Synthesis and characterisation of four- and eight-membered ring auralactam complexes

Article abstract of DOI:10.1016/S0022-328X(00)00817-2

The reactions of the cyclo-aurated gold(III) dihalide complex [{C₆H₃(CH₂NMe₂)-2-(OMe)-5}AuCl ₂] with N-cyanoacety-lurethane [NCCH₂C(O)NHCO₂Et], 2-benzoylacetanilide [PhC(O)CH₂C(O)NHPh] and acetoacetanilide [MeC(O)CH₂C(O)NHPh], and [{C₆H₄(CH₂NMe₂)-2}AuCl₂] with acetoacetanilide in dichloromethane with excess silver(I) oxide gives the first examples of auralactam complexes, containing Au-NR-C(O)-CHR′ four-membered rings. A single-crystal X-ray diffraction study on the complex [{C₆H₄(CH₂NMe ₂)-2}Au{NPhC(O)CH(COMe)}] reveals similar structural features to related metallalactam complexes of platinum(II) and palladium(II). When a CDCl₃ solution of the complex [{C₆H₃(CH₂NMe ₂)-2-(OMe)-5}Au{N(CO₂Et)C(O)CHCN}] is allowed to stand for 18 h, a novel dimerisation reaction occurs, giving the insoluble product [{C₆H₃(CH₂NMe ₂)-2-(OMe)-5}Au{N(CO₂Et)C(O)CHCN}] ₂·2CDCl₃, characterised by an X-ray structure determination. The dimer contains an eight-membered Au-N-C(O)-C-Au-N-C(O)-C ring.

Full text of DOI:10.1016/S0022-328X(00)00817-2

www.elsevier.nl/locate/jorganchem
Journal of Organometallic Chemistry 620 (2001) 182–189
Synthesis and characterisation of four- and eight-membered ring
auralactam complexes
William Henderson *, Brian K. Nicholson, Allen G. Oliver
Department of Chemistry, Uni6ersity of Waikato, Pri6ate Bag 3105, Hamilton, New Zealand
Received 30 August 2000; received in revised form 5 October 2000; accepted 5 October 2000
Abstract
The reactions of the cyclo-aurated gold(III) dihalide complex [{C6H3(CH2NMe2)-2-(OMe)-5}AuCl2] with N-cyanoacety-
lurethane [NCCH2C(O)NHCO2Et], 2-benzoylacetanilide [PhC(O)CH2C(O)NHPh] and acetoacetanilide [MeC(O)CH2C(O)NHPh],
and [{C6H4(CH2NMe2)-2}AuCl2] with acetoacetanilide in dichloromethane with excess silver(I) oxide gives the first examples of
¸¹¹¹º
auralactam complexes, containing AuꢀNRꢀC(O)ꢀCHR% four-membered rings. A single-crystal X-ray diffraction study on the
¸¹¹¹¹¹¹º
complex [{C6H4(CH2NMe2)-2}Au{NPhC(O)CH(COMe)}] reveals similar structural features to related metallalactam complexes
of platinum(II) and palladium(II). When
a
CDCl3 solution of the complex [{C6H3(CH2NMe2)-2-(OMe)-
¸¹¹¹¹¹¹¹¹¹º
5}Au{N(CO2Et)C(O)CHCN}] is allowed to stand for 18 h, a novel dimerisation reaction occurs, giving the insoluble product
[{C6H3(CH2NMe2)-2-(OMe)-5}Au{N(CO2Et)C(O)CHCN}]2·2CDCl3, characterised by an X-ray structure determination. The
¸¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹º
dimer contains an eight-membered AuꢀNꢀC(O)ꢀCꢀAuꢀNꢀC(O)ꢀC ring. © 2001 Elsevier Science B.V. All rights reserved.
Keywords: Gold; Metallacycle; Lactam; Dimerisation reaction; Crystal structures
1. Introduction
tems, as well as other related metallacyclic complexes
[8,9]. Complexes 1 generally appear to mimic the chem-
istry of related platinum(II) complexes with cis-halide
ligands, such as cis-[PtCl2(PPh3)2], but the reactivity
towards thioureas in the presence of Ag2O base has
been found to be very different. With platinum(II),
four-membered metallacycles, e.g. 5 are formed [10],
but with the gold(III) complexes 1a and 1b desulfurisa-
tion of the (1,3-dimethyl)thiourea occurs, giving com-
plex gold–silver–sulfide–halide aggregate cations [11].
This suggests that while there may be many similarities
between metallacycles of platinum(II) and gold(III),
differences are also to be expected.
Small-ring metallacycles have attracted interest over
a considerable period of time, for their basic structures
and chemistry, and because metallacycles are involved
in many metal-catalysed reactions of small molecules
[1]. There is a very extensive metallacyclic chemistry of
platinum(II) [2], but in marked contrast the chemistry
of related metallacycles of isoelectronic gold(III) is
scarcely developed. However, in recent years there has
been much interest in the synthesis of gold(III) com-
plexes, containing two cis halide ligands, together with
an ancillary cyclometallated ligand which provides sta-
bility to the gold(III) centre, moderating its oxidising
tendencies [3]. Such complexes, e.g. 1a [4] and 1b [5] are
ideal precursors for the study of auracyclic chemistry,
and recently we and others have described the syntheses
of a range of four-membered ring complexes, including
the first examples of auracyclobutane 2 [6], aurau-
reylene 3 [7], and auracyclobutan-3-one 4 [8] ring sys-
* Corresponding author. Tel.: +64-7-8384656; fax: +64-7-
8384219.
E-mail address: w.henderson@waikato.ac.nz (W. Henderson).
0022-328X/01/$ - see front matter © 2001 Elsevier Science B.V. All rights reserved.
PII: S0022-328X(00)00817-2

W. Henderson et al. / Journal of Organometallic Chemistry 620 (2001) 182–189
183
Fig. 1. Molecular structure and atom labelling scheme of
[{C6H4(CH2NMe2)-2}A¸u{¹N¹P¹h¹C¹(O¹)CºH(COMe)}] (6d). Thermal el-
lipsoids are at the 50% probability level, and hydrogen atoms are not
shown.
Table 1
,
Selected bond lengths (A) and angles (°) for [{C6H4(CH2NMe2)-
2}A¸u{¹N¹P¹h¹C¹(O¹)CºH(COMe)}] (6d)
AuꢀC(11)
AuꢀN(2)
Au···C(1)
N(2)ꢀC(1)
C(1)ꢀC(2)
O(2)ꢀC(3)
2.027(3)
2.097(3)
2.616(3)
1.356(4)
1.536(5)
1.220(5)
AuꢀC(2)
AuꢀN(1)
O(1)ꢀC(1)
N(2)ꢀC(21)
C(2)ꢀC(3)
C(3)ꢀC(4)
2.076(3)
2.157(3)
1.226(4)
1.425(4)
1.495(5)
1.504(6)
C(11)ꢀAuꢀC(2)
C(2)ꢀAuꢀN(2)
C(2)ꢀAuꢀN(1)
102.06(13)
66.65(12)
174.54(12)
C(11)ꢀAuꢀN(2)
C(11)ꢀAuꢀN(1)
N(2)ꢀAuꢀN(1)
C(1)ꢀN(2)ꢀAu
O(1)ꢀC(1)ꢀN(2)
N(2)ꢀC(1)ꢀC(2)
C(3)ꢀC(2)ꢀC(1)
C(1)ꢀC(2)ꢀAu
O(2)ꢀC(3)ꢀC(4)
168.64(12)
81.74(12)
109.42(11)
96.1(2)
130.3(3)
104.7(3)
113.7(3)
91.5(2)
C(1)ꢀN(2)ꢀC(21) 123.4(3)
C(21)ꢀN(2)ꢀAu
O(1)ꢀC(1)ꢀC(2)
O(1)ꢀC(1)···Au
C(2)ꢀC(3)ꢀC(4)
C(3)ꢀC(2)ꢀAu
O(2)ꢀC(3)ꢀC(2)
140.5(2)
124.9(3)
174.9(3)
118.5(3)
113.8(2)
121.5(4)
Previously we have synthesised metallalactam com-
plexes of platinum(II) and palladium(II) by reaction of
metal dihalide complexes with N-cyanoacetylurethane
[12,13], 2-benzoylacetanilide [14], acetoacetanilide [15],
or cyanoacetylurea [16] in the presence of silver(I) oxide
base. In this paper we report the synthesis of the first
examples of auralactam complexes using the same
methodology. Surprisingly, few gold(III) complexes
containing amide (amidate) ligands appear to have been
reported [17], though such species may be important in
the metabolism of gold(I) drugs [18].
120.0(4)
acetacetanilide, and 1a with acetoacetanilide in reflux-
ing dichloromethane in the presence of excess silver(I)
oxide gave good yields of the auralactam complexes
6a–6d. The complexes are all soluble in polar organic
2. Results and discussion
2.1. Synthesis and characterisation of four-membered
ring auralactam complexes
The reactions of the gold(III) dichloride complex 1b
with N-cyanoacetylurethane, 2-benzoylacetanilide or

184
W. Henderson et al. / Journal of Organometallic Chemistry 620 (2001) 182–189
solvents such as dichloromethane, and are relatively
stable, but turn purple on prolonged storage in air at
room temperature, especially when exposed to sunlight.
When complex 6a is allowed to stand overnight in
CDCl3, it dimerises to form an insoluble product, which
is discussed in Section 2.2.
via nitrogen, giving an intermediate complex such as 9,
since in the reaction of cis-[PtCl2(PPh3)2] with N-
cyanoacetylurethane, the nitrogen-bonded intermediate
10 was able to be isolated [23]. Cyclisation of 9 would
then occur, giving the observed isomer of complexes 6.
A single-crystal X-ray diffraction study has been
carried out on complex 6d; the molecular structure is
shown in Fig. 1, while Table 1 gives selected bond
lengths and angles. The structure shows a distorted
square-planar gold(III) centre, which is part of the
four-membered lactam ring. The largest deviation from
the Au, N(1), N(2), C(2), C(11) least-squares plane is
,
0.041(1) A for Au. The bond angles about the gold
centre deviate considerably from an idealised square-
planar geometry, the largest distortion being the con-
stricted N(2)ꢀAuꢀC(2) ‘bite’ angle of 66.65(12)°. Similar
acute angles around 67° have been observed for platina-
and palladalactam complexes [12,14,15]. The
goldꢀcarbon bond lengths reflect the different hybridis-
ation of the carbon atoms, with the goldꢀsp2 carbon
,
bond AuꢀC(11) being shorter [2.027(3) A] than the
goldꢀsp3 carbon [AuꢀC(2) 2.076(3) A]. The
,
goldꢀnitrogen bonds also differ, with the AuꢀN(1) da-
,
tive bond being longer [2.157(3) A] than the AuꢀN(2)
,
covalent bond [2.097(3) A]. The AuꢀN(2) bond is
longer than the PdꢀN(lactam) bond in the analogous
palladium complex 7 [2.033(9) A] [15], partly due to the
high trans-influence of the aryl carbon compared to
,
bipyridyl, since the radius of Au(III) is normally only
,
about 0.02 A greater than that of Pd(II) (e.g. the AuꢀCl
,
bonds in Ph3PAuCl3 [19] are 0.02 A on average longer
than the PdꢀCl bonds in [Ph3PPdCl3]− [20]).
The geometry of the cyclo-aurated N,N-dimethylben-
zylamine ligand is similar to those of previously re-
ported complexes. The ligand bite angle N(1)ꢀAuꢀ
C(11) [81.74(12)°] approaches the ideal 90°. Compen-
sating for the two acute bond angles of the ring sys-
tems, the N(1)ꢀAuꢀN(2) and C(11)ꢀAuꢀC(2) bond
angles are more obtuse [109.42(11) and 102.06(13)°,
respectively]. The five-membered ring formed by
AuꢀC(11)ꢀC(12)ꢀC(17)ꢀN(1) has a significant fold an-
gle [34.9(2)°] between the planes defined by
AuꢀC(11)ꢀC(12)ꢀN(1) and N(1)ꢀC(12)ꢀC(17)ꢀC(11).
The NMR spectra of complexes 6 show the expected
features. Due to the presence of two different groups on
the gold-bonded quaternary carbon, the benzylic CH2
protons are non-equivalent and give an AB spin system
of two doublets. The same inequivalency is also ex-
pected for the NMe2 groups; for complexes 6b, 6c and
6d the two signals were resolved in their 1H-NMR
spectra, but in complex 6a they were not resolved, and
appeared as a broadened singlet. Separate NMe reso-
nances were also observed in the 13C-NMR spectra of
6a–6d, typically separated by 0.1–0.2 ppm. Similar
effects were observed previously for the cyclo-octadiene
CH groups of platinalactam complexes [12]. In com-
The auralactam ring is slightly puckered, with an
angle of 10.5(4)° between the Au, N(2), C(2) and N(2),
C(1), C(2) planes; the fold angle is similar to those of
related platina- and palladalactam complexes. The
complex is the expected isomer with the two low trans-
influence N atoms mutually cis, due to antisymbiosis
[21]. This is also found for other gold(III) complexes,
including thiosalicylate complexes 8, where the low
trans-influence O and N atoms are mutually cis [22].
The Cl atom trans to the high trans-influence aryl
carbon of 1 would be expected to be the most labile,
and substituted first. The nitrogen of the organic
reagent is expected to bond to the gold centre initially

W. Henderson et al. / Journal of Organometallic Chemistry 620 (2001) 182–189
185
Scheme 1.
plexes 6a, 6b and 6c, two of the three aromatic proton
signals (H14 and H16, Scheme 1) show long range
4J(HH) (‘W’) coupling, of 2–3 Hz.
reflected in the bond angles around the gold atom
compared to the four-membered auralactam 6d. The
most acute angle is 81.78(11)° for C(11)ꢀAuꢀN(1),
which is part of the five-membered ring formed by the
cyclometallated benzylamine ligand. As with 6d, this
five-membered ring shows puckering, with a fold angle
of 39.1(2)° through the Au, N(1), C(11), C(12) and the
C(12), C(17), N(1) planes.
2.2. Formation and characterisation of the dimeric
complex 11
On standing a CDCl3 solution of the auralactam
complex 6a overnight, colourless crystals were de-
posited, which were insoluble in all common solvents
tested, e.g. chloroform and methanol. Due to this insol-
ubility, it was not possible to obtain NMR or electro-
spray mass spectra. In order to characterise the
product, a single-crystal X-ray diffraction study was
carried out. The molecular structure of 11 and atom
numbering scheme (Fig. 2) show that the product is a
dimer, containing an eight-membered ring system and
two gold atoms. The molecule crystallises about the
crystallographic inversion centre, with a molecule of
CDCl3 per asymmetric unit. Table 2 gives selected bond
lengths and angles for 11.
The plane of the bridging cyanoacetylurethane group
lies almost perpendicular [83.82(5)°] to the gold coordi-
nation plane. In 11, the atoms of the cyanoacety-
lurethane ligand are twisted about the plane of the
ligand, which may be to accommodate the eight-mem-
bered metallacycle. Thus, the atoms N(3), O(2), O(4),
C(3), C(4), C(5) and C(6) are effectively coplanar, with
,
a maximum deviation of 0.094(3) A [for C(4)], while the
cyanide group is skewed from the plane of the ligand.
,
Atom N(2) lies 0.232(10) A out of this plane. The
urethane carbonyl oxygen O(3) is twisted with respect
,
to the plane, and lies 0.234(7) A outside the mean
plane.
The coordination sphere around the gold(III) centre
is a slightly distorted square plane with no atom dis-
,
placed more than 0.071(1) A (Au) from the plane. The
goldꢀnitrogen bonds are slightly longer [AuꢀN(3)
,
2.116(3), AuꢀN(1) 2.137(3) A] than the goldꢀcarbon
Fig. 2. Molecular structure of [{C6H3(CH2NMe2)-2-(OMe)-
5}Au{N(CO2Et)C(O)CHCN}]2·2CDCl3 (11), with atom numbering
scheme. Thermal ellipsoids are displayed at the 50% probability level,
and hydrogen atoms [except H(2a) and H(2a)%] and CDCl3 molecules
of crystallisation are omitted for clarity.
,
bonds [AuꢀC(11) 2.031(3), AuꢀC(2%) 2.098(3) A]. As
with the four-membered ring auralactam 6d, the longer
AuꢀN bond occurs for the NMe2 group. The less-con-
strained geometry in the eight-membered ring is

186
W. Henderson et al. / Journal of Organometallic Chemistry 620 (2001) 182–189
Table 2
,
Selected bond lengths (A) and angles (°) for [{C6H3(CH2NMe2)-2-
(OMe)-5}Au{N(CO2Et)C(O)CH(CN)}]2·2CDCl3 (11)
AuꢀC(11)
AuꢀN(3)
2.031(3)
2.116(3)
2.098(3)
1.152(5)
1.374(4)
1.237(4)
1.353(4)
1.464(4)
AuꢀC(2%)
AuꢀN(1)
N(3)ꢀC(4)
O(3)ꢀC(4)
O(4)ꢀC(5)
C(2)ꢀC(3)
C(5)ꢀC(6)
2.098(3)
2.137(3)
1.384(4)
1.211(4)
1.450(4)
1.523(4)
1.499(5)
C(2)ꢀAu%
N(2)ꢀC(1)
N(3)ꢀC(3)
O(2)ꢀC(3)
O(4)ꢀC(4)
C(1)ꢀC(2)
complex has also been observed, indicating that the
chemistry of gold(III) shows more variation than that
of the isoelectronic platinum(II), and suggests that the
metallacyclic chemistry of gold(III) is worthy of de-
tailed investigations.
C(11)ꢀAuꢀC(2%)
C(2%)ꢀAuꢀN(3)
C(2%)ꢀAuꢀN(1)
C(3)ꢀN(3)ꢀC(4) 124.3(2)
C(4)ꢀN(3)ꢀAu 119.8(2)
C(4)ꢀO(4)ꢀC(5) 115.7(2)
C(1)ꢀC(2)ꢀC(3) 108.9(2)
C(3)ꢀC(2)ꢀAu%
92.89(12)
90.53(10)
173.03(10)
C(11)ꢀAuꢀN(3)
C(11)ꢀAuꢀN(1)
N(3)ꢀAuꢀN(1)
C(3)ꢀN(3)ꢀAu
N(2)ꢀC(1)ꢀC(2)
C(1)ꢀC(2)ꢀAu%
O(2)ꢀC(3)ꢀN(3)
N(3)ꢀC(3)ꢀC(2)
O(3)ꢀC(4)ꢀN(3)
O(4)ꢀC(5)ꢀC(6)
175.52(10)
81.78(11)
95.04(9)
114.3(2)
178.7(3)
106.2(2)
118.7(3)
121.6(3)
128.5(3)
107.1(3)
111.0(2)
O(2)ꢀC(3)ꢀC(2) 119.6(3)
O(3)ꢀC(4)ꢀO(4) 123.6(3)
O(4)ꢀC(4)ꢀN(3) 107.8(2)
3. Experimental
3.1. Materials and instrumentation
The chloroform of crystallization in the lattice forms
The complexes [{C6H4(CH2NMe2)-2}AuCl2] (1a) [4]
and [{C6H3(CH2NMe2)-2-(OMe)-5}AuCl2] (1b) [5] were
prepared by literature methods. N-Cyanoacety-
lurethane, 2-benzoylacetanilide and acetoacetanilide
were used as supplied by Aldrich. Dichloromethane and
light petroleum (b.p. 40–60°C) were distilled from
CaH2 prior to use, and Et2O was distilled from sodium
benzophenone ketyl. All reactions were carried out
under a nitrogen atmosphere, and were shielded from
light.
,
,
a weak bond to O(2), with CꢀH 0.99 A, O···H 2.30 A
and the CꢀH···O angle 152.6°.
2.3. Discussion
It is possible to speculate on the mechanism and
driving force for the dimerisation reaction. The
goldꢀN(CO2Et) bond of 6a is trans to the very high
trans-influence aurated phenyl ring, and so the AuꢀN
bond may break, giving a zwitterionic intermediate 12.
The gold(III) centre is more labile than platinum(II);
rates of cyanide exchange indicate that the lability of
gold(III) is about two orders of magnitude greater than
that of platinum(II) [24]. Additionally, Parish and co-
workers have found that in the complex 1c one of the
acetate ligands (trans to the aryl group) undergoes
exchange more rapidly than the acetate group trans to
the NMe2 group [25]. The relief of some ring strain in
the four-membered ring will assist the ring opening;
recall that the NꢀAuꢀC bond angle in the four-mem-
bered ring of 6d is 66.65(12)°, but in the dimer 11 it is
90.53(10)°. In 12, the negative charge on N can be
resonance stabilised by the two adjacent carbonyl
groups, and in this regard it is noteworthy that a
dimeric species was only observed from complex 6a,
and not 6b–6d, where less electron-withdrawing phenyl
groups are bonded to the lactam nitrogen. Head-to-tail
dimerisation of two intermediates 12 could then give
the observed dimer 11, promoted by its insolubility.
In conclusion, we have synthesised the first examples
of auralactam complexes; the structure of one of these
shows it to be similar to other platina– and pallada–
lactam complexes. The formation of a novel dimeric
1H-NMR spectra were recorded at 300.133 MHz on
a Bruker AC300P instrument, or at 400.131 MHz on a
Bruker DRX instrument. 13C-NMR spectra were ob-
tained at either 75.47 or 100.61 MHz on the same
instruments. A combination of DEPT-135, 13C–1H cor-
relation, heteronuclear multiple quantum correlation
(HMQC), and heteronuclear multiple bond correlation
(HMBC) techniques were used to assign individual
resonances. The ROESY technique was used to assign
the aromatic resonances of complex 6b. The atom
numbering used is given in Scheme 1. Electrospray
mass spectra were recorded on a VG Platform II instru-
ment in positive-ion mode, in 1:1 MeCN–H2O. In-
frared spectra were recorded as KBr disks on a
Bio-Rad FTS40 spectrometer. Melting points were de-
termined on a Reichert–Jung hotstage apparatus and
are uncorrected.
3.2. Synthesis of [{C6H3(CH2NMe2)-2-
¸¹¹¹¹¹¹¹¹¹º
(OMe)-5}Au{N(CO2Et)C(O)CHCN}] (6a)
A mixture of [{C6H3(CH2NMe2)-2-(OMe)-5}AuCl2]
(46 mg, 0.11 mmol), N-cyanoacetylurethane (17 mg,
0.11 mmol) and silver(I) oxide (45 mg, excess) in deoxy-

W. Henderson et al. / Journal of Organometallic Chemistry 620 (2001) 182–189
187
3.4. Prepara¸ti¹on¹¹of¹[¹{C¹6ºH3(CH2NMe2)-2-
(OMe)-5}Au{NPhC(O)CHC(O)CH3}] (6c)
genated CH2Cl2 (20 ml) was refluxed for 3 h. The silver
salts were removed by filtration with no precautions to
exclude air, and the solvent removed from the filtrate to
give a pale tan solid. The product was recrystallised
from CH2Cl2–light petroleum to give 46 mg (83%) of
6a. Found: C, 36.5; H, 3.8; N, 8.0; C16H20N3AuO4
requires C, 37.3; H, 3.9; N, 8.2%. IR: w(CN) 2224(s);
w(CO) 1746(s), 1700(s) cm−1. M.p. (dec.) 210–213°C.
ES-MS (cone voltage 20 V): m/z 516 [M+H]+ (100%),
A mixture of [{C6H3(CH2NMe2)-2-(OMe)-5}AuCl2]
(52 mg, 0.120 mmol), acetoacetanilide (23 mg, 0.130
mmol) and silver(I) oxide (23 mg, excess) in deoxy-
genated CH2Cl2 (20 ml) was refluxed for 4 h. The silver
salts were removed by filtration in air affording a light
brown solution. The solvent was removed giving the
crude product, which was redissolved in CH2Cl2 (ca. 3
ml) and precipitated by the addition of Et2O (ca. 50
ml). The tan precipitate of 6c was filtered and dried (40
mg, 63%). Found: C, 44.9; H, 4.1; N, 5.6;
C20H23N2AuO3 requires: C, 44.8; H, 4.3; N, 5.2%. IR:
w(CO) 1641(s) cm−1. M.p. (dec.) 186–191°C. 1H-
1
533 [M+NH4]+ (30%), 1048 [2M+NH4]+ (90%). H-
3
NMR, l 7.10 [d, 1H, H13, J(H13, H14) 8], 7.05 [d 1H,
4
3
H16, J(H16, H14) 2], 6.81 [dd, 1H, H14, J(H14, H13) 8,
4J(H14, H16) 2], 4.26 [q, 2H, ethyl CH2, J(H, H) 7],
3
4.16 [d, 2H, H17a,b, 2J(Ha, Hb) 2], 3.81 (s, 3H, H19), 3.26
(s, 6H, H18), 1.67 (s, 1H, AuꢀCH), 1.35 [t, 3H, ethyl
CH3, 3J(H, H) 7]. 13C-{1H}-NMR, l 166.0 [s, ring
C(O)], 158.6 (s, C12), 139.5 [s, ester C(O)], 138.2 (s,
C11), 124.1 (s, C15), 117.4 (s, C13), 117.2 (s, C16), 116.1
(s, CN), 114.5 (s, C14), 72.4 (s, C17), 62.5 (s, ethyl CH2),
55.6 (s, C19), 51.8 (s, C18a), 51.7 (s, C18b), 18.4 (s,
AuꢀCH), 14.5 (s, ethyl CH3).
3
NMR, l 7.38 [t, 2H, H23, J(H23, H22/24) 8], 7.22 [dd,
3
4
2H, H22, J(H22, H23) 8, J(H22, H24) 1], 7.14 [t, 1H.
3
4
H24, J(H24, H23) 8, 7.09 [d, 1H, H16, J(H16, H14) 2],
3
7.06 [d, 1H, H13, J(H13, H14) 8], 6.74 [dd, 1H, H14,
3J(H14, H13) 8, J(H14, H16) 2], 4.00 [d, AB spin system,
4
2
2H, H17a,b, J(Ha, Hb) 14], 3.86 (s, 3H, H19), 3.41 (s,
1H, AuꢀCH), 2.82 (s, 3H, H18), 2.79 (s, 3H, H18), 2.41
[s, 3H, C(O)CH3]. 13C-{1H}-NMR,
l
203.1 [s,
C(O)CH3], 170.4 [s, ring C(O)], 158.5 (s, C12), 141.7 (s,
C11), 141.3 (s, C21), 137.4 (s, C15), 129.2 (s, C23), 126.4
(s, C22), 125.2 (s, C24), 123.9 (s, C13), 116.9 (s, C16),
114.3 (s, C14), 71.5 (s, C17), 55.6 (s, OCH3), 50.9 (s,
C18a), 50.8 (s, C18b), 48.2 (s, AuꢀCH), 27.7 [s,
C(O)CH3].
3.3. Preparation of [{C6H3(CH2NMe2)-2-(OMe)-5}-
¸¹¹¹¹¹¹º
Au{NPhC(O)CHC(O)Ph]] (6b)
[{C6H3(CH2NMe2)-2-(OMe)-5}AuCl2] (52 mg, 0.120
mmol), 2-benzoylacetanilide (29 mg, 0.122 mmol) and
silver(I) oxide (62 mg, excess) were refluxed in degassed
CH2Cl2 (20 ml) for 2.5 h. Removal of the silver salts by
filtration gave a deep yellow solution. Removal of the
solvent resulted in a dark tan solid, which was recrys-
tallised by addition of light petroleum (30 ml) to a
CH2Cl2 (2 ml) solution. This product was filtered and
dried in vacuo to give 6b (48 mg, 66%). Found: C, 50.4;
H, 4.2; N, 4.8; C25H25N2AuO3 requires: C, 50.2; H, 4.2;
N, 4.7%. IR: w(CO) 1643(vs) cm−1. M.p. (dec.) 197–
3.5. Preparation of
¸¹¹¹¹¹¹º
[{C6H4(CH2NMe2)-2}Au{NPhC(O)CH(COMe)}] (6d)
A
deoxygenated mixture of [{C6H4(CH2NMe2)-
2}AuCl2] (34 mg, 0.084 mmol), acetoacetanilide (16 mg,
0.089 mmol) and silver(I) oxide (ca. 100 mg, excess) in
CH2Cl2 (20 ml) was refluxed for 2.5 h. Silver salts were
removed by filtration affording a pale yellow solution.
The solvent was removed and the tan product recrys-
tallised by addition of Et2O (ca. 40 ml) to a CH2Cl2 (3
ml) solution, to give 6d (60 mg, 36%). Crystals of single
crystal X-ray diffraction quality were grown by vapour
diffusion of Et2O into a CH2Cl2 solution. Found: C,
45.0; H, 4.1; N, 5.7; C19H21AuN2O2 requires: C, 45.1;
H, 4.2; N, 5.5%. IR: w(CO) 1641(s) cm−1. ESMS (cone
voltage 20 V): m/z 507 [M+H]+ (100%), 1013 [2M+
1
3
201°C. H-NMR, l 8.17 [dd, 2H, H32, J(H32, H33) 8,
4J(H33, H34) 2], 7.50 [t, 1H, H34, J(H34, H33) 7, J(H34,
H32) 2], 7.43 [dist. t, 2H, H23, J(H23, H22/24) 8], 7.35
3
4
3
3
[dist. t, 2H, H33, J(H33, H32/34) 8], 7.24 [d, 2H, H22,
3J(H22, H23) 8, J(H22, H24) 1], 7.11 [t, 1H, H24, J(H24,
4
3
4
3
H23) 8), J(H24, H22) 1], 6.98 [d, 1H, H13, J(H13, H14)
4
8], 6.72 [d, 1H, H16, J(H16, H14) 3], 6.64 [dd, 1H, H14,
3J(H14, H13) 8, J(H14, H16) 3], 4.19 (s, AuꢀCH), 3.93
4
1
H]+ (40%). M.p. (dec.) 184–187°C. H-NMR, l 7.45
[AB spin system, 2H, H17a,b, 2J(Ha, Hb) 37], 3.51 (s, 3H,
H19), 2.75 (s, 3H, H18), 2.74 (s, 3H, H18). 13C-{1H}-
NMR, l 196.9 [s, C(O)Ph], 170.3 [s, ring C(O)], 158.2
(s, C12), 141.9 (s, C11), 141.5 (s, C21), 138.8 (s, C31),
137.6 (s, C15), 132.6 (s, C34), 129.2 (s, C33), 129.0 (s,
C32), 128.5 (s, C23), 126.4 (s, C22), 125.1 (s, C24), 124.1
(s, C13), 117.6 (s, C16), 114.1 (s, C14), 71.5 (s, C17), 55.2
(s, C19), 50.8 (s, C18a), 50.7 (s, C18b), 44.4 (s, AuꢀCH).
3
3
[d, H15, J(H, H) 7], 7.37 [dist. t, H23, J(H, H) 7], 7.21
3
3
[dd, H22, J(H, H) 7], 7.20 [dist t, H24, J(H, H) 8], 7.15
3
3
[t, H16, J(H, H) 7], 7.15 [t, H13, J(H, H) 8], 7.13 [t,
H14, 3J(H, H) 8], 4.04 [AB spin system, 2H, H17a,b
,
2J(Ha, Hb) 33], 3.40 (s, 1H, AuꢀCH), 2.83 (s, 3H, H18),
2.79 (s, 3H, H18), 2.40 [s, 3H, C(O)CH3]. 13C-{1H}-
NMR, l 201.3 [s, C(O)CH3], 169.5 [s, ring C(O)], 146.4
(s, C12), 145.4 (s, C21), 133.2 (s, C11), 132.6 (s, C15),

188
W. Henderson et al. / Journal of Organometallic Chemistry 620 (2001) 182–189
128.5 (s, C23), 128.1 (s, C13), 127.4 (s, C24), 123.9 (s,
C22), 123.5 (s, C14), 122.6 (s, C16), 72.8 (s, C17), 52.0 (s,
C18a), 51.8 (s, C18b), 48.4 (s, AuꢀCH), 14.5 [s,
C(O)CH3].
3.6. X-ray crystallography
Data were collected on a Siemens SMART CCD
diffractometer for 6d and on an Enraf–Nonius CAD4
diffractometer for 11 using Mo–Ka radiation (u=
,
0.71073 A) at 203(2) K, and were corrected for absorp-
tion using SADABS [26]. Cell and final refinement
parameters for both structures are given in Table 3.
Table 3
Crystal, collection and refinement data for [{C6H4(CH2NMe2)-
2}Au{NPhC(O)CH(COMe)}] (6d) and [{C6H4(CH2NMe2)-2-(OMe)-
5} Au {N(CO2Et)C(O)CH(CN)}]2·2CDCl3 (11)
3.6.1. Complex 6d
6d
11
The location of the gold atom was determined by
Patterson methods. Remaining atoms were located
from residual electron-density maps, and refined rou-
tinely. All non-hydrogen atoms were refined anisotropi-
cally. Hydrogen atoms were included in calculated
positions, with Uiso 1.5 times that of the atom to which
they are bonded (for methyl hydrogens) and 1.2 times
for all other hydrogen atoms.
Crystal data
Empirical formula
Formula weight
Crystal system
Space group
C19H21AuN2O2
506.34
Triclinic
C16H20AuN3O4·CDCl3
636.70
Monoclinic
P21/c
(
P1
Unit cell dimensions
,
a (A)
8.721(1)
10.7841(1)
11.0297(1)
61.6520(1)
84.37(1)
79.537(1)
897.662(12)
2
12.359(1)
15.1831(1)
12.5665(1)
90
113.740(1)
90
2158.52(2)
4
1.959
,
b (A)
,
c (A)
3.6.2. Complex 11
h (°)
i (°)
k (°)
Colourless crystals of the dimer precipitated from an
NMR solution of 6a in CDCl3 during an 18-h data
collection. Colloidal gold and/or silver (from the Ag2O
reagent) was also observed, indicating some decomposi-
tion. Energy dispersive X-ray (EDAX) analysis of a
crushed crystal of 11 on a scanning electron microscope
indicated the presence of Au and Cl.
3
,
V (A )
Z
Dcalc (g cm−3
)
1.873
Data collection
Crystal size (mm)
Theta range for
data collection (°)
0.40×0.30×0.22
2.10–28.13
0.34×0.30×0.22
1.80–28.17
Atoms not located in the initial electron density map
were located from subsequent electron density maps.
All heavy atoms were refined with anisotropic thermal
parameters. Hydrogen atoms were included in calcu-
lated positions with methyl hydrogens assigned thermal
parameters 1.5 times the Uiso of the atom to which they
are bonded, and all others with thermal parameters
20% greater than the Uiso of the atom to which they are
bonded.
Reflections collected 8901
5196
Independent
reflections
Absorption
coefficient
3935 [Rint=0.0193] 4955 [Rint=0.0193]
8.207
7.211
(mm−1
)
Max/min
transmission
F(000)
0.2654, 0.1378
488
0.2998, 0.1929
1228
Structure analysis and refinement
Solution by Patterson methods Direct methods
Refinement method Full-matrix Full-matrix
least-squares on F2 least-squares on F2
4. Supplementary material
Data/restraints/param 3935/0/220
4955/0/251
eters
Crystallographic data for the structural analyses have
been deposited with the Cambridge Crystallographic
Data Centre, CCDC, no. 149443 for compound 6d, and
no. 149444 for compound 11. Copies of this informa-
tion may be obtained free of charge from The Director,
CCDC, 12 Union Road, Cambridge CB2 1EZ, UK
Goodness-of-fit on
1.104
1.065
F2
Final R indices
[I\2|(I)]
R1=0.0188,
wR2=0.0475
R1=0.0213,
wR2=0.0524
R1=0.0236,
wR2=0.0536
w=1/[|2(F2o)
R indices (all data) R1=0.0197,
wR2=0.0480
Weighting scheme a w=1/[|2(Fo2)
(Fax:
+44-1223-336033;
e-mail:
deposit@ccdc.
+(0.0135P)2
+1.1058P]
1.845
+(0.0237P)2
+3.6911P]
1.257
cam.ac.uk or www: http://www.ccdc.cam.ac.uk).
Largest difference
−3
,
peak (e A
)
Acknowledgements
Largest difference
−1.087
−1.663
−3
,
hole (e A
Solution by
)
We thank the University of Waikato for financial
support, including a scholarship (to A.G. Oliver). The
New Zealand Lottery Grants Board is thanked for
Grants-in-Aid towards the purchase of the mass spec-
SHELXS 97 [27]
SHELXL 97 [27]
SHELXS 96 [27]
SHELXL 97 [27]
Refinement by
a P=(F2o+2F2c)/3.

W. Henderson et al. / Journal of Organometallic Chemistry 620 (2001) 182–189
189
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(University of Auckland) is thanked for providing the
X-ray data sets.
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