scholarly journals A review of functional linear carbon chains (oligoynes, polyynes, cumulenes) and their applications as molecular wires in molecular electronics and optoelectronics

2021 ◽  
Author(s):  
Martin R. Bryce
Keyword(s):  
Molecular Electronics ◽  
Molecular Wires ◽  
Carbon Chains

This review presents the multi-faceted applications of oligoynes in molecular electronics and optoelectronics, as well as recent insights for the design and properties of sp-hybridised carbon wires.

Reduced bond length alternation and helical molecular orbitals in donor and acceptor substituted linear carbon chains

2018 ◽  
Vol 17 (08) ◽  
pp. 1850049 ◽  
Author(s):  
AbhayRam Balakrishnan ◽  
R. Shankar ◽  
S. Vijayakumar
Keyword(s):  
Bond Length ◽  
Molecular Electronics ◽  
Chain Length ◽  
Molecular Wires ◽  
Molecular Orbitals ◽  
Bond Length Alternation ◽  
Dft Methods ◽  
Carbon Chains ◽  
Donor And Acceptor ◽  
Molecular Orbital Analysis

Increasing chain length and end group substitution of polyynes play a crucial role in molecular electronics and nanomaterials. The studies on linear carbon chains are lesser when compared to other carbon allotropes like graphene, fullerenes, nanotube, etc. This prompted us to study the linear carbon chains of different lengths and substitutions. The electronic and optical properties of X–C[Formula: see text]–X ([Formula: see text]–15 and [Formula: see text], NH2, CN, OH) molecules have been studied by using CAM-B3LYP/6-31G* level of theory of DFT methods. Linear carbon chains with odd values of n show lower bond length alternation (BLA) values similar to that of cumulenes and may have metallic property, but the substitution of donor/acceptor molecules does not decrease the BLA significantly. Molecular orbital analysis of linear carbon chains shows that NH2 or NO2 substituted polyynes have helical molecular orbitals for smaller chain lengths which may make a good candidate for molecular wires in molecular devices. As the chain length increases, the helicity decreases and finally disappears. Also, it is seen that for smaller odd values of [Formula: see text] for donor, substituted polyynes have a singlet ground, whereas all the odd [Formula: see text] values of acceptor substitution have triplet ground state.

Redox-Active Molecular Wires Incorporating Ruthenium(II) σ-Arylacetylide Complexes for Molecular Electronics

2008 ◽  
Vol 27 (4) ◽  
pp. 509-518 ◽  
Author(s):  
Céline Olivier ◽  
BongSoo Kim ◽  
Daniel Touchard ◽  
Stéphane Rigaut
Keyword(s):  
Molecular Electronics ◽  
Molecular Wires ◽  
Redox Active

scholarly journals Electron rectification through donor-acceptor-heterocyclics connected to cumulenic bridge: a computational study

2007 ◽  
Vol 5 (3) ◽  
pp. 793-812 ◽  
Author(s):  
J. Laxmikanth Rao
Keyword(s):  
Molecular Electronics ◽  
Molecular Orbital ◽  
Density Functional ◽  
Computational Study ◽  
Potential Drop ◽  
Molecular Wires ◽  
Frontier Molecular Orbital ◽  
Double Bonds ◽  
Acceptor Side ◽  
Donor Acceptor

AbstractDensity Functional Theory (DFT) calculations and Frontier Molecular Orbital (FMO) analysis have been carried out at B3LYP/6-31G(d,p) level of theory on some Donor-Bridge-Acceptor (D-B-A) molecules for their electrical rectification behavior. The donor-acceptor-heterocyclics (D/A-heterocyclics) (namely thiophene, furan and pyrrole rings) are attached as donor and acceptors to the two ends of cumulenic bridge. FMO analysis indicates that the molecules having even number of double bonds in the bridge, possess a complete localization of the MOs i.e., the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) are localized on the donor and the acceptor side of the molecules respectively, and LUMO+1 is localized on the donor side, where as in case of odd number of double bonds in the bridge, both the HOMO and LUMOs are delocalized all over the molecule. The Potential Drop (PD) in the former case decreases as the number of double bonds increases in the bridge and due to the presence of the mutually orthogonal and noninteracting π-clouds, they can act as molecular rectifiers. For the molecules with the odd number of double bonds due to the low-lying LUMO delocalized all over the molecule, may find application as molecular wires in molecular electronics circuits.

Inter-porphyrin coupling: how strong should it be for molecular electronics applications?

2002 ◽  
Vol 06 (12) ◽  
pp. 795-805 ◽  
Author(s):  
Jeffrey R. Reimers ◽  
Noel S. Hush ◽  
Maxwell J. Crossley
Keyword(s):  
Molecular Electronics ◽  
Coupling Strength ◽  
Molecular Wires ◽  
Model Compounds ◽  
Naturally Occurring ◽  
Functional Units ◽  
Device Properties

Porphyrins and phthalocyanines have now been assembled in a multitude of different architectures, each of which may be identified with a different scenario of the coupling acting between the porphyrins. The synthetic flexibility of these compounds makes possible the design of particular molecules for specific applications in molecular electronics, both in naturally occurring and synthetic devices. Here, we form an overview of these features and focus on the coupling strength, considering what values are appropriate for different molecular electronics applications. In particular, we focus on model compounds that have been prepared as mimics of naturally occurring photosynthetic functional units, oligoporphyrins molecular wires, and stacked systems in which small changes in geometry can affect significant changes in the inter-porphyrin coupling and hence produce dramatic changes in device properties.

A comparison of potential molecular wires as components for molecular electronics

2002 ◽  
Vol 32 (2) ◽  
pp. 96-103 ◽  
Author(s):  
Neil Robertson ◽  
Craig A. McGowan
Keyword(s):  
Molecular Electronics ◽  
Molecular Wires

THE EFFECT OF METAL-MOLECULE NANO-CONTACTS WITH DIFFERENT END GROUPS IN MOLECULAR ELECTRONICS

2009 ◽  
Vol 23 (30) ◽  
pp. 5657-5669 ◽  
Author(s):  
SEIFOLLAH JALILI ◽  
ABDOLHAKIM PANGH
Keyword(s):  
Electron Transport ◽  
Molecular Electronics ◽  
Atomic System ◽  
Transmission Function ◽  
Molecular Wires ◽  
Atomic Systems ◽  
Current Voltage ◽  
Electron Transport Properties ◽  
Current Voltage Characteristics ◽  
Function Density

We investigated the electron transport properties of thiophen-bithiol-based molecular wires through atomic metal–thiophen–metal systems using the first principle methods. Various metal–thiophen–metal atomic systems are constructed with different end atoms (S, Se, and Te). The electron transport of the atomic system is systematically studied by analysis of transmission function, density of states, and current–voltage characteristics of the systems.

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