Multifunctional behavior of molecules comprising stacked cytosine–Ag^I–cytosine base pairs; towards conducting and photoluminescence silver-DNA nanowires

Abstract

Tuning the conducting and photoluminescence properties of molecules comprising silver(i)–cytosine base pairs.

Addressing the properties of “Metallo-DNA” with a Ag(i)-mediated supramolecular duplex

“…35 Interestingly, the recently reported [Ag(1-Me-cytosine) 2 ] + complex features similarly short Ag/Ag distances (2.902-3.088(2)Å) as 1. 36 This nding indicates that the ribose moiety of the nucleoside does not impose additional steric hinderance to inter-complex interactions allowing short argentophilic bonding.…”

“…22 For monovalent silver ions the tendency to participate in metallophilic interactions 51 makes such systems particularly interesting. However, studies on the electrical properties of Ag(I)-DNA are rather few [39][40][41][42] and only the most recent work by Galindo et al 36 is on material that has been crystallographically characterised.…”

“…35 Our ndings of non-conductivity are in agreement with the conductivity measurements and the electrostatic force microscopy (EFM) experiments of Galindo et al on microcrystals of [Ag(I)(methyl-cytosine) 2 ] + that has similarly short Ag/Ag distances. 36 To examine the charge mobility further, EFM was employed as this can sensitively probe the polarisation of individual bres. To allow this, the gel 1 MeOH was diluted with methanol by a factor of twenty, drop-cast onto a Sih100i/200 nm SiO 2 slide, and kept in a methanol-saturated environment to allow selfhealing.…”

“…Analogous arrays of Ag(I) ions have recently been shown to be a feature in the solid state structure of simple nucleobase complexes of the form [Ag(I)-(N3alkyl-cytosine) 2 ] + isolated from organic solvent. 35,36 Such metallo-DNA systems are frequently considered as molecular or nano-wires 22,37,38 on account of the contiguous linear array of metal ions produced. However, studies on their electrical properties are rather scant [39][40][41][42] and only one, reported while our manuscript was under review, is for a crystallographically characterised material.…”

“…However, studies on their electrical properties are rather scant [39][40][41][42] and only one, reported while our manuscript was under review, is for a crystallographically characterised material. 36 Here, we report the metal-mediated nucleoside complex, [Ag(I)-(N3-cytidine) 2 ], 1 that self-assembles to yield a metallo-DNA analogue in both solid and gel states. This compound provides a convincing model of a metallo-DNA duplex, containing, as it does, both the nucleobase and ribose moieties, allowing the physico-chemical properties of such systems to be examined.…”