Syntheses, X-ray structures and AACVD studies of group 11 ditelluroimidodiphosphinate complexes

Article abstract of DOI:10.1039/b617429a

Reactions of Na(tmeda)[N(ⁱPr₂PTe)₂] with CuCl, AgI or AuCl (in the presence of PPh₃) in THF produced the coinage metal ditelluroimidodiphosphinate complexes {Cu[N(ⁱPr ₂PTe)₂]}₃, (5), {Ag[N(ⁱPr ₂PTe)₂]}₆ (6) and Au(PPh₃)[N( ⁱPr₂PTe)₂] (7), respectively. Complexes 5, 6 and 7 were characterized in the solid state by X-ray crystallography. Complex 5 is trimeric and exhibits a highly distorted Cu₃Te₃ ring. In contrast, the Ag(i) complex 6 is a hexamer, and forms a twelve-membered Ag₆Te₆ ring. The replacement of the ⁱPr groups on phosphorus by Ph results in an intriguing structural change to a tetramer with a boat-shaped Ag₄Te₄ ring in {Ag[N(Ph ₂PTe)₂}₄·2THF (8). The gold(i) complex 7 is monomeric. Aerosol-assisted chemical vapour deposition (AACVD) of compounds 5, 6 and 7 yields CuTe, Ag₇Te₄, AuTe₂ and Au films, respectively. The films were grown at temperatures of 300-500 °C and characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive analysis of X-rays (EDAX). The Royal Society of Chemistry 2007.

Full text of DOI:10.1039/b617429a

View Article Online / Journal Homepage / Table of Contents for this issue
PAPER
www.rsc.org/dalton | Dalton Transactions
Syntheses, X-ray structures and AACVD studies of group 11
ditelluroimidodiphosphinate complexes†
May C. Copsey,a Arunkumar Panneerselvam,b Mohammad Afzaal,b Tristram Chivers*a and Paul O’Brien*b
Received 29th November 2006, Accepted 12th February 2007
First published as an Advance Article on the web 27th February 2007
DOI: 10.1039/b617429a
Reactions of Na(tmeda)[N(iPr2PTe)2] with CuCl, AgI or AuCl (in the presence of PPh3) in THF
produced the coinage metal ditelluroimidodiphosphinate complexes {Cu[N(iPr2PTe)2]}3, (5),
{Ag[N(iPr2PTe)2]}6 (6) and Au(PPh3)[N(iPr2PTe)2] (7), respectively. Complexes 5, 6 and 7 were
characterized in the solid state by X-ray crystallography. Complex 5 is trimeric and exhibits a highly
distorted Cu3Te3 ring. In contrast, the Ag(I) complex 6 is a hexamer, and forms a twelve-membered
Ag6Te6 ring. The replacement of the iPr groups on phosphorus by Ph results in an intriguing structural
change to a tetramer with a boat-shaped Ag4Te4 ring in {Ag[N(Ph2PTe)2}4·2THF (8). The gold(I)
complex 7 is monomeric. Aerosol-assisted chemical vapour deposition (AACVD) of compounds 5, 6
and 7 yields CuTe, Ag7Te4, AuTe2 and Au films, respectively. The films were grown at temperatures of
300–500 ◦C and characterized by X-ray powder diffraction (XRD), scanning electron microscopy
(SEM) and energy dispersive analysis of X-rays (EDAX).
Introduction
Binary metal tellurides have been shown to have interesting
properties and many potential uses. Recent work has focused on
the production of thin films or nanoparticles of group 12 (Zn, Cd,
Hg)1 or group 15 (Sb, Bi)2 tellurides in view of their applications
in photooptical and thermoelectric devices, respectively. The
traditional syntheses of metal tellurides have involved either the
Chart 1
high-temperature (500–600 ◦C) reaction between the elements3 or
aqueous methods that employ the extremely toxic reagent H2Te.4
As an alternative to these procedures the use of a single-source
1995, Woollins and co-workers initiated the chemistry of the
selenium analogue 3a.13 Much of the early development of the
coordination chemistry of these ligands with both main group14
and transition metals14,15 was focused on the phenyl derivatives.
In 2004 it was demonstrated that metal complexes incorporating
the more volatile iso-propyl ligand 3b are excellent precursors
for the production of a variety of binary metal selenides by
CVD techniques.16,17 This method can also be employed for the
generation of thin films of the important ternary material CuInSe2
by thermal decomposition of a copper(I) complex of 3b in the
presence of a related indium precursor, In[N(iPr2PSe)2]Cl.18
The recent preparation of the ditelluroimidodiphosphinate
anions 4a and 4b has paved the way for investigations of analogous
tellurium systems.19–21 Simple metathesis reactions of the sodium
salt of 4b with metal halides have led to the synthesis of complexes
of group 12 and 15 metals,20 as well as a lanthanum(III) complex
and a uranium(III) complex, the latter providing the first example
of actinide–tellurium bonds.22 Interestingly, the reactions of 4b
with group 13 halides gives rise to a novel chalcogen-transfer
process resulting in the formation of Ga2Te2 and In3Te3 rings.23
Subsequent chemical vapour deposition studies demonstrated
that several of these new tellurium-containing compounds can
indeed act as single-source precursors for binary metal tellurides,
including thin films of CdTe,24 In2Te3,25 and hexagonal Sb2Te3
nanoplates.2a
molecular precursor in which the metal and tellurium atoms are
in close proximity has been investigated by various groups.5,6 To the
best of our knowledge, there have been no reports of the generation
of copper, silver or gold telluride thin films by this approach.
Copper telluride thin films have been employed in various devices,
including solar cells, photodetectors and microwave-shielding
coatings.7–9 Silver tellurides find wide applications as thermoelec-
tronic or magnetic materials as a result of their thermoelectric
and magneto-resistive behaviour.10 The low-temperature phase
of monoclinic silver telluride is a semiconductor with a narrow
band gap, whereas the high-temperature phase is a superionic
conductor. A recent paper by Zhang and co-workers describes the
controlled hydrothermal synthesis of nanostructured thin films of
Cu2Te and Ag2Te by the reaction of metal foils with Te powder in
hydrazine.11
The dichalcogenoimidodiphosphinate anions 1 and 2 were first
synthesized by Schmidpeter et al. in the 1960s (Chart 1).12 In
aDepartment of Chemistry, University of Calgary, Calgary, AB, T2N 1N4,
Canada. E-mail: chivers@ucalgary.ca; Fax: +1 403 289 9488; Tel: +1 403
220 5741
bThe School of Chemistry and The School of Materials, The Univer-
sity of Manchester, Oxford Road, Manchester, UK M13 9PL. E-mail:
paul.obrien@manchester.ac.uk; Fax: +44 (0)161 275 4616; Tel: +44 (0)161
275 4652
In this investigation we have synthesized the first ditelluroimi-
dodiphosphinate group 11 complexes, for structural comparison
† The HTML version of this article has been enhanced with colour images.
1528 | Dalton Trans., 2007, 1528–1538
This journal is
The Royal Society of Chemistry 2007
©

View Article Online
Table 1 Selected bond lengths (A) and bond angles (◦) for
{Cu[N(iPr2PTe)2]}3 (5)
˚
with the analogous dithio and diseleno species, and evaluated their
use as single-source precursors for the formation of copper, silver
and gold telluride thin films.
Cu(1)–Te(1)
Cu(1)–Te(5)
2.563(2)
2.696(2)
Cu(1)–Te(2)
Cu(1)–Te(6)
2.591(1)
2.890(2)
Results and discussion
Cu(2)–Te(2)
Cu(2)–Te(3)
Cu(2)–Te(4)
2.533(2)
2.505(1)
2.563(2)
Cu(3)–Te(4)
Cu(3)–Te(5)
Cu(3)–Te(6)
2.566(1)
2.531(1)
2.531(1)
Syntheses and characterization of group 11 complexes
The ditelluroimidodiphosphinate complexes {Cu[N(iPr2PTe)2]}3
(5) and {Ag[N(iPr2PTe)2]}6 (6) (Chart 2) were readily prepared
in good yield by the metathesis reactions of the reagent
Na(tmeda)[N(iPr2PTe)2]20 with CuCl and AgI, respectively. In
contrast, the reaction of AuCl with Na(tmeda)[N(iPr2PTe)2] was
very vigorous, immediately producing a dark red solution and a
precipitate of gold metal, even at low temperatures.26 However,
the stable gold complex Au(PPh3)[N(iPr2PTe)2] (7) was prepared
in good yield by treating the sodium complex of 4b with a sol-
ution of (PPh3)AuCl. The reaction of the sodium salt of 4a,
Na(tmeda)[N(Ph2PTe)2], with an equimolar quantity of AgI
produced the homoleptic complex {Ag[N(Ph2PTe)2]}4 (8) in 69%
yield.
Cu(1)–Cu(3)
2.637(2)
Cu(2)–Cu(3)
2.626(1)
Te(1)–Cu(1)–Te(2) 113.16(5)
Te(1)–Cu(1)–Te(5) 118.18(6)
Te(2)–Cu(1)–Te(5)
Te(2)–Cu(2)–Te(3) 128.73(5)
Te(2)–Cu(2)–Te(4) 107.50(5)
Te(3)–Cu(2)–Te(4)
Te(4)–Cu(3)–Te(5)
Te(4)–Cu(3)–Te(6)
Te(5)–Cu(3)–Te(6)
123.71(5)
113.12(4)
134.10(5)
112.47(5)
99.94(5)
two central, highly distorted Cu3Te3 rings. The distortion of these
central rings results in surprisingly short copper–copper distances
of 2.626(1) and 2.637(2) A. Two of the ligands are equivalent with
similar metrical parameters, each containing one tellurium which
is complexed to one copper centre and one tellurium bridging
two copper centres. The unique ligand Te(5)–P(5)–N(3)–P(6)–
Te(6) can be viewed as asymmetrically bridging both Cu(1) and
Cu(3) centres with significantly longer tellurium copper distances
˚
˚
˚
to Cu(1): Cu(1)–Te(6) 2.890(2) A and Cu(1)–Te(5) 2.696(2) A,
˚
cf. Cu(3)–Te(6) and Cu(3)–Te(5) = 2.531(1) A. Cu(2) and Cu(3)
display trigonal planar geometry (sum of bond angles around
Cu are 359.9◦ and 359.7◦, respectively). Disregarding the longer
Cu(1)–Te(6) bond, the geometry of the Cu(1) center is highly
distorted from trigonal planar (sum of bond angles around Cu(1)
is 331.3◦). This suggests a significant interaction with Te(6) and
therefore the Cu(1) geometry is more accurately described as
intermediate between tetrahedral and trigonal planar.
Chart 2
X-Ray crystal structures
The analogous copper(I) complexes of the dithio and diseleno
ligands 2b and 3b, respectively, are also trimeric and consist of
a central six-membered Cu3E3 (E = S, Se) ring.18,27a However, in
contrast to complex 5, both structures are considerably more open
and there are no indications of metal–metal interactions [d(Cu–
The molecular structure of the copper(I) derivative 5 was de-
termined by X-ray crystallography. Crystallographic data are
summarized in Table 5. As indicated in Fig. 1, this complex is
trimeric in the solid state. Selected bond distances and bond
angles are given in Table 1. Complex 5 consists of three six-
membered CuTe2P2N rings, which are linked together to form
˚
Cu) = 3.75–4.00 A]. The longer, more labile copper–tellurium
bonds in 5 may impart more flexibility to the structure, thus
allowing one of the ligands to function in a doubly bridging mode,
which brings two of the copper atoms in closer proximity than
in the analogous sulfur or selenium complexes. We note, however,
that the trimeric Cu(I) complex of the phenyl-substituted dithio
˚
ligand 2a exhibits two short (2.637 and 2.625 A) and one long
(3.581 A) Cu–Cu contacts.
27b
˚
An X-ray structural determination of complex 6 revealed a novel
arrangement consisting of six Ag[N(iPr2PTe)2] units to give the
hexamer {Ag[N(iPr2PTe)2]}6 as shown in Fig. 2. The molecule
lies on an inversion centre so the two halves of the hexamer
are crystallographically equivalent. The silver centres are each
bound to two tellurium centres from one ligand and one tellurium
from an adjacent Ag[N(iPr2PTe)2] moiety. Each silver centre is
coordinated equally (Table 2) between two bridging tellurium
centres of adjacent [N(iPr2PTe)2] ligands forming a central twelve-
membered Ag6Te6 ring. Two pairs of silver atoms in the twelve-
membered ring have noticeably shorter metal–metal distances,
˚
Ag(2)–Ag(3A) 2.945(2) A and Ag(3)–Ag(2A) 2.955(2), which
are in the range for which metallophilic silver–silver interactions
should be considered.28,29 However, the geometry at the metal
Fig. 1 Molecular structure of {Cu[N(iPr2PTe)2]}3 (5). Thermal ellipsoids
are shown at 50%. Hydrogen atoms have been omitted for clarity.
This journal is
The Royal Society of Chemistry 2007
Dalton Trans., 2007, 1528–1538 | 1529
©

View Article Online
Table 2 Selected bond lengths (A) and bond angles (◦) for
Table 3 Selected bond lengths (A) and bond angles (◦) for
{Ag[N(Ph2PTe)2]}4 (8)
˚
˚
{Ag[N(iPr2PTe)2]}6 (6)
Ag(1)–Te(1)
Ag(1)–Te(2)
Ag(1)–Te(3)
2.725(1)
2.690(2)
2.724(1)
Ag(2)–Te(3)
Ag(2)–Te(4)
Ag(2)–Te(6A)
2.721(1)
2.692(1)
2.784(2)
Ag(1)–Te(1)
Ag(1)–Te(2)
Ag(1)–Te(3)
Ag(1)–Te(4)
2.880(1)
2.8901(9)
2.792(1)
2.816(1)
Ag(2)–Te(4)
2.764(1)
2.827(1)
2.928(1)
2.992(2)
3.243(1)
Ag(2)–Te(1A)
Ag(2)–Te(2A)
Ag(2)–Ag(2A)
Ag(1)–Ag(2)
Ag(3)–Te(6)
Ag(3)–Te(5)
Ag(2)–Ag(3A)
2.794(1)
2.725(1)
2.945(2)
Ag(3)–Te(1)
Ag(3)–Ag(2A)
2.756(1)
2.955(2)
Te(1)–Ag(1)–Te(2)
Te(1)–Ag(1)–Te(3)
Te(2)–Ag(1)–Te(3)
Te(1A)–Ag(2)–Te(4)
Te(2A)–Ag(2)–Te(4)
93.11(3)
124.08(3)
111.01(3)
151.02(3)
100.38(4)
Te(1)–Ag(1)–Te(4)
Te(2)–Ag(1)–Te(4)
Te(3)–Ag(1)–Te(4)
Te(1A)–Ag(2)–Te(2A)
99.55(3)
116.10(3)
111.93(3)
93.42(3)
Te(1)–Ag(1)–Te(2)
Te(1)–Ag(1)–Te(3)
Te(2)–Ag(1)–Te(3)
Te(3)–Ag(2)–Te(4)
Te(3)–Ag(2)–Te(6A)
120.54(4) Te(4)–Ag(2)–Te(6A)
111.47(4) Te(1)–Ag(3)–Te(5)
127.87(4) Te(1)–Ag(3)–Te(6)
119.16(5) Te(5)–Ag(3)–Te(6)
111.31(4)
129.53(4)
133.13(4)
108.44
116.34(4)
Fig. 3 Molecular structure of {Ag[N(Ph2PTe)2]}4 (8). Thermal ellipsoids
are shown at 50%. Hydrogen atoms and lattice molecules of THF have
been omitted for clarity.
Fig. 2 Molecular structure of {Ag[N(iPr2PTe)2]}6 (6). Thermal ellipsoids
are shown at 50%. Hydrogen atoms and methyl groups have been omitted
for clarity.
exhibit distorted tetrahedral geometry, each being coordinated to
four tellurium centres. The other silver atoms, Ag(2) and Ag(2A),
are each bound to three tellurium centres and display distorted
trigonal planar geometry. These two silver centres are held 2.992(2)
centres is nearly perfect trigonal planar in each case suggesting
there is little interaction between the metal centres (sum of the
bond angles: Ag(2) 360.0◦, Ag(3) 357.9◦). Thus it is not possible
to establish if the proximity of the silver centres is a consequence of
the bridging tellurium centres or due to a metallophilic interaction.
The analogous silver complex of the diseleno ligand 3b is
trimeric in the solid state and, as in the case of the copper complex
of 3b, no sign of metal–metal interaction is observed.18 Complex
6 is only the second example of a hexameric species formed by a
metal complex of dichalcogenoimidodiphosphinate ligands. The
sodium complex, {Na[N{(PhO)2PO}2]}6 is also hexameric in the
solid state,30 presumably due to the spatial requirements of the
phenoxy substituents on the phosphorus centres of the ligand. In
the case of complex 6, the large sizes of the metal and chalcogen
are more likely to be the contributing factors.
In contrast to the iso-propyl-substituted silver complex 6, X-
ray crystallography revealed 8 to be tetrameric in the solid state,
{Ag[N(Ph2PTe)2]}4 (Fig. 3). The molecule lies on an inversion
centre, making the two halves of the molecule crystallographically
equivalent. Selected bond lengths and bond angles for 8 are
summarized in Table 3. The complex contains a central eight-
membered Ag4Te4 ring. There are two distinct silver environments.
The atoms Ag(1) and the crystallographic equivalent Ag(1A)
˚
˚
A from each other, cf. 3.243(1) A for Ag(1)–Ag(2), which is in the
range for reported silver–silver interactions.29 Although the close
Ag · · · Ag contact in 8 is similar in distance to those observed for
6, the distortion of the geometry of these silver atoms towards
pyramidal (sum of bond angles around Ag(2) is 344.8◦) in 8,
in contrast to the trigonal planar geometry observed in 6, is
suggestive of a metallophilic interaction in the former.
Attention to gold–chalcogen chemistry has increased recently
due to the interest in these compounds for chemotherapy.31 This
has led to a number of gold selenide complexes being characterized
and, in particular, a detailed study of gold complexes of ligand 3a
has been carried out, with examples of the metal centre being two,
three or four coordinate.32
An X-ray structural determination of Au(PPh3)[N(iPr2PTe)2]
(7) revealed a monomeric species (Fig. 4) with a trigonal planar
gold(I) centre (sum of the bond angles around Au(1) is 359.4◦)
coordinated to one [N(iPr2PTe2)2]− ligand and one molecule of
triphenylphosphine. The gold centre is bound equally between the
two tellurium centres of the ditelluroimidodiphosphinate ligand to
form the six-membered AuTe2P2N metallacycle. The Au–Te bond
distances are in the range of previously reported Au–Te bonds,
2.533–2.666 A.33 The six-membered ring has a twist conformation,
˚
1530 | Dalton Trans., 2007, 1528–1538
This journal is The Royal Society of Chemistry 2007
©

View Article Online
fluxional process may be occurring to cause each tellurium centre
to become equivalent on the NMR timescale. Low temperature
NMR experiments were conducted on complexes 5, 6 and 8,
however only singlets were observed in all cases.
Deposition of thin films
The chemical vapour deposition studies of compounds 5, 6 and
7 were conducted in an aerosol-assisted (AA) CVD kit. The pre-
cursors have very high molecular masses ranging from 962–3668 g
mol−1 and would be unsuitable for use in conventional CVD exper-
iments due to lack of thermal stability and volatility. However, the
AACVD technique allows the transfer of aerosols to the reaction
site where the aerosol droplets evaporate depositing the precursor
on the glass substrate. The physical properties of compounds
analysed by thermogravimetric analysis (TGA) indicates◦a single
◦
decomposition step between 208–297 C for 5, 210–355 C for 6
◦
and 206–317 C for 7. Prior to each deposition, the reactor was
purged with argon for approx. 15 min at the deposition tempera-
ture in order to minimise the risk of producing oxidised films.
Copper telluride thin films were deposited from {Cu[N(i-
Pr2PTe)2]}3 (5) on glass substrates by AACVD. The copper pre-
cursor was dissolved in 20 mL toluene and the deposition process
occurred over a period of 90 min in the temperature range 300 to
500 ◦C, with an argon flow rate of 160 sccm. The deposited grey
films were non-adherent and could be easily wiped off the surface,
indicating that the copper telluride particles were weakly adsorbed
on the glass substrate. The XRD patterns of all the deposited
films showed a mixture of orthorhombic CuTe (JCPDS 13-0258),
hexagonal Te (JCPDS 36-1452) and phosphorus (JCPDS 25-
0608) (Fig. 5). The unit cell parameters of the deposited films are
compared with literature values in Table 4. There is some notable
deviation for the films deposited at 300 ◦C as a consequence of
phosphorus doping within the crystal lattice. The SEM studies
revealed that the copper telluride particles have hexagonal shapes
at 300 ◦C (Fig. 6). With an elevation in growth temperature to
350 ◦C, transparent individual sheets of CuTe along with CuTe
spherical particles are observed. Stacking of sheets is observed
at 400–500 ◦C. The tellurium rods are formed at all deposition
temperatures. In all cases, EDAX analyses on the sheets indicate
that they are copper rich (49–52%) along with phosphorus incor-
poration (5–12%). The high copper content may be due to the
formation of individual tellurium rods, which reduces the avail-
ability of tellurium for the production of copper telluride sheets.
The deposition of silver telluride thin films was attempted from
toluene solutions of {Ag[N(iPr2PTe)2]}6 (6) on glass substrates in
Fig. 4 Molecular structure of Au(PPh3)[N(iPr2PTe)2] (7). Thermal el-
lipsoids are shown at 50%. Hydrogen atoms◦ have been omitted for
˚
clarity. Selected bond lengths (A) and angles ( ): Au(1)–Te(1) 2.616(7),
Au(1)–Te(2) 2.639(1), Au(1)–P(3), 2.309(2), Te(1)–Au(1)–Te(2) 118.63(2),
Te(1)–Au(1)–P(3) 119.98(4), Te(2)–Au(1)–P(3), 120.78(4).
the gold centre lies in the same plane as the nitrogen and the
˚
tellurium centres with P(1) lying above (0.62 A) and P(2) below
˚
(0.64 A) this plane. Interestingly, structural characterization of
the triphenylphosphine gold(I) complexes of ligands 2a and 3a,
showed the gold centre to be asymmetrically bound between the
two chalcogen centres,32 suggesting a weaker interaction with one
side of the ligand, which is not observed in the case of complex 7.
There are relatively few structurally characterized examples of
gold–tellurium bonds, the majority of which involve binary AuxTey
anions. Hence, the isolated molecular complex 7 can be considered
a rare example of a gold(I) complex of a telluride ligand.32
NMR characterization of group 11 complexes of 4
The iso-propyl-substituted complexes 5–7 each exhibit a single
resonance (d 23.2–26.8) in their respective 31P NMR spectra,
indicating equivalence of the phosphorus centres in solution on the
NMR time scale at room temperature. Consistently, one doublet
(d −640 to −770) is observed in each of the 125Te NMR spectra of
5–7. The magnitudes of the 1JTeP (1290–1350 Hz) are comparable
to those observed for covalent complexes of 4b with group 12 and
group 15 metals (1282–1339 Hz).20 In contrast to the homoleptic
complexes of 4b with cadmium and mercury,20 no coupling to
the spin-active silver nuclei was observed in the 31P or 125Te
NMR spectra for compound 6 suggesting that this coinage-metal
complex is fluxional in solution. The phenyl-substituted complex
8 exhibited a singlet at d −14.4 with 1JTeP = 1361 Hz but, as with
complex 6 no coupling to spin-active silver nuclei was observed.
We were unable to detect the 125Te NMR resonance for 8 owing to
low solubility.
Examination of the solid-state structures of complexes 5, 6 and
8 reveals that there is more than one tellurium environment in
each of the structures. However, in each case only one signal is
observed in the 31P and 125Te NMR spectra. This suggests that
the solid-state structures do not remain intact in solution, and a
Fig. 5 XRD pattern of CuTe films deposited at 400 ◦C. The additional
diffraction peaks are identified as Te (*) and P (#).
This journal is
The Royal Society of Chemistry 2007
Dalton Trans., 2007, 1528–1538 | 1531
©

View Article Online
Table 4 A comparison between literature and observed unit cell parameters of deposited materials
Deposition temperature/◦C Materials deposited Literature lattice constants/A
Refined lattice constants/A
˚
˚
Precursor
{Cu[N(iPr2PTe)2]}3
300
350
400
450
500
CuTe + Te
CuTe + Te
CuTe + Te
CuTe + Te
CuTe + Te
a: 4.09; b: 6.95; c: 3.15
a: 4.4579(3); c: 5.9270(6)
a: 4.09; b: 6.95; c: 3.15
a: 4.4579(3); c: 5.9270(6)
a: 4.09; b: 6.95; c: 3.15
a: 4.4579(3); c: 5.9270(6)
a: 4.09; b: 6.95; c: 3.15
a: 4.4579(3); c: 5.9270(6)
a: 4.09; b: 6.95; c: 3.15
a: 4.4579(3); c: 5.9270(6)
a: 4.055(2); b: 7.046(5); c: 3.152(2)
a: 4.4571(9); c: 5.919(3)
a: 4.088(5); b: 6.948(4); c: 3.146(3)
a: 4.462(4); c: 5.932(4)
a: 4.088(2); b: 6.942(3); c: 3.177(3)
a: 4.4564(3); c: 5.9275(7)
a: 4.092(2); b: 6.950(3); c: 3.147(1)
a: 4.4560(5); c: 5.926(1)
a: 4.087(4); b: 6.950(4); c: 3.150(2)
a: 4.4563(9); c: 5.920(2)
{Ag[N(iPr2PTe)2]}6
300
350
400
450
500
Ag7Te4 + Te
Ag7Te4 + Te
Ag7Te4 + Te
Ag7Te4 + Te
Ag7Te4 + Te
a: 13.457; c: 8.4564
a: 4.4579(3); c: 5.9270(6)
a: 13.457; c: 8.4564
a: 4.4579(3); c: 5.9270(6)
a: 13.457; c: 8.4564
a: 4.4579(3); c: 5.9270(6)
a: 13.457; c: 8.4564
a: 4.4579(3); c: 5.9270(6)
a: 13.457; c: 8.4564
a: 4.4579(3); c: 5.9270(6)
a: 13.444(5); c: 8.469(3)
a: 4.4577(9); c: 5.919(2)
a: 13.451(2); c: 8.467(2)
a: 4.451(1); c: 5.917(3)
a: 13.465(6); c: 8.472(4)
a: 4.425(3); c: 5.964(9)
a: 13.460(4); c: 8.473(3)
a: 4.455(3); c: 5.922(5)
a: 13.457(2); c: 8.467(2)
a: 4.456(1); c: 5.923(1)
{Au(PPh3)[N(iPr2PTe)2}
300
350
AuTe2
a: 8.76(1); b: 4.41(5); c: 10.15(1) a: 8.75(1); b: 4.403(2); c: 10.157(9)
b: 125.200(2) b: 125.15(1)
a: 8.76(1); b: 4.41(5); c: 10.15(1) a: 8.75(2); b: 4.406(3); c: 10.16(1)
AuTe2 + Au
b: 125.200(2)
a: 4.0786
b: 125.28(2)
a: 4.0779(3)
400
AuTe2 + Au
a: 8.76(1); b: 4.41(5); c: 10.15(1) a: 8.776(8); b: 4.401(3); c: 10.164(7)
b: 125.200(2)
a: 4.0786
b: 125.194(8)
a: 4.0773(5)
a: 4.0777(2)
400
450
Au
a: 4.0786
AuTe2 + Au
a: 8.76(1); b: 4.41(5); c: 10.15(1) a: 8.77(1); b: 4.409(2); c: 10.17(1)
b: 125.200(2)
a: 4.0786
b: 125.24(1)
a: 4.0786(2)
a: 4.0778(3)
450
500
Au
a: 4.0786
AuTe2 + Au
a: 8.76(1); b: 4.41(5); c: 10.15(1) a: 8.74(2); b: 4.416(3); c: 10.15(1)
b: 125.200(2)
a: 4.0786
a: 4.0786
b: 125.04(2)
a: 4.0799(4)
a: 4.0799(4)
500
Au
Fig. 6 SEM images of copper telluride films deposited at (a) 300 ◦C, (b) 350 ◦C, (c) 400 ◦C, (d) 450 ◦C and (e) 500 ◦C.
1532 | Dalton Trans., 2007, 1528–1538
This journal is
The Royal Society of Chemistry 2007
©

View Article Online
the range 300–500 ◦C with a dynamic argon flow rate of 140 sccm
for 60 min. Substrate temperatures below 300 ◦C were too low
to initiate deposition. The XRD pattern of as-deposited samples
indicated the formation of both Te (JCPDS 36-1452) and Ag7Te4
(JCPDS 18-1187) (Fig. 7). The presence of hexagonal Te was
revealed by its characteristic diffraction peaks from the primary
reflections of 2h at 23.05◦, corresponding to the (100) plane, and
additional reflections of 2h at 38.30, 40.45, 46.05, 49.8 and 57.05◦
for the (102), (110), (003), (201) and (202) planes, respectively. The
observation of above-mentioned diffraction peaks at high depo-
sition temperatures confirms the presence of Te. Two additional
peaks at 2h values of 27.05 and 43.45◦ correspond with both Te and
Ag7Te4. The refined cell parameters of the deposited films indicate
slight deviations from literature unit cell values as a consequence
of phosphorus doping (Table 4). The presence of both Te and
Ag7Te4 is supported by SEM/EDAX studies (Fig. 8). The SEM
analysis shows heterogeneous growth occurring at 300 ◦C. The
formation of micron-size tellurium tubes along with truncated
hexagonal plates and spheres of Ag7Te4 is observed. The selected
area electron diffraction (SAED) pattern embedded in Fig. 8(b)
confirms the single crystallinity of the resulting hexagonal plates.
The EDAX analysis on the tubes confirms the presence of only
tellurium whereas EDAX on the plates and spheres shows 50%
silver, 39% tellurium and 10% phosphorus.
Fig. 7 XRD pattern of Ag7Te4 films deposited at (a) 300 ◦C, (b) 350 ◦C,
(c) 400 ◦C, (d) 450 ◦C and (e) 500 ◦C. The additional diffraction peaks are
identified as Te (*) and Ag7Te4 and Te (ꢀ).
As the deposition temperature is increased (350–450 ◦C), only
spherical particles are observed in SEM (Fig. 8(c) and 8(d)).
The EDAX indicates silver-deficient (∼22%) and tellurium-rich
(∼72%) films with trace amounts of phosphorus (∼6%). The phos-
phorus impurity could be due to incomplete decomposition of 6
at these deposition temperatures. At 450–500 ◦C, agglomerations
of spheres with uneven surfaces are evident. Similarly, at 500 ◦C,
EDAX analysis indicates high tellurium content within the films
without any phosphorus contamination. The tellurium-rich films
are a consequence of the formation of a mixture of both Te and
Ag7Te4. The possible evaporation of silver from the sur◦face of
films at higher temperatures cannot be ruled out. At 500 C, the
absence of phosphorus contamination in the films is possibly due
to rupturing of P–Te bonds. The surface of the spheres can also
be etched by treating the film deposited at 500 ◦C with 0.5 M
HCl for 30 s. The compactness of the interior of the spheres is
clearly evident. No obvious correlation between the sphere size
and deposition temperatures is found. The calculated sphere sizes
are 1.52 lm (300 ◦C), 2.88 lm (350 ◦C), 2.12 lm (400 ◦C), 1.24 lm
(450 ◦C) and 1.61 lm (500 ◦C).
Gold telluride thin films are deposited from Au(PPh3)-
[N(iPr2PTe)2] (7) on glass with an argon flow rate of 160 sccm
◦
◦
between 300–500 C for 60 min. At 300–350 C, only grey films
Fig. 8 SEM images of Ag7Te4 films deposited at (a) and (b) 300 ◦C, (c) 350 ◦C, (d) 400 ◦C, (e) 450 ◦C and (f) 500 ◦C. The inset in (b) shows the SAED
of truncated hexagonal plates. The inset in (f) shows the morphology of the film at 450 ◦C after etching.
This journal is
The Royal Society of Chemistry 2007
Dalton Trans., 2007, 1528–1538 | 1533
©

View Article Online
Fig. 10 A typical XRD pattern of a gold film deposited at 450 ◦C.
Fig. 9 A typical XRD pattern of monoclinic AuTe2 film deposited at
300 ◦C.
the precursor inlet (Fig. 10). No appreciable difference is found in
the calculated unit cell parameters of either the AuTe2 or the Au
films (Table 4). At deposition temperatures >350 ◦C, formation of
individual gold particles along with AuTe2 is due to the depletion
of tellurium under CVD conditions. Also gold has a high affinity
for tellurium due to its soft character, resulting in formation
of AuTe2 followed by Au particles. More recently, the AACVD
technique has been employed for the fabrication of metallic gold
nanoparticles as thin films from a colloidal gold precursor.34
The SEM studies (Fig. 11) show that the films grown at 300 and
350 ◦C have poor film coverage, consisting of granules with broad
were deposited, whereas at higher temperatures (400–500 ◦C),
a mixture of grey and pinkish films was formed. All the films
were found to be non-adherent to the substrate. The XRD
◦
studies of films grown at 300 C exclusively show the formation
of monoclinic AuTe2 (Calaverite, JCPDS 75-1416) (Fig. 9). A
mixture of monoclinic AuTe2 and cubic Au (JCPDS 04-0784) was
deposited at 350 ◦C as observed by XRD. At growth temperatures
400–500 ◦C, two types of deposits were observed: a mixture of
monoclinic AuTe2 and Au film closest to the precursor inlet (cooler
part of the reactor) and only a cubic Au film further away from
Fig. 11 SEM images of (i) AuTe2 films deposited at (a) 300 ◦C, (b) 350 ◦C; (ii) a mixture of AuTe2 and Au particles formed at (c) 400 ◦C, (e) 450 ◦C, (g)
500 ◦C and (iii) pure Au particles deposited at (d) 400 ◦C, (f) 450 ◦C and (h) 500 ◦C. The inset in (f) shows the SAED pattern of gold nanoparticles at
400 ◦C.
1534 | Dalton Trans., 2007, 1528–1538
This journal is
The Royal Society of Chemistry 2007
©

View Article Online
distribution of sizes and morphologies. The EDAX analysis shows
gold-deficient (∼30–31%) and tellurium-rich (∼68–69%) films
with traces of phosphorus. At 400–500 ◦C, the films are comprised
of micrometer-sized parallelepiped AuTe2 along with anisotropic
gold nanostructures. The gold films are composed of well-defined
faceted crystals including triangular, cubic and polyhedral parti-
cles. Some gold particles seem to be agglomerates of two, three,
or more smaller particles. In other places, two or more particles
can be observed in close proximity but not conjointed. Bare glass
substrate is also evident between the particles, indicating that less
than one monolayer has been deposited. The SAED pattern of
gold particles (inset in Fig. 11(f)) indicated a (102) spot which is
generally not found in the face-centered cubic (FCC) system of
gold. However, this extra reflection is expected for a hexagonal
closed-packed (HCP) system of the metals. This can be attributed
to the faulted regions arising from the dislocations caused by a slip
in the (111) family of planes.35 The EDAX analysis on AuTe2 shows
32–37% gold and 63–68% tellurium depending on growth temper-
atures. The purity of the gold films was also confirmed by the
EDAX.
used to deposit crystalline copper, silver, gold telluride and
gold films by AACVD. As-deposited copper and silver telluride
films are contaminated with tellurium and phosphorus, whereas,
compound 7 yields AuTe2 and Au films along with traces of
phosphorus depending on the growth temperature. The deposited
films show varied morphologies, namely hexagons and sheets for
copper telluride films, truncated hexagons and spheres for silver
telluride films, micrometre-sized parallelepiped gold telluride films
and polydispersed gold nanoparticles.
Experimental
Reagents and general procedures
All reactions and the manipulations of products were performed
under an argon atmosphere using standard Schlenk techniques or
in an inert-atmosphere glove box. The solvent THF was dried by
distillation over Na/benzophenone under a nitrogen atmosphere
prior to use. The reagents Na[N(R2PTe)2](tmeda) (4a, R = Ph:
i
4b, R = Pr) were prepared by the literature procedures.19,20
It is well known that spherical gold nanoparticles exhibit a
surface plasmon absorption band around at 520 nm.36 Fig. 12
shows UV-Vis absorption spectra of the gold films at 400–500 ◦C,
with a broad red shift at 554 nm, indicating high polydispersity,
both in size and shape, which implies quite a broad range of
possible resonance frequencies.
The reagents CuCl, AgI, AuCl and PPh3 were obtained from
commercial sources and used as received.
Elemental analyses were performed by Analytical Services,
Department of Chemistry, University of Calgary.
Spectroscopic methods
The 1H, 31P and 125Te NMR spectra were obtained in d8-THF on
a Bruker DRX 400 spectrometer operating at 399.592, 161.765
and 126.082 MHz, respectively. 1H NMR spectra were referenced
to the solvent signal and the chemical shifts are reported relative
to Me4Si. 31P NMR spectra were referenced externally to an 85%
solution of H3PO4 and the chemical shifts are reported relative
to H3PO4. The 125Te NMR spectra were referenced externally to
a saturated solution of H6TeO6 and the 125Te chemical shifts are
reported relative to Me2Te [d(Me2Te) = d(H6TeO6) + 712].
Instrumentation
The TGA measurements were carried out by using a Seiko
Fig. 12 UV-Vis spectra of gold thin films grown at (a) 400 ◦C, (b) 450 ◦C
◦
SSC/S200 model under a heating rate of 10 C min−1 under
and 500 ◦C on glass using aerosol-assisted CVD.
nitrogen. The XRD studies were carried out using Cu-Ka
radiation on a Bruker AXS D8 Advance diffractometer. The
sample was mounted flat and was scanned between 10 to 80◦
in steps of 0.05 with a count time of 5.5 s. The films were carbon-
coated using Edward’s E306A coating system before carrying out
SEM analyses. SEM analyses were performed using a Philips XL
30FEG instrument, whereas EDAX was carried out using a DX4
instrument. TEM analyses were conducted on a Philips CM200,
200KV DX4EDS. The sample was briefly sonicated in ethanol,
which produces a suspension and then a drop of the suspension
was placed on a TEM grid and allowed to dry.
Conclusions
Copper, silver and gold complexes of the ditelluroimidodiphosphi-
nate ligand have been synthesized and structurally characterized.
These are rare examples of coinage metal complexes of a telluride
ligand. When compared to the corresponding dithio and diseleno
ligands, the larger tellurium donors, and longer metal–tellurium
bonds, impart a greater deal of flexibility to the structures that
are observed. In particular, larger ring sizes are observed for
the silver(I) complexes, also allowing both tellurium atoms of
the ditelluro ligand to function in bridging modes. The coinage
metal centers are brought closer together in the solid state and
in the tetrameric silver complex 8, this results in metallophilic
(d10–d10) interactions. The compounds 5, 6 and 7 have been
Deposition of thin films
The precursor (0.10 g) was dissolved in toluene (10 to 20 mL)
in a round-bottom flask and the deposition was carried out for
60 or 90 min. Argon was used as a carrier gas with flow rates
This journal is
The Royal Society of Chemistry 2007
Dalton Trans., 2007, 1528–1538 | 1535
©

View Article Online
of 140 or 160 sccm for the deposition. The argon flow rate was
controlled by a Platon flow gauge. Seven glass substrates (approx.
1 × 3 cm) were placed inside the reactor tube and they were
annealed at the desired temperature for 15 min before carrying
out the deposition. The precursor solution in a round-bottom
flask was kept in a water bath above the piezoelectric modulator
of a PIFCO ultrasonic humidifier (model no. 1077). The aerosol
droplets of the precursor thus generated were transferred into the
hot wall zone of the reactor by carrier gas. The reactor was placed
in a Carbolite furnace. After each CVD run, the reactor was cooled
to room temperature under an inert atmosphere.
For crystallographic data in CIF or other electronic format see
DOI: 10.1039/b617429a
Synthesis of {Cu[N(iPr2PTe)2]}3 (5). The reagent Na(tmeda)-
[N(iPr2PTe)2], (Na4b), was prepared by using a modification of the
literature procedure.20 A solution of Na4b (1.286 g, 2.00 mmol)
in THF (15 mL) was added slowly to a suspension of CuCl
(0.200 g, 2.00 mmol) in THF (10 mL) at −78 ◦C. The mixture
was stirred for 1 h to give a bright yellow cloudy reaction mixture.
The precipitate was removed by filtration, and the solvent was
removed in vacuo. The resulting yellow solid was washed with cold
hexane (5 mL) and dried in vacuo (0.842 g, 1.48 mmol, 74%). X-
Ray quality crystals were grown from a concentrated solution in
hexane. Mp 73◦◦C (dec.), 134–136 ◦C melts to a red oil. NMR data
(300 MHz, 23 C, C4D8O): 1H d 2.12–2.05 (m, 2 H, -CH(CH3)2),
X-Ray crystallography
A suitable crystal of the complex was coated with Paratone oil,
mounted on a thin glass fibre and frozen in the cold nitrogen
stream of the goniometer. Data were collected at 173(2) K on
a Nonius CCD-four circle Kappa FR540C diffractometer using
1
1.29–1.16 (m, 12 H, -CH(CH3)2); 31P d 26.8 (s, JP-Te 1310 Hz);
125Te d −686 (d, 1JP-Te 1315 Hz). Analytical data were obtained on
a sample that was recrystallized from THF. Anal. Calc. (%) for
C44H100Cu3N3P6O2Te6: C 28.64, H 5.46, N 2.28. Found: C 28.56,
H 5.61, N 2.57.
˚
graphite-monochromated Mo-Ka radiation (k = 0.71073 A) with
u and x scans. The unit-cell parameters were calculated and
refined from the full data set. Data reduction was performed by
using Nonius HKL DENZO and SCALEPACK software.37 An
absorption correction was applied to the data (SCALEPACK).37
The structures were solved by direct methods and Patterson
(SHELXS-97)38 and refined by a full-matrix least squares method
based on F2 using SHELXL-97.39 Except as mentioned below, all
non-hydrogen atoms were refined anisotropically. Hydrogen atoms
were calculated geometrically and were riding on their respective
atoms. Thermal ellipsoid plots were generated using the program
XSHELL (SHELXTL-97).39
Synthesis of {Ag[N(iPr2PTe)2]}6 (6). A clear yellow solution
of (Na4b) (1.929 g, 3.00 mmol) in THF (20 mL) was added slowly
to a suspension of AgI (0.702 g, 3.00 mmol) in THF (20 mL),
wrapped in foil, at 23 ◦C. The mixture was stirred for 1 h to give
a clear pale yellow solution. The solvent was removed in vacuo
and the resulting yellow solid was redissolved in toluene (20 mL).
The NaI by-product was removed by filtration. The clear yellow
solution was reduced to dryness in vacuo and diethyl ether (10 mL)
was added. Removal of the diethyl ether in vacuo yielded a yellow
crys◦talline solid (1.243 g, 2.03 mmol, 68%). Mp 134◦◦C (dec.), 152–
154 C melts to a red oil. NMR data (300 MHz, 23 C, C7D8): 1H d
1.96–1.84 (m, 2 H, -CH(CH3)2), 1.23–1.12 (m, 12 H, -CH(CH3)2);
In compound 9 there was a two-part disorder of the phenyl
ring attached to P3 and the thermal parameters were best refined
by using a 50 : 50 mixture and mild restraints. The structure
includes two molecules of lattice THF for each tetramer. These
were modeled over two positions, refining best as a 50 : 50 mixture.
Crystallographic data are summarized in Table 5.
1
1
31P d 26.2 (s, JP-Te 1294 Hz); 125Te d −771 (d, JP-Te 1290 Hz).
Anal. Calc. (%) for C72H168Ag6N6P12Te12: C 23.57, H 4.62, N 2.29.
Found: C 23.71, H 4.20, N 2.49.
CCDC reference numbers 612707–612711.
Table 5 Selected crystal data, data collection and refinement parameters for complexes 5–8
5
6
7
8
Formula
Formula weight
C36H84Cu3N3P6Te6
1701.10
P1
C72H168Ag6N6P12Te12
3668.18
P1
C30H43AuNP3Te2
962.73
P2(1)/n
8.656(2)
43.228(9)
9.907(2)
90
113.36(3)
90
3403(1)
4
C104H96Ag4N4O2P8Te8
3133.89
P1
¯
¯
¯
Space group
˚
a/A
14.007(3)
14.424(3)
16.538(3)
83.97(3)
76.89(3)
62.51(3)
2886.8(13)
2
14.514(3)
14.799(3)
16.306(3)
72.73(3)
67.47(3)
69.23(3)
2972.1(13)
1
10.580(2)
15.079(3)
17.761(4)
98.44(3)
100.97(3)
103.11(3)
2655.3(11)
1
˚
b/A
˚
c/A
a/◦
b/◦
c /◦
3
˚
V/A
Z
d
calc/g cm−3
1.957
4.260
2.049
4.053
1.879
6.164
1.960
3.050
l/mm−1
F(000)
Reflections collected
1620
55172
1728
54940
1832
33665
1488
18045
Independent reflections (Rint
)
10186 (0.0407)
0.0511
0.1445
10470 (0.0692)
0.0457
0.0956
5774 (0.070)
0.0387
0.1117
9349 (0.0257)
0.0359
0.0971
R
wR
1536 | Dalton Trans., 2007, 1528–1538
This journal is
The Royal Society of Chemistry 2007
©

View Article Online
Synthesis of Au(PPh3)[N(iPr2PTe)2] (7). A solution of PPh3
(0.262 g, 1.00 mmol) in THF (10 mL) was added to a stirred
suspension of AuCl (0.232 g, 1.00 mmol) in THF (10 mL)
at 23 ◦C. The yellow suspension immediately became a clear
colourless solution. The solution was cooled to −78 ◦C and
added dropwise to a stirred yellow solution of (Na4b) (0.643 g,
1.00 mmol) in THF (20 mL), also cooled to −78 ◦C, over 30 min.
The resulting clear orange solution was stirred at −78 ◦C for 1 h.
Fortin, F. M. Winnik and D. Maysinger, J. Mol. Med., 2005, 83, 377;
(e) T. J. Boyle, S. D. Bunge, T. M. Alam, G. P. Holland, T. J. Headley
and G. Avilucea, Inorg. Chem., 2005, 44, 1309; (f) T. Nakashima and T.
Kawai, Chem. Commun., 2005, 1643.
2 (a) S. S. Garje, D. J. Eisler, J. S. Ritch, M. Afzaal, P. O’Brien and
T. Chivers, J. Am. Chem. Soc., 2006, 128, 3120; (b) W. Wang, B.
Poudel, J. Yang, D. Z. Wang and J. F. Ren, J. Am. Chem. Soc.,
2006, 128, 3120; (c) J.-P. Ge and Y.-D. Li, J. Mater. Chem., 2003, 13,
911.
3 R. Coustal, J. Chim. Phys. Phys.–Chim. Biol., 1958, 38, 277.
4 C. J. Warren, R. C. Haushalter and A. B. Bocarsly, J. Alloys Compd.,
1995, 229, 175.
5 A. N. Gleizes, Chem. Vap. Deposition, 2000, 6, 155.
6 H. B. Singh and N. Sudha, Polyhedron, 1996, 15, 745.
7 C. Nascu, I. Pop, V. Ionscu, E. Indra and I. Bratu, Mater. Lett., 1997,
32, 73.
8 M. A. Korzhuev, Phys. Solid State, 1998, 40, 217.
9 H. M. Pathan, C. D. Lokhande, D. P. Amalnerkar and T. Seth, Appl.
Surf. Sci., 2003, 218, 290.
10 M. Kobayashi, K. Ishikawa, F. Tachibana and H. Okazaki, Phys. Rev.
B, 1988, 38, 3050.
11 L. Zhang, Z. Ai, F. Jia, L. Liu, X. Hu and J. C. Yu, Chem.–Eur. J., 2006,
12, 4185.
◦
The reaction solution was warmed slowly to 23 C over 1 h and
changed to a dark red colour. The solvent was removed in vacuo
to give an oily red solid. The product was dissolved in diethyl
ether (30 mL) and filtered to remove NaCl. The s◦olution was
reduced in volume to ca. 20 mL and stored at −18 C for 24 h,
yielding a yellow crystalline solid. The solution was decanted and
the product was washed with cold n-hexane (1 × 5 mL) (0.620 g,
0.64 mmol, 64%). X-Ray quality crystals were grown from a diethyl
◦
◦
eth◦er solution at 23 C. Mp 148–150 C. NMR data (300 MHz,
1
23 C, C7D8): H d 7.62–7.69 (m, 6 H, -P(C6H5)3), 7.02–7.00 (m,
9 H, -P(C6H5)3), 1.77–1.71 (m, 4 H, −CH(CH3)2), 1.21–1.08 (m,
12 (a) A. Schmidpeter, R. Bohm and H. Groeger, Angew. Chem., Int. Ed.
Engl., 1964, 3, 704; (b) A. Schmidpeter and K. Stoll, Angew. Chem.,
Int. Ed. Engl., 1967, 6, 252; (c) A. Schmidpeter and K. Stoll, Angew.
Chem., Int. Ed. Engl., 1968, 7, 549.
13 P. Bhattacharyya, A. M. Z. Slawin, D. J. Williams and J. D. Woollins,
J. Chem. Soc., Dalton Trans., 1995, 2489.
1
i
24 H, -CH(CH3)2); 31P d 23.2 (s, JP-Te 1348 Hz, Pr2PTe), 37.5
(broad s, PPh3); 125Te d −642 (d, 1JP-Te 1353 Hz). Anal. Calc. (%) for
C30H43AuNP3Te2: C 37.43, H 4.50, N 1.45. Found C 36.84, H 4.58,
N 1.46.
14 For a review, see: C. Silvestru and J. E. Drake, Coord. Chem. Rev., 2001,
223, 117.
Synthesis of {Ag[N(Ph2PTe)2]}4 (8). A yellow solution of
(Na4a) (0.778 g, 1 mmol) in THF (20 mL) was added dropwise
to a stirred suspension of AgI (0.235 g, 1 mmol) in THF (10 mL)
at −78 ◦C. The reaction mixture was allowed to warm to room
temperature and stirred for 2 h resulting in a bright orange
solution. A small amount of precipitate was formed which was
removed by filtration through Celite, to give a clear orange
solution. Reduction in volume of the solvent (approx. 5 mL) under
vacuum, addition of hexane (5 mL) and storage at 23 ◦C for 24 h,
resulted in a crop of bright orange crystals (0.540 g, 69%). Mp
dec. at 163 ◦C; brown oil formed at 235 ◦C. NMR data (300 MHz,
23 ◦C, C4D8O): 1H d 7.81–7.74 (m, 8 H, -P(C6H5)2), 7.24–7.22 (m,
12 H, -P(C6H5)2), 3.63–3.60 (m, 2 H, -C4H8O), 1.79–1.75 (m, 2
H, -C4H8O); 31P d −14.4 (s, 1JP-Te 1361 Hz). Carbon analyses were
consistently low by 2–3% possibly due to partial loss of lattice
THF molecules.
15 For a review, see: T. Q. Ly and J. D. Woollins, Polyhedron, 1998, 176,
451.
16 M. Afzaal, D. Crouch, M. A. Malik, M. Motevalli, P O’Brien, J.-H.
Park and J. D. Woollins, Eur. J. Inorg. Chem., 2004, 171.
17 D. J. Crouch, P. O’Brien, M. A. Malik, P. J. Skabara and S. P. Wright,
Chem. Commun., 2003, 1454.
18 M. Afzaal, D. J. Crouch, P. O’Brien, J. Raftery, P. J. Skabara, A. J. P.
White and D. J. Williams, J. Mater. Chem., 2004, 14, 233.
19 G. G. Briand, T. Chivers and M. Parvez, Angew. Chem., Int. Ed., 2002,
41, 3468.
20 T. Chivers, D. J. Eisler and J. S. Ritch, Dalton Trans., 2005, 2675.
21 T. Chivers, D. J. Eisler, J. S. Ritch and H. M. Tuononen, Angew. Chem.,
Int. Ed., 2005, 44, 4953.
22 A. J. Gaunt, B. L. Scott and M. P. Neu, Angew. Chem., Int. Ed., 2006,
45, 1638.
23 M. C. Copsey and T. Chivers, Chem. Commun., 2005, 39,
4938.
24 S. S. Garje, J. S. Ritch, D. J. Eisler, M. Afzaal, P. O’Brien and T. Chivers,
J. Mater. Chem., 2006, 966.
25 S. S. Garje, M. C. Copsey, M. Afzaal, P. O’Brien and T. Chivers,
J. Mater. Chem., 2006, 4542.
26 The formation of Au0 suggests that a redox process is occurring in this
reaction. It is likely that the reduction of Au1 to Au0 is accompanied
by oxidation of 4b to produce the dark red dimer (TePiPr2NiPr2PTe–)2,
known to form by the one-electron oxidation of 4b (ref. 21). A similar
redox couple has been observed in the reaction of 4b with group 13
halides (ref. 23).
Acknowledgements
Financial support from the University of Calgary and NSERC
(Canada) (TC and MCC), EPSRC (UK) (POB and MA) and
The University of Manchester (AP) is gratefully acknowledged.
The authors wish to thank Ms Judith Shackleton for help-
ful discussions of the XRD data and Dr P. Kyritsis (Uni-
versity of Athens) for communication of unpublished results
(ref. 27b).
27 (a) D. J. Birdsall, A. M. Z. Slawin and J. D. Woollins, Inorg. Chem.,
1999, 38, 4152; (b) D. Maganas, S. Parsons and P. Kyritsis, private
communication, 2006.
28 T. Chivers, M. Parvez and G. Schatte, Angew. Chem., Int. Ed., 1999, 38,
2217.
29 (a) M.-C. Brandys and R. J. Puddephatt, Chem. Commun., 2001, 1508;
(b) T. C. Deivaraj and J. J. Vittal, J. Chem. Soc., Dalton Trans., 2001,
329.
30 H. Bock, H. Scho¨del, Z. Havlas and E. Herrmann, Angew. Chem., Int.
Ed. Engl., 1995, 34, 1355.
References
31 F. Shaw III, Gold - Progress in Chemistry, Biochemistry and Technology,
ed. H. Schmidbaur, John Wiley and Sons, Chichester, 1999.
32 J. D. E. T. Wilton-Ely, A. Schier and H. Schmidbaur, Inorg. Chem.,
2001, 40, 4656.
1 For recent examples, see: (a) M.-O. Piepenbrock, T. Stimer, S. M. Kelly
and M. O’Neill, J. Am. Chem. Soc., 2006, 128, 7087; (b) Z. Tang, Y.
Wang, S. Shanbhag, M. Giersig and N. A. Kotov, J. Am. Chem. Soc.,
2006, 128, 6730; (c) M. V. Kovalenko, E. Kaufmann, D. Pachinger, J.
Roither, M. Huber, J. Stangl, G. Hesser, F. Scha¨ffler and W. Heiss, J. Am.
Chem. Soc., 2006, 128, 3516; (d) J. Lovric, H. S. Bazzi, Y. Cuie, G. R. A.
33 (a) P. J. Bonasia, D. E. Gindelberger and J. Arnold, Inorg. Chem.,
1993, 32, 5126; (b) D. M. Smith, L. C. Roof, M. A. Ansari,
J. M. McConnachie, J. C. Bollinger, M. A. Pell, R. J. Salm and
This journal is
The Royal Society of Chemistry 2007
Dalton Trans., 2007, 1528–1538 | 1537
©

View Article Online
J. A. Ibers, Inorg. Chem., 1996, 35, 4999; (c) J. Olkowska-Oetzel, P.
Serillano, A. Eichhofer and D. Fenske, Eur. J. Inorg. Chem., 2004,
1100.
37 Z. Otwinowski and W. Minor, HKL DENZO and SCALEPACK v
1.96: Processing of X-ray Diffraction Data Collected in Oscillation
Mode.
38 G. M. Sheldrick, SHELXS 97-2: Program for the Solution of Crystal
Structures, University of Go¨ttingen, Go¨ttingen, Germany, 1997.
39 G. M. Sheldrick, SHELXL 97-2: Program for the Refinement of Crystal
Structures, University of Go¨ttingen, Go¨ttingen, Germany, 1997.
34 R. G. Palgrave and I. P. Parkin, J. Am. Chem. Soc., 2006, 128,
1587.
35 K. Bahadur and P. V. Sastry, Proc. Phys. Soc., 1961, 78, 594.
36 S. Link and M. A. El-Sayed, J. Phys. Chem. B, 1999, 103, 8410.
1538 | Dalton Trans., 2007, 1528–1538
This journal is
The Royal Society of Chemistry 2007
©