Alignment of chevron-shaped molecules for photonic and electronic applicationsElectronic supplementary information (ESI) available: synthetic details and analytical data for three chevron-shaped molecules. See http://www.rsc.org/suppdata/jm/b2/b201801m/

Hybrid SAM/LB device structures: manipulation of the molecular orientation for nanoscale electronic applications

“…Molecular electronics represents the ultimate challenge in device miniaturisation and the molecular diode, 1 an organic counterpart of the pn junction, is once more the subject of intense theoretical [2][3][4] and experimental [5][6][7][8][9][10][11][12] interest. There are few reported examples, with only seven different bridged donor-acceptor chromophores so far exhibiting rectification when contacted by non-oxidisable electrodes: two neutral 6,7 and three cationic 8-10 D-p-A dyes with substituent groups for self-assembly and/or LB deposition and two chevron-shaped D-p-A-p-D dyes 11,12 that align in LB films without requiring long substituent alkyl tails. At forward bias, electrons tunnel from the electrode to the lowest unoccupied molecular orbital of the acceptor at one end of the device and from the highest occupied molecular orbital of the donor to the electrode on the opposite side.…”

Do alkyl tunnelling barriers contribute to molecular rectification?

“…Although protected by a silver overlay before breaking the vacuum, ambiguity arises because the top electrode is oxidisable. Electrical asymmetry has since been confirmed for four LB film-forming dyes contacted by gold [12][13][14][15] but this in itself also fails to provide proof of molecular rectification. The chromophore is geometrically offset by the alkyl tail [Au/ (C n H 2n11 -D-p-A)/Au] and Krzeminski et al 16 have attributed the observed rectification in part to an asymmetric profile of the electrostatic potential.…”

Molecular rectification: self-assembled monolayers of a donor–(π-bridge)–acceptor chromophore connected via a truncated Au–S–(CH2)3bridge

“…[4][5][6] For this reason, more recent reports of rectification from gold/(LB film)/ gold structures of p-bridged donor-acceptor materials, viz. three cationic dyes [7][8][9] and an extensively studied zwitterion, Z-b-(Nhexadecyl-4-quinolinium)-a-cyano-4-styryldicyanomethanide (C 16 H 33 -Q3CNQ), [10][11][12] have also failed to provide unambiguous evidence of molecular rectification.…”