed and perspectives are provided, hoping to encourage the community to accelerate the realization of fully scalable molecular electronics for a new era of integrated microsystems and applications.
Collapse
Affiliation(s)
- Tianming Li
- Research Center for Materials, Architectures and Integration of Nanomembranes (MAIN), Chemnitz University of Technology, 09126, Chemnitz, Germany
- Material Systems for Nanoelectronics, Chemnitz University of Technology, 09111, Chemnitz, Germany
| | - Vineeth Kumar Bandari
- Research Center for Materials, Architectures and Integration of Nanomembranes (MAIN), Chemnitz University of Technology, 09126, Chemnitz, Germany
- Material Systems for Nanoelectronics, Chemnitz University of Technology, 09111, Chemnitz, Germany
| | - Oliver G Schmidt
- Research Center for Materials, Architectures and Integration of Nanomembranes (MAIN), Chemnitz University of Technology, 09126, Chemnitz, Germany
- Material Systems for Nanoelectronics, Chemnitz University of Technology, 09111, Chemnitz, Germany
- Nanophysics, Dresden University of Technology, 01069, Dresden, Germany
| |
Collapse
|
5
|
D’Astolfo P, Wang X, Liu X, Kisiel M, Drechsel C, Baratoff A, Aschauer U, Decurtins S, Liu SX, Pawlak R, Meyer E. Energy Dissipation from Confined States in Nanoporous Molecular Networks. ACS NANO 2022; 16:16314-16321. [PMID: 36150702 PMCID: PMC9620977 DOI: 10.1021/acsnano.2c05333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 09/06/2022] [Indexed: 06/16/2023]
Abstract
Crystalline nanoporous molecular networks are assembled on the Ag(111) surface, where the pores confine electrons originating from the surface state of the metal. Depending on the pore sizes and their coupling, an antibonding level is shifted upward by 0.1-0.3 eV as measured by scanning tunneling microscopy. On molecular sites, a downshifted bonding state is observed, which is occupied under equilibrium conditions. Low-temperature force spectroscopy reveals energy dissipation peaks and jumps of frequency shifts at bias voltages, which are related to the confined states. The dissipation maps show delocalization on the supramolecular assembly and a weak distance dependence of the dissipation peaks. These observations indicate that two-dimensional arrays of coupled quantum dots are formed, which are quantitatively characterized by their quantum capacitances and resonant tunneling rates. Our work provides a method for studying the capacitive and dissipative response of quantum materials with nanomechanical oscillators.
Collapse
Affiliation(s)
- Philipp D’Astolfo
- Department
of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
| | - Xing Wang
- Department
of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Xunshan Liu
- Department
of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Marcin Kisiel
- Department
of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
| | - Carl Drechsel
- Department
of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
| | - Alexis Baratoff
- Department
of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
| | - Ulrich Aschauer
- Department
of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Silvio Decurtins
- Department
of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Shi-Xia Liu
- Department
of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Rémy Pawlak
- Department
of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
| | - Ernst Meyer
- Department
of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
| |
Collapse
|
6
|
Liza N, Lu Y, Blair EP. Designing boron-cluster-centered zwitterionic Y-shaped clocked QCA molecules. NANOTECHNOLOGY 2022; 33:465201. [PMID: 35944440 DOI: 10.1088/1361-6528/ac8810] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 08/09/2022] [Indexed: 06/15/2023]
Abstract
Quantum-dot cellular automata (QCA) is a nanoscale, transistor-less device technology. A single molecule may provide an elementary QCA device known as a cell. Molecular redox centers function as quantum dots, and the configuration of mobile charge on the dots encodes device states useful for classical computing. Molecular QCA may support ultra-high device densities and THz-scale switching speeds at room temperature. An applied electric field may be used to clock molecular QCA, providing power gain to boost weakened signals, as well as quasi-adiabatic device operation for minimal power dissipation in QCA devices and circuits. A zwitterionic, Y-shaped, three-dot molecule may function as a field-clocked QCA cell. We focus on the design of a counterion built into the center of the cell.Ab initiocomputations demonstrate that choice of counterion determines the number of mobile charges for encoding the device state on the three quantum dots. We useB5H52-orB4CH5-as the central counterionic linker for two different Y-shaped, three-dot QCA molecules. While both molecules support the desired device states, the number of trapped charges in the counterion determines the number of mobile holes on the molecular quantum dots. This, in turn, determines whether the device state is encoded by a hole or an electron. This choice of encoding determines how the molecular QCA cell responds to a clocking field. The two counterions studied here lead to two QCA molecules with opposite responses to the clock, similar to the complementary responses of PMOS and NMOS transistors to gated voltage control.
Collapse
Affiliation(s)
- Nishattasnim Liza
- Electrical and Computer Engineering Department, Baylor University, Waco, TX, United States of America
| | - Yuhui Lu
- Electrical and Computer Engineering Department, Baylor University, Waco, TX, United States of America
| | - Enrique P Blair
- Electrical and Computer Engineering Department, Baylor University, Waco, TX, United States of America
| |
Collapse
|
7
|
Tan J, Li H, Ji C, Zhang L, Zhao C, Tang L, Zhang C, Sun Z, Tan W, Yuan Q. Electron transfer-triggered imaging of EGFR signaling activity. Nat Commun 2022; 13:594. [PMID: 35105871 PMCID: PMC8807759 DOI: 10.1038/s41467-022-28213-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 12/06/2021] [Indexed: 02/06/2023] Open
Abstract
In vivo electron transfer processes are closely related to the activation of signaling pathways, and, thus, affect various life processes. Indeed, the signaling pathway activation of key molecules may be associated with certain diseases. For example, epidermal growth factor receptor (EGFR) activation is related to the occurrence and development of tumors. Hence, monitoring the activation of EGFR-related signaling pathways can help reveal the progression of tumor development. However, it is challenging for current detection methods to monitor the activation of specific signaling pathways in complex biochemical reactions. Here we designed a highly sensitive and specific nanoprobe that enables in vivo imaging of electronic transfer over a broad range of spatial and temporal scales. By using the ferrocene-DNA polymer “wire”, the electrons transferred in a biochemical reaction can flow to persistent luminescent nanoparticles and change their electron distribution, thereby altering the optical signal of the particles. This electron transfer-triggered imaging probe enables mapping the activation of EGFR-related signaling pathways in a temporally and spatially precise manner. By offering precise visualization of signaling activity, this approach may offer a general platform not only for understanding molecular mechanisms in various biological processes but also for promoting disease therapies and drug evaluation. Here, the authors design a nanoprobe for in vivo imaging of electronic transfer, consisting of a ferrocene-DNA polymer to transfer electrons to luminescent nanoparticles, changing their optical signal. Using this probe, they map activation of EGFR signalling during tumour treatment.
Collapse
Affiliation(s)
- Jie Tan
- Molecular Science and Biomedicine Laboratory (MBL), Institute of Chemical Biology and Nanomedicine, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, School of Physics and Electronics, Hunan University, Changsha, 410082, China
| | - Hao Li
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Bio-medicine Ministry of Education, School & Hospital of Stomatology, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, China
| | - Cailing Ji
- Molecular Science and Biomedicine Laboratory (MBL), Institute of Chemical Biology and Nanomedicine, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, School of Physics and Electronics, Hunan University, Changsha, 410082, China
| | - Lei Zhang
- Molecular Science and Biomedicine Laboratory (MBL), Institute of Chemical Biology and Nanomedicine, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, School of Physics and Electronics, Hunan University, Changsha, 410082, China
| | - Chenxuan Zhao
- Department of Chemistry, ZJU-NHU United R&D Center, Zhejiang University, Hangzhou, 310027, P. R. China
| | - Liming Tang
- Molecular Science and Biomedicine Laboratory (MBL), Institute of Chemical Biology and Nanomedicine, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, School of Physics and Electronics, Hunan University, Changsha, 410082, China
| | - Caixin Zhang
- Molecular Science and Biomedicine Laboratory (MBL), Institute of Chemical Biology and Nanomedicine, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, School of Physics and Electronics, Hunan University, Changsha, 410082, China
| | - Zhijun Sun
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Bio-medicine Ministry of Education, School & Hospital of Stomatology, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, China.
| | - Weihong Tan
- Molecular Science and Biomedicine Laboratory (MBL), Institute of Chemical Biology and Nanomedicine, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, School of Physics and Electronics, Hunan University, Changsha, 410082, China.
| | - Quan Yuan
- Molecular Science and Biomedicine Laboratory (MBL), Institute of Chemical Biology and Nanomedicine, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, School of Physics and Electronics, Hunan University, Changsha, 410082, China. .,The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Bio-medicine Ministry of Education, School & Hospital of Stomatology, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, China.
| |
Collapse
|
8
|
Liza N, Murphey D, Cong P, Beggs DW, Lu Y, Blair EP. Asymmetric, mixed-valence molecules for spectroscopic readout of quantum-dot cellular automata. NANOTECHNOLOGY 2021; 33:115201. [PMID: 34875643 DOI: 10.1088/1361-6528/ac40c0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 12/07/2021] [Indexed: 06/13/2023]
Abstract
Mixed-valence compounds may provide molecular devices for an energy-efficient, low-power, general-purpose computing paradigm known as quantum-dot cellular automata (QCA). Multiple redox centers on mixed-valence molecules provide a system of coupled quantum dots. The configuration of mobile charge on a double-quantum-dot (DQD) molecule encodes a bit of classical information robust at room temperature. When arranged in non-homogeneous patterns (circuits) on a substrate, local Coulomb coupling between molecules enables information processing. While single-electron transistors and single-electron boxes could provide low-temperature solutions for reading the state of a ∼1 nm scale molecule, we propose a room-temperature read-out scheme. Here, DQD molecules are designed with slightly dissimilar quantum dots.Ab initiocalculations show that the binary device states of an asymmetric molecule have distinct Raman spectra. Additionally, the dots are similar enough that mobile charge is not trapped on either dot, allowing device switching driven by the charge configuration of a neighbor molecule. A technique such as tip-enhanced Raman spectroscopy could be used to detect the state of a circuit comprised of several QCA molecules.
Collapse
Affiliation(s)
- Nishattasnim Liza
- Electrical and Computer Engineering Department, Baylor University, Waco, TX, United States of America
| | - Dylan Murphey
- Electrical and Computer Engineering Department, Baylor University, Waco, TX, United States of America
| | - Peizhong Cong
- Electrical and Computer Engineering Department, Baylor University, Waco, TX, United States of America
| | - David W Beggs
- Electrical and Computer Engineering Department, Baylor University, Waco, TX, United States of America
| | - Yuihui Lu
- Electrical and Computer Engineering Department, Baylor University, Waco, TX, United States of America
| | - Enrique P Blair
- Electrical and Computer Engineering Department, Baylor University, Waco, TX, United States of America
| |
Collapse
|
9
|
Fatayer S, Albrecht F, Tavernelli I, Persson M, Moll N, Gross L. Probing Molecular Excited States by Atomic Force Microscopy. PHYSICAL REVIEW LETTERS 2021; 126:176801. [PMID: 33988431 DOI: 10.1103/physrevlett.126.176801] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 10/12/2020] [Accepted: 03/24/2021] [Indexed: 06/12/2023]
Abstract
By employing single charge injections with an atomic force microscope, we investigated redox reactions of a molecule on a multilayer insulating film. First, we charged the molecule positively by attaching a single hole. Then we neutralized it by attaching an electron and observed three channels for the neutralization. We rationalize that the three channels correspond to transitions to the neutral ground state, to the lowest energy triplet excited states and to the lowest energy singlet excited states. By single-electron tunneling spectroscopy we measured the energy differences between the transitions obtaining triplet and singlet excited state energies. The experimental values are compared with density functional theory calculations of the excited state energies. Our results show that molecules in excited states can be prepared and that energies of optical gaps can be quantified by controlled single-charge injections. Our work demonstrates the access to, and provides insight into, ubiquitous electron-attachment processes related to excited-state transitions important in electron transfer and molecular optoelectronics phenomena on surfaces.
Collapse
Affiliation(s)
- Shadi Fatayer
- IBM Research-Zurich, Säumerstrasse 4, 8803 Rüschlikon, Switzerland
| | - Florian Albrecht
- IBM Research-Zurich, Säumerstrasse 4, 8803 Rüschlikon, Switzerland
| | - Ivano Tavernelli
- IBM Research-Zurich, Säumerstrasse 4, 8803 Rüschlikon, Switzerland
| | - Mats Persson
- Surface Science Research Centre, Department of Chemistry, University of Liverpool, Liverpool L693BX, United Kingdom
| | - Nikolaj Moll
- IBM Research-Zurich, Säumerstrasse 4, 8803 Rüschlikon, Switzerland
| | - Leo Gross
- IBM Research-Zurich, Säumerstrasse 4, 8803 Rüschlikon, Switzerland
| |
Collapse
|
10
|
Madrid-Úsuga D, Reina JH. Molecular Structure, Quantum Coherence, and Solvent Effects on the Ultrafast Electron Transport in BODIPY- C60 Derivatives. J Phys Chem A 2021; 125:2518-2531. [PMID: 33754739 DOI: 10.1021/acs.jpca.1c00603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Photoinduced electron transfer in multichromophore molecular systems is defined by a critical interplay between their core unit configuration (donor, molecular bridge, and acceptor) and their system-solvent coupling; these lead to energy and charge transport processes that are key in the design of molecular antennas for efficient light harvesting and organic photovoltaics. Here, we quantify the ultrafast non-Markovian dissipative dynamics of electron transfer in D-π-A molecular photosystems comprising 1,3,5,7-tetramethyl-8-phenyl-4,4-difluoroboradiazaindacene (BODIPY), Zn-porphyrin, fulleropyrrolidine, and fulleroisoxazoline. We find that the stabilization energy of the charge transfer states exhibits a significant variation for different polar (methanol, tetrahydrofuran (THF)) and nonpolar (toluene) environments and determine such sensitivity according to the molecular structure and the electron-vibration couplings that arise at room temperature. For the considered donor-acceptor (D-A) dyads, we show that the stronger the molecule-solvent coupling, the larger the electron transfer rates, regardless of the dyads' electronic coherence properties. We find such coupling strengths to be the largest (lowest) for methanol (toluene), with an electron transfer rate difference of 2 orders of magnitude between the polar and nonpolar solvents. For the considered donor-bridge-acceptor (D-B-A) triads, the molecular bridge introduces an intermediate state that allows the realization of Λ or cascaded-type energy mechanisms. We show that the latter configuration, obtained for BDP-ZnP-[PyrC60] in methanol, exhibits the highest transfer rate of all of the computed triads. Remarkably, and in contrast with the dyads, we show that the larger charge transfer rates are obtained for triads that exhibit prolonged electron coherence and population oscillations.
Collapse
Affiliation(s)
- Duvalier Madrid-Úsuga
- Centre for Bioinformatics and Photonics-CIBioFi, Universidad del Valle, Calle 13 No. 100-00, Edificio E20 No. 1069, 760032 Cali, Colombia.,Departamento de Física, Universidad del Valle, 760032 Cali, Colombia
| | - John H Reina
- Centre for Bioinformatics and Photonics-CIBioFi, Universidad del Valle, Calle 13 No. 100-00, Edificio E20 No. 1069, 760032 Cali, Colombia.,Departamento de Física, Universidad del Valle, 760032 Cali, Colombia
| |
Collapse
|
11
|
Wang CH, Chen KJ, Wu TH, Chang HK, Tsuchido Y, Sei Y, Chen PL, Horie M. Ring rotation of ferrocene in interlocked molecules in single crystals. Chem Sci 2021; 12:3871-3875. [PMID: 34163655 PMCID: PMC8179491 DOI: 10.1039/d0sc06876d] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 01/21/2021] [Indexed: 12/21/2022] Open
Abstract
This work describes unique molecular motions of ferrocene-containing interlocked molecules observed by single-crystal X-ray crystallography. The rotational flexibility of ferrocene is achieved using combinations of ferrocene-tethered ammonium and 30-membered ring dibenzo-crown ether. By contrast, ferrocene was locked in the complex with an 18-membered ring dibenzo-crown ether and CH2Cl2. When the complex was heated at 358 K, CH2Cl2 was removed from the complex, which led to drastic structural changes, including a semieclipsed-to-disordered transition of ferrocene and flipping of the dibenzo-crown ether.
Collapse
Affiliation(s)
- Chi-Hsien Wang
- Department of Chemical Engineering, National Tsing Hua University 101, Section 2, Kuang-Fu Road Hsinchu 30013 Taiwan
| | - Kai-Jen Chen
- Department of Chemical Engineering, National Tsing Hua University 101, Section 2, Kuang-Fu Road Hsinchu 30013 Taiwan
| | - Tsung-Huan Wu
- Department of Chemical Engineering, National Tsing Hua University 101, Section 2, Kuang-Fu Road Hsinchu 30013 Taiwan
| | - Hung-Kai Chang
- Department of Chemical Engineering, National Tsing Hua University 101, Section 2, Kuang-Fu Road Hsinchu 30013 Taiwan
| | - Yoshitaka Tsuchido
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology 4259 Nagatsuta, Midori-ku Yokohama 226-8503 Japan
- Department of Chemistry, Faculty of Science, Tokyo University of Science 1-3 Kagurazaka, Shinjuku-ku Tokyo 162-8601 Japan
| | - Yoshihisa Sei
- Open Facility Center, Tokyo Institute of Technology 4259 Nagatsuta, Midori-ku Yokohama 226-8503 Japan
| | - Pei-Lin Chen
- Instrumentation Center, National Tsing Hua University 101, Section 2, Kuang-Fu Road Hsinchu 30013 Taiwan
| | - Masaki Horie
- Department of Chemical Engineering, National Tsing Hua University 101, Section 2, Kuang-Fu Road Hsinchu 30013 Taiwan
| |
Collapse
|