Multimetallic Complexes and Functionalized Nanoparticles Based on Unsymmetrical Dithiocarbamate Ligands with Allyl and Propargyl Functionality

The new, unsymmetrical
dithiocarbamate ligands, KS2CN­(CH2CHCH2)­Me and KS2CN­(CH2CCH)­Me,
are formed from the respective amines on reaction with KOH and carbon
disulfide. The homoleptic complexes [Ni­{S2CN­(CH2CHCH2)­Me}2] and [M­{S2CN­(CH2CCH)­Me}2] (M = Ni, Pd,
Pt) are formed on reaction with suitable metal precursors. Conversion
between the two pendant functionalities was confirmed by hydrogenation
of [Ni­{S2CN­(CH2CCH)­Me}2] to yield [Ni­{S2CN­(CH2CHCH2)­Me}2]. The monodithiocarbamate compounds of group
8, 10, and 11 metals, [Ru­{S2CN­(CH2CHCH2)­Me}­(dppm)2]+, [Ru­(CHCHC6H4Me-4)­{S2CN­(CH2CHCH2)­Me}­(CO)­(PPh3)2], [Ni­{S2CN­(CH2CHCH2)­Me}­(dppp)]+, and [Au­{S2CN­(CH2CHCH2)­Me}­(PPh3)] were formed successfully. Using
KS2CN­(CH2CCH)­Me, the complex [Ru­{S2CN­(CH2CCH)­Me}­(dppm)2]+ was obtained from cis-[RuCl2(dppm)2]. One palladium example, [Pd­{S2CN­(CH2CCH)­Me}­(PPh3)2]+,
was also isolated in low yield. However, under the typical conditions
employed, a rearrangement reaction prevented isolation of further
group 10 propargyl-dithiocarbamate products. Over the extended reaction
time required, Me­(HCCCH2)­NCS2– was found to undergo a remarkable, atom-efficient
cyclization to form the thiazolidine-2-thione, H2CCCH2N­(Me)­C­(S)­S, in high yield, with MeCCHN­(Me)­C­(S)­S
as the minor product. The reactivity of the pendant triple bonds in
[Ni­{S2CN­(CH2CCH)­Me}2] was
probed in the reaction with [RuH­(CO)­(S2P­(OEt)2)­(PPh3)2] to form the trimetallic example
[Ni­{S2CN­(Me)­CH2CHCHRu­(CO)­(S2P­(OEt)2)­(PPh3)2}2], while the copper­(I) catalyzed reaction with benzylazide yielded
the triazole product, [Ni­{S2CN­(Me)­CH2(C2HN3)­Bz}2]. KS2CN­(CH2CCH)­Me was also used to prepare the gold nanoparticles,
Au@S2CN­(CH2CCH)­Me. Structural
studies are reported for [Ru­(CHCHC6H4Me-4)­{S2CN­(CH2CHCH2)­Me}­(CO)­(PPh3)2] and [Ru­{S2CN­(CH2CCH)­Me}­(dppm)2]­PF6.