Organogold(I) macrocycles and [2]catenanes containing pyridyl and bipyridyl substituents - Organometallic catenanes as ligands

Article abstract of DOI:10.1139/V05-229

The synthesis of achiral gold(I) macrocycles [RCH(4-C₆H ₄OCH₂C=CAu)₂(μ-Ph₂PZPPh ₂)] and the corresponding chiral gold(I) [2]catenanes, bearing substituents R = 2-pyridyl, 4-pyridyl, and 4-(

Full text of DOI:10.1139/V05-229

111
Organogold(I) macrocycles and [2]catenanes
containing pyridyl and bipyridyl substituents —
Organometallic catenanes as ligands1
Nicolle C. Habermehl, Fabian Mohr, Dana J. Eisler, Michael C. Jennings, and
Richard J. Puddephatt
Abstract: The synthesis of achiral gold(I) macrocycles [RCH(4-C6H4OCH2CϵCAu)2(µ-Ph2PZPPh2)] and the correspond-
ing chiral gold(I) [2]catenanes, bearing substituents R = 2-pyridyl, 4-pyridyl, and 4-(2,2′-bipyridyl), is reported. The
gold(I) compounds form by self-assembly on reaction of oligomeric digold(I) diacetylides [{RCH(4-C6H4OCH2CϵCAu)2}n]
or the isocyanide complexes [RCH(4-C6H4OCH2CϵCAuCϵN-t-Bu)2] with diphosphine ligands Ph2PZPPh2, Z = CC or
(CH2)n with n = 2–5, or on reaction of [Au2(O2CCF3)2(µ-Ph2PZPPh2)] with diacetylenes RCH(4-C6H4OCH2CϵCH)2 in
the presence of a base. The equilibrium between macrocycles and chiral [2]catenanes in solution was established by
NMR spectroscopy, while the structures of several [2]catenanes in the solid state were established crystallographically.
The coordination of the gold(I) compounds with R = 4-(2,2′-bipyridyl) to platinum(IV), by formation of the corre-
sponding [PtIMe3(bipy)] units, is established, showing that organometallic [2]catenanes can act as ligands.
Key words: gold, macrocycle, catenane, platinum.
Résumé : On a réalisé la synthèse des macrocycles achiraux d’or(I) de formule générale [RCH(4-C6H4OCH2CϵCAu)2-
(µ-Ph2PZPPh2)] et des [2]caténanes chiraux d’or(I) correspondants portant les groupes R = 2-pyridyle, 4-pyridyle et 4-
(2,2′-bipyridyle). Les composés d’or(I) forment des produits d’autoassemblage par réaction des diacétylures de dior(I)
oligomères de formule générale [{(RCH(4-C6H4OCH2CϵCAu)2}n] ou des complexes d’isocyanures de formule générale
[RCH(4-C6H4OCH2CϵCAuCϵN-t-Bu)2] avec des ligands diphosphine Ph2PZPPh2 (Z = CC ou (CH2)n avec n = 2, 3, 4,
5) ou par réaction de [Au2(O2CCF3)2(µ-Ph2PZPPh2)] avec des dérivés diacétylènes RCH(4-C6H4OCH2CϵCH)2, en pré-
sence de base. On a établit la nature de l’équilibre entre les macrocycles et les [2]caténanes chiraux en solution à
l’aide de la spectroscopie RMN alors que plusieurs structures de [2]caténanes à l’état solide ont été établies par diffrac-
tion des rayons X. En montrant que les [2]caténanes organométalliques peuvent agir comme ligands avec formation des
unités correspondantes [PtIMe2(bipy)], on a démontré que les composés d’or(I) avec R = 4-(2,2′-bipyridyle) peuvent
donner une coordination avec le platine(IV).
Mots clés : or, macrocycle, caténane, platine.
[Traduit par la Rédaction] Habermehl et al. 123
Introduction
was incorporated into the backbone of a [2]catenane and
then used to coordinate to silver(I) (15). This example sug-
gests a general method for growing more complex architec-
tures from [2]catenane building blocks by introducing donor
groups as substituents and then using these donor groups to
form complexes with transition metals, as shown in
Scheme 1. In the simplest case A, a macrocycle can act as a
ligand, but a metal centre can also act as template to assem-
ble two or more macrocycles as in case B. If the macro-
cycles form a [2]catenane, then the analogous forms of
coordination will give a [2]catenane coordinated to two
metal centres (case C) or to a polymer of [2]catenanes (case
The field of chemistry that encompasses the design, syn-
thesis, and functionalization of mechanically interlocked
molecules such as catenanes, rotaxanes, and knots has un-
dergone great advances in recent decades, with the use of the
coordinate bond allowing the directed self-assembly of these
molecules in high yields (1–7). A natural extension to this
field is the synthesis of coordination polymers (8–11) such
as poly[2]catenanes (12–15). For example, a poly(bis-
[2]catenane) that contains covalent, coordinate, and mechan-
ical linkages has been reported in which a bipyridine unit
Received 16 June 2005. Published on the NRC Research Press Web site at http://canjchem.nrc.ca on 21 February 2006.
This article is dedicated to Dr. Arthur J. Carty in recognition of his pioneering research in cluster chemistry and his outstanding
service to science in Canada.
N.C. Habermehl, F. Mohr, D.J. Eisler, M.C. Jennings, and R.J. Puddephatt.2 Department of Chemistry, University of Western
Ontario, London, ON N6A 5B7, Canada.
1This article is part of a Special Issue dedicated to Professor Arthur Carty.
2Corresponding author (e-mail: pudd@uwo.ca).
Can. J. Chem. 84: 111–123 (2006)
doi:10.1139/V05-229
© 2006 NRC Canada

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Can. J. Chem. Vol. 84, 2006
Scheme 1.
Scheme 2.
M = metal, L = ligand
MLn
P-Z-P = Ph2PZPPh2, Z = (CH2)3 or (CH2)4
O
N
A
B
Au
P
P
H
R
MLn
N
N
Z
Au
N
MLn
LnM
N
C
O
N
MLn
LnM
N
D
x
O
Z
O
Au
Au
P
D). This article describes attempts to develop this chemistry
by using organogold macrocycles and [2]catenanes with
pyridyl or bipyridyl groups as substituents, and reports the
first example of the use of an organometallic [2]catenane as
a ligand.
P
H
R
R
H
Z
P
P
Au Au
The ligands pyridine and 2,2′-bipyridyl (bipy) form stable
complexes with transition-metal ions (16), and appropriate
substitution of the two pyridyl rings in 2,2′-bipyridyl has
given many symmetrical or unsymmetrical derivatives that
are useful for the synthesis of helicates, ladders, rods, cate-
nanes, and coordination polymers (2, 16–24). In earlier
papers, we have reported that macrocyclic organogold(I)
O
O
Scheme 3.
O
OCH2CCH
Au
complexes,
such
as
[RCH(C6H4OCH2CϵCAu)2(µ-
Cl-Au-SMe2
base
H
H
R
Ph2P(CH2)nPPh2)] with R,R′ = H, alkyl, or aryl and n = 3 or
4, may spontaneously and reversibly form [2]catenanes
[RCH(C6H4OCH2CϵCAu)2(µ-Ph2P(CH2)nPPh2)]2, probably
by a mechanism involving cleavage of a gold–phosphorus
bond followed by threading/unthreading and recoordination
(Scheme 2) (25, 26). It is then a natural extension to prepare
the corresponding organogold complexes with R = pyridyl or
2,2′-bipyridyl, to form organometallic [2]catenanes that have
the potential to act as ligands. Another important feature of
these compounds is that the macrocycles are achiral but the
[2]catenanes are chiral, and so the pyridyl and 2,2′-bipyridyl
donors may act as chiral ligands (25). The syntheses and
structures of the organogold complexes with pyridyl and
bipyridyl substituents, and some preliminary studies of their
properties, are described in the following.
R
Au
O
x
OCH2CCH
3a, R = 2-py
3b, R = 4-py
2a, R = 2-py
2b, R = 4-py
2c, R = 4-(2,2'-bipy)
Ph2P-Z-PPh2
O
Ph
Au
Ph
P
H
R
Z
P
Au
Ph
Results and discussion
Ph
O
4a, R = 2-py, Z = CC;
Synthesis of gold(I) compounds
4b, R = 4-py, Z = CC
The ligands RCH(C6H4OCH2CϵCH)2, containing sub-
stituents R = 2-pyridyl (2a), 4-pyridyl (2b), and 4-(2,2′-
bipyridyl) (2c), were prepared by condensation of phenyl
propargyl ether with the corresponding carboxaldehydes
(RCH=O), 1a (R = 2-pyridyl), 1b (R = 4-pyridyl), and 1c
(R = 4-(2,2′-bipyridyl) (27, 28)) by the established general
method (25, 26). Reaction of the diacetylene ligands 2a and
2b with chloro(dimethylsulfide)gold(I) in the presence of a
base gave the insoluble oligomeric digold(I) diacetylides
([RCH(C6H4OCH2CϵCAu)2]x) 3a, R = 2-pyridyl, and 3b,
5a, R = 2-py, Z = (CH2)2; 5b, R = 4-py, Z = (CH2)2
6a, R = 2-py, Z = (CH2)3; 6b, R = 4-py, Z = (CH2)3
7a, R = 2-py, Z = (CH2)4; 7b, R = 4-py, Z = (CH2)4
8a, R = 2-py, Z = (CH2)5; 8b, R = 4-py, Z = (CH2)5
R = 4-pyridyl, as shown in Scheme 3. The CϵC stretching
frequencies observed by IR spectroscopy (3a, 2000 cm–1;
3b, 2013 cm–1) are about 100 cm–1 lower than the corre-
sponding CϵC stretching frequencies for the free ligands
(2a, 2120 cm–1; 2b, 2118 cm–1), which indicates that the
© 2006 NRC Canada

Habermehl et al.
113
Scheme 4.
Scheme 5.
Reagents: (i) [Au2(O2CCF3)2(Ph2PZPPh2)], base
P-Z-P = Ph2PZPPh2
OCH2CCH
O
Z
O
Z
O
Ph
Au
Ph
(i)
Au
Au
P
H
P
P
P
H
H
R
H
R
Z
N
N
P
N
P
Au
Ph
Au
Au
OCH2CCH
Ph
O
N
O
O
2c
6c, Z = (CH2)3
7c, Z = (CH2)4
6*-aS, Z = (CH2)3
7*-aS, Z = (CH2)4
O
Au
P
diacetylenes are both σ bonded and π bonded to the gold(I)
centres to form oligomeric structures (29, 30). Reaction of
these oligomeric digold(I) complexes (3a and 3b) with
diphosphine ligands then gave the macrocyclic digold(I)
H
R
Z
P
Au
complexes,
[RCH(C6H4OCH2CϵCAu)2{µ-Ph2P-Z-PPh2}]
(4–8) (Scheme 3), many of which exist as an equilibrium
mixture of the macrocyclic complexes depicted in Scheme 3
and the corresponding [2]catenane. An alternative route to
the complexes 4–8 is to react the oligomers 3 with tert-butyl
isocyanide to give the soluble isocyanide derivatives
RCH(C6H4OCH2CϵCAuCϵN-t-Bu)2 and then to displace
the isocyanide ligands by the appropriate diphosphine ligand
(Ph2P-Z-PPh2).
Attempts to prepare the corresponding complexes with
R = 4-(2,2′-bipy) by this procedure were unsuccessful be-
cause the desired products, [RCH(C6H4OCH2CϵCAu)2{µ-
Ph2P-Z-PPh2}], were always formed as a mixture with the
chloride complex [Au2Cl2(µ-Ph2P-Z-PPh2)], and this
chlorogold impurity was not easily separated. The pure
digold(I) complexes containing the 4-(2,2′-bipy) group were
therefore prepared by reaction at low temperature of the
diacetylene ligand 2c with [Au2(O2CCF3)2(µ-Ph2P–Z–PPh2)],
which is conveniently prepared in situ from [Au2Cl2(µ-Ph2P–
Z–PPh2)] and silver trifluoroacetate (Scheme 4).
In cases where the macrocyclic complexes 6 and 7 are in
equilibrium with the [2]catenane isomers, the presence of a
prochiral carbon at the hinge group (CHR) leads to forma-
tion of [2]catenanes 6* and 7*, which are axially chiral with
C2 symmetry (25). These chiral [2]catenanes are formed as
racemates, which have the stereochemical descriptors aR and
aS (the symbol “a” in aR/aS indicates axial chirality (31,
32)), as illustrated in Scheme 5. The interconversion of ring
and catenane is known to be catalysed by traces of free
phosphine and so probably involves ring-opening by cleav-
age of an Au—P bond, followed by threading or dethreading
(25, 26).
O
6, Z = (CH2)3
7, Z = (CH2)4
6*-aR, Z = (CH2)3
7*-aR, Z = (CH2)4
O
O
Au
Au
P
P
P
H
R
R
H
Z
Z
P
Au
Au
O
O
prised of two interlocked 24-membered rings, while 7a* is
comprised of two 25-membered rings.
Of the complexes studied, only 6b* (R = 4-pyridyl, Z =
(CH2)3, Fig. 1) showed no disorder, so its structure will be
discussed first. The complex crystallized in space group
P21/c with Z = 4, and hence contains equal amounts of the
enantiomers 6b*-aR and 6b*-aS. As seen in previous exam-
ples of gold(I) [2]catenanes (25, 26, 33–35), an intermacro-
cycle aurophilic interaction is observed for the [2]catenane,
with Au(1)—Au(2) = 3.2097(8) Å, while the second
gold···gold distance (Au(3)—Au(4) = 3.404 Å) indicates
only a weak Au···Au interaction (36). A combination of the
secondary Au···Au bonding and several intermacrocycle
aryl···aryl bonding interactions provides the driving force for
the catenation (25, 26, 33–36). There is significant bowing
of the P-Au-C-C-C groups away from linearity with angles
P-Au-C, Au-C-C, and C-C-C in the ranges 169.3(5)°–
171.4(4)°, 167(2)°–174(2)°, and 169(2)°–178(2)°, respec-
tively, and this bowing appears to be correlated to the short
Au···Au contacts.
Characterization of the gold(I) complexes
The structures of the singly braided [2]catenane com-
plexes 6a* (R = 2-py), 6b* (R = 4-py), 6c* (R = 4-(2,2′-
bipy), and 7a* (R = 2-py) were determined crystallographi-
cally and are shown in Figs. 1–4. They form by [2+2] self-
assembly of the appropriate digold(I) diacetylide unit and
diphosphine ligand to give two mechanically interlocked
rings. The [2]catenanes 6a*, 6b*, and 6c* are each com-
The aryl twist angles, defined as the angles between the
planes of the C6H4 groups and the C-C-C plane of the
“hinge carbon atom”, are important in determining the
favorability of [2]catenane formation (25, 26). Optimum aryl
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Can. J. Chem. Vol. 84, 2006
Fig. 1. Molecular structure of [2]catenane 6b* (R = 4-pyridyl, Z = (CH2)3): above, a single chiral [2]catenane, and below, a racemic
pair of [2]catenanes with connecting N···HC hydrogen bonds (only the gold atoms are numbered). Selected bond distances (Å) and an-
gles (°): Au(1)—Au(2) 3.2097(8); Au(1)—P(1) 2.269(4); Au(2)—P(2) 2.275(4); Au(3)—P(3) 2.268(4); Au(4)—P(4) 2.275(5); Au(1)—
C(11) 1.97(2); Au(2)—C(21) 2.01(2); Au(3)—C(31) 2.02(2); Au(4)—C(41) 1.93(2); C(11)—C(12) 1.19(2); C(21)—C(22) 1.16(2);
C(31)—C(32) 1.15(2); C(41)—C(42) 1.18(2); P(1)-Au(1)-C(11) 169.3(5); P(2)-Au(2)-C(21) 171.4(4); P(3)-Au(3)-C(31) 171.2(4); P(4)-
Au(4)-C(41) 170.1(6); Au(1)-C(11)-C(12) 170(2); Au(2)-C(21)-C(22) 167(1); Au(3)-C(31)-C(32) 170(1); Au(4)-C(41)-C(42) 174(2);
C(11)-C(12)-C(13) 177(2); C(21)-C(22)-C(23) 178(2); C(31)-C(32)-C(33) 175(2); C(41)-C(42)-C(43) 169(2).
Au(3)
O(14)
Au(1)
Au(4)
P(3)
N(65)
P(4)
P(2)
N(55)
Au(2)
Au(3)
P(3)
O(34)
4
2
3
3
1
4
1
2
twist angles are in the range 45°–90° (25, 26) and in com-
plex 6b* these angles are 83° and 82° in one macrocycle
and 72° and 71° in the other (the corresponding twist angles
in the parent bis(phenol) are 44° and 87°). In the structures
of all other known complexes with unsymmetrical hinge
groups (RCH), there is disorder of the substituent R on ei-
ther side of the plane of the macrocycle. The well-ordered
structure of 6b* appears to result from favorable pairwise
hydrogen bonding between the nitrogen atom of one of the
4-pyridyl substituents and a meta-hydrogen atom of a
phenylphosphorus group on a neighbouring molecule (37),
as shown in Fig. 1. The nitrogen atom N(55) of the 4-pyridyl
group of one ring interacts with an aryl CH group of a
neighbour with N(55)···C(2C) = 3.22 Å, N···H = 2.35 Å, and
angle C-H···N = 154°. No close intermolecular aryl–aryl in-
teractions were observed (38, 39). The pairs of chiral hydro-
gen-bonded [2]catenanes (Fig. 1) are related by an inversion
centre and so comprise a racemic aR–aS couple.
The structures of complexes 6a* and 6c* (Figs. 2 and 3)
are similar to that of 6b* but they each show disorder in the
RCH(C6H4)2 region. The aryl twist angles associated with
the two disorder components A and B in 6a*were for com-
ponent A: 88°,25° (ring 1) and 85°,29° (ring 2); and for
component B: 85°,43° (ring 1) and 89°,41° (ring 2). The val-
ues of the aryl twist angles of 25° and 29° are the smallest
yet observed in a [2]catenane (25, 26). For comparison, the
aryl twist angles in the related bis(phenol) RCH(C6H4OH)2
(R = 2-pyridyl) were 87°,44°. The closest gold···gold con-
tacts in 6a* are the intermacrocycle distances Au(1)—
Au(4) = 3.1574(5) Å and Au(2)—Au(3) = 3.555 Å.
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Habermehl et al.
115
Fig. 2. Molecular structure of [2]catenane 6a* (R = 2-pyridyl, Z = (CH2)3) showing only the A disorder component. Selected bond dis-
tances (Å) and angles (°): Au(1)—Au(4) 3.1574(5); Au(1)—P(1) 2.276(2); Au(2)—P(2) 2.275(2); Au(3)—P(3) 2.280(2); Au(4)—P(4)
2.273(2); Au(1)—C(11) 1.990(8); Au(2)—C(21) 1.991(7); Au(3)—C(31) 2.008(8); Au(4)—C(41) 1.990(8); C(11)—C(12) 1.18(1);
C(21)—C(22) 1.19(1); C(31)—C(32) 1.18(1); C(41)—C(42) 1.19(1); P(1)-Au(1)-C(11) 170.4(2); P(2)-Au(2)-C(21) 168.3(2); P(3)-
Au(3)-C(31) 173.0(2); P(4)-Au(4)-C(41) 168.9(2); Au(1)-C(11)-C(12) 170.4(8); Au(2)-C(21)-C(22) 172.2(7); Au(3)-C(31)-C(32)
175.3(7); Au(4)-C(41)-C(42) 171.7(8); C(11)-C(12)-C(13) 178.9(9); C(21)-C(22)-C(23A) 171(1); C(21)-C(22)-C(23B) 176(1); C(31)-
C(32)-C(33) 175.1(9); C(41)-C(42)-C(43A) 173(1); C(41)-C(42)-C(43B) 158(1).
O(34A)
Au(3)
P(3)
P(4)
Au(4)
P(2)
N(67A)
Au(2)
O(24A)
P(1)
Au(1)
N(57A)
O(14A)
Fig. 3. Molecular structure of [2]catenane 6c* (R = 4-(2,2′-bipyridyl), Z = (CH2)3); only one disorder component is shown. Selected
bond distances (Å) and angles (°): Au(1)—Au(2) 3.2195(7); Au(1)—P(1) 2.269(3); Au(2)—P(2) 2.281(3); Au(3)—P(3) 2.271(4);
Au(4)—P(4) 2.266(3); Au(1)—C(11) 2.02(1); Au(2)—C(21) 1.99(2); Au(3)—C(31) 2.00(2); Au(4)—C(41) 2.04(1); C(11)—C(12)
1.16(2); C(21)—C(22) 1.18(2); C(31)—C(32) 1.18(2); C(41)—C(42) 1.17(2); P(1)-Au(1)-C(11) 170.8(4); P(2)-Au(2)-C(21) 170.2(4);
P(3)-Au(3)-C(31) 170.5(4); P(4)-Au(4)-C(41) 171.2(4); Au(1)-C(11)-C(12) 170(1); Au(2)-C(21)-C(22) 174(1); Au(3)-C(31)-C(32)
166(1); Au(4)-C(41)-C(42) 171(1); C(11)-C(12)-C(13) 177(1); C(21)-C(22)-C(23) 174(2); C(31)-C(32)-C(33A) 177(2); C(41)-C(42)-
C(43) 175(1).
O44
Au(4)
N75B
N83B
P4
O14
N59A
P1
Au(1)
N55A
Au(3)
P2
Au(2)
P3
O24
O34A
Complex 6c* (Fig. 3) was also disordered around the two
CH(4-(2,2′-bipy))(C6H4)2 units of the [2]catenane and the
disorder was modeled as A/B = 51/49 for each component
of the interlocked rings. The aryl twist angles for the two
distributions were found to be: A: 88°,52° (ring 1) and
70°,56° (ring 2); and B: 69°,36° (ring 1) and 50°,45° (ring
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Can. J. Chem. Vol. 84, 2006
Fig. 4. Molecular structure of [2]catenane 7a* (R = 2-pyridyl, Z = (CH2)4) with only one disorder component shown. Selected bond
distances (Å) and angles (°): Au(1)—P(1) 2.361(6); Au(2)—P(4) 2.277(6); Au(1A)—P(2) 2.272(6); Au(3)—P(3) 2.256(7); Au(1)—
C(11) 1.94(3); Au(2)—C(22) 2.00(3); Au(1A)—C(5) 1.98(3); Au(3)—C(16) 2.09(3); P(1)-Au(1)-C(11) 176.4(6); P(4)-Au(2)-C(22)
173.1(8); P(2)-Au(1A)-C(27) 176.1(7); P(3)-Au(3)-C(16) 177.8(7); Au(1)-C(11)-C(10) 169(2); Au(2)-C(21)-C(22) 166(3); Au(1A)-C(5)-
C(6) 169(2); Au(3)-C(16)-C(17) 168(2); C(5)-C(6)-C(7) 176(3); C(9)-C(10)-C(11) 176(3); C(16)-C(17)-C(18) 170(3); C(20)-C(21)-
C(22) 174(3).
O(2)
Au(1)
C(11)
P(1)
O(3)
P(3)
N(2)
Au(3)
N(1)
Au(2)
P(4)
Au(1A)
O(4)
P(2)
O(1)
2). In complex 6c*, the nitrogen atoms of the two pyridyl
rings in each 4-(2,2′-bipy) group adopt an approximately
planar s-trans conformation, as is typical for free 2,2′-
bipyridyl ligands (16). In the disordered structure, the angles
between the two pyridyl rings of each 2,2′-bpy group were:
A: 31° and 9°; and B: 34° and 17°. As in the complexes 6a*
and 6b*, there was one strong and one weak Au···Au inter-
have Cs symmetry so that the two phosphorus atoms are
equivalent and will resonate as a singlet in the 31P NMR
spectrum. In contrast, the chiral [2]catenanes 6* and 7* have
C2 symmetry and so the two phosphorus atoms in each inter-
locked ring of the [2]catenane will be nonequivalent and
will resonate as two doublets in the 31P NMR spectrum (25,
26). The gold(I) complexes 4, 5, 7, and 8, containing the
diphosphines Ph2P-Z-PPh2 with Z = CϵC, (CH2)2, (CH2)4,
and (CH2)5, respectively, all give a singlet resonance in their
31P NMR spectra and so are presumed to exist in solution as
the macrocyclic complexes. In the solid state, the gold(I)
complex with R = 2-pyridyl and Z = (CH2)4 exists as a
[2]catenane 7a*, but this is presumed to dissociate back to
the macrocycle 7a in solution. However, the gold(I) com-
action (36) with Au(1)···Au(2)
= 3.2195(7) Å and
Au(3)···Au(4) = 3.442 Å in 6c*. No significant inter-
catenane hydrogen bonding or π stacking of aryl groups was
observed in the crystal structure of complex 6c*.
The structure of 7a* showed disorder at the RCH(C6H4)2
units, similar to that in 6a* and 6c*, but there was a second
form of disorder arising from the presence of an inversion
centre at the midpoint of the Au(1)···Au(1A) unit. The inter-
locked 25-membered rings in 7a* (Fig. 4) are much less
congested than the 24-membered rings in 6a*–6c* and there
are no short gold···gold distances. The shortest intra-
catenane Au···Au distance is Au(1A)—Au(2) = 5.138 Å,
which is too long to be indicative of an aurophilic interac-
tion (36). The main forces favoring catenation in this case
are aryl···aryl attractions (25, 26).
plexes 6, with Z = (CH2)3, give several resonances in the 31
P
NMR spectra, indicating that they exist as a mixture of iso-
mers in solution. For example, the macrocyclic complex 6a
(R = 2-py) gave a singlet resonance at δ(31P) 35.93 and was
in equilibrium with the [2]catenane 6a*, which gave an
“AB” multiplet with δ(31P) 31.89 and 32.18, with coupling
4J(PAPB) = 6 Hz. In the 1H NMR spectra, there are some sig-
nificant differences in chemical shift between the macro-
cyclic and [2]catenane structures. For example, 6a has
δ(CHpy) 5.54 and δ(C6H4) 7.01 and 7.12, whereas 6a* has
NMR spectroscopy
It is possible to distinguish between the macrocycle and
[2]catenane structures by NMR spectroscopy based on the
molecular symmetry. Thus, the achiral ring complexes 4–8
δ(CHpy) 5.07 and δ(C6H4) 6.16 and 6.78. Ring current ef
-
fects from the adjacent phenylphosphorus groups in the
[2]catenane cause these diagnostic shifts. Slow crystalliza-
© 2006 NRC Canada

Habermehl et al.
117
tion of this complex (6a/6a*) gave the pure [2]catenane 6a*,
which, on dissolution in CD2Cl2, gave only the resonances
of the [2]catenane. Equilibration occurred slowly in solution,
over a period of several days at room temperature. In dilute
solution the equilibrium favours the macrocycle 6a but, at
high concentration, more of the [2]catenane 6a* and other
higher molecular weight isomers (25, 26) are observed. The
slow equilibration of 6a and 6a* is expected, based on ear-
lier studies (25, 26), and is assumed to result from the very
compact structure of 6a* in which the gold atoms are
sterically protected from external reagents.
The NMR features described for 6a and 6a* were typical
of all the macrocycles and [2]catenanes studied, and full de-
tails are given in the Experimental section. In particular, the
proton resonances of the [2]catenanes with the diphosphine
ligand Ph2P(CH2)3PPh2 occurred at higher field than in the
macrocyclic complexes, with large upfield shifts observed
for the RCH (∆δ ca. 0.45) and C6H4 (∆δ ca. 0.4 and 0.8)
proton resonances. The shielding arises from the close con-
tacts with the phenyl groups of the interlocked gold macro-
cycle and is a useful indicator of [2]catenane formation (25, 26).
change to give [Au2Me2(µ-Ph2P(CH2)4PPh2)], identified by
1
comparison of its H and 31P NMR spectra with those of an
authentic sample (40, 41). The organoplatinum product was
an insoluble solid, whose IR spectrum (KBr disc) showed a
band owing to ν(CϵC) at 2120 cm–1 (cf. 7c, 2131 cm–1), but
which was not fully characterized.
The only successful reaction was that of fac-[PtMe3I]4
(42), which is inert to methyl transfer reactions, with the
2,2′-bipyridine complex 6c/6c*, which gave the products
[PtMe3I(6c)], 9 and [(PtMe3I)2(µ-6c*)], 9*, shown in
Scheme 6. The mixture of complexes 9/9* was isolated as an
air-stable, pale-orange solid, but attempts to separate the iso-
mers by recrystallization were unsuccessful, so they were
characterized spectroscopically.
The presence of the PtIMe3 group reduces the symmetry
of 9 with respect to 6c, by loss of the plane of symmetry
containing the bipyridyl group in 6c, and so there are also
more potential isomers of 9* compared with 6c*. The
nonequivalence that arises from the presence of the PtIMe3
group causes broadening rather than splitting of most reso-
nances as described in the following. The NMR spectra were
recorded as a mixture of 9/9* in about a 3:1 molar ratio, but
assignments were possible based on correlations in the
Coordination and quaternization studies
1
COSY H NMR spectrum and on peak intensities. The 31P
As shown in Scheme 1 for the 4-pyridyl derivative, the
gold(I) macrocyclic complexes and [2]catenanes can, in
principle, form extended structures by coordination of the
pyridyl or bipyridyl groups to suitable metal ions. By varia-
tion of the stoichiometry of the reaction (pyridyl:metal) and
by use of either the macrocyclic complex or the [2]catenane,
the resulting products are the molecularly discrete com-
plexes A, B, and C, and the polymeric complex D. Similar
chemistry could be achieved by quaternization of the pyridyl
nitrogen atoms by reaction with alkyl halides. However, the
chemistry proved to be difficult as a result of the lability of
the gold(I) centres, especially with respect to cleavage of the
gold–acetylide bonds.
The reaction of complex 6b/6b* with benzyl bromide or
with 1,4-bis(bromomethyl)benzene gave only [Au2Br2(µ-
Ph2P(CH2)3PPh2)] as the isolated gold-containing product.
Attempts were then made to quaternize the pyridyl nitrogen
atom of the parent diacetylene ligand 2b with 1,4-
bis(bromomethyl)benzene, but this too was unsuccessful. A
milder form of self-assembly might be possible by using hy-
drogen bond donors, such as phenol derivatives, to form sec-
ondary bonds to the pyridyl substituents of 6b/6b*. Attempts
were made to crystallize 6b/6b* in the presence of 1,4-
C6H4(OH)2 and other bis(phenol) derivatives, but they were
not successful. Slow decomposition of 6b/6b* occurred in-
stead. The reaction of complex 6b/6b* with metal halides
MBr2 (M = Zn, Cd, or Hg) led only to acetylide for bromide
exchange reactions to give [Au2Br2(µ-Ph2P(CH2)3PPh2)].
The 2,2′-bipyridyl complex 6c/6c* gave similar results, and
this complex also reacted with AgPF6 to give an intractable
black precipitate. It seems clear then that most electrophiles
react with the gold–acetylide bond instead of or in addition
to reacting with the free pyridyl or bipyridyl group.
NMR spectrum of 9 contained a broad singlet shifted from
the corresponding resonance of the macrocyclic gold com-
plex 6c [9, δ 34.67; 6c, δ 35.92]. The 1H NMR spectrum of 9
contained two broad resonances assigned to the methyl-
platinum groups in a 1:2 ratio at δ 0.62, 2J(PtH) = 74 Hz and
2
δ 1.46, J(PtH) = 70 Hz. In principle, each isomer should
give three Me-Pt resonances since the bipyridine is unsym-
metrical, but there is evidently accidental degeneracy of the
resonances of the methylplatinum groups trans to nitrogen.
1
These H NMR parameters of 9 are typical of complexes
[PtIMe3(LL)] with LL = 2,2 bipyridyl or its derivatives (40–
43). The 31P NMR spectrum of 9* contained a broad AB
multiplet resonance shifted from the corresponding reso-
4
nance of the gold [2]catenane 6c (9*, δ 32.73, 32.82, J(PP)
not resolved; 6c*, δ 31.83, 32.34, 4J(PP) = 6 Hz). The
2
methylplatinum resonances for 9* were at δ 0.43, J(PtH) =
2
74 Hz and δ 1.14, J(PtH) = 70 Hz, significantly shifted
from those of the macrocyclic complex 9 as a result of the
catenation. The bipyridyl protons and several protons of the
macrocycles of 9 and 9* showed significant deshielding on
coordination of the bipyridyl to platinum(IV), as listed in the
Experimental section.
Further evidence for coordination of the bipyridyl group
to platinum(IV) was obtained by ESI-MS of the mixture of
9/9* in dichloromethane solution. As expected, based on the
easy cleavage of the mechanical link (25, 26), no peaks for
the [2]catenane were observed, but a low intensity envelope
of peaks was observed at m/z 1602, assigned to [9·H]+, and a
major peak was observed at m/z = 1474, assigned to [9 – I]+.
The IR spectrum of the mixture of 9/9* gave a single peak
owing to ν(CϵC) at 2129 cm–1, shifted only slightly from
the corresponding peak for 6/6* at ν(CϵC) = 2132 cm–1.
The reaction of 2,2′-bipyridyl with [PtMe2(µ-SMe2)]2 oc-
curs by displacement of the dimethylsulfide ligands to give
[PtMe2(bipy)] (42), but the reaction of 7c with [PtMe2(µ-
SMe2)]2 occurred primarily by methyl for acetylide ex-
Conclusions
Achiral digold(I) macrocycles and chiral tetragold(I)
© 2006 NRC Canada

118
Can. J. Chem. Vol. 84, 2006
Scheme 6.
Au
Au
O
P
O
P
Au
O
P
H
H
H
N
N
N
N
N
N
O
P
O
P
Au
Au
O
P
Au
6c
6c*
[PtMe3I]4
[PtMe3I]4
Au
O
P
Au
P
O
Au
O
P
H
H
H
Me
N
Me
Me
Me
Pt
I
N
N
Me
N
Me
Me
Me
O
P
N
Au
Pt
I
Pt
O
P
Au
O
Au
N
Me
P
I
9
9*
[2]catenanes, each bearing 2-pyridyl, 4-pyridyl, or 4-(2,2′-
bipyridyl) substituents at the hinge group, have been pre-
pared and the structures of four [2]catenane complexes have
been determined. The presence of the pyridyl or bipyridyl
functional substituent does not complicate the synthesis.
However, preliminary studies suggest that the ability of the
new gold macrocycles and [2]catenanes to give an extensive
coordination chemistry through use of the pendant nitrogen-
donor groups will be limited as a result of the lability of the
Au—C and Au—P bonds. One successful example was es-
tablished in the use of the bipyridyl derivative 6c/6c* as
ligand for the inert PtIMe3 group, and this appears to be the
first example of the use of an organometallic [2]catenane as
a ligand. The aim of using the coordination chemistry to pre-
pare an organometallic poly[2]catenane according to
Scheme 1, D, is yet to be achieved.
(CH2)3PPh2)], [Au2Cl2(µ-Ph2P(CH2)4PPh2)] (44), [PtMe2(µ-
SMe2)]2 (45), and [(PtIMe3)4] (42) were prepared according
to the literature. Gold compounds were protected from light
by use of darkened reaction flasks.
Caution: Some gold acetylides are potentially explosive;
they should be prepared in small quantities and not subjected
to shock.
(2-C5H4N)CH(4-C6H4OCH2CϵCH)2 (2a)
A solution of 2-pyridinecarboxaldehyde (1a, 0.78 g,
7.3 mmol) and phenyl propargyl ether (46) (2.00 g,
15.1 mmol) in glacial acetic acid (5 mL) was cooled to 0 °C.
Concentrated sulfuric acid (2 mL) was added slowly, then
the mixture was heated for 5 h at 100 °C. The mixture was
cooled, water was added, and the solution was neutralized
by addition of aq. NaOH. The aqueous phase was extracted
with diethyl ether, then the combined organic phases were
washed with saturated aqueous sodium bicarbonate and then
with water. The organic phase was dried over Na2SO4, fil-
tered, and the solvent removed under reduced pressure to
give an orange oil. Purification by flash chromatography
gave the product as a yellow oil. Yield: 1.66 g (65%). IR
Experimental
NMR spectra were recorded by using Varian Mercury 400
and Varian Inova 400 spectrometers. 1H and 13C NMR
chemical shifts are reported with respect to TMS reference
and 31P NMR chemical shifts are reported relative to 85%
H3PO4 as an external standard. IR spectra were recorded as
KBr discs or as Nujol mulls between NaCl plates using a
PerkinElmer 2000 FT-IR spectrometer. High-resolution mass
spectra were measured by using a Finnigan MAT 8400 spec-
trometer, and ESI-MS by using a Micromass LCT spectrom-
eter, often using formic acid or CsI to aid ionization.
1
(Nujol mull, cm–1): 2120 (CϵC stretch). H NMR (CDCl3)
4
4
δ: 2.51 (t, 2H, JHH = 2 Hz, CϵCH), 4.65 (d, 4H, JHH
=
3
2 Hz, OCH2), 5.61 (s, 1H, CHpy), 6.90 (d, 4H, JHH = 9 Hz,
C6H4), 7.08 (m, 5H, C6H4 + py-H3), 7.13 (ddd, 1H, JHH
3
=
4
3
8, 5 Hz, JHH = 1 Hz, py-H5), 7.60 (dt, 1H, JHH = 8 Hz,
4JHH = 2 Hz, py-H4), 8.59 (ddd, 1H, JHH = 5 Hz, JHH
=
3
4
2 Hz, JHH = 1 Hz, py-H6). 13C NMR δ: 55.77 (OCH2),
5
The
complexes
[AuCl(SMe2)],
[Au2Cl2(µ-Ph2P-
57.56 (CHpy), 75.42 (CϵCH), 78.61 (CϵCH), 114.72,
© 2006 NRC Canada

Habermehl et al.
119
130.23, 135.93, 156.16 (C6H4), 121.39, 123.62, 136.55,
149.34, 163.42 (py). EI-MS (m/z) calcd. for C24H19NO2:
353.1415; found: 353.1413.
Digold(I) diacetylide 3b
This was prepared similarly and isolated as a beige solid.
Yield: 95%. IR (KBr disc, cm–1) : 2013 ν(CϵC). Anal.
calcd. for C24H17Au2NO2: C 38.68, H 2.30, N 1.88; found: C
39.14, H 2.05, N 2.34.
(4-C5H4N)CH(4-C6H4OCH2CϵCH)2 (2b)
Prepared following the procedure described for 2a, using
4-pyridinecarboxaldehyde (1b, 1.4 mL, 14.7 mmol), phenyl
propargyl ether (4.0 g, 30.3 mmol), glacial acetic acid
(20 mL), and concd. sulfuric acid (4 mL). The product was
isolated as a dark orange oil. Yield: 3.81 g (74%). IR (Nujol
(2-C5H4N)CH(4-C6H4OCH2CϵCAuCϵN-t-Bu)2
A mixture of 3a (0.075 g, 0.10 mmol) and t-BuNC
(22 mL, 0.195 mmol) in CH2Cl2 (10 mL) was stirred for 3 h.
The mixture was filtered through Celite, the volume was re-
duced to 2 mL under vacuum, and pentane (10 mL) was
added to precipitate the product as a pale yellow solid.
Yield: 0.07 g (90%). IR (KBr disc, cm–1): 2228 ν(NϵC),
1
mull, cm–1): 2118 (CϵC stretch). H NMR (CDCl3) δ: 2.53
4
4
(t, 2H, JHH = 2 Hz, CϵCH), 4.67 (d, 4H, JHH = 2 Hz,
3
OCH2), 5.40 (s, 1H, CHpy), 6.91 (d, 4H, JHH = 8 Hz,
C6H4), 7.00 (d, 4H, JHH = 8 Hz, C6H4), 7.02 (d, 2H, JHH
1
3
3
2141 ν(CϵC). H NMR (CD2Cl2) δ: 1.54 (s, 18H, Bu), 4.73
=
3
3
(s, 4H, OCH2), 5.53 (s, 1H, CHpy), 7.89 (d, 4H, JHH
=
5 Hz, py-H3 + py-H5), 8.48 (d, 2H, JHH = 5 Hz, py-H2 +
py-H6). 13C NMR δ: 54.85 (CHpy), 56.04 (OCH2), 75.74
(CϵCH), 78.74 (CϵCH), 115.09, 130.47, 135.56, 156.58
(C6H4), 124.74, 149.98, 153.42 (py). EI-MS (m/z) calcd. for
C24H19NO2: 353.1415; found: 353.1413.
9 Hz, C6H4), 7.08 (d, 4H, 3JHH = 9 Hz, C6H4), 7.11–7.13 (m,
2H, py-H3 + py-H5), 7.62 (m, 1H, py-H4), 8.55 (d, 1H,
3JHH = 5 Hz, py-H6). Anal. calcd. for C34H35Au2N3O2: C
44.80, H 3.87, N 4.61; found: C 44.71, H 3.30, N 4.56.
(4-C5H4N)CH(4-C6H4OCH2CϵCAuCϵN-t-Bu)2
4-(2,2′-bpy)CH(4-C6H4OCH2CϵCH)2 (2c)
This was prepared in a similar way from 3b (0.075 g,
To a solution of phenyl propargyl ether (46) (3.34 g,
25.3 mmol) and 2,2′-bipyridine-4-carboxaldehyde (27, 28)
(1.86 g, 10.1 mmol) in glacial acetic acid (25 mL) was
added concd. sulfuric acid (15 mL). The reaction mixture
was stirred for 17 h then poured into water (150 mL) and
neutralized by addition of sodium hydroxide. A brown oil
separated and was extracted into diethyl ether (3 × 50 mL).
The combined organic phases were washed with aqueous so-
dium carbonate, then the organic phase was dried (MgSO4),
filtered, and the solvent removed under reduced pressure.
Chromatography of the residue on a silica gel column with
1:1 petroleum spirits (bp 60–90 °C) – ethyl acetate as eluant
gave the product as a yellow oil. Yield: 1.94 g (45%). IR
0.10 mmol). Yield: 0.065 g (71%). IR (KBr disc, cm–1):
1
2226 ν(NϵC), 2139 ν(CϵC). H NMR (CD2Cl2) δ: 1.54 (s,
18H, Bu), 4.73 (s, 4H, OCH2), 5.53 (s, 1H, Chpy), 7.89 (d,
3
3
4H, JHH = 9 Hz, C6H4), 7.08 (d, 4H, JHH = 9 Hz, C6H4),
7.11–7.13 (m, 2H, py-H3 + py-H5), 7.62 (m, 1H, py-H4),
3
8.55 (d, 1H, JHH = 5 Hz, py-H6). MALDI-TOF MS m/z:
912 [P + H]+. Anal. calcd. for C34H35Au2N3O2: C 44.80, H
3.87, N 4.61; found: C 45.28, H 3.63, N 4.67.
Macrocyclic complex 4a (R = 2-pyridyl, Z = CϵC)
A mixture of 3a (0.05 g, 0.067 mmol) and Ph2PCCPPh2
(0.023 g, 0.058 mmol) in CH2Cl2 (10 mL) was stirred for
1 h. The mixture was filtered through Celite, the volume was
reduced to 2 mL under vacuum, and pentane (10 mL) was
added to precipitate the product as a cream solid. Yield:
0.057 g (85%). IR (KBr disc, cm–1): 2133 ν(CϵC). 1H NMR
(CD2Cl23) δ: 4.78 (s, 4H, OCH2), 5.53 (s, 1H, CHpy), 7.00
(d, 4H, JHH = 8 Hz, C6H4), 7.08–7.13 (m, 6H, C6H4 + py-
H3 + py-H5), 7.45–7.62 (m, 13H, PPh + py-H4), 7.67–7.82
1
(neat, cm–1): 2121 (CϵC stretch). H NMR (CDCl3) δ: 2.51
4
4
(t, 2H, JHH = 2 Hz, CϵCH), 4.66 (d, 4H, JHH = 2 Hz,
3
OCH2), 5.53 (s, 1H, CHbpy), 6.91 (d, 4H, JHH = 9 Hz,
3
C6H4), 7.02 (d, 1H, JHH = 5 Hz, bpy-H5), 7.05 (d, 4H,
3
3JHH = 9 Hz, C6H4), 7.28 (dd, 1H, JHH = 8, 5 Hz, bpy-H5′),
3
4
7.79 (dt, 1H, JHH = 8 Hz, JHH = 1 Hz, bpy-H4′), 8.23 (s,
3
1H, bpy-H3), 8.37 (d, 1H, JHH = 8 Hz, bpy-H3′), 8.58 (d,
3
(m, 8H, PPh), 8.53 (d, 1H, JHH = 4 Hz, py-H6). 31P NMR
3
3
1H, JHH = 5 Hz, bpy-H6), 8.63 (dd, 1H, JHH = 5 Hz,
4JHH = 1 Hz, bpy-H6′). 13C NMR δ: 54.90 (CHbpy), 55.77
(OCH2), 75.53 (CϵCH), 78.50 (CϵCH), 114.83, 130.27,
135.39, 156.30 (C6H4), 121.27 (bpy-C3′), 121.95 (bpy-C3),
123.66 (bpy-C5′), 124.40 (bpy-C5), 136.87 (bpy-C4′),
149.08 (bpy-C6′), 149.23 (bpy-C6), 154.32, 156.00, 156.15
(bpy-C2, -C2′, -C4). EI-MS (m/z) calcd. for C29H22N2O2:
430.1681; found: 430.1674.
δ: 18.85 (s). ESI-MS m/z: 1272 [4a + Cs+]. Anal. calcd. for
C50H37Au2O2NP2: C 52.69, H 3.27, N 1.23; found: C 52.21,
H 2.91, N 1.28. The following complexes were similarly
prepared.
Macrocyclic complex 4b (R = 4-pyridyl, Z = CϵC)
Pale orange solid. Yield: 85%. IR (KBr disc, cm–1): 2132
1
ν(CϵC). H NMR (CD2Cl2) δ: 4.80 (s, 4H, OCH2), 5.40 (s,
1H, CHpy), 6.92–7.04 (m, 10H, C6H4 + py-H3 + py-H5),
7.46–7.60 (m, 12H, PPh), 7.68–7.78 (m, 8H, PPh), 8.44 (d,
Digold(I) diacetylide 3a
To a solution of [AuCl(SMe2)] (0.73 g, 2.48 mmol) in
THF (40 mL) and MeOH (30 mL) was added a solution of
2a (0.44 g, 1.31 mmol) and Et3N (0.2 mL) in THF (5 mL).
The mixture was stirred for 30 min, and the pale yellow pre-
cipitate of the product was isolated by filtration, washed
with THF, MeOH, and ether, and dried under vacuum. Yield:
0.86 g (88%). IR (KBr disc, cm–1): 2000 ν(CϵC). Anal.
calcd. for C24H17Au2NO2: C 38.68, H 2.30, N 1.88; found: C
38.21, H 2.00, N 1.69.
3
2H, JHH = 5 Hz, py-H2 + py-H6).31P NMR δ: 18.82 (s).
MALDI-TOF MS m/z: 1140 (4b + H)+. Anal. calcd. for
C50H37Au2O2NP2: C 52.69, H 3.27, N 1.23; found: C 52.99,
H 3.13, N 1.47.
Macrocyclic complex 5a (R = 2-pyridyl, Z = (CH2)2)
Pale pink solid. Yield: 65%. IR (KBr disc, cm–1): 2132
1
ν(CϵC). H NMR (CD2Cl2) δ: 2.51 (s, 4H, PCH2), 4.78 (s,
© 2006 NRC Canada

120
Can. J. Chem. Vol. 84, 2006
3
4H, OCH2), 5.52 (s, 1H, CHpy), 7.02 (d, 4H, JHH = 9 Hz,
m/z: 1304 (7a + Cs+). Anal. calcd. for C52H45Au2O2NP2: C
53.30, H 3.87, N 1.20; found: C 52.97, H 3.91, N 1.23. Slow
crystallization of 7a gave the [2]catenane 7a*, but on disso-
lution it quickly reverted back to 7a.
3
C6H4), 7.13 (m, 2H, py-H3 + py-H5), 7.19 (d, 4H, JHH
=
9 Hz, C6H4), 7.42–7.68 (m, 21H, PPh + py-H4), 8.55 (d, 1H,
3JHH = 4 Hz, py-H6). 31P NMR δ: 40.38 (s). ESI-MS m/z:
1276 (5a + Cs+). Anal. calcd. for C50H41Au2O2NP2: C 52.51,
H 3.61, N 1.22; found: C 52.21, H 3.62, N 1.22.
Macrocyclic complex 7b (R = 4-pyridyl, Z = (CH2)4)
Cream solid. Yield: 76%. IR (KBr disc, cm–1): 2132
1
ν(CϵC). H NMR (CD2Cl2) δ: 1.73 (br s, 4H, PCH2CH2),
Macrocyclic complex 5b (R = 4-pyridyl, Z = (CH2)2)
Cream solid. Yield: 73%. IR (KBr disc, cm–1): 2132
2.35 (br, 4H, PCH2), 4.78 (s, 4H, OCH2), 5.40 (s, 1H,
CHpy), 6.88–7.06 (m, 6H, C6H4 + py-H3 + py-H5), 7.08 (d,
1
ν(CϵC). H NMR (CD2Cl2) δ: 2.51 (s, 4H, PCH2), 4.79 (s,
3
4H, OCH2), 5.40 (s, 1H, CHpy), 7.00–7.06 (m, 6H, C6H4 +
4H, JHH = 8 Hz, C6H4), 7.41–7.51 (m, 12H, PPh), 7.56–
3
py-H3 + py-H5), 7.11 (d, 4H, 3JHH = 8 Hz, C6H4), 7.41–7.69
7.65 (m, 8H, PPh), 8.44 (d, 2H, JHH = 6 Hz, py-H2 + py-
(m, 20H, PPh), 8.45 (d, 2H, JHH = 6 Hz, py-H2 + py-H6).
H6). 31P NMR δ: 38.90 (s). Anal. calcd. for C52H45Au2O2NP2:
3
31P NMR δ: 40.37 (s). ESI-MS m/z: 1276 (5b + Cs+). Anal.
calcd. for C50H41Au2O2NP2: C 52.51, H 3.61, N 1.22; found:
C 52.95, H 3.31, N 1.97.
C 53.30, H 3.87, N 1.20; found: C 53.13, H 3.54, N 1.33.
Macrocyclic complex 8a (R = 2-pyridyl, Z = (CH2)5)
Cream solid. Yield: 85%. IR (KBr disc, cm–1): 2132
1
ν(CϵC). H NMR (CD2Cl2) δ: 1.57 (br, 6H, PCH2CH2CH2),
Macrocyclic complex 6a and [2]catenane 6a* (R = 2-
pyridyl, Z = (CH2)3)
2.36 (br, 4H, PCH23), 4.78 (s, 4H, OCH2), 5.57 (s, 1H,
CHpy), 7.02 (d, 4H, JHH = 9 Hz, C6H4), 7.10–7.15 (m, 6H,
C6H4 + py-H3 + py-H5), 7.42–7.54 (m, 12H, PPh), 7.59–
Cream solid. Yield: 88%. IR (KBr disc, cm–1): 2132
1
ν(CϵC). 6a: H NMR (CD2Cl2) δ: 1.80 (br, 2H, PCH2CH2),
2.46 (br, 4H, PCH2), 4.77 (s, 4H, OCH2), 5.54 (s, 1H,
CHpy), 7.01 (d, 4H, JHH = 9 Hz, C6H4), 7.09 (m, 2H, py-
H3 + py-H5), 7.12 (d, 4H, JHH = 9 Hz, C6H4), 7.41–7.69
3
7.70 (m, 9H, PPh + py-H4), 8.55 (d, 1H, JHH = 4 Hz, py-
H6). 31P NMR δ: 37.56 (s). ESI-MS m/z: 1318 (8a + Cs+).
Anal. calcd. for C53H47Au2O2NP2: C 53.68, H 3.99, N 1.18;
found: C 53.44, H 3.73, N 1.22.
3
3
3
(m, 21H, PPh + py-H4), 8.54 (d, 1H, JHH = 4 Hz, py-H6).
31P NMR (CD2Cl2) δ: 35.93 (s). 6a*: H NMR δ: 2.25 (br,
1
4H, PCH2CH2), 2.75 (br, 8H, PCH2), 4.65 (br m, 8H,
Macrocyclic complex 8b (R = 4-pyridyl, Z = (CH2)5)
3
Cream solid. Yield: 72%. IR (KBr disc, cm–1): 2132
OCH2), 5.07 (s, 2H, CHpy), 6.16 (d, 8H, JHH = 7 Hz,
C6H4), 6.78 (d, 8H, JHH = 7 Hz, C6H4), 6.90 (m, 2H, py-
3
1
ν(CϵC). H NMR (CD2Cl2) δ: 1.56 (br, 6H, PCH2CH2CH2),
H3), 7.16 (m, 2H, py-H5), 7.30–7.65 (m, 42H, PPh + py-
2.35 (br, 4H, PCH2), 4.77 (s, 4H, OCH2), 5.42 (s, 1H,
CHpy), 6.89–7.08 (m, 10H, C6H4 + py-H3 + py-H5), 7.42–
7.52 (m, 12H, PPh), 7.58–7.68 (m, 8H, PPh), 8.46 (d, 2H,
3JHH = 6 Hz, py-H2 + py-H6). 31P NMR δ: 37.56 (s). Anal.
calcd. for C53H47Au2O2NP2: C 53.68, H 3.99, N 1.18; found:
C 53.94, H 3.74, N 1.23.
H4), 8.42 (d, 2H, JHH = 4 Hz, py-H6). 31P NMR δ: 31.89
3
4
4
(d, JPP = 6 Hz), 32.18 (d, JPP = 6 Hz). ESI-MS m/z: 1290
(6a +H)+. Anal. calcd. for C51H43Au2O2NP2: C 52.91, H
3.74, N 1.21; found: C 52.74, H 3.71, N 1.24.
Macrocyclic complex 6b and [2]catenane 6b* (R = 4-
pyridyl, Z = (CH2)3)
Synthesis from t-BuNC derivatives — 6a/6a*
Cream solid. Yield: 89%. IR (KBr disc, cm–1): 2132
To a solution of (2-C5H4N)CH(4-C6H4OCH2CϵCAuCϵN-
t-Bu)2 (0.022 g, 0.024 mmol) in CH2Cl2 (10 mL) was added
Ph2P(CH2)3PPh2 (0.01 g, 0.023 mmol). The mixture was
stirred for 1 h, the volume was reduced to 2 mL, and
pentane (10 mL) was added to precipitate the product. Yield:
0.024 g (89%). Spectroscopic data were as described above
for 6a/6a*. 6b/6b* (90%), 7a (73%), and 8a (65%) were
similarly prepared.
1
ν(CϵC). 6b: H NMR (CD2Cl2) δ: 1.82 (br, 2H, PCH2CH2),
2.47 (m, 4H, PCH2), 4.78 (s, 4H, OCH2), 5.41 (s, 1H,
CHpy), 6.97 (d, 4H, 3JHH = 8 Hz, C6H4), 7.01 (d, 4H, 3JHH
=
3
8 Hz, C6H4), 7.05 (d, 2H, JHH = 6 Hz, py-H3 + py-H5),
7.42–7.64 (m, 20H, PPh), 8.45 (d, 2H, 3JHH = 6 Hz, py-H2 +
1
py-H6). 31P NMR (CD2Cl2) δ: 35.92 (s). 6b*: H NMR δ:
1.82 (br, 4H, PCH2CH2), 2.76 (br, 8H, PCH2), 4.67 (s, 8H,
3
OCH2), 4.96 (s, 2H, CHpy), 6.19 (d, 8H, JHH = 8 Hz,
3
3
C6H4), 6.63 (d, 8H, JHH = 8 Hz, C6H4), 6.74 (d, 4H, JHH
=
Macrocyclic complex 6c and [2]catenane 6c* (R = 4-
(2,2′-bipyridyl), Z = (CH2)3)
6 Hz, py-H3 + py-H5), 7.42–7.64 (m, 40H, PPh), 8.32 (d,
3
4H, JHH = 6 Hz, py-H2 + py-H6). 31P NMR δ: 31.83 (d,
To a solution of [Au2Cl2(µ-Ph2P(CH2)3PPh2)] (0.505 g,
0.58 mmol) in CH2Cl2 (20 mL) was added AgO2CCF3
(0.254 g, 1.15 mmol). The mixture was stirred for 2 h, then
filtered through Celite to remove AgCl. The filtrate was
added to a solution of 2c (0.58 mmol) and Et3N (3.2 mL) in
CH2Cl2 (40 mL) at –78 °C, and the mixture was stirred for
2 h then allowed to warm to room temperature. The organic
phase was washed with water (50 mL), then dried over
MgSO4, and the volume was reduced to 5 mL, and pentane
(80 mL) was added to precipitate the product as a pale-
orange solid, identified as a mixture of 6c and 6c*. Yield:
73%. Recrystallization from CH2Cl2–pentane gave the pure
[2]catenane as a white solid. IR (KBr disc, cm–1): 2132
4
4JPP = 6 Hz), 32.15 (d, JPP = 6 Hz). ESI-MS m/z: 1290
(6a +H)+. Anal. calcd. for C51H43Au2O2NP2: C 52.91, H
3.74, N 1.21; found: C 53.37, H 3.42, N 1.54.
Macrocyclic complex 7a (R = 2-pyridyl, Z = (CH2)4)
Cream solid. Yield: 88%. IR (KBr disc, cm–1): 2132
1
ν(CϵC). H NMR (CD2Cl2) δ: 1.73 (br s, 4H, PCH2CH2),
2.35 (br, 4H, PCH2), 4.77 (s, 4H, OCH2), 5.53 (s, 1H,
3
CHpy), 7.01 (d, 4H, JHH = 9 Hz, C6H4), 7.12 (m, 2H, py-
3
H3 + py-H5), 7.15 (d, 4H, JHH = 9 Hz, C6H4), 7.42–7.52
(m, 12H, PPh), 7.57–7.65 (m, 9H, PPh + py-H4), 8.53 (d,
3
1H, JHH = 3 Hz, py-H6). 31P NMR δ: 38.89 (s). ESI-MS
© 2006 NRC Canada

Habermehl et al.
121
1
ν(CϵC). 6c: H NMR (CD2Cl2) δ: 1.84 (m, 2H, PCH2CH2),
OCH2), 5.04 (s, 2H, CHbpy), 6.01 (m, 8H, C6H4), 6.62 (m,
8H, C6H4), 7.1–7.5 (m, 44H, PPh + bpy-H5+ bpy-H5′), 7.77
(m, 2H, bpy-H4′), 8.01 (s, 2H, py-H3), 8.32 (br, 2H, bpy-H3′),
8.72 (m, 2H, py-H6), 8.87 (m, 2H, bpy-H6′). 31P NMR δ:
32.82, 32.73 (br). Anal. calcd. for C59H55Au2IN2O2P2Pt: C
44.24, H 3.46, N 1.75; found: C 43.87, H 3.27, N 1.54.
2.47 (m, 4H, PCH2), 4.79 (s, 4H, OCH2), 5.52 (s, 1H,
CHbpy), 7.05 (d, 4H, JHH = 9 Hz, C6H4), 7.07 (d, 1H, bpy-
3
3
H5), 7.11 (d, 4H, JHH = 9 Hz, C6H4), 7.28 (m, 1H, bpy-
H5′), 7.35–7.60 (m, 20H, PPh), 7.80 (dt, 1H, 3JHH = 7, 8 Hz,
4JHH = 2 Hz, bpy-H4′), 8.21 (s, 1H, bpy-H3), 8.40 (d, 1H,
3JHH = 8 Hz, bpy-H3′), 8.54 (d, 1H, JHH = 5 Hz, bpy-H6),
3
3
8.59 (d, 1H, JHH = 4 Hz, bpy-H6′). 31P NMR δ: 35.92 (s).
X-ray crystal structure determinations
1
6c*: H NMR δ: 1.80 (br, 4H, PCH2CH2), 2.29 (br, 8H,
Crystals of 6a*·Cl(CH2)2Cl were grown by slow diffusion
of hexane into a solution of 6a* in 1,2-dichloroethane.
Similarly, crystals of 6b*·CH2Cl2 were obtained from
dichloromethane–pentane; crystals of 6c*·H2Cl2 from
dichloromethane–hexane; and crystals of 7a* from 1,2-
dichloroethane – diethyl ether. Data were collected using a
Nonius Kappa-CCD diffractometer with Mo-Kα radiation
(λ = 0.710 73 Å) at 150 K with COLLECT software (47).
The unit cell parameters were calculated and refined from
the full data set. Crystal cell refinement and data reduction
were carried out with the DENZO package (47). The data
were scaled using SCALEPACK (47). The SHELXTL-NT
V6.1 package (47) was used to solve the structures of 6a*,
6b*, and 6c* by direct methods, and to solve the structure of
7a* by Patterson methods. The structure solutions were fol-
lowed by successive difference Fourier transformations and
refined with full-matrix least-squares on F2. Non-hydrogen
atoms were refined anisotropically. The hydrogen atoms
were calculated geometrically, riding on their respective car-
bon atoms. Crystal data and refinement parameters are listed
in Table 1.3
PCH2), 4.68 (br s, 8H, OCH2), 5.08 (s, 2H, CHbpy), 6.20
3
4
(dd, 8H, JHH = 8 Hz, JHH = 3 Hz, C6H4), 6.69 (d, 8H,
3JHH = 8 Hz, C6H4), 6.82 (br, 2H, bpy-H5), 7.10–7.49 (m,
3
42H, PPh + bpy-H5′), 7.77 (t, 2H, JHH = 8 Hz, bpy-H4′),
7.96 (s, 2H, py-H3), 8.35 (br, 2H, bpy-H3′), 8.42 (d, 2H,
3JHH = 6 Hz, py-H6), 8.52 (d, 2H, JHH = 4 Hz, bpy-H6′).
3
31P NMR δ: 31.83 (d, JPP = 6.0 Hz), 32.23 (d, JPP
=
4
4
6.0 Hz). ESI-MS m/z: 1235 (6c + H+). Anal. calcd. for
C56H46Au2N2O2P2: C 54.47, H 3.75, N 2.27; found: C 54.25,
H 3.96, N 2.11.
Macrocyclic complex 7c (R = 4-(2,2′-bipyridyl), Z = (CH2)4)
This was prepared in a similar way to 6b but using
Ph2P(CH2)4PPh2. Orange solid. Yield: 78%. IR (KBr
disc, cm–1): 2131 ν(CϵC). H NMR (CD2Cl2) δ: 1.73 (br,
1
4H, PCH2CH2), 2.34 (br, 4H, PCH2), 4.80 (s, 4H, OCH2),
5.52 (s, 1H, CHbpy), 7.05 (m, 5H, C6H4 + bpy-H5), 7.14 (d,
3
4H, JHH = 9 Hz, C6H4), 7.27 (m, 1H, bpy-H5′), 7.42–7.50
(m, 12H, PPh), 7.57–7.63 (m, 8H, PPh), 7.79 (dt, 1H, 3JHH
=
4
8 Hz, JHH = 2 Hz, bpy-H4′), 8.19 (s, 1H, bpy-H3), 8.39 (d,
3
3
1H, JHH = 8 Hz, bpy-H3′), 8.53 (d, 1H, JHH = 5 Hz, bpy-
2-pyCH(C6H4OH)2
H6), 8.58 (d, 1H, JHH = 5 Hz, bpy-H6′). 31P NMR δ: 38.90
3
No crystallographic complexity.
(s). ESI-MS m/z: 1249 (7c + H+). Anal. calcd. for
C57H48Au2N2O2P2: C 54.82, H 3.87, N 2.24; found: C 54.43,
H 3.77, N 2.09.
6a*·C2H4Cl2
There was disorder associated with the acetylide ligands
and they were modeled as 50/50 isotropic for one ring of the
[2]catenane and as 65:35 for the other ring of the
[2]catenane.
Complexes 9/9*
To a solution of [PtMe3I]4 (1.5 × 10–5 mol) in CH2Cl2
(10 mL) was added 6c/6c* (6.0 × 10–5 mol) and the solution
stirred for 1 h. The volume of the solution was concentrated
to ~2 mL at reduced pressure, then diethyl ether (40 mL)
was added to precipitate the product as a pale-orange solid.
Yield: 0.08 g (84%). IR (KBr disc, cm–1): 2129 ν(CϵC).
6b*·3CH2Cl2
The molecule showed no disorder. There were three di-
chloromethane molecules of solvation: one was refined
anisotropically, one was refined isotropically, and one was
disordered. The disordered dichloromethane molecule was
modeled as a 55:45 mixture of isotropic atoms complete
with hydrogens. The C—Cl distance was fixed at 1.65 Å,
and some of the Cl—Cl distances were fixed at 2.74 Å.
ESI-MS (m/z): 1602, [9 + H]+; 1474, [9 – I]+. 9: H NMR
1
(CD2Cl2) δ: 0.62 (s, 3H, 2JPtH = 74 Hz, MePt trans to I), 1.46
2
(s, 6H, JPtH = 70 Hz, MePt trans to N), 1.82 (m, 2H,
PCH2CH2), 2.64 (m, 4H, PCH2), 4.80 (s, 4H, OCH2), 5.61
(s, 1H, CHbpy), 6.98 (d, 4H, JHH = 9 Hz, C6H4), 6.95 (m,
1H, bpy-H5), 7.10 (d, 4H, JHH = 9 Hz, C6H4), 7.28 (m, 1H,
3
3
6c*·CH2Cl2
bpy-H5′), 7.2–7.5 (m, 20H, PPh), 7.97 (m, 1H, bpy-H4′),
8.20 (s, 1H, bpy-H3), 8.40 (m, 1H, bpy-H3′), 8.80 (d, 1H,
3JHH = 5 Hz, bpy-H6), 8.91 (m, 1H, bpy-H6′). 31P NMR δ:
The molecule showed some disorder for the bipyridyl–
diacetylide ligands. For one ring of the [2]catenane, the
bipyridyl group was modeled as a 51:49 isotropic mixture;
in the other ring of the [2]catenane, there was more exten-
sive disorder and the bipyridyl group and one phenylene
group were modeled as a 51:49 mixture. There were three
1
2
34.67 (s). 9*: H NMR δ: 0.43 (s, 6H, JPtH = 74 Hz, MePt
2
trans to I), 1.10 (s, 12H, JPtH = 70 Hz, MePt trans to N),
1.80 (br, 4H, PCH2CH2), 2.46 (br, 8H, PCH2), 4.41 (br, 8H,
3 Supplementary data for this article are available on the journal Web site (http://canjchem.nrc.ca) or may be purchased from the Depository
of Unpublished Data, Document Delivery, CISTI, National Research Council Canada, Ottawa, ON K1A 0R6, Canada. DUD 4084. For more
information on obtaining material refer to http://cisti-icist.nrc-cnrc.gc.ca/irm/unpub_e.shtml. CCDC 275188–275192 contain the crystallo-
graphic data for this manuscript. These data can be obtained, free of charge, via http://www.ccdc.cam.ac.uk/conts/retrieving.html (Or from
the Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; fax +44 1223 336033; or de-
posit@ccdc.cam.ac.uk).
© 2006 NRC Canada

122
Can. J. Chem. Vol. 84, 2006
Table 1. Crystallographic data and experimental parameters for X-ray structure analyses of the 2-pyridylbis(phenol) and of
[2]catenanes 6a*, 6b*, 6c*, and 7a*.
Compound
Formula
2-pyCH(C6H4OH)2 6a*·Cl(CH2)2Cl
6b*·3CH2Cl2
6c*·CH2Cl2
7a*
C18H15NO2
C104H90Au4Cl2N2O4P4 C105H92Au4Cl6N2O4P4 C56.5H47Au2ClN2O2P2 C104H90Au4N2O4P4
Fw
277.31
Monoclinic
C2/c
19.2706(5)
9.8267(2)
17.4670(4)
90
121.059(1)
90
2 833.5(1)
8
2 414.43
Triclinic
P-1
2 570.25
Monoclinic
P2(1)/c
12.2843(3)
22.4961(6)
35.9454(9)
90
96.180(1)
90
9 875.7(4)
4
1 277.28
Monoclinic
P2(1)/n
12.2811(2)
22.4781(4)
38.6828(7)
90
95.255(1)
90
10 633.7(3)
8
1 171.76
Triclinic
P-1
Cryst. Syst.
Space group
a (Å)
b (Å)
c (Å)
12.4285(1)
12.6883(1)
29.8997(4)
92.062(1)
101.313(1)
104.334(1)
4 461.76(8)
2
10.7552(3)
14.5857(3)
15.7336(4)
115.413(1)
96.354(1)
90.744(1)
2 210.6(1)
1
α (°)
β (°)
γ (°)
V (Å3)
Z
dcalcd (g cm–3)
1.300
1.797
1.729
1.596
1.760
µ (mm–1)
F(000)
Reflections
0.085
1 168
14 668
6.743
2 340
59 523
6.203
4 984
82 874
5.664
4 968
95 071
6.743
1 136
23 677
Unique refl. (Rint) 3 249
16 290 (0.080)
17 433 (0.112)
18 691 (0.091)
7 775 (0.062)
Parameters
192
747
987
905
348
θ range (°)
2.56–27.53
1.074
2.55–25.35
1.009
2.91–25.03
1.014
2.55–25.02
1.018
2.55–25.00
1.048
GOF on F2
R, Rw (I > 2σ(I))
0.0417, 0.0985
0.0456, 0.0871
0.069, 0.145
0.064, 0.148
0.067, 0.132
R, Rw (all data)
0.0688, 0.1094
0.0886, 0.0976
0.1836, 0.1797
0.1429, 0.1774
0.1272, 0.1838
10. C. Janiak. Dalton Trans. 2781 (2003).
11. H.W. Roesky and M. Andruh. Coord. Chem. Rev. 236, 91
(2003).
12. T. Takata, N. Kihara, and Y. Furusho. Adv. Polym. Sci. 171, 1
(2004).
13. A. Godt. Eur. J. Org. Chem. 1639 (2004).
14. D.A. Leigh and R.A. Smith. Cyclic polymers. 2nd ed. Edited
by J.A. Semlyen. Kluwer Academic, Dordrecht. 2000.
Chap.13.
sites of solvation that were modeled isotropically at reduced
occupancy (site 200 (15%:10%); site 300 (25%); site 400
(25%:25%)) with fixed bond distances.
7a*
The [2]catenane was 50:50 disordered as a result of an in-
version centre at the midpoint of the Au(1)···Au(1A) vector,
with all other atoms at 50% occupancy. In addition, 50:50
disorder of the individual pyCH(C6H4)2 groups was ob-
served. Because of the extensive disorder, only the gold and
phosphorus atoms were refined with anisotropic parameters.
15. C. Hamers, O. Kocian, F.M. Raymo, and J.F. Stoddart. Adv.
Mater. 10, 1366 (1998).
16. E.C. Constable. Adv. Inorg. Chem. 34, 1 (1989).
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5476 (2002).
Acknowledgments
We thank the Natural Sciences and Engineering Research
Council of Canada (NSERC) for financial support. RJP
thanks the Government of Canada for a Canada Research
Chair.
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