Synthesis, structural characterization and luminescence studies of di- and trinuclear gold(I) alkynyl-phosphine complexes

Article abstract of DOI:10.1002/zaac.200900503

Reactions of the polymer (Au^IC₂Ph)_n with polyphosphine ligands [l,4-bis(2-diphenylphosphino-lH-imidazol-l-yl)-benzene (dpib), l,3,5-tris(4-diphenylphosphinophenyl)benzene (tppb), 2,2'-bis(diphenylphosphanyl)-4,4'-bipyridin

Full text of DOI:10.1002/zaac.200900503

ARTICLE
DOI: 10.1002/zaac.200900503
Synthesis, Structural Characterization and Luminescence Studies of Di- and
Trinuclear Gold(I) Alkynyl-phosphine Complexes
Igor O. Koshevoy,[a] Laura Koskinen,[a] Ekaterina S. Smirnova,[a,c] Matti Haukka,[a]
Tapani A. Pakkanen,[a] Alexei S. Melnikov,[b] and Sergey P. Tunik*[c]
Keywords: Polynuclear complexes; Akynyl ligands; Luminescence; Gold; NMR spectroscopy
Abstract. Reactions of the polymer {AuIC2Ph}n with polyphosphine li- 3, whereas none of these intermolecular bondings were found in the
gands [1,4-bis(2-diphenylphosphino-1H-imidazol-1-yl)-benzene (dpib), crystal structures of compounds 1, 2, and 4. Complexes 1–4 are lumines-
1,3,5-tris(4-diphenylphosphinophenyl)benzene (tppb), 2,2'-bis(diphenyl- cent both in solution (CH2Cl2) and in solid state under laser irradiation
phosphanyl)-4,4'-bipyridine
(dpbp),
and
3,6-bis(diphenylphos- (λex = 308 nm). In solution, the diphosphine complexes 1–4 display dual
phanyl)pyridazine (dppz)] afforded four gold(I) alkynyl-polyphosphine emission corresponding to ligand centered transitions (λem = 360–
complexes [{AuC2Ph}2(μ-dpib)] (1), [{AuC2Ph}3(μ3-tppb)] (2), 375 nm) along with weaker contribution from MLCT excited states at
[{AuC2Ph}2(μ-dpbp)] (3), and [{AuC2Ph}2(μ-dppz)] (4) in nearly quan- ca. 490 nm. The long wavelength component of the emission plays a
titative yield. The compounds obtained were characterized using ele- dominant role in the solid state luminescence spectra of complexes 1,
mental analysis, ESI-MS, X-ray crystallography, and polynuclear NMR 3, and 4 (460, 544, 520 nm, respectively) whereas the triphosphine com-
spectroscopy. Intermolecular aurophilic interaction together with π–π plex 2 shows dual luminescence (372 and 520 nm) with considerable
and σ–π stacking build up the supramolecular 3D network of complex contribution from ligand centered excited state.
phinophenyl)benzene (tppb), which contain extended aromatic
spacers between the coordinating phosphorus atoms. Four
Introduction
polynuclear gold(I) alkynyl-phosphine complexes based on
these ligands and on two other diphosphines reported earlier
[16, 17] were prepared and structurally characterized. Their
absorption and emission spectra were studied and compared
with those of the closely analogous mononuclear gold(I) al-
kynyl-phosphine compounds.
Synthesis, molecular structure, and reactivity of gold(I) al-
kynyl-phosphine complexes attract growing attention because
of their unique photophysical properties [1–11] and ability to
build up supramolecular polynuclear ensembles based on
auro(metallo)philic interaction [5, 6, 12–15]. These polymetal-
lic aggregates are very often stabilized by bridging ligands of
various natures, of which polyphosphines are most widely
used. Chemical and physical properties of the resulting com-
pounds are determined to a large extent by the nature of bridg-
ing ligands, their electronic and, particularly, steric characteris-
tics, which play a decisive role in the design of supramolecular
architecture.
Results and Discussion
Synthesis of Phosphine Ligands
Two novel phosphine ligands: 1,4-bis(2-diphenylphosphino-
1H-imidazol-1-yl)-benzene (dpib) and 1,3,5-tris(4-diphenyl-
phosphinophenyl)benzene (tppb), have been synthesized by re-
In the present communication we report the synthesis of two
di- and triphosphine ligands: 1,4-bis(2-diphenylphosphino-1H-
imidazol-1-yl)-benzene (dpib) and 1,3,5-tris(4-diphenylphos-
* Dr. S. P. Tunik
Fax: +7-812-4286939
E-Mail: stunik@inbox.ru
[a] Department of Chemistry
University of Joensuu
Joensuu, 80101, Finland
[b] Department of Physics
St.-Petersburg State University
Ulijanovskaja 3
198504, St. Petersburg, Russia
[c] Department of Chemistry
St.-Petersburg State University
Universitetskii pr. 26
198504, St.-Petersburg, Russia
Scheme 1. Synthesis of phosphine ligands (dpib) and (tppb).
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I. O. Koshevoy, S. P. Tunik et al.
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action of the corresponding organic precursors with n-BuLi gold alkynyl-phosphine complexes in nearly quantitative yield
followed by addition of the corresponding amount of Ph2PCl (Scheme 2).
(Scheme 1) in moderate and excellent yield, respectively.
The solid state structures of the compounds obtained were
Composition and structure of these compounds were estab- established using X-ray crystallography, crystal data are sum-
lished using elemental analysis and 1H-NMR spectroscopy. marized in Table 1. ORTEP views of the molecular structures
The data obtained (see Experimental Section) are in complete of complexes 1–4 are shown in Figure 1, Figure 2, Figure 3,
agreement with the structures shown in Scheme 1.
and Figure 4, the main structural parameters are given in cap-
tions to the figures.
Synthesis and Structural Characterization of Complexes 1–4
Reactions of phenylacetylene-gold polymer with a stoichio-
metric amount of di(tri)-phosphines afford di- and trinuclear
Figure 1. ORTEP view of the structure of 1. Selected structural param-
eters: Au(1)–C(1) 2.001(4) Å, Au(1)–P(1) 2.2712(9) Å, C(1)–C(2)
1.202(5) Å,
178.19(10)°.
C(2)–C(1)–Au(1)
175.0(3)°,
C(1)–Au(1)–P(1)
In the obtained complexes the phosphine ligands bridge two
(1, 3, 4) and three (2) AuI atoms, which are also bound to the
alkynyl ligands to give molecules with several chromophoric
gold(I) atoms. Coordination of the gold-alkynyl fragment to
Scheme 2. Synthesis of the gold complexes 1–4.
Table 1. Crystallographic data for complexes 1–4.
1
2
3
4
empirical formula
formula weight
temp /K
λ /Å
C52H38Au2N4P2
1174.74
C91H68Au3P3
1845.26
120(2)
0.71073
Monoclinic
P21/c
C62H50Au2N2OP2
1294.91
120(2)
C44H32Au2N2P2
1044.59
120(2)
100(2)
0.71073
0.71073
Monoclinic
C2/c
0.71073
crystal system
space group
a /Å
Triclinic
Triclinic
¯
¯
P1
P1
8.3182(4)
10.6887(3)
12.1967(5)
88.373(2)
87.413(2)
85.265(2)
1079.28(7)
1
25.5244(5)
17.5430(4)
15.9046(3)
90
22.1340(11)
11.4410(7)
20.7580(8)
90
10.4098(7)
12.0023(5)
15.8675(14)
84.864(5)
77.967(5)
68.410(4)
1802.7(2)
2
b /Å
c /Å
α /°
β /°
91.4014(10)
90
99.707(3)
90
γ /°
V /Å3
7119.5(3)
4
5181.4(5)
4
Z
ρcalc /Mg m–3
μ(Mo-Kα) /mm–1
No. reflns.
Unique reflns.
GOOF (F2)
Rinat)
1.807
1.722
1.660
1.924
6.905
6.282
5.762
8.252
19103
78662
30312
34411
4928
12477
5927
8976
1.071
1.014
1.102
1.060
0.0404
0.0721
0.0626
0.1575
2 2
0.0518
0.0350
0.0724
0.0329
R1 (I ≥ 2σ)
0.0266
0.0226
b)
wR2 (I ≥ 2σ)
0.0521
0.0381
a) R1 = Σ--Fo-–-Fc--.Σ-Fo-.b) wR2 = [Σ[w(Fo –Fc ) ].Σ[w(Fo ) ]]1.2
.
2
2 2
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Di- and Trinuclear Gold(I) Alkynyl-phosphine Complexes
Figure 2. ORTEP view of the structure of 2. Selected structural param-
eters: Au(1)–C(13) 1.981(11) Å, Au(2)–C(51) 2.006(12) Å, Au(3)–
C(77) 1.988(15) Å, Au(1)–P(1) 2.269(3) Å, Au(2)–P(2) 2.277(3) Å,
Au(3)–P(3) 2.266(4) Å, C(1)–Au(1)–P(1) C13–Au1–P1 177.5(4)°,
C51–Au2–P2 175.5(3)°, C77–Au3–P3–179.6(5)°, C(14)–C(13)–Au(1)
178.9(12)°, C(52)–C(51)–Au(2) 169.2(11)°, C(78)–C(77)–Au(3)
173.9(14)°.
Figure 4. ORTEP view of the structure of 4. Selected structural param-
eters: Au(1)–C(1) 1.991(3) Å, Au(1)–P(1) 2.2613(9) Å, C(1)–C(2)
1.196(5) Å, C(1)–Au(1)–P(1) 175.6°, C(2)–C(1)–Au(1) 177.0(3)°.
Figure 3. (A) ORTEP view of the structure of 3. (B) 3D network formed by the molecules of 3 in the solid state. Selected structural parameters:
Au(1)–C(1) 1.995(5) Å, Au(1)–P(1) 2.2663(12) Å, C(1)–C(2) 1.203(7) Å, Au–Au 2.990(7) Å, C(2)–C(1)–Au(1) 174.2(4)°, C(1)–Au(1)–P(1)
174.69(14)°.
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I. O. Koshevoy, S. P. Tunik et al.
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the phosphorus functions of the bridging polyphosphine li- joined together to form an infinite zig-zag chain through auro-
gands to form di- and trinuclear complexes is the general struc- philic interaction with an intermolecular Au–Au distance of
tural motif of the studied molecules. The arrangement around 3.1361(9) Å [18].
the AuI atoms is expectedly very close to linear and gold to
The NMR spectroscopic data (see Experimental Section and
ligand bond lengths, Au–C(alkynyl) (1.981–2.006 Å), Au–P Figures S1–S3) show that in solution the complexes under
(2.2613–2.2770) Å, fall in the range typical for the other study are presented in their molecular form (including 3) and
gold(I) alkynyl-phosphine complexes, see for example [14, 18, the structures found in the solid state remain unchanged in
19]. Unusual zig-zag conformation of the molecule in complex solution. The 31P NMR spectra of compounds 1–4 display a
1 is very probably dictated by minimization of intramolecular singlet resonance in the area typical for the phosphines coordi-
hindrance between essentially nonlinear 1,2-substituted phe- nated to gold(I)-alkynyl fragments [5, 20] with a characteristic
nylene-bis(imidazole) spacer and phenyl substituents at the lowfield coordination shift relative to the starting phosphines.
phosphorus atoms.
Careful assignment of the proton spectra was performed on the
1
In compound 2, the aromatic rings of the 1,3,5-tris(4-phe- basis of H COSY experiments (Figures S1–S3) and compari-
nyl)benzene spacer are not coplanar in the crystal cell and evi- son of the data obtained with the previously reported spectro-
dently are able to rotate freely around single C–C bonds in scopic characteristics of closely analogous diphosphine-gold
solution that points to the lack of conjugation in this system complexes [5, 20]. In the H NMR spectra of compounds 1–4
and apparently makes all three gold(I) atoms independent a set of high field resonances (7.50–7.25 ppm), which repre-
1
1
chromophores. The molecular conformation of compound 4 sent an “ortho-meta-para” combination according to the H
shown in Figure 4 is very similar to the structures found earlier COSY spectra, evidently belongs to the phenyl rings of the
[19, 20] for other diphosphines with linear 1,4-phenylene spa- alkynyl ligands. In turn a more complicated set of the low-
cers. Free rotation around single P–C bond between the phos- field signals (8.90–7.2 ppm) displays 2D connectivity and 31P–
phorus atom and the phenylene spacer of the diphosphine is 1H coupling constants corresponding to the protons of phenyl
allowed. It is evident that because of structural constraints rings and spacers of the phosphine ligands. Relative intensities
none of the complexes under study is able to form intramolecu- and multiplicities of the signals fit well the molecular struc-
lar aurophilic bonds, which were found earlier for molecules tures found in the solid state.
of this sort [21, 14, 22] on the basis on the polyphosphine
The UV.Vis spectra of complexes 1–4 in CH2Cl2 (Table 2)
backbones, which can bring the gold atoms into positions fa- display quite similar spectroscopic patterns in the near UV re-
vorable for AuI–AuI bond formation. The structures of com- gion (230–300 nm). All spectra show strong absorption bands
pounds 1, 2, and 4 do not display intermolecular aurophilic in the range 265–285 nm together with higher energy (HE)
interactions [13, 23] and make possible formation of either UV absorption at shorter wavelength. The former bands are
molecular dimers [20, 24–27] or solid state supramolecular usually assigned to the transition from σ(Au–P) orbital to an
structures [18]. In contrast to the structures of compounds 1, empty π* antibonding orbital centered at aryl fragments of ei-
2, and 4, the crystal packing of complex 3 results in formation ther phosphine or alkynes, whereas HE absorption is associ-
of an infinite “staircase-like” chain of the molecules bound to ated with π–π* intraligand transitions in this type of com-
each other through AuI–AuI bonds (2.99 Å) and face-to-face plexes [2, 14, 19, 28]. The tails of lower energy bands extend
interaction between 1,4-bpy spacers and phenyl rings of the down to 370 nm and may mask very weak absorption origi-
alkynyl ligands as shown in Figure 3, (B). These aromatic sys- nated from metal centered electronic transitions.
tems are nearly coplanar with distances of 4.2–4.5 Å between
Excitation of complexes 1–4 with λex = 308 nm both in solid
the corresponding planes. This observation clearly points to π- state and in solution showed relatively weak blue-green lumi-
stacking interaction, which strengthens bonding in the molecu- nescence (see Figure 5 and Table 2). In dichloromethane solu-
lar chain. Moreover, these chains are additionally linked to tion (Figure 5 B) all complexes show dual emission with the
each other through edge-to-face CH-π interactions to form a more intense short wavelength component at 375.5, 360,
3D network. This structural motif looks very similar to the 375.5, 377 nm for 1–4, respectively. The less intensive long
supramolecular design of the crystal structure of Me3P–Au– wavelength component is substantially redshifted to appear at
C2{C6H2Me2}C2–Au–PMe3, in which individual molecules are ca. 490 nm. A similar type of dual luminescence behavior was
Table 2. Spectroscopic data of 1–4 in degassed CH2Cl2 and in solid state at 298 K.
Complex
λabs .nm (10–5ε .cm–1·m–1)
λem .nm (λex = 308 nm)
1
2
3
4
solution
solid state
solution
solid state
solution
solid state
solution
solid state
256sh (0.65), 268.5 (0.68), 282 (0.52)
375.5, 491
421, 442, 451, 462, 487
360, 490
371.5, 520
375.5, 491
544
270.5 (1.1), 282.5 (1.1)
239 (5.2), 270 (3.4), 282 (3.3)
282sh (1.9), 238 (2.7), 269 (2.2)
377, 491
520
798
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Di- and Trinuclear Gold(I) Alkynyl-phosphine Complexes
already found for analogous gold(I) alkynyl-polyphosphine
In the case of linear diphosphine complex PhC2Au–Ph2P–
complexes: (PhC2Au-)(dppe) [24], PhC2Au–Ph2P–C6H4PPh2– C6H4PPh2–Au–C2Ph [19], the low energy emission band was
Au–C2Ph [19], and {PhC2Au-}4[1,4,8,11-tetra(diphenylphos- assigned to σ(Au–P)/π*(Arbridge) transitions localized onto
phinomethyl)-1,4,8,11-tetraazacyclotetradecane] [27] in di- aryl moieties of the bridging phosphine ligand. However, in
chloromethane solution. In these cases the higher energy emis- the case of (PhC2Au-)(dppe) [24], and the tetranuclear gold-
sion was assigned to π/π* intraligand excited states in the tetraphosphine complex {PhC2Au-}4[1,4,8,11-tetra(diphenyl-
aromatic rings of phenylalkynyl and phosphine ligands.
phosphinomethyl)-1,4,8,11-tetraazacyclotetradecane]
[27],
Figure 5. Emission spectra of complexes 1–4 in solid state (A) and in CH2Cl2 solution (B) at 25 °C, λex = 308 nm.
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I. O. Koshevoy, S. P. Tunik et al.
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which show intramolecular aurophilic contacts, the long wave- complete involvement of the central gold atoms into aurophilic
length emission can be assigned to the triplet state (dδ*)1(pσ)1 interaction.
localized onto the orbitals responsible for intramolecular
Au–Au bonds [24] or for the formation of oligomeric auro-
Experimental Section
philic aggregates [27]. This suggestion is strongly supported
by the concentration dependence of relative intensities of the
low (560 nm) and high (425 nm) energy emission bands in the
dichloromethane solution of the latter compound [27], which
display substantial growth of the low energy emission compo-
nent with an increase in the complex concentration. This ex-
perimental observation is in agreement with the system de-
scription, which includes formation of supramolecular
aggregates supported by aurophilic interactions between the
molecules under study and a shift of the reaction equilibrium
to the aggregation at higher complex concentrations. More-
General Comments
Au(tht)Cl (tht = tetrahydrothiophene) [29], (AuC2Ph)n [30], 2,2'-bis(di-
phenylphosphanyl)-4,4'-bipyridine (dpbp) [16], 3,6-bis(diphenylphos-
phanyl)pyridazine (dppz) [17], 1-[4-(1H-imidazol-1-yl)phenyl]-1H-
imidazole [31], and 1,3,5-tris(4-bromophenyl)benzene [32] were syn-
thesized according to published procedures. Preparation of the phos-
phines was carried out in a nitrogen atmosphere. Tetrahydrofurane was
distilled over Na-benzophenoneketyl in a nitrogen atmosphere prior to
1
use. Other reagents and solvents were used as received. Solution H,
13C, and 31P NMR spectra were recorded with Bruker Avance 400
over, for the alkynyl-polyphosphine complexes containing in- and Bruker DPX 300 spectrometers. The chemical shifts .ppm were
referenced to residual solvent resonances and external 85 % H3PO4 in
the 1H, 13C, and 31P spectra, respectively. The 2D COSY spectra were
run using standard Bruker pulse sequence. Microanalyses were carried
out in the analytical laboratory of St.-Petersburg State University. UV.
Vis spectra were recorded with a Shimadzu UV 3600 spectrophotome-
ter.
tramolecular aurophilic bonds, one can observe the only low
energy emission in the 500–750 nm range [28]. For complexes
1–4, the formation of aurophilic supramolecular aggregates in
solution looks hardly probable for 1, 2, and 4 and the weak
low energy emission bands should be assigned to
σ(Au–P)/π*(Arbridge) excited states. In the case of complex
3, the solid-state structure of this complex points to the possi-
bility to form supramolecular aurophilic bonding additionally
supported by π–π and π–σ stacking. Thus, the origin of the
long wave length emission for 3 (which is very similar to that
observed in the solid state samples) can be assigned either to
σ(Au–P)/π*(Arbridge) excited states or to the transitions lo-
calized inside aurophilic {Au2} fragments, similar to the as-
signment made in the earlier works [24, 27].
Solid state emission spectra of compounds 1–4 are shown in
Figure 5 A. Complex 1 displays strong emission in the range
400–600 nm, which can be interpreted as a combination of a
vibronic-structured band between 400 and 500 nm and long
wavelength shoulder with the maximum at ca. 500 nm. Vibra-
tional progression spacing of ca. 1000 nm may be interpreted
as metal perturbed vibrational spectrum of excited state aro-
matic moieties in 1 that is completely in line with the assign-
ment of this emission to π / π* intraligand excited states
analogously to the interpretation of solution luminescence
given above. Similarly, the low energy shoulder in this emis-
sion spectrum can be assigned to σ(Au–P) / π*(Arbridge) ex-
cited states. The trinuclear complex 2 displays unstructured
dual emission with short and long wavelength components
centered at 371 and ca. 520 nm, respectively, in solid state.
Their assignment is evidently analogous to that one for emis-
sion bands observed for complex 1. In contrast to compounds
Synthesis
1,4-Bis(2-diphenylphosphino-1H-imidazol-1-yl)-benzene (dpib): 1-
[4-(1H-imidazol-1-yl)phenyl]-1H-imidazole (1 g, 4.76 mmol) was sus-
pended in THF (100 cm3), the mixture was cooled to –78 °C and a
1.6 m solution of n-BuLi in hexane (8 cm3, 12.8 mmol) was added
within 5 min. The orange mixture was stirred below –70 °C for 1.5 h.
Afterwards, neat PPh2Cl (2.6 g, 11.8 mmol) was added dropwise. The
reaction mixture was stirred at this temperature for further 1 h and was
afterwards slowly warmed to room temperature and left overnight
whilst stirring. The reaction was quenched by addition of solid NH4Cl.
Afterwards, the volatiles were evaporated, the orange-brown residue
was washed with methanol (3 ! 20 cm3), diethyl ether (10 cm3) and
dried. The crude product was extracted with CH2Cl2 (3 ! 10 cm3),
diluted with diethyl ether (3 cm3) and the solution was passed through
a layer of silica gel (70–230 mesh, 2 ! 5 cm). The solvents were
evaporated, the colorless solid was washed with methanol once again
and vacuum dried. Yield 1.3 g (47 %). Analytically pure sample was
obtained by recrystallization from CH2Cl2.hexane. Anal. C36H28N4P2:
calcd. C 74.73; H 4.88; N 9.68 %; found: C 74.65; H 4.92; N 9.70 %.
1
31P{1H} NMR (CDCl3): δ = –29.5 (s). H NMR (CDCl3): δ = 7.25
(s, -C6H4-, 4 H), 7.29 (dd, (-P-C3N2H2), 2 H, J(H-H) 1.2, J(P-H)
1.9 Hz), 7.33–7.38 (m, Ph, 12 H), 7.41 (d, (-P-C3N2H2), 2 H, J(H-H)
1.2 Hz), 7.42–7.49 (m, Ph, 8 H).
1,3,5-Tris(4-diphenylphosphinophenyl)benzene (tppb): 1,3,5-tris(4-
bromophenyl)benzene (1.55 g, 2.86 mmol) was dissolved in THF
1 and 2, the solid state luminescence spectra of complexes 3 (40 cm3), the solution was cooled down to –78 °C and a 1.6 m solution
of n-BuLi in hexane (7 cm3, 11.2 mmol) was added within 5 min. A
and 4 display only long wavelength bands at ca. 544 and ca.
pale suspension was formed and stirred below –70 °C for 2 h. After-
520 nm, respectively. In the case of complex 3, major contri-
bution of the low energy emission is probably related to the
wards, neat PPh2Cl (2.5 g, 11.3 mmol) was added dropwise. The re-
sulting yellow solution was stirred at this temperature for further 1 h
formation of a supramolecular structure, which is shown in
and slowly warmed to room temperature. The solution was left over-
Figure 3, where emission from π / π* intraligand excited
states is effectively quenched because of π-stacking and edge-
to-face CH-π interactions in the crystal cell. In turn, the low
energy emission ascribed to the transitions localized at the
night whilst stirring. Afterwards, the pale-yellow solution was filtered
and the solvents were removed under vacuo. The solid residue was
washed with methanol (3 ! 20 cm3), diethyl ether-hexane mixture
(1:2 v.v, 2 ! 15 cm3) and vacuum dried. A colorless solid was ob-
{Au2} fragment (see above) is relatively enhanced because of tained and dissolved in CH2Cl2 (ca. 50 cm3), passed through a layer
800
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Di- and Trinuclear Gold(I) Alkynyl-phosphine Complexes
of Silica (70–230 mesh, 2 ! 5 cm), diluted with hexane (20 cm3) and C50H36N2Au2P2: calcd. C 53.57; H 3.21; N 2.50 %; found: C 53.62;
evaporated to give microcrystalline product of sufficient purity. Yield
2.3 g (94 %). Analytically pure sample was obtained by a chromato-
graphic separation on Silica [3 ! 20 cm, eluent CH2Cl2-hexane (3:4, 5.0 Hz), 8.16 (m, 2 H, (P-(NC5H3)), J(H-P) 7.7, J (H-H) 1 Hz), 7.52
H 3.34; N 2.25 %. 31P{1H} NMR (CDCl3): δ = 42.2 (s). 1H NMR
(CDCl3): diphosphine: δ = 8.90 (d, 2 H, (P-(NC5H3), 2 H, J(H-H)
4
v.v)] and subsequent recrystallization from THF.methanol. Anal.
(m, 2 H, (P-(NC5H3)), 7.8 (m, ortho-H, (Ph-P), 8 H, J(H-H) 8.6, J(P-
H) 12 Hz), 7.26 (t, para-H, (Ph-P), 4 H, J(H-H) 7.6 Hz), 7.51 (m,
meta-H, (Ph-P), 8 H, J(H-H) 8.6, 7.6, J(P-H) 2 Hz); {Au(C2Ph)}2: δ =
7.50 (m, meta-H + ortho-H, 8 H), 7.26 (m, para-H, 2 H).
C60H45P3: calcd. C 83.91; H 5.24 %; found: C 83.03; H 5.43 %.
1
31P{1H} NMR (CDCl3): δ = –6.1 (s). H NMR (CDCl3): δ = 7.80 (s,
-C6H3-, 3 H), 7.67 (dd, meta-H, (-C6H4-P), 6 H, J(H-H) 8.2, J(P-H)
1.4 Hz), 7.43 (m, ortho-H, (-C6H4-P), 6 H, J(H-H), J(P-H) 8.0 Hz),
7.40–7.37 (m, Ph, 30 H).
[{AuC2Ph}2(μ-dppz)] (4): (AuC2Ph)n (110 mg, 0.369 mmol) was sus-
pended in CH2Cl2 (10 cm3). dppz (86 mg, 0.192 mmol) was added to
the suspension to give a colorless transparent solution within a few
minutes. It was diluted with toluene (10 cm3) and stirred for 30 min. in
the absence of light. The resulting solution was passed through Al2O3
(0.5 ! 2 cm, neutral, ≈ 150 mesh) and concentrated to ca 5 cm3. A
colorless microcrystalline solid was precipitated by centrifugation,
washed with toluene (5 cm3), diethyl ether (2 ! 5 cm3) and vacuum
dried. Yield: 182 mg (91 %). Analytically pure sample was obtained
by recrystallization from CH2Cl2.hexane at room temperature. Single
crystals of 4 suitable for X-ray analysis were grown by slow evapora-
tion of CH2Cl2.hexane solution at room temperature. Anal.
C44H32N2Au2P2: calcd. C 50.57; H 3.06; N 2.68 %; found: C 50.57;
H 3.41; N 2.61 %. 31P{1H} NMR (CDCl3): δ = 40.2 (s). 1H NMR
[{AuC2Ph}2(μ-dpib)] (1): (AuC2Ph)n (110 mg, 0.369 mmol) was sus-
pended in CH2Cl2 (20 cm3) and dpib (112 mg, 0.192 mmol) was
added to the reaction mixture. The yellow suspension turned into a
colorless transparent solution within a few minutes. The reaction mix-
ture was diluted with toluene (10 cm3) and stirred for 30 min in the
absence of light. The resulting solution was passed through Al2O3
(0.5 ! 2 cm, neutral, ≈ 150 mesh) and concentrated to ca. 5 cm3. A
colorless microcrystalline solid was precipitated by centrifugation,
washed with toluene (5 cm3), diethyl ether (2 ! 5 cm3) and vacuum
dried. Yield 212 mg (94 %). Single crystals of 1 suitable for X-ray
analysis were grown by slow evaporation of CH2Cl2.toluene solution
at room temperature. Anal. C50H38N4Au2P2: calcd. C 52.17; H 3.30;
N 4.87 %; found: C 52.07; H 3.45; N 4.71 %. 31P{1H} NMR (CDCl3):
3
(CDCl3): diphosphine: δ = 7.95 (m, -C4H2N2-, 2 H, J(H-H) 8.0, J(P-
1
4
δ = 12.0 (s, br). H NMR (CDCl3): diphosphine: δ = 7.34 (s, -C6H4-
H) 4.7, J(P-H) 4.6 Hz), 7.80 (m, ortho-H, (Ph-P), 8 H, J(H-H) 8.4,
, 4 H), 7.76 (d, (-P-C3N2H2), 2 H, J(H-H) 1,5 Hz), 7.20 (d, (-P-
C3N2H2), 2 H, J(H-H) 1.5 Hz), 7.72 (m, ortho-H, (Ph-P), 8 H, J(H-H)
8.5, J(P-H) 12 Hz), 7.47 (t, para-H, (Ph-P), 4 H, J(H-H) 7.6 Hz), 7.51
(m, meta-H, (Ph-P), 8 H, J(H-H) 8.6, 7.6, J(P-H) 2 Hz); {Au(C2Ph)}2:
δ = 7.37 (m, orto.meta-H, 4 H), 7.26 (m, orto.meta-H, 4H + para-H,
6 H).
J(P-H) 13, J(P-H) 2 Hz), 7.56 (t, para-H, (Ph-P), 4 H, J(H-H) 7.6 Hz),
7.51 (m, meta-H, (Ph-P), 8 H, J(H-H) 8.4, 7.6, J(P-H) 2 Hz);
{Au(C2Ph)}2: δ = 7.49 (m, orto.meta-H, 4 H), 7.24 (m, orto.meta-H,
4H + para-H, 2 H).
Photophysical Measurements
[{AuC2Ph}3(μ3-tppb)] (2): (AuC2Ph)n (110 mg, 0.369 mmol) was
suspended in CH2Cl2 (10 cm3). tppb (113 mg, 0.132 mmol) was added
to the suspension to give a colorless transparent solution within a few
minutes. The reaction mixture was diluted with toluene (10 cm3) and
stirred for 30 min. in the absence of light. The resulting solution was
passed through Al2O3 (0.5 ! 2 cm, neutral, ≈ 150 mesh) and concen-
trated to ca. 5 cm3. A colorless microcrystalline solid was precipitated
by centrifugation, washed with toluene (5 cm3), diethyl ether
(2 ! 5 cm3) and vacuum dried. Yield 196 mg (93 %). Single crystals
of 2 suitable for X-ray analysis were grown by slow evaporation of
CH2Cl2.toluene solution at room temperature. Anal. C84H60P3Au3:
calcd. C 57.55; H 3.45 %; found: C, 58.01; H, 3.67 %. 31P{1H} NMR
An Excimer laser LPX 100 (Lambda Physik) was used to induce lumi-
nescence. Laser pulse duration was 35 ns, pulse energy 160 mJ, repeti-
tion rate 1–25 Hz, excitation wavelength 308 nm. Emission spectra
were recorded with a SD2000 spectrometer (Ocean Optics). Halogen
lamp LS-1-CAL (Ocean Optics) and deuterium lamp DH2000 (Ocean
Optics) were used to calibrate the absolute spectral response of the
spectral system in the range 200–875 nm. All solutions were carefully
degassed before measurements.
X-ray Structure Determinations
1
(CDCl3): δ = 41.8 (s). H NMR (CDCl3): diphosphine: δ = 7.81 (s,
The crystals of compounds 1–4 were immersed in cryo-oil, mounted
in a Nylon loop, and measured at a temperature of 100–120 K. The
X-ray diffraction data were collected with a Nonius KappaCCD dif-
fractometer using Mo-Kα radiation (λ = 0.710 73 Å). The Denzo-Sca-
lepack [33] or EvalCC [34] program packages were used for cell re-
finements and data reductions. The structures were solved by direct
methods using the SHELXS-97 [35] program with the WinGX [36]
graphical user interface. A semi-empirical absorption correction (SAD-
ABS) [37] was applied to all data. Structural refinements were carried
-C6H3-, 3 H), 7.77 (dd, meta-H, (-C6H4-P), 6 H, J(H-H) 8.3, J(P-H)
2 Hz), 7.69 (m, ortho-H, (-C6H4-P), 6 H, J(H-H) 8.3, J(P-H) 12 Hz),
7.67 (m, ortho-H, (Ph-P), 12 H, J(H-H) 8.5, J(P-H) 12.2 Hz), 7.54 (t,
para-H, (Ph-P), 6 H, J(H-H) 6.8 Hz), 7.51 (m, meta-H, (Ph-P), 12 H,
J(H-H) 8.5, 6.8, J(P-H) 2 Hz); {Au(C2Ph)}3: δ = 7.47 (m, orto.meta-
H, 6 H), 7.25 (m, orto.meta-H, 6H + para-H, 3 H).
[{AuC2Ph}2-(μ-dpbp)] (3): (AuC2Ph)n (110 mg, 0.369 mmol) was
suspended in CH2Cl2 (10 cm3). dpbp (101 mg, 0.192 mmol) was
added and yellow suspension turned into a colorless transparent solu- out using SHELXL-97 [35]. The low data quality and high residual
tion within minutes. It was diluted with toluene (10 cm3) and stirred electron density in complex 4 was due to the weakly diffracting crystal.
for 30 min. in the absence of light. The resulting solution was passed
Also, in complex 4 the carbon atoms in toluene of crystallization were
refined with equal anisotropic displacement parameters. In complex 2
through Al2O3 (0.5 ! 2 cm, neutral, ≈ 150 mesh) and concentrated to
ca. 5 cm3. A pale-yellow microcrystalline solid was precipitated by the H2O hydrogen atoms were located from the difference Fourier map
centrifugation, washed with toluene (5 cm3), diethyl ether but constrained to ride on their parent atom, with Uiso = 1.5. Other
(2 ! 5 cm3) and vacuum dried. Yield 198 mg (92 %). Analytically
pure sample was obtained by recrystallization from CH2Cl2.toluene.
Single crystals of 3 suitable for X-ray analysis were grown by slow
evaporation of CH2Cl2.benzene solution in 5 °C. Anal.
hydrogen atoms were positioned geometrically and constrained to ride
on their parent atoms, with C–H = 0.95–0.98 Å and Uiso = 1.2–1.5 Ueq
(parent atom). The crystallographic details are summarized in Table 1.
Selected bond lengths and angles are given in figure captions.
Z. Anorg. Allg. Chem. 2010, 795–802
© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.zaac.wiley-vch.de
801

I. O. Koshevoy, S. P. Tunik et al.
ARTICLE
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CCDC-751649, CCDC-751650, CCDC-751651, and CCDC-751652
(1–4) contain the supplementary crystallographic data for this paper.
These data can be obtained free of charge from The Cambridge Crys-
tallographic Data Centre, 12 Union Road, Cambridge CB21EZ via
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Acknowledgement
Financial support from Academy of Finland (I.O.K.), Russian Founda-
tion for Basic Research (grants 09-03-91279 INISa, 09-03-12309) and
Russian Science and Innovation Federal Agency (contract
02.513.12.3088) is gratefully acknowledged.
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Received: October 25, 2009
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802
www.zaac.wiley-vch.de
© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Z. Anorg. Allg. Chem. 2010, 795–802