Supplementary Material (ESI) for Chemical Communications
This journal is © The Royal Society of Chemistry 2001
Supplementary Material
Experimental part :
All operations were carried out using standart Schlenk tube or Fischer-Porter bottle
techniques under argon for the synthesis or in a glove box under nitrogen for the preparation
of the samples for analysis.
- Synthesis of colloids 2a and 2b :
A solution of Pt2(dba)3 (180mg; 0.165 mmol) in 40 mL of freshly distilled and deoxygenated
THF in a Fischer- Porter bottle was pressurized with 1 bar of CO during 30 minutes at room
temperature under vigorous stirring. During this time, the solution changed color from violet
to brown (attesting then of the formation of the Ptx(CO)y(THF)z intermediate colloid) and the
medium remained homogeneous. The mixture was evaporated to dryness and the resulting
solid was washed with pentane to eliminate the dba (5x20mL; until the solution turned
colorless). The colloid was then dried under vacuum before redissolution with a THF solution
containing the dithiol ligand (0.1 eq. per introduced Pt) : propanedithiol (3.5L; 0.035 mmol)
for colloid 2a and octanedithiol (6L; 0.0496 mmol) for colloid 2b. The dissolution of the Pt
colloid was very fast and the resulting mixture was a homogeneous brown solution. After
evaporation to dryness, colloids 2a and 2b could be isolated as dark-brown powders.
- Pt particles connected to gold :
The connexion of Pt particles to Au particles was realized by mixing together a solution of
colloid 2b with a gold colloidal solution (prepared following the Turkevich method30 in the
ratio Pt/Au 10/1.
- Synthesis of colloids 3a, 3b and 3c :
The synthesis of colloids colloids 3a, 3b and 3c was realized in the same way as the colloids
2a or 2b, the only difference being the quantity of the ligand (0.15 eq. per introduced Pt).
- Condensation products of 3a and 3c with 3b :
The condensation products of 3a and 3c with 3b were obtained by mixing together an equal
volume of a 3a (or 3c) solution with a 3b solution.
Supplementary Material (ESI) for Chemical Communications
This journal is © The Royal Society of Chemistry 2001
Schemes
Scheme 1 : synthesis of Pt colloids stabilized by bifunctional ligands and [Pt]o self-assemblies
trough hydrogen bonding networks
1)
Pt2(dba)3
1 bar CO
THF; r.t.
0.1 or 0.15 eq./Pt ligand
THF; r.t.
Ptx(CO)y(THF)z
colloid 1
Ptx(CO)y(THF)z(ligand)w
colloids 2 or 3
Ligands:
HS-(CH2)n-SH with n=3 (colloid 2a) or 8 (colloid 2b)
HS-C6H4-X with X = OH (colloid 3a), NH2 (colloid 3b) or COOH (colloid 3c)
S
2)
3a + 3b
[Pt]o assembly :
Pt
S
H
S
N
HO
S
Pt
H
Scheme 2 : Pt octanedithiol stabilized particles connected to gold particles
[Au]o "Turkevich" particles + [Pt]o(S-S)
[Au]/[Pt] = 1/10
H2O/THF
[Au]o(S-S)[Pt]o assemblies
Supplementary Material (ESI) for Chemical Communications
This journal is © The Royal Society of Chemistry 2001
Figures with captions
Fig 1 HREM micrograph of Pt particles stabilized by propanedithiol (a) and TEM
micrograph of [Pt]o(S-S)[Au]o assemblies (b)
Fig 2 TEM (a) and HREM (b) micrographs of disks resulting from the condensation of 3a and
3b in the presence of water
Supplementary Material (ESI) for Chemical Communications
This journal is © The Royal Society of Chemistry 2001
Fig. 3 TEM and HREM micrographs of platinum nanotubes at different magnifications (a)
X15000 (b) X100000K (c) X600000
Fig 4 TEM (a) and HREM (b) micrographs of Pt particles stabilized by HS-C6H4-OH(colloid
3a)
Supplementary Material (ESI) for Chemical Communications
This journal is © The Royal Society of Chemistry 2001
Fig 5 (Graphical Abstract figure) TEM micrographs of platinum nanotubes