Spin polarization in the electron transmission of radicals is important for understanding single-molecule conductance experiments focusing on shot noise, Kondo properties, or magnetoresistance. We study how stable radical substituents can affect such spin polarization when attached to oligo(p-phenyleneethynylene) (OPE) backbones. We find that it is not straightforward to translate the spin density on a stable radical substituent into spin-dependent transmission for the para-connected wires under study here, owing to increased steric interactions compared with meta-connected wires, and a resulting twisting of the radical substituent and OPE π systems. The most promising example is a t-butyl nitroxide substituent, which, despite little pronounced spin delocalization onto the backbone, yields a spindependent transmission feature, which one might be able to shift toward the Fermi energy by additional substituents. We also find that for bulkier substituents, dispersion interactions with the substituent can lead to twisting of one of the outer OPE rings, reducing the overall conductance. As a further potential design consideration, attaching radicals via linkers might increase the possibilities for spin-dependent intermolecular and molecule− electrode interactions.

Spin polarization in the electron transmission of radicals is important for understanding single-molecule conductance experiments focusing on shot noise, Kondo properties or magnetoresistance. We study how stable radical substituents can affect such spin polarization when attached to oligo(p- phenyleneethynylene) (OPE) backbones. We find that it is not straightforward to translate the spin density on a stable radical substituent into spin-dependent transmission for the para-connected wires under study here, owing to increased steric interactions compared with meta-connected wires, and a resulting twisting of the radical substituent and OPE π systems. The most promising example is a t-butyl nitroxide substituent, which, despite little pronounced spin delocalization onto the backbone, yields a spin-dependent transmission feature which one might be able to shift towards the Fermi energy by additional substituents. We also find that for bulkier substituents, dispersion interactions with the substituent can lead to twisting of one of the outer OPE rings, reducing the overall conductance. As a further potential design consideration, attaching radicals via linkers might increase the possibilities for spin-dependent intermolecular and molecule-electrode interactions.

We present here a novel resist formulation with active thiol groups at the surface. The material is UV curable, and can be patterned at the micro- and nanoscale by UV nanoimprint lithography. The resist formulation development, its processing, patterning and surface characterization are presented here. In addition, a possible application, including its use to modify the electrical properties of graphene devices is shown. The cured material is highly transparent, intrinsically hydrophilic and can be made more hydrophilic following a UV-ozone or an O2 plasma activation. We evaluated the hydrophilicity of the polymer for different polymer formulations and curing conditions. In addition, a protocol for patterning of the polymer in the micro and nanoscale by nanoimprinting is given and preliminary etching rates together with the polymer selectivity are measured. The main characteristic and unique advantage of the polymer is that it has thiol functional groups at the surface and in the bulk after curing. These groups allow for direct surface modifications with thiol-based chemistry e.g., thiol-ene reactions. We prove the presence of the thiol groups by Raman spectroscopy and perform a thiol-ene reaction to show the potential of the easy “click chemistry”. This opens the way for very straightforward surface chemistry on nanoimprinted polymer samples. Furthermore, we show how the polymer improves the electrical properties of a graphene field effect transistor, allowing for optimal performance at ambient conditions.

Spin polarization in the electron transmission of radicals is important for understanding single-molecule conductance experiments focusing on shot noise, Kondo properties or magnetoresistance. We study how stable radical substituents can affect such spin polarization when attached to oligo(p- phenyleneethynylene) (OPE) backbones. We find that it is not straightforward to translate the spin density on a stable radical substituent into spin-dependent transmission for the para-connected wires under study here, owing to increased steric interactions compared with meta-connected wires, and a resulting twisting of the radical substituent and OPE π systems. The most promising example is a t-butyl nitroxide substituent, which, despite little pronounced spin delocalization onto the backbone, yields a spin-dependent transmission feature which one might be able to shift towards the Fermi energy by additional substituents. We also find that for bulkier substituents, dispersion interactions with the substituent can lead to twisting of one of the outer OPE rings, reducing the overall conductance. As a further potential design consideration, attaching radicals via linkers might increase the possibilities for spin-dependent intermolecular and molecule-electrode interactions.

Spin polarization in the electron transmission of radicals is important for understanding single-molecule conductance experiments focusing on shot noise, Kondo properties or magnetoresistance. We study how stable radical substituents can affect such spin polarization when attached to oligo(p- phenyleneethynylene) (OPE) backbones. We find that it is not straightforward to translate the spin density on a stable radical substituent into spin-dependent transmission for the para-connected wires under study here, owing to increased steric interactions compared with meta-connected wires, and a resulting twisting of the radical substituent and OPE π systems. The most promising example is a t-butyl nitroxide substituent, which, despite little pronounced spin delocalization onto the backbone, yields a spin-dependent transmission feature which one might be able to shift towards the Fermi energy by additional substituents. We also find that for bulkier substituents, dispersion interactions with the substituent can lead to twisting of one of the outer OPE rings, reducing the overall conductance. As a further potential design consideration, attaching radicals via linkers might increase the possibilities for spin-dependent intermolecular and molecule-electrode interactions.