7 research outputs found
Controlling spin interference in single radical molecules
Quantum interference (QI) dominates the electronic properties of single molecules even at room temperature and can lead to a large change in their electrical conductance. To take advantage of this for nanoelectronic applications, a mechanism to electronically control QI in single molecules needs to be developed. In this paper, we demonstrate that controlling the quantum interference of each spin in a stable open-shell organic radical with a large π-system is possible by changing the spin state of the radical. We show that the counterintuitive constructive spin interference in a meta-connected radical changes to destructive interference by changing the spin state of the radical from a doublet to a singlet. This results in a significant change in the room temperature electrical conductance by several orders of magnitude, opening up new possibilities for spin interference based molecular switches for energy storage and conversion applications
Connectivity-Dependent Conductance of 2,2′-Bipyridine-Based Metal Complexes
The present work provides an insight into the effect of connectivity isomerization of metal-2,2′-bipyridine complexes. For that purpose, two new 2,2′-bipyridine (bpy) ligand systems, 4,4′-bis(4-(methylthio)phenyl)-2,2′-bipyridine (Lmeta) and 5,5′-bis(3,3-dimethyl-2,3-dihydrobenzothiophen-5-yl)-2,2′-bipyridine (Lpara) were synthesized and coordinated to rhenium and manganese to obtain the corresponding complexes MnLmeta(CO)3Br, ReLmeta(CO)3Br, MnLpara(CO)3Br, MoLpara(CO)4 and ReLpara(CO)3Br. The experimental and theoretical results revealed that coordination to the para system, i.e., the metal ion peripheral to the conductance path, gave a slightly increased conductance compared to the free ligand attributed to the reduced highest occupied molecular orbital (HOMO)–least unoccupied molecular orbital (LUMO) gap. The meta-based system formed a destructive quantum interference feature that reduced the conductance of a S···S contacted junction to below 10–5.5 G o, reinforcing the importance of contact group connectivity for molecular wire conductance
Controlling Spin Interference in Single Radical Molecules
Quantum interference (QI) dominates the electronic properties
of
single molecules even at room temperature and can lead to a large
change in their electrical conductance. To take advantage of this
for nanoelectronic applications, a mechanism to electronically control
QI in single molecules needs to be developed. In this paper, we demonstrate
that controlling the quantum interference of each spin in a stable
open-shell organic radical with a large π-system is possible
by changing the spin state of the radical. We show that the counterintuitive
constructive spin interference in a meta-connected
radical changes to destructive interference by changing the spin state
of the radical from a doublet to a singlet. This results in a significant
change in the room temperature electrical conductance by several orders
of magnitude, opening up new possibilities for spin interference based
molecular switches for energy storage and conversion applications
Single-Molecule Mechanoresistivity by Intermetallic Bonding
The metal-electrode interface is key to unlocking emergent behaviour in all organic electrified systems,
from battery technology to molecular electronics. In the latter, interfacial engineering has enabled
efficient transport, higher device stability, and novel functionality. Mechanoresistivity – the change in
electrical behaviour in response to a mechanical stimulus and a pathway to extremely sensitive force
sensors – is amongst the most studied phenomena in molecular electronics, and the molecule-electrode
interface plays a pivotal role in its emergence, reproducibility, and magnitude. In this contribution, we
show that organometallic molecular wires incorporating a Pt(II) cation show mechanoresistive
behaviour of exceptional magnitude, with conductance modulations of more than three orders of
magnitude upon compression by as little as 1 nm. We synthesised series of cyclometalated Pt(II)
molecular wires, and used scanning tunnelling microscopy – break junction techniques to characterise
their electromechanical behaviour. Mechanoresistivity arises from an interaction between the Pt(II)
cation and the Au electrode triggered by mechanical compression of the single-molecule device, and
theoretical modelling confirms this hypothesis. Our study provides a new tool for the design of functional
molecular wires by exploiting previously unreported ion-metal interactions in single-molecule devices,
and develops a new framework for the development of mechanoresistive molecular junctions
Single‐Molecule Mechanoresistivity by Intermetallic Bonding
The metal-electrode interface is key to unlocking emergent behaviour in all organic electrified systems, from battery technology to molecular electronics. In the latter, interfacial engineering has enabled efficient transport, higher device stability, and novel functionality. Mechanoresistivity – the change in electrical behaviour in response to a mechanical stimulus and a pathway to extremely sensitive force sensors – is amongst the most studied phenomena in molecular electronics, and the molecule-electrode interface plays a pivotal role in its emergence, reproducibility, and magnitude. In this contribution, we show that organometallic molecular wires incorporating a Pt(II) cation show mechanoresistive behaviour of exceptional magnitude, with conductance modulations of more than three orders of magnitude upon compression by as little as 1 nm. We synthesised series of cyclometalated Pt(II) molecular wires, and used scanning tunnelling microscopy – break junction techniques to characterise their electromechanical behaviour. Mechanoresistivity arises from an interaction between the Pt(II) cation and the Au electrode triggered by mechanical compression of the single-molecule device, and theoretical modelling confirms this hypothesis. Our study provides a new tool for the design of functional molecular wires by exploiting previously unreported ion-metal interactions in single-molecule devices, and develops a new framework for the development of mechanoresistive molecular junctions
Single‐Molecule Mechanoresistivity by Intermetallic Bonding
The metal‐electrode interface is key to unlocking emergent behaviour in all organic electrified systems, from battery technology to molecular electronics. In the latter, interfacial engineering has enabled efficient transport, higher device stability, and novel functionality. Mechanoresistivity – the change in electrical behaviour in response to a mechanical stimulus and a pathway to extremely sensitive force sensors – is amongst the most studied phenomena in molecular electronics, and the molecule‐electrode interface plays a pivotal role in its emergence, reproducibility, and magnitude. In this contribution, we show that organometallic molecular wires incorporating a Pt(II) cation show mechanoresistive behaviour of exceptional magnitude, with conductance modulations of more than three orders of magnitude upon compression by as little as 1 nm. We synthesised series of cyclometalated Pt(II) molecular wires, and used scanning tunnelling microscopy – break junction techniques to characterise their electromechanical behaviour. Mechanoresistivity arises from an interaction between the Pt(II) cation and the Au electrode triggered by mechanical compression of the single‐molecule device, and theoretical modelling confirms this hypothesis. Our study provides a new tool for the design of functional molecular wires by exploiting previously unreported ion‐metal interactions in single‐molecule devices, and develops a new framework for the development of mechanoresistive molecular junctions.</jats:p
Single-Molecule Mechanoresistivity by Intermetallic Bonding.
The metal-electrode interface is key to unlocking emergent behaviour in all organic electrified systems, from battery technology to molecular electronics. In the latter, interfacial engineering has enabled efficient transport, higher device stability, and novel functionality. Mechanoresistivity - the change in electrical behaviour in response to a mechanical stimulus and a pathway to extremely sensitive force sensors - is amongst the most studied phenomena in molecular electronics, and the molecule-electrode interface plays a pivotal role in its emergence, reproducibility, and magnitude. In this contribution, we show that organometallic molecular wires incorporating a Pt(II) cation show mechanoresistive behaviour of exceptional magnitude, with conductance modulations of more than three orders of magnitude upon compression by as little as 1 nm. We synthesised series of cyclometalated Pt(II) molecular wires, and used scanning tunnelling microscopy - break junction techniques to characterise their electromechanical behaviour. Mechanoresistivity arises from an interaction between the Pt(II) cation and the Au electrode triggered by mechanical compression of the single-molecule device, and theoretical modelling confirms this hypothesis. Our study provides a new tool for the design of functional molecular wires by exploiting previously unreported ion-metal interactions in single-molecule devices, and develops a new framework for the development of mechanoresistive molecular junctions