Binuclear ten-membered ring cyclometallated complexes of digold(I) and their reactions with iodine and bromine

Article abstract of DOI:10.1515/znb-2004-11-1229

The cyclometallated digold(I) complexes [Au₂(μ-2-C ₆H4CH₂PPh₂)₂] (10) and [Au ₂(μ-2-CH₂ C₆H₄PPh ₂)₂] (11) have been synthesized by the

Full text of DOI:10.1515/znb-2004-11-1229

Binuclear Ten-Membered Ring Cyclometallated Complexes of Digold(I)
and their Reactions with Iodine and Bromine
Martin A. Bennetta, Suresh K. Bhargavab, David C. R. Hocklessa, Fabian Mohrb,∗
,
Kellie Wattsa, Lee L. Wellinga, and Anthony C. Willisa
a Research School of Chemistry, Australian National University, Canberra, ACT 0200, Australia
b School of Applied Sciences, RMIT University, GPO Box 2476 V, Melbourne, Victoria 3001,
Australia
∗ Present address: Departamento de Qu´ımica Inorga´nica, Instituto de Ciencia de
Materiales de Arago´n, Universidad de Zaragoza-C.S.I.C., 50009 Zaragoza, Spain
Reprint requests to Prof. Dr. M. A. Bennett. E-mail: bennett@rsc.anu.edu.au
Z. Naturforsch. 59b, 1563 – 1569 (2004); received September 7, 2004
Unserem Freund und Kollegen Herrn Professor Dr. Hubert Schmidbaur in Anerkennung seiner scho¨-
nen Arbeiten auf dem Gebiet der Goldchemie zum 70. Geburtstag gewidmet
The cyclometallated digold(I) complexes [Au2(µ-2-C6H4CH2PPh2)2] (10) and [Au2(µ-2-CH2
C6H4PPh2)2] (11) have been synthesized by the reaction of Li[2-C6H4CH2PPh2] and Li[2-CH2
C6H4PPh2], respectively, with [AuBr(PEt3)]. A single crystal X-ray structure analysis of 10 shows
˚
the linearly coordinated gold(I) atoms to be separated by 3.0035(9) A in a puckered ten-membered
ring. Both complexes add one mol equivalent of iodine to form initially gold(I)-gold(III) com-
plexes [Au(µ-2-C6H4CH2PPh2)2AuI2] (14a) and [Au(µ-2-CH2C6H4PPh2)2AuI2] (17), which iso-
merize to the corresponding salts [Au(κ2-P,C-C6H4CH2PPh2)2][AuI2] (13a) and [Au(κ2-P,C-CH2
C6H4PPh2)2][AuI2] (16). In 13a the gold(III) cation is planar coordinated by a pair of chelate P-C
donor ligands, the phosphorus and carbon atoms being, separately, mutually cis, as shown by X-ray
structural analysis. From the reaction of 10 with 2 mol equivalents of bromine, the neutral chelate
complex [AuBr2(κ2-P,C-C6H4CH2PPh2)] (15) has been isolated and structurally characterized.
Key words: Gold(I), Cyclometallated Complexes, Phosphine Complexes
Introduction
plexes [Au2X2(µ-2-C6H4PPh2)2] (X = Cl, Br, I; 4a –
4c) and [Au2X2(µ-2-C6H3-n-Me-PPh2)2] (X = Cl,
Br, I, n = 5, 5a – 5c; n = 6, 6a – 6c), which, though
isolable, are not thermodynamically stable [1b, 2, 6].
In the case of 4a– 4c and 5a – 5c, the rearrangement
products are digold(I) complexes of the ditertiary phos-
phines 2,2’-Ph2C6H4C6H4PPh2 and 2,2’-Ph2P(5,5’-
Me2C6H3C6H3)PPh2, (7a – 7c) and (8a – 8c), respec-
tively, derived from C-C coupling at the gold cen-
tres. In contrast, in the 6-methyl substituted series the
products are the heterovalent gold(I)-gold(III) com-
plexes 9a – 9c [2]. No C-C coupling is observed in
the last case, presumably because of steric hindrance
by the 6-methyl substituent, although in one instance
in the 2-C6H4PPh2 series (X = C6F5; Y = Z = H), a
gold(I)-gold(III) species analogous to 9 has been de-
tected as an intermediate in the C-C coupling pro-
cess [7]. The observed behaviour has been ratio-
nalised on the basis of high-level ab initio calcula-
tions [8].
We have shown that carbanions such as [2-C6H4
PPh2]− and [2-C6H3-n-Me-PPh2]− (n = 5, 6) form
dinuclear gold(I) complexes 1 – 3 in which the lin-
early coordinated metal atoms are separated by only
˚
ca. 2.86 A, a distance that is comparable with the
˚
distance between the atoms in gold metal (2.88 A)
[1, 2]. Compounds 1 – 3 belong to an extensive fam-
ily in whose members gold atoms are held in close
contact by a pair of 1,3-bifunctional ligands, for ex-
ample, 2-pyridyldimethylphosphine [3] and phospho-
rus bis(ylides) [R2P(CH2)2] (R = Me, Et, Ph) [4] in-
troduced by Schmidbaur and coworkers. The Au-Au
separations are usually in the range of 2.80 – 3.10 A
suggestive of an attractive interaction (aurophilicity)
between the 5d10 metal centres [5].
˚
Complexes 1 – 3 undergo oxidative addition with
◦
halogens, even at −70 C, to give initially the ho-
movalent metal-metal bonded dihalodigold(II) com-
c
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M. A. Bennett et al. · Binuclear Ten-Membered Ring Cyclometallated Complexes of Digold(I)
In the light of these results, it seemed worthwhile to
examine the oxidative addition behaviour of digold(I)
complexes analogous to 1 – 3 in which the metal
atoms are held further apart by the interposition of
a methylene group in the bridging carbanionic unit,
i.e., the complexes [Au2(µ-2-C6H4CH2PPh2)2] (10)
Fig. 1. Molecular structure of 10. Displacement ellipsoids
show 30% probability levels; hydrogen atoms have been
˚
or [Au2(µ-2-CH2C6H4PPh2)2] (11). We hoped to see omitted for clarity. Selected bond lengths (A): Au(1)···Au(2)
3.0035(9), Au(1)-P(1) 2.296(4), Au(2)-P(2) 2.297(4), Au(1)-
whether digold(II) complexes analogous to 4 – 6 could
be detected or isolated, and whether C-C coupling
would occur. The results of this study are reported in
C(1)-C(2) 113(1), P(2)-C(20)-C(21) 110(1).
this paper.
C(22) 2.02(2), Au(2)-C(3) 2.07(2). Selected bond angles (◦)
P(1)-Au(1)-C(22) 176.9(5), C(3)-Au(2)-P(2) 176.0(4), P(1)-
Results
As reported by Abicht and Issleib [9], the din-
uclear complex 10 results in high yield as a
colourless, microcrystalline solid from the reac-
tion of (2-lithiobenzyl)diphenylphosphine, Li[2-
membered ring complex [Au2(µ-SCH2CH2PEt2)2]
C6H4CH2PPh2], with [AuX(PEt3)] (X = Cl, Br).
Complex 11 is obtained similarly from the reaction
of [AuBr(PEt3)] with (2-diphenylphosphino) benzyl-
lithium, Li[2-CH2C6H4PPh2], which results from the
lithiation of diphenyl(2-tolyl)phosphine [10]. Both
complexes show parent ions in their EI mass spectra,
˚
˚
(12) (3.104 A), but is ca. 0.14 A greater than
those in the eight-membered ring complexes 1 and 2
[1a, 2]. The Au-P and Au-C distances in 10 [2.296(4),
˚
˚
2.297(4) A and 2.02(2), 2.07(4) A, respectively] are
similar to those in 1 and 2. The coordination about each
gold atom is close to linear and there are no unusual
bond lengths or angles that would indicate strain. The
P-Au-C units are not coplanar, the dihedral angle be-
tween the planes Au(1)-Au(2)-P(1)-C(22) and Au(1)-
Au(2)-P(2)-C(3) being 40.7◦.
1
singlet resonances at ca. δ = 36 in their 31P{ H}
NMR spectra and doublets due to the CH2 groups in
their 1H NMR spectra [J = ca. 10 Hz]. The structure
of complex 10, determined by single crystal X-ray
analysis, is shown in Fig. 1; it contains two gold atoms
bridged by a pair of C6H4CH2PPh2 ligands to give a
puckered ten-membered ring similar to that found in
[Au2(µ-SCH2CH2PEt2)2] 12 [11].
Treatment of complex 10 with one mol equiv. of
◦
iodine in CH2Cl2 or toluene at −70 C gives an or-
ange solution whose 31P{ H} NMR spectrum con-
1
The intramolecular Au···Au distance in 10, tains a pair of doublets at δ = 42.5 and 33.2 (2JPP
=
˚
3.0035(9) A, is significantly less than that in the ten- 2.3 Hz), the singlet due to 10 being absent. The species
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M. A. Bennett et al. · Binuclear Ten-Membered Ring Cyclometallated Complexes of Digold(I)
1565
responsible for this spectrum can be isolated as an
orange-yellow solid in a fairly pure state, as judged
by 31P NMR spectroscopy, by evaporating the solution
◦
below 0 C, but it isomerizes above this temperature
to a second species, which shows a 31P NMR singlet
at δ = 52.5. The two species apparently co-exist in
the almost colourless solution at room temperature, but
only the second compound precipitates as a colourless
solid, which has been shown by single-crystal X-ray
analysis (Fig. 2) to be the gold(III)-gold(I)salt [Au(κ 2-
P,C-C6H4CH2PPh2)2][AuI2] (13a). The gold(III) cen-
tre in the cation is planar coordinated by a pair of five-
membered chelate C6H4CH2PPh2 groups, while the
anion is the well-known, linear [AuI2]− species. The
formulation has been confirmed by elemental analysis
and by FAB mass spectrometry, which shows a parent
ion peak at m/z 747.2 due to the cation in positive ion
mode, and a parent ion peak at m/z 450.8 due to the
Fig. 2. Molecular structure of the cation of 13a. Dis-
placement ellipsoids show 30% probability levels; hydrogen
atoms have been omitted for clarity. Selected bond lengths
anion in negative ion mode.
The reaction of complex 10 with 1 mol equiv. of
bromine in CH2Cl2 appears to be very similar to that
˚
(A): Au(1)-P(1) 2.350(2), Au(1)-P(2) 2.347(2), Au(1)-
with iodine. At −70 ◦C a pair of doublets appears in the
C(3) 2.089(9), Au(1)-C(22) 2.076(9). Selected bond angles
(◦) P(1)-Au(1)-P(2) 103.46(9), C(3)-Au(1)-C(22) 96.6(4),
P(2)-Au(1)-C(3) 170.2(3), P(1)-Au(1)-C(22) 167.3(3), P(2)-
Au(1)-C(22) 81.4(3), P(1)-Au(1)-C(3) 80.5(3).
1
31P{ H} NMR spectrum at δ = 43.7 and 30.2 (2JPP
=
2.3 Hz). On warming to room temperature, the solution
turns almost colourless and the main species present
shows a singlet 31P resonance at δ = 51.4 assignable
to [Au(κ2-P,C-C6H4CH2PPh2)2][AuBr2] (13b). The
initial products in both halogenation reactions are
clearly not digold(II) complexes analogous to 4 – 6, but
are most reasonably formulated on the basis of their
analysis (Fig. 3) to be the monomeric, planar gold(III)
complex [AuBr2(κ2-P,C-C6H4CH2PPh2)] (15), which
contains the same five-membered chelate ring system
as 13a. It is noteworthy that the 31P chemical shifts of
14a and 15 are ca. 20 ppm deshielded relative to those
of 10, 13a and 13b containing µ-C6H4CH2PPh2, as ex-
pected for five-membered ring chelate complexes [12].
The reaction of complex 11 with 1 mol equiv. of
1
31P{ H} NMR spectra as gold(I)-gold(III) complexes
[Au(µ-C6H4CH2PPh2)2AuX2] [X = I (14a), Br (14b)].
The reaction of 2 mol equiv. of bromine with a solu-
tion of 10 in CH2Cl2 has also been investigated briefly iodine in CH2Cl2 resembles that of ◦10. The brown
1
on an NMR scale. The 31P{ H} NMR spectrum of the solid isolated after reaction at −70 C shows in its
1
solution is complex, containing a singlet at δ = 59.7 31P{ H} NMR spectrum a pair of equally intense
together with resonances in the region of δ = 33−37, singlets at δ = 31.7 and 48.1, together with a sin-
one or more of which could correspond to the or- glet at δ = 52.3, the latter increasing at the expense
ange complex [Au2Br4(µ-C6H4CH2PPh2)2] isolated of the first two over time. The elemental analysis
by Abicht and Issleib [9]. The yellow, crystalline solid of the pale yellow solid that was obtained by crys-
that deposited from the solution was shown by X-ray tallisation at room temperature corresponded to the
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M. A. Bennett et al. · Binuclear Ten-Membered Ring Cyclometallated Complexes of Digold(I)
Discussion
The main effect of the increased separation of the
gold atoms in the ten-membered ring complexes 10
˚
and 11 (ca. 3.0 A) relative to that in their eight-
˚
membered ring analogues 1 – 3 (ca. 2.9 A) is that
the first detectable product of reaction of iodine or
bromine arises from oxidative addition at only one
of the metal centres, leading to the gold(I)-gold(III)
complexes 14 and 17, respectively. In contrast, in
the eight-membered ring series a halogen adds ini-
tially to each gold atom, giving metal-metal bonded
digold(II) complexes which, as summarised in the In-
troduction, then undergo further change via gold(I)-
gold(III) complexes such as 9. In the latter, only one
of the two P-C groups acts as a bidentate chelate
to the gold(III) atom, whereas in 13 and 16 both P-
C ligands chelate to the gold(III) atom, leading to
the salts [Au(P-C)2][AuX2]. This difference in be-
haviour probably stems from the greater flexibility
imparted to the system by the additional methylene
groups and the greater stability of the five-membered
chelate rings relative to their four-membered counter-
part. In further contrast to the eight-membered ring
series, we have found no evidence for C-C coupling
in the ten-membered systems, which may also re-
flect the reduced strain in the five-membered rings in
13 and 16.
Fig. 3. Molecular structure of 15. Displacement ellipsoids
show 30% probability levels; hydrogen atoms are shown
as spheres of arbitrary radius. Selected bond distances
˚
(A): Au(1)-P(1) 2.273(2), Au(1)-Br(1) 2.491(1), Au(1)-
Br(2) 2.4670(9), Au(1)-C(7) 2.072(8). Selected bond angles
(◦) Br(1)-Au(1)-Br(2) 92.55(3), Br(1)-Au(1)-P(1) 92.66(6),
Br(1)-Au(1)-C(7) 169.2(2), P(1)-Au(1)-C(7) 80.3(2).
empirical formula AuI(CH2C6H4PPh2) and the FAB-
MS spectrum showed parent ion peaks due to the
cation [Au(CH2C6H4PPh2)2]+ and the anion [AuI2]−.
An X-ray structural analysis to be reported else-
where has confirmed the formulation [Au(κ 2-P,C-
CH2C6H4PPh2)2][AuI2] (16) analogous to 13a. The
species responsible for the pair of singlets is presum-
ably [Au(µ-2-CH2C6H4PPh2)2AuI2] (17), analogous
to 14a.
Despite these differences, the chemistry reported
here shows similarities to systems that are based
on digold(I) complexes containing eight mem-
The molecular structures of 13a (cation only) and 15
are shown in Figs 2 and 3, together with atom labelling.
In the cation of 13a, the phosphorus and carbon bered rings. Thus, treatment of dialkyldithiocarbama-
atoms of the P,C-chelate groups are, separately, mu- todigold(I), [Au2(µ-S2CNR2)2] (R= n-Bu), with halo-
tually cis. The envelope-shaped five-membered rings gens at room temperature gives the salts [Au(κ 2-
in 13a and 15 subtend angles of 80 – 85◦ at the gold S2CNR2)2][AuX2] [17], analogous to 13a and 16,
atoms, causing the P-Au-P angles in 13a to open out and, in the case of R = Et, intermediate digold(II)
to ca. 105◦. The Au-C distances fall in the range complexes [Au2X2(µ-S2CNEt2)2] have been iso-
˚
2.07-2.12 A, similar to the Au-C bond length of lated [18]. In this series, the formation of dibro-
2.10(4) A in [AuBr2{κ-P,C-CH(CH2Br)C6H4PPh2}] mogold(III) complexes [AuBr2(κ2-S2CNEt2)] by the
˚
[13], and significantly greater than those in C,N- addition of bromine (2 mol. equiv.) on the digold(I)
cycloaurated complexes containing 2-C6H4N=N or precursors has also been reported [19], which par-
2-C6H4CH2NMe2, which are in the range of 1.99– allels the formation of the chelate complex 15 in
˚
2.03 A [14, 15]. This may be a consequence of the our system. Depending on the solvent, the action
larger size of phosphorus relative to nitrogen. The Au- of iodine on the digold(I) methylenethiophosphi-
P distances in 13 and 15, and the Au-Br distances in nate complex [Au2{µ-Ph2P(S)CH2}2] can give ei-
the latter, are also close to the corresponding distances ther a homonuclear digold(II) complex [Au2I2{µ-
in [AuBr2{κ-P,C-CH(CH2Br)C6H4PPh2}] [13]. The Ph2P(S)CH2}2] or a heterodinuclear gold(I)-gold(III)
Au-I distance in the [AuI2]− ion of 13a [2.5276(9) A] complex [Au{µ-Ph2P(S)CH2}2AuI2] [20], the latter
˚
is almost identical to that reported for [n-Bu4N][AuI2] being analogous to complexes 14a and 17 in our
˚
[2.529(1) A] [16].
systems.
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M. A. Bennett et al. · Binuclear Ten-Membered Ring Cyclometallated Complexes of Digold(I)
1567
Experimental Section
stirred suspension of [AuBr(PEt3)] (1.0 g, 2.6 mmol) in
ether (30 ml) at −70 ◦C. The mixture was stirred overnight.
Solvents were removed by cannulation and the residue was
stirred with methanol (10 ml) for 15 min and filtered. The
resulting colourless, crystalline solid was washed with ether
and hexane. For final purification the solid was dissolved in
CH2Cl2 (ca. 400 ml) and the solution was filtered through
Celite. Evaporation in vacuo gave 11 (0.85 g, 72%) as
a colourless solid. M. p. 230 ◦C. – MS (EI, 70 eV): m/z
944 [M+] – 1H NMR (300 MHz, CDCl3): δ = 7.3 − 7.6
(m, 24H), 6.7 (t, 2H), 6.5 (t, 2H), (PPh2, C6H4), 2.6 (d,
All manipulations were performed in an atmosphere of
dry nitrogen using standard Schlenk techniques, although the
solid gold complexes, once isolated, were air-stable. Solvents
were dried by standard methods, distilled and stored under
nitrogen. The following instruments were used for spectro-
scopic measurements: Varian XL-200E (1H at 200 MHz, 31
P
at 80.96 MHz), Varian Gemini (1H at 300 MHz), Bruker As-
pect 2000 (31P at 80.96 MHz) and VG ZAB-2SEQ (high
resolution EI and FAB mass spectra). The NMR chemi-
cal shifts (δ) are given in ppm relative to TMS (1H) and
85% H3PO4 (31P), referenced either to residual solvent sig-
nals (1H) or externally (31P). Coupling constants are given
in Hz. Elemental analyses were carried out by staff of
the Microanalytical Laboratory of the Australian National
University. The compounds (2-tolyl)diphenylphosphine [21],
(2-bromobenzyl)diphenylphosphine [22] and [AuBr(PEt3)]
[23] were prepared as described in the literature.
1
J = 10 Hz, 4H, CH2) – 31P{ H} NMR (80.96 MHz,
CDCl3): δ = 36.2 – C38H32Au2P2 ·CH2Cl2 (1029.5): calcd.
C 45.5, H 3.3, P 6.0, Cl 6.9; found C 46.0, H 3.3, P 5.9,
Cl 6.6.
Bis{bis(2-diphenylphosphinomethyl)phenyl}gold(III)
diiodoaurate(I) (13a) and bis{bis(2-diphenylphosphino)-
benzyl}gold(III) diiodoaurate(I) (16): A suspension of 10
or 11 (50 mg, 0.053 mmol) in toluene or dichloromethane
(ca. 10 ml) was cooled to −70 ◦C and treated with a slight
molar excess of iodine in the same solvent. The solution
was stirred for 30 min at low temperature, then allowed to
come to room temperature and stirred for a further 30 min.
The solution had changed colour from brown to yellow and
some precipitate had formed. The solution was concentrated
in vacuo and the solid was filtered off, washed with toluene,
and air-dried. Yields were ca. 50%. Crystals suitable for
X-ray diffraction were obtained by slow diffusion of hexane
into dichloromethane solutions. 31P NMR data are reported
in the text. 13a: MS (FAB, NBA matrix, positive ion mode):
747.2 [cation M+] – MS (FAB, NBA matrix, negative ion
mode): 450.8 [anion M−] – C38H32Au2I2P2 (1198.4): calcd.
C 38.1, H 2.7, P 5.2; found C 38.1, H 3.0, P 5.4. – 16: MS
(FAB, NBA matrix, positive ion mode): 747.2 [cation M+] –
MS (FAB, NBA matrix, negative ion mode): 450.8 [anion
M−] – C38H32Au2I2P2 (1198.4): calcd. C 38.1, H 2.7,
I 21.2; found C 38.2, H 2.5, I 21.2.
Bis(2-diphenylphosphinomethyl)phenyldigold(I) (10): To
a solution of (2-bromobenzyl)diphenylphosphine (1.0 g,
2.8 mmol) in ether (15 ml) was added dropwise a 1.4 M so-
lution of n-butyllithium in hexane (2.0 ml, 2.8 mmol) and
the mixture was stirred for 2 h at room temperature. The red
supernatant was removed by cannulation from the precipi-
tated colourless solid and the latter was washed with hexane
(3 × 5 ml). The solid was suspended in ether and the slurry
was added by cannula to a stirred solution of [AuBr(PEt3)]
(0.99 g, 2.5 mmol) in ether (15 ml), the temperature being
◦
maintained below −65 C. The mixture was stirred at low
temperature for 2 h, then at room temperature for 1.5 h, the
flask being shielded from light. After removal of the sol-
vent by cannulation, the solid was washed with methanol
(10 ml), ether (3×15 ml) and hexane (3×15 ml) and dried
in vacuo. For final purification the solid was dissolved in
CH2Cl2 (ca. 50 ml) and the solution was filtered through
Celite. Evaporation in vacuo gave 10 (0.82 g, 69%) as a
◦
colourless solid. M. p. 210 C. – MS (EI, 70 eV): m/z 944
Dibromo{(2-diphenylphosphinomethyl)phenyl}gold(III)
(15): A solution of 10 (ca. 10 mg) in CD2Cl2 (ca. 0.5 ml)
in an NMR tube was cooled in dry ice/acetone and treated
with 2 mol equiv. of bromine. The mixture was then a◦llowed
to warm slowly to room temperature. Above −20 C the
[M+] – 1H NMR (300 MHz, CD2Cl2): δ = 7.7 − 7.8 (m,
8H), 7.4 – 7.6 (m, 14H), 7.0 (t, 2H), 6.7 (t, 2H), 6.6 (d, 2H)
(PPh2, C6H4), 4.0 (d, J = 11 Hz, 4H, CH2) – 31P{ H} NMR
1
(80.96 MHz, CD2Cl2): δ = 37.0 – C38H32Au2P2 (944.5):
calcd. C 48.3, H 3.4, P 6.6; found C 48.4, H 3.5, P 6.3. Sin-
gle crystals suitable for X-ray diffraction were obtained by
slow evaporation of a dichloromethane solution of 10.
1
main feature of the 31P{ H} NMR spectrum was a singlet
at δ = 59.4 due to 15. The solution was evaporated to
dryness in vacuo, the residue was dissolved in toluene, and
the solution was layered with hexane. On standing at room
temperature, a pale yellow, crystalline solid deposited that
was identified as a 1:1 toluene solvate of 15 by single-crystal
X-ray structural analysis.
Bis(2-diphenylphosphinobenzyl)digold(I) (11): To
a
stirred solution of n-butyllithium (1.85 ml, 2.96 mmol) in
hexane (30 ml) containing TMEDA (0.45 ml) was added
slowly at room temperature a solution of diphenyl(2-
tolyl)phosphine (0.80 g, 2.88 mmol). The mixture was
X-Ray crystallography: The crystal and refinement data
stirred for 2 h and the bright yellow, crystalline solid was for compounds 10, 13a and 15 are summarised in Table 1. All
separated by filtration and dried in vacuo. It was then three structures were solved by direct methods (SIR 92) [24].
suspended in hexane (ca. 25 ml) and added slowly to a Hydrogen atoms were included at geometrically determined
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M. A. Bennett et al. · Binuclear Ten-Membered Ring Cyclometallated Complexes of Digold(I)
Table 1. Crystallographic de-
tails for complexes 10, 13a,
and 15.
Compound
Formula
10
13a
15
C38H32Au2P2
944.55
C38H32Au2I2P2
1198.36
triclinic
C19H16AuBr2P·C7H8
Mr [g/mol]
Crystal system
Space group
724.22
monoclinic
P21/a (# 14)
18.922(3)
10.163(5)
19.786(3)
90
113.19(1)
90
3498(2)
monoclinic
C2/c (# 15)
31.738(5)
9.568(3)
18.450(4)
90
118.31(1)
90
4933(2)
¯
P1 (# 2)
˚
a [A]
10.204(3)
11.548(2)
18.056(2)
107.22
˚
b [A]
˚
c [A]
α [◦]
β [◦]
γ [◦]
94.35
11.29(2)
1853.2(8)
2
3
˚
V [A ]
Z
4
8
Crystal habit
Crystal size [mm3]
Dcalcd. [g/cm3]
θ Range [◦]
Diffractometer
colourless needle
0.30×0.12×0.03
1.794
4.35 to 60.07
Rigaku AFC6R
16.32 (Cu-Kα )
1.5418
colourless plate
0.32×0.13×0.07
2.147
2.02 to 27.55
Rigaku AFC6S
9.642 (Mo-Kα )
0.7107
pale yellow block
0.40×0.20×0.20
1.950
2.02 to 27.55
Rigaku AFC6S
9.31 (Mo-Kα )
0.7107
µ [mm−1
]
˚
λ [A]
Temperature [K]
293
296
293
Absorption correction
analytical
0.692 / 0.190
4857[I > 2σ(I)]
2918
analytical
0.538 / 0.278
8539[I > 3σ(I)]
5096
empirical
1.00 / 0.67
6037[I > 3σ(I)]
3234
Tmax/Tmin
Measured refls
Independent refls
Rint
0.073
0.0212
0.020
F(000)
Parameters
1792
379
1108
401
2752
271
S
1.537
1.249
1.56
R1
wR2
0.0485
0.0572
1.30 / −2.08
0.0353
0.0362
1.45 / −0.92
0.035
0.038
1.19 / −0.82
−3
˚
∆ρmax/∆ρmax [eA
]
positions, which were periodically recalculated but not re- tre, deposition codes CCDC 250220 (15), 250221 (10)
fined. Analytical absorption corrections [25] were applied for and 250222 (13a). Copies of the data can be obtained
complexes 10 and 13a. All calculations were performed us- free of charge on application to The Director, CCDC, 12
ing the teXsan crystallographic software package [26]. The Union Road, Cambridge, CB2 1EZ, UK (E-mail: deposit@
crystal of 15 contained a disordered toluene molecule having ccdc.cam.ac.uk).
two possible orientations. The atom sites corresponding to
the two images of the molecule were refined, with individual
Acknowledgement
We wish to thank Mr. Michael Migliorisi (RMIT Univer-
sity) for experimental assistance and FM is grateful to the
Australian Government for the award of an Australian Post-
graduate Scholarship.
isotropic displacement parameters and appropriate restraints,
employing the CRYSTALS program [27].
Crystallographic data for the structures have been de-
posited with the Cambridge Crystallographic Data Cen-
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