ic402048a_si_002.cif (28.63 kB)
Ring-Closing Metathesis and Nanoparticle Formation Based on Diallyldithiocarbamate Complexes of Gold(I): Synthetic, Structural, and Computational Studies
dataset
posted on 2014-03-03, 00:00 authored by Saira Naeem, Stefano
A. Serapian, Anita Toscani, Andrew J. P. White, Graeme Hogarth, James D. E. T. Wilton-ElyThe gold(I) complexes [Au{S2CN(CH2CHCH2)2}(L)] [L =
PPh3, PCy3, PMe3, CNtBu, IDip] are prepared from KS2CN(CH2CHCH2)2 and [(L)AuCl]. The compounds
[L2(AuCl)2] (L2 = dppa, dppf) yield
[(L2){AuS2CN(CH2CHCH2)2}2], while the cyclic complex [(dppm){Au2S2CN(CH2CHCH2)2}]OTf is obtained from [dppm(AuCl)2] and
AgOTf followed by KS2CN(CH2CHCH2)2. The compound [Au2{S2CN(CH2CHCH2)2}2] is prepared
from [(tht)AuCl] (tht = tetrahydrothiophene) and the diallyldithiocarbamate
ligand. This product ring-closes with [Ru(CHPh)Cl2(SIMes)(PCy3)] to yield [Au2(S2CNC4H6)2], whereas ring-closing
of [Au{S2CN(CH2CHCH2)2}(PR3)] fails. Warming [Au2{S2CN(CH2CHCH2)2}2] results in formation of gold nanoparticles
with diallydithiocarbamate surface units, while heating [Au2(S2CNC4H6)2] with NaBH4 results in nanoparticles with 3-pyrroline dithiocarbamate
surface units. Larger nanoparticles with the same surface units are
prepared by citrate reduction of HAuCl4 followed by addition
of the dithiocarbamate. The diallydithiocarbamate-functionalized nanoparticles
undergo ring-closing metathesis using [Ru(CHC6H4OiPr-2)Cl2(SIMes)].
The interaction between the dithiocarbamate units and the gold surface
is explored using computational methods to reveal no need for a countercation.
Preliminary calculations indicate that the Au–S interactions
are substantially different from those established in theoretical
and experimental studies on thiolate-coated nanoparticles. Structural
studies are reported for [Au{S2CN(CH2CHCH2)2}(PPh3)] and [Au2{S2CN(CH2CHCH2)2}2]. In the latter, exceptionally short intermolecular
aurophilic interactions are observed.
