Mononuclear and polynuclear chain complexes of a series of multinucleating N/S donor ligands

FULL PAPER

Mononuclear and Polynuclear Chain Complexes of a Series of Multinucleating

N/S Donor Ligands

Tanya K. Ronson,^[a]Harry Adams,^[a]and Michael D. Ward*^[a]

Keywords: Chelates / Coordination chemistry / Copper / Silver / Helical structures

We have prepared a series of five ligands with potentially

N,S-bidentate chelating arms derived from 3-[2-(methylsul-

fanyl)phenyl]pyrazole linked to central aromatic spacers by

methylene units. Complexes with a variety of architectures

polymers with silver(I) and copper(I) ions, but in this case the

sequence of bridging ligands between one metal centre and

the next follows a zig-zag path rather than being helical. The

1,8-naphthyl-spaced ligand L⁴only forms mononuclear com-

have been obtained, including simple mononuclear com- plexes with copper(I) and silver(I) ions showing that this

plexes and polynuclear chain complexes. The p-xylyl-spaced

spacer is not large enough to enforce a bridging coordination

mode. The three-armed ligand L⁵, prepared from 2,4,6-tris-

(bromomethyl)mesitylene, also forms a mononuclear complex

ligand L¹forms one-dimensional helical coordination poly-

mers with copper(I) and silver(I) ions. These polymers display

interligand aromatic stacking interactions within each helical

chain. The m-xylyl-spaced ligand L²forms a coordination

with silver(

However, when excess silver(

I

) ions, where one of the three arms is pendant.

I) ions are present two of these

polymer with copper(

larger silver(

I

) but a mononuclear complex with the

mononuclear complexes can be assembled into the trinuclear

complex [Ag₃(L⁵)₂](ClO₄)₃.

Germany, 2005)

I

) ion in which the central phenyl ring is in-

volved in an η¹π-type Ag···C interaction with the Ag^I. The

3,3Ј-biphenyl-spaced ligand L³also forms one-dimensional

whose complexes depend on the nature of the spacer sepa-

rating the two chelating components. Potentially bridging

N,S-donor ligands of this general type have been of some

interest recently with respect to coordination with soft me-

tal ions such as Cu^Iand Ag^I; the combination of flexible

bridging ligands with metal ions, which are tolerant of a

wide range of coordination geometries has led to a remark-

able collection of oligomeric and polymeric structures.^[3]

The complexes described in this paper illustrate in particu-

lar the propensity of the N,S-donor bridging ligands to af-

ford one-dimensional helical coordination polymers, in con-

trast to the discrete M₂L₂dinuclear double helicates which

tend to form with the analogous N,O-donor ligands con-

taining pyrazolylphenolate donor sites that we described re-

cently.^[4]

Introduction

Metal-directed self assembly of elaborate polynuclear

complexes relies in part on a good match between the stereo-

electronic properties of the metal ion and the arrangement

and type of donor sites on the bridging ligand.^[1]With re-

spect to the ligands, a minimum condition is that the bind-

ing sites must be arranged so that they bridge two or more

metal centres, otherwise simple mononuclear complexes will

result. If a bridging ligand is conformationally flexible, the

competition between bridging and chelating coordination

modes is an important factor in determining the course of

a self-assembly reaction. To this end we have been investiga-

ting the coordination chemistry of ligands in which two

N,N-bidentate, chelating pyrazolylpyridine groups are con-

nected by a range of different spacer groups, which results

in different separations between the two metal-ion binding

sites. Depending on the nature of the spacer (a phenyl

group, a biphenyl group, 1,8-naphthyl, and so on) and the

coordination preferences of the metal ion, complexes have

been isolated ranging in complexity from simple mononu-

clear species to dodecanuclear truncated-tetrahedral

cages.^[2]

Results and Discussion

Syntheses and Structures of the Ligands

The ligands are shown in Scheme 1. 3-[2(Methylsulfanyl)-

phenyl]pyrazole was prepared as described earlier,^[5]and

was treated with an appropriate bromomethylated aromatic

compound under phase-transfer conditions^[2]to give the

new ligands L¹–L⁵. The ligands L¹, L², L³and L⁴contain

two potentially bidentate N,S-chelating units, with pyrazolyl

and thioether donors, but differ in length due to variation

in the length of the spacer unit. In contrast ligand L⁵is a

In this paper we describe the synthesis and coordination

behaviour of a related series of ligands based on N,S-donor

chelating (pyrazolyl/thioether) fragments, the structures of

[a] Department of Chemistry, University of Sheffield,

Sheffield S3 7HF, UK

E-mail: m.d.ward@sheffield.ac.uk

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DOI: 10.1002/ejic.200500704

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T. K. Ronson, H. Adams, M. D. Ward

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Scheme 1.

potentially hexadentate tripodal ligand with three bidentate

arms linked to a central aromatic unit though methylene

1

groups. The ligands were characterised by H NMR and

¹³C NMR spectroscopy, mass spectrometry and elemental

analyses. Ligands L¹, L⁴and L⁵were also characterised by

X-ray crystallography and their structures are shown in Fig-

ure 1, Figure 2, and Figure 3.

Figure 1. Molecular structure of L¹. Symmetry operation to gener-

ate equivalent atoms: (–x, y, 3/2 – z).

Figure 2. Molecular structure of L⁴. Symmetry operation to gener-

ate equivalent atoms: (1–x, y, 1/2 – z).

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Eur. J. Inorg. Chem. 2005, 4533–4549

Mononuclear and Polynuclear Chain Complexes of Multinucleating N/S Donor Ligands

FULL PAPER

arity with angles of 39.5, 38.5 and 23.9° between the meth-

ylsulfanylphenyl and pyrazole rings. One of the (methylsul-

fanylphenyl)pyrazole units [involving atoms S(3) and N(6)]

adopts a cisoid conformation, resulting again (as in L¹,

above) in a relatively short N(6)···S(3) separation of

2.832 Å, and a near-linear N(6)···S(3)–C(39) angle of

175.7°, both consistent with an intermolecular donor-ac-

ceptor interaction involving the lone pair of N(3) and the

S–C σ* orbital.^[7]The torsion angle between these pyrazolyl

and sulfanylphenyl rings is 23.9°. The other two methylsul-

fanylphenyl-pyrazole units, which have approximately

transoid conformations, have a greater degree of twist be-

tween the aromatic rings (39.5 and 38.5°) because there is

no N···S interaction which tends to keep the rings con-

cerned more coplanar. Sulfur atoms S(1) and S(2) are not

Figure 3. Molecular structure of L⁵.

For L¹the molecule lies astride a twofold axis of sym- involved in any intermolecular N···S contacts comparable

metry through the centre of the phenyl spacer, such that the to that seen for S(3).

two halves are crystallographically equivalent. The (methyl-

sulfanylphenyl)pyrazole units adopt a cisoid configuration

with the methyl group pointing away from the lone pairs

of the pyrazole nitrogen atoms. The chelating units show a

significant deviation from planarity with an angle of 26.6°

Complexes with L¹

The reaction of L¹with one equivalent of [Cu(CH₃CN)₄]-

between the methylsulfanylphenyl and pyrazole rings. The PF₆in dry acetonitrile under nitrogen resulted in a pale

cisoid arrangement of the rings is, on the face of it, surpris- yellow solution. Diethyl ether diffusion into the reaction

ing because it brings the lone pairs of electrons on N(2) mixture gave pale yellow crystals whose elemental analysis

and S(1) into proximity; in polypyridyl ligands such as 2,2Ј- indicates the stochiometry [CuL¹][PF₆], i.e. a 1:1 metal/li-

bipyridine, and the higher oligomers by contrast, adjacent gand ratio as expected for a complex between a tetradentate

pyridyl rings are always transoid so that the nitrogen lone ligand and a metal ion with preference for tetrahedral ge-

–

pairs can avoid each other.^[6]In fact the non-bonded N(2)··· ometry. The presence of the PF₆anion was confirmed by

S(1) distance of 2.863(2) Å is in agreement with the known the presence of peaks at 839 and 558 cm^–1in the IR spec-

propensity of divalent S (and Se) atoms to become involved trum,^[8]and the electrospray mass spectrum showed a mol-

in relatively short contacts with nucleophilic atoms.^[7]The ecular ion peak at m/z = 545 for {CuL¹}⁺.

nucleophile [here, pyrazolyl N(2)] tends to approach the S

The X-ray crystal structure (Figure 4) shows that the

atom of an S–X bond in a direction corresponding to elong- crystalline material is an infinite one-dimensional helical

ation of that bond, because of the involvement of the S–X coordination polymer {[CuL¹](PF₆)}_ϱ; helical chains have

σ* orbital in the interaction; in consequence the N···S–C become well known recently with examples based on N,S-

angle should be nearly linear, consistent with other steric chelating^[4]and other^[9]bridging ligands. The Cu^Iion and

–

constraints, and in fact the angle N(2)–S(1)–C(14) is almost the phosphorus atom of the PF₆are at special positions

perfectly linear at 177.9(1)°.

such that the asymmetric unit contains half a Cu^Iion, half

–

L⁴also lies astride a twofold axis of symmetry which lies a ligand and half a PF₆ion. Each Cu^Iion is in a four-

through the centre of the naphthyl spacer. The (methylsul- coordinate environment, coordinated by an N,S-chelating

fanylphenyl)pyrazole units this time adopt a transoid con- arm from each of two separate ligands. Each ligand there-

figuration, unlike the cisoid configuration observed in L¹; fore bridges two metal ions. The Cu···Cu separation be-

the chelating units show a significant deviation from plan- tween metals linked by the same bridging ligand is 9.85 Å.

arity with an angle of 34.7° between the methylsulfanyl- The geometry around the Cu^Iion is distorted tetrahedral

phenyl and pyrazole rings. The two chelating arms are ar- with an angle of 75.5° between the two Cu(NS) planes (Fig-

ranged on opposite sides of the plane of the central naph- ure 4, a); the twist angle within each bidentate (methylsul-

thyl spacer, and rotation of the methylsulfanylphenyl rings fanylphenyl)pyrazole unit is 28.7°. The ligands are arranged

would be required in order for both arms to chelate to a around the Cu^Iions such that each polymeric chain is heli-

single metal ion. It is clear from these structures that in L¹cal with equal amounts of each enantiomer in the crystal.

the bidentate units are too far apart from one another to There are interligand aromatic stacking interactions within

coordinate to a single metal ion, and L¹must necessarily each helical strand, which is a common feature of helical

act as a bridging ligand. However, this is not the case for complexes.^[10]Each central phenyl spacer is stacked to a

L⁴where a tetradentate chelating mode is also possible. (methylsulfanyl)phenyl ring from a ligand on each side of

There is no evidence for any inter- or intramolecular N···S it, with the stacked rings inclined at 6.7° to each other. The

interactions of the type seen for L¹.

distance between these stacked rings (distance of atoms in

Molecules of L⁵have no internal symmetry in the crystal. one from the mean plane of the other) is in the range 3.2–

The chelating units show a significant deviation from plan- 3.7 Å. The angle between the planes of alternating central

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Figure 4. (a) Structure of the metal complex unit of {[CuL¹](PF₆)}_ϱshowing the coordination geometry around the Cu^Icentres. (b) Two

views of the one-dimensional helical chain of {[CuL¹](PF₆)}_ϱ, with alternate ligands shaded differently for clarity. The bottom view shows

the interligand aromatic stacking interactions within each chain.

phenyl rings is 73.6°, hence stacking can be seen in two N,S-chelating arm from two separate ligands. The nitrate

almost perpendicular directions (Figure 4, b) (Table 1).

counterions are non-coordinating. The Ag···Ag separation

is 7.62 Å, significantly shorter than the inter-metal separa-

tion in {[CuL¹](PF₆)}_ϱ. The geometry around the Ag^Iion

is almost tetrahedral with an angle of 80.2° between the two

Ag(NS) planes. The bidentate (methylsulfanylphenyl)-

pyrazole unit show large deviations from planarity with

twist angles between the two rings of 43.5 and 47.8°. The

central phenyl spacers of successive ligands in the chain are

oriented at 72.5° to each other. Unlike in {[CuL¹](PF₆)}_ϱ,

only every second phenyl spacer is involved in interligand

stacking interactions, being sandwiched between pyrazolyl

rings on either side of it to which it is near-parallel (6.9°

between planes); the distance between the stacked rings is

3.1–3.5 Å (Table 2).

Table 1. Selected bond lengths [Å] and angles [°] for {[CuL¹]-

(PF₆)}_ϱ.

Cu(1)–N(2A)

Cu(1)–N(2)

2.014(2)

Cu(1)–S(2A)

Cu(1)–S(2)

2.2933(8)

118.65(12)

129.48(7)

87.61(6)

129.48(7)

108.80(4)

N(2A)–Cu(1)–N(2)

N(2A)–Cu(1)–S(2A)

N(2)–Cu(1)–S(2A)

N(2A)–Cu(1)–S(2)

N(2)–Cu(1)–S(2)

S(2A)–Cu(1)–S(2)

Symmetry transformations used to generate equivalent atoms: –x,

y, –z + 1/2.

Reaction of L¹in methanol with a solution of one equiv-

alent of AgNO₃in H₂O gave a white powder after filtration,

whose elemental analysis indicated the composition

{[AgL¹](NO₃)}_ϱ. The IR spectrum confirmed the presence

Table 2. Selected bond lengths [Å] and angles [°] for {[AgL¹]-

(NO₃)}_ϱ.

–

of the NO₃counterion with a broad band centred around

Ag(1)–N(4)

Ag(1)–N(2)

2.231(5)

2.410(5)

1339 cm^–1, and the FAB mass spectrum (see Experimental

Section) showed peaks arising from 1:1, 2:1 and 2:1 Ag/L¹

fragments.

Ag(1)–S(1)

Ag(1)–S(2)

2.4782(18)

2.6950(18)

120.82(17)

150.59(13)

77.71(13)

75.52(13)

99.66(13)

126.93(6)

N(4)–Ag(1)–N(2)

N(4)–Ag(1)–S(1)

N(2)–Ag(1)–S(1)

N(4)–Ag(1)–S(2)

N(2)–Ag(1)–S(2)

S(1)–Ag(1)–S(2)

X-ray quality crystals were grown from slow evaporation

of the filtrate; the structure of the complex (Figure 5) shows

it to be an infinite helical polymer {[AgL¹](NO₃)·MeOH}_ϱ,

with a similar structure to {[CuL¹](PF₆)}_ϱ. Each Ag^Iion is

in a four-coordinate N₂S₂environment, coordinated by a

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Mononuclear and Polynuclear Chain Complexes of Multinucleating N/S Donor Ligands

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Figure 5. (a) Structure of the metal complex unit of {[AgL¹](NO₃)}_ϱshowing the coordination geometry around the Ag^Icentres. (b)

Structure of the one-dimensional helical chain of {[AgL¹](NO₃)}_ϱwith alternate ligands shaded differently for clarity.

Complexes with L²

two Cu(NS) planes (Figure 6, a); the twist angle within each

bidentate (methylsulfanylphenyl)pyrazole unit is 28.6°.

There are no close π-π stacking interactions within each

chain (Table 3).

The reaction of L²with one equivalent of [Cu(CH₃-

CN)₄]BF₄in dry acetonitrile under nitrogen resulted in a

colourless solution. Diethyl ether diffusion into the reaction

mixture gave almost colourless crystals whose elemental

analysis indicates a 1:1 metal/ligand ratio. The IR spectrum

The reaction of L²with one equivalent of [Ag(CH₃CN)₄]-

BF₄in dry acetonitrile under nitrogen resulted in a colour-

less solution. Diethyl ether diffusion into the reaction mix-

ture gave almost colourless crystals whose elemental analy-

sis was consistent with the formulation [Ag(L²)](BF₄). The

–

confirms the presence of the BF₄counterion at 1056 cm^–1.

The electrospray mass spectrum shows a peak at m/z = 545

for the mononuclear species {CuL²}⁺. The X-ray crystal

structure (Figure 6) shows that the crystalline material is an

–

IR spectrum showed the presence of the BF₄counterion

with a broad band at 1050 cm^–1. The electrospray mass

spectrum showed a molecular ion peak at m/z = 589 for

{AgL²}⁺with no peaks for higher oligomers. The X-ray

structure of the complex shows it to be the mononuclear

complex [Ag(L²)](BF₄), in contrast to the infinite chain that

was observed with Cu^I. There are two unique molecules in

the asymmetric unit, which are associated into a dimer by

face-to-face π-stacking between the phenyl rings of the aro-

matic spacers with an average distance of 3.60 Å between

the overlapping rings.

infinite

one-dimensional

coordination

polymer

{[CuL²](BF₄)}_ϱ. However, unlike the structure of

{[CuL¹](PF₆)}_ϱthe chains are not helical. Each ligand is

folded back on itself with the two coordinating arms almost

overlapping but pointing in opposite directions, coordinat-

ing to separate Cu^Iions.

–

The Cu^Iion and the boron atom of the BF₄are at spe-

cial positions such that the asymmetric unit contains half a

Cu^Iion, half a ligand and half of an anion, as well as frac-

tions of two acetonitrile and a diethyl ether molecule which

The two complex molecules in the asymmetric unit dis-

are also at special positions. Each Cu^Iion is in a four-coor- play similar geometries. If only the N,S-donors are consid-

dinate environment, coordinated by an N,S-chelating arm ered, both Ag^Iions are in a flattened tetrahedral environ-

from each of two separate ligands. The Cu···Cu separation ment [angles of 80.8° and 80.6° between the Ag(NS) pla-

between metals linked by the same bridging ligand is nes], coordinated by an L²ligand acting as a tetradentate

6.17 Å, significantly shorter than that found in chelate. One of the bidentate arms shows a larger dihedral

{[CuL¹](PF₆)}_ϱ(9.85 Å). The geometry around the Cu^Iion twist [44.9° and 49.3° for the molecules containing Ag(1)

is distorted tetrahedral with an angle of 77.2° between the and Ag(2), respectively] between the two rings than the

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Figure 6. (a) Structure of the metal complex unit of {[CuL²](BF₄)}_ϱshowing the coordination geometry around the Cu^Icentres. (b)

Structure of the one-dimensional chain of {[CuL²](BF₄)}_ϱ, with alternate ligands shaded differently for clarity.

Table 3. Selected bond lengths [Å] and angles [°] for {[CuL²]- interacts with one edge of a phenyl ring,^[11]is still well

known^[12]with many dozens of examples in the Cambridge

(BF₄)}_ϱ.

Structural Database. It is characterised by a contact in the

range 2.4–2.8 Å between the Ag^Iion and one C atom such

that the Ag–C vector is near-perpendicular to the aromatic

ring, as we see for [Ag(L²)](BF₄), where these angles are 77°

Cu(1)–N(2A)

Cu(1)–N(2)

Cu(1)–S(1A)

Cu(1)–S(1)

N(2A)–Cu(1)–N(2)

N(2A)–Cu(1)–S(1A)

N(2)–Cu(1)–S(1A)

N(2A)–Cu(1)–S(1)

N(2)–Cu(1)–S(1)

S(1A)–Cu(1)–S(1)

2.057(2)

2.2992(7)

113.93(12)

84.10(6)

130.48(6)

84.10(6)

Table 4. Selected bond lengths [Å] and angles [°] for [AgL²](BF₄).

Ag(1)–N(1)

Ag(1)–N(4)

2.331(3)

2.408(3)

119.85(4)

Symmetry transformations used to generate equivalent atoms:

x, –y + 2, –z.

Ag(1)–S(2)

Ag(1)–S(1)

Ag(1)–C(1)

2.6311(10)

2.6602(11)

2.763(3)

Ag(2)–N(101)

Ag(2)–N(104)

Ag(2)–S(102)

Ag(2)–S(101)

2.367(3)

2.446(3)

other [17.7° and 22.7° for the molecules containing Ag(1)

and Ag(2), respectively]. The average Ag–N bond length is

2.39 Å and the average Ag–S bond length is 2.64 Å

(Table 4). However, the near-linearity of the N–Ag–N

angles [169° at each metal centre] results in a large gap in

the Ag^Icoordination sphere, which is filled by an interac-

tion of each Ag^Iion with the “capping” phenyl ring. The

Ag^Iions do not sit centrally above the phenyl rings but are

slightly offset, such that they interact with just one C atom

(dotted line in Figure 7). The Ag(1)···C(1) separation is

2.76 Å, and the corresponding Ag(2)···C(101) separation in

the independent molecule is 2.74 Å. This type of η¹interac-

tion of an Ag^Iion with a phenyl ring, although less com-

mon than the η²π-type interaction in which the metal ion

2.6100(10)

2.6686(11)

2.737(3)

169.09(10)

116.08(7)

70.66(7)

Ag(2)–C(101)

N(1)–Ag(1)–N(4)

N(1)–Ag(1)–S(2)

N(4)–Ag(1)–S(2)

N(1)–Ag(1)–S(1)

N(4)–Ag(1)–S(1)

S(2)–Ag(1)–S(1)

N(101)–Ag(2)–N(104)

N(101)–Ag(2)–S(102)

N(104)–Ag(2)–S(102)

N(101)–Ag(2)–S(101)

N(104)–Ag(2)–S(101)

S(102)–Ag(2)–S(101)

76.45(8)

110.44(8)

107.77(3)

168.91(10)

114.65(7)

72.36(7)

74.70(8)

112.09(8)

108.22(3)

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Mononuclear and Polynuclear Chain Complexes of Multinucleating N/S Donor Ligands

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for Ag(1) and 83° for Ag(2). In this case, this results in where 1.0 denotes a perfect trigonal bipyramid and 0.0 de-

a coordination geometry about the metal ions that is best notes a perfect square pyramid.^[13]

described as trigonal bipyramidal, with the C and two S

The presence of this metal–carbon interaction with Ag^I,

donors forming the trigonal plane and the two N donors but not Cu^I, is likely to be an important factor in explaining

being axial. The τ parameter for this complex is 0.67 [0.64 why {[CuL²](BF₄)}_ϱforms an infinite chain whereas

for the independent complex molecular containing Ag(2)], [Ag(L²)](BF₄) is mononuclear; the binding mode in

[Ag(L²)](BF₄) in which both bidentate arms of L²coordi-

nate to the same metal ion necessarily brings the phenyl

spacer into close contact with the metal ion. In addition,

this mononucleating, tetradentate coordination mode

would be harder to achieve with the smaller Cu^Iions in any

case.

Complexes with L³

The reaction of L³with one equivalent of [Cu(CH₃CN)₄]-

BF₄in ethanol resulted in a suspension from which an off-

white solid was isolated after filtration. The infrared spec-

trum showed a broad band centred around 1083 cm^–1for

–

the BF₄counterions and the FAB mass spectrum showed

peaks consistent with 1:1, 1:2 and 2:2 Cu/L³fragments; the

elemental analysis was consistent with a 1:1 metal/ligand

ratio.

X-ray quality crystals were grown by diffusion of diethyl

ether vapour into a solution of the complex in MeCN. The

Figure 7. Structure of the metal complex unit of [AgL²](BF₄). The

Ag···C interaction to the phenyl ring is shown with a dashed line.

Figure 8. (a) Structure of the metal complex unit of {[CuL³](BF₄)}_ϱ·1.53CH₃CN·0.47Et₂O showing the coordination geometry around

the Cu^Icentres. (b) Structure of the one-dimensional polymeric chain of {[CuL³](BF₄)}_ϱ·1.53CH₃CN·0.47Et₂O, with alternate ligands

shaded differently for clarity.

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structure of the complex (Figure 8) shows it to be the one-

The reaction of L³with one equivalent of [Ag(CH₃CN)₄]-

dimensional coordination polymer {[CuL³](BF₄)}_ϱwith BF₄in dry acetonitrile under nitrogen resulted in a colour-

one Cu^Iion and one complete ligand in the asymmetric less solution. Diethyl ether diffusion into the reaction mix-

unit. Unlike the complexes of L¹, the structure of ture gave almost colourless crystals whose elemental analy-

{[CuL³](BF₄)}_ϱis not helical. Rather, the sequence of sis indicates a 1:1 metal/ligand ratio. The IR spectrum con-

bridging ligands between one ligand and the next follows a firms the presence of the BF₄^–counterion at 1061 cm^–1. The

zig-zag path. The Cu^Iions are in a four-coordinate N₂S₂FAB mass spectrum shows peaks arising from 1:1, 1:2 and

environment with an almost tetrahedral geometry [angle of 2:2 Ag/L³fragments. The X-ray crystal structure (Figure 9)

87.2° between the Cu(NS) planes]. The Cu···Cu separation shows that the crystalline material is another infinite one-

between metal atoms which are linked by the same bridging dimensional coordination polymer {[AgL³](BF₄)}_ϱ. One of

ligand is 10.645 Å, and the separation between alternate the coordinating arms [containing S(4) and N(7)] is disor-

Cu^Icentres is almost identical at 10.649 Å. The twist angle dered and has been modelled over two sites; unless other-

within the biphenyl spacer is 40.6° and the twist angles wise stated only the major component of this disorder will

within each bidentate (methylsulfanylphenyl)pyrazole units be discussed. Each metal/ligand chain shows a clear zig-zag

are 34.7 and 36.7°. Unlike the structure of L¹there is no (non-helical) structure, similar to that of {[CuL³](BF₄)}_ϱ.

face-to-face π-stacking within the polymer chains (Table 5). The Ag···Ag separations between metal atoms which are

linked by the same bridging ligand are 8.95 and 9.05 Å,

less than the equivalent distances in {[CuL³](BF₄)}_ϱ. The

separations between alternate Ag^Icentres are however

greater at 11.97 Å.

Table 5. Selected bond lengths [Å] and angles [°] for {[CuL³]-

(BF₄)}_ϱ·1.53CH₃CN·0.47Et₂O.

Cu(1)–N(1)

Cu(1)–N(3)

1.961(5)

1.996(5)

The Ag^Iions in each chain alternate between being four-

coordinate [Ag(1)] and three-coordinate [Ag(2)]. Ag(1) is in

an almost tetrahedral N₂S₂environment [angle of 87.2° be-

tween the Ag(NS) planes], coordinated by two bidentate

arms from separate ligands. Ag(2) is in an N₂S environment

approximating a T-shape, with the silver atom sitting ca.

0.1 Å above the plane of the donor atoms [N(4), N(5) and

S(2)]. The remaining donor atom [S(3)] is too far from the

Cu(1)–S(2)

Cu(1)–S(1)

2.3045(17)

2.3567(18)

127.27(18)

128.63(14)

92.35(14)

94.48(15)

107.71(14)

103.55(6)

N(1)–Cu(1)–N(3)

N(1)–Cu(1)–S(2)

N(3)–Cu(1)–S(2)

N(1)–Cu(1)–S(1)

N(3)–Cu(1)–S(1)

S(2)–Cu(1)–S(1)

Figure 9. (a) Structure of the metal complex unit of {[AgL³](BF₄)}_ϱshowing the asymmetric unit and the coordination geometry around

the Ag^Icentres. (b) Structure of the one-dimensional polymeric chain of {[AgL³](BF₄)}_ϱ, with alternate ligands shaded differently for clarity.

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Mononuclear and Polynuclear Chain Complexes of Multinucleating N/S Donor Ligands

FULL PAPER

metal to be considered as forming a normal coordinate typical for this series (average Cu–N 2.03 Å, average Cu–S

bond [Ag(2)···S(3), 3.02 Å compared to 2.6934(12) Å for 2.30 Å, Table 7). The bidentate arms are not individually

Ag(2)–S(2), Table 6] but may interact weakly with Ag(2). coplanar with substantial dihedral twists of 38.7° and 36.5°

The bonds to the N-donors are slightly shorter than those between the pyrazolyl and methylsulfanylphenyl rings.

to Ag(1) [Ag(2)–N(4) 2.213(3) Å, Ag(2)–N(5) 2.191(3) Å] as

a consequence of the lower coordination number. Despite

the low coordination numer there is no evidence for ad-

ditional Ag···C contacts of the type described above for

[Ag(L²)](BF₄). The twist angles within the biphenyl spacers

are 35.4 and 34.2° and the twist angles within each biden-

tate (methylsulfanyl)phenyl-pyrazole units are in the range

37.7–47.4°. There is no face-to-face π-stacking within the

polymer chains. However there is a CH-π interaction be-

tween one of the rings of the biphenyl spacer and the CH

in the 4-position of the next biphenyl spacer (separation of

2.78 Å between the H⁴of the biphenyl unit and the centroid

of the relevant phenyl ring).

Table 6. Selected bond lengths [Å] and angles [°] for {[AgL³]-

(BF₄)}_ϱ.

Ag(1)–N(7Ј)

Ag(1)–N(1)

Ag(1)–N(7)

Ag(1)–S(4)

Ag(1)–S(4Ј)

Ag(1)–S(1)

Ag(2)–N(5)

Ag(2)–N(4)

2.133(8)

2.215(3)

2.328(9)

2.632(3)

2.810(3)

2.8543(13)

2.191(3)

2.213(3)

2.6934(12)

173.3(2)

161.2(2)

119.95(13)

78.4(2)

Figure 10. Molecular structure of the metal complex unit of

[CuL⁴](PF₆).

Ag(2)–S(2)

N(7Ј)–Ag(1)–N(1)

N(1)–Ag(1)–N(7)

N(1)–Ag(1)–S(4)

N(7)–Ag(1)–S(4)

N(7Ј)–Ag(1)–S(4Ј)

N(1)–Ag(1)–S(4Ј)

N(7Ј)–Ag(1)–S(1)

N(1)–Ag(1)–S(1)

N(7)–Ag(1)–S(1)

S(4)–Ag(1)–S(1)

S(4Ј)–Ag(1)–S(1)

N(5)–Ag(2)–N(4)

N(5)–Ag(2)–S(2)

N(4)–Ag(2)–S(2)

Table 7. Selected bond lengths [Å] and angles [°] for [CuL⁴](PF₆)·

2MeCN·2H₂O.

75.6(3)

110.28(12)

109.4(2)

73.54(9)

101.4(2)

98.75(7)

97.49(7)

164.86(12)

115.06(9)

79.00(9)

Cu(1)–N(4)

Cu(1)–N(1)

2.020(4)

2.032(4)

Cu(1)–S(1)

Cu(1)–S(2)

N(4)–Cu(1)–N(1)

N(4)–Cu(1)–S(1)

N(1)–Cu(1)–S(1)

N(4)–Cu(1)–S(2)

N(1)–Cu(1)–S(2)

2.2973(14)

2.2998(14)

121.28(9)

115.85(11)

92.81(12)

93.24(11)

115.43(11)

The reaction of L⁴with one equivalent of [Ag(CH₃CN)₄]-

BF₄in ethanol resulted in a suspension from which an off-

Complexes with L⁴

Reaction of L⁴with one equivalent of [Cu(CH₃CN)₄]PF₆white solid was isolated after filtration. The elemental

in dry acetonitrile under nitrogen resulted in a colourless analysis of the powder is consistent with the formulation

solution. Diethyl ether diffusion into the reaction mixture [AgL⁴](BF₄). The IR spectrum showed the presence of the

gave colourless crystals whose elemental analysis was con- BF₄^–counterion with a broad band at 1071 cm^–1. The FAB

sistent with a 1:1 metal/ligand ratio. The IR spectrum mass spectrum showed a molecular ion peak at m/z = 641

showed peaks at 841 and 557 cm^–1for the PF₆^–counterions. for {AgL⁴}⁺with no peaks for higher oligomers. The crys-

The FAB mass spectrum showed a molecular ion peak at tal structure of the complex shows it to be the mononuclear

m/z = 595 for {CuL⁴}⁺but no peaks for higher oligomers. complex [Ag(L⁴)](BF₄) (Figure 11). There are two unique

A subsequent X-ray crystal structure determination (Fig- complex molecules in the unit cell which are associated into

ure 10) showed that the crystalline material is the mononu- a dimer by weak, long-range Ag···N interactions (Ͼ 3 Å)

clear complex [Cu(L⁴)](PF₆), in obvious contrast to the between the Ag^Iion of one complex and the pyrazolyl N

polymeric structures obtained with L¹, L²and L³. The Cu^Iatoms of another. The two silver ions are 4.20 Å apart,

ion is in a distorted tetrahedral N₂S₂environment [angle which precludes any Ag···Ag interaction between them, and

of 85.6° between the Cu(NS) planes] with L⁴acting as a the two naphthalene spacers are at opposite sides of the

tetradentate chelate. The bond lengths to the Cu^Iion are dimer.

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4541

T. K. Ronson, H. Adams, M. D. Ward

FULL PAPER

where the sulfur atom is not coordinated to the metal shows

a greater dihedral angle between the pyrazole and methyl-

sulfanylphenyl rings (58.0°) than the arm where both donor

atoms are coordinated (21.5°).

The NMR spectra of [CuL⁴](PF₆) and [AgL⁴](BF₄) show

that the complexes have twofold symmetry in solution.

Complexes with L⁵

The reaction of L⁵with 1.5 equivalents of Ag(ClO₄)₄·

H₂O in dry acetonitrile under nitrogen resulted in a colour-

less solution. Diethyl ether diffusion into the reaction mix-

ture gave colourless crystals whose elemental analysis indi-

cates the stochiometry [AgL⁵](ClO₄), i.e. a 1:1 metal/ligand

ratio rather than the 3:2 ratio expected for a complex be-

tween a hexadentate ligand and a metal ion with preference

for tetrahedral geometry. The IR spectrum showed the pres-

–

ence of the ClO₄counterions at 1091 and 623 cm^–1, and

the FAB mass spectrum showed a molecular ion peak at

m/z = 835 for the fragment {AgL⁵}⁺all indicating forma-

tion of a 1:1 complex.

Figure 11. Molecular structure of the metal complex unit of

[AgL⁴](BF₄) showing the stacking of two independent molecules in

the unit cell.

X-ray crystallography confirmed (Figure 12) that the

complex is mononuclear, with some obvious structural simi-

larities to [AgL²](BF₄) as a consequence of the meta substi-

tution pattern of the central phenyl spacer. The Ag^Iion is

bound by two of the bidentate N,S-donor arms of L⁵with

the third arm pendant. As we saw with [AgL²](BF₄), the

orientation of the two chelating bidentate arms to the same

face of the phenyl spacer necessarily results in a close con-

tact between the metal ion and the phenyl ring, resulting in

an η¹π-type interaction with C(2) of the phenyl ring

[Ag(1)···C(2), 2.70 Å (dotted line in Figure 12; Table 9),

with the angle between the Ag–C vector and the phenyl

plane being 89°]. The Ag^Icentre is therefore five coordinate;

the τ parameter of 0.12 indicates that the geometry is best

described as square-based pyramidal, with S(2) being the

“axial” donor. Although the third pendant arm is directed

One Ag^Iion [Ag(2)] is in a flattened tetrahedral environ-

ment [angle of 75.6° between the Ag(NS) planes] coordi-

nated by an L⁴ligand acting as a tetradentate chelate. The

Ag–N bonds are 2.246(10) and 2.367(9) Å and the Ag–S

bonds are longer at 2.468(3) and 2.785(4) Å and are typical

of the silver complexes in this series. One of the bidentate

arms shows a larger dihedral twist between the two rings

than the other [59.0° for the arm containing N(11) and

S(11), and 22.8° for the arm containing N(14) and S(12)].

The other Ag^Iion is in a three-coordinate N₂S environment

with all donor atoms coming from a single L⁴molecule.

Here the remaining sulfur atom is too far from the metal

to be considered as forming a normal coordinate bond

[Ag(1)–S(1) = 3.02 Å compared to 2.445(3) Å for Ag(1)–

S(2), Table 8]. The coordination environment is almost

planar with the Ag(1) sitting ca. 0.1 Å above the plane of

the donor atoms. The bond to one of the N-donors is signif-

icantly longer than that to the other N-donor [Ag(1)–N(1),

2.146(9) Å; Ag(1)–N(4), 2.446(9) Å]. The bidentate arm

Table 8. Selected bond lengths [Å] and angles [°] for [AgL⁴](BF₄).

Ag(1)–N(1)

Ag(1)–S(2)

Ag(1)–N(4)

Ag(2)–N(14)

Ag(2)–N(11)

Ag(2)–S(11)

Ag(2)–S(12)

N(1)–Ag(1)–S(2)

N(1)–Ag(1)–N(4)

S(2)–Ag(1)–N(4)

N(14)–Ag(2)–N(11)

N(14)–Ag(2)–S(11)

N(11)–Ag(2)–S(11)

N(14)–Ag(2)–S(12)

N(11)–Ag(2)–S(12)

S(11)–Ag(2)–S(12)

2.146(9)

2.445(3)

2.446(9)

2.246(10)

2.367(9)

2.468(3)

2.785(4)

161.3(3)

114.0(3)

83.6(2)

110.5(3)

162.7(3)

85.3(2)

81.5(3)

108.8(2)

100.35(13)

Figure 12. Molecular structure of the metal complex unit of

[AgL⁵](ClO₄). The Ag···C interaction to the phenyl ring is shown

with a dashed line.

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Mononuclear and Polynuclear Chain Complexes of Multinucleating N/S Donor Ligands

FULL PAPER

1

towards the same face of the aromatic spacer as the two (ClO₄)_x} species. The H NMR spectrum showed a sym-

other arms, the remaining donor atoms are not interacting metrical structure in solution with identical chemical shifts

with the Ag^Icentre [Ag(1)–N(6), 4.69 Å; Ag(1)–S(3), to that of [AgL⁵](ClO₄), suggesting that [Ag₃(L⁵)₂]³⁺only

3.71 Å]. All three bidentate arms show substantial devia- exists in the solid state. Attempts to isolate pure [Ag₃-

tions from planarity (twist angles of 17.7 and 33.5° between (L⁵)₂](ClO₄)₃by using a smaller excess of Ag(ClO₄)₄·H₂O

the pyrazolyl and methylsulfanylphenyl rings for the coordi- were unsuccessful resulting in a mixture of [Ag₃(L⁵)₂]-

nated arms and 34.6° for the non-coordinated arm).

(ClO₄)₃and [Ag(L⁵)₂](ClO₄).

In the crystal structure of [Ag₃(L⁵)₂](ClO₄)₃(Figure 13),

the pendant arms of two mononuclear {Ag(L⁵)}⁺units are

coordinated to another Ag^Iion, linking two such units to-

gether via a third Ag^Icentre. The two terminal Ag^Iions

[Ag(1), Ag(3)] are in the familiar five-coordinate environ-

ments from two bidentate N,S-chelating ligand arms and

an η¹π-type interaction with the capping phenyl ring

[Ag(1)···C(2), 2.79 Å; Ag(3)···C(102), 2.83 Å, Table 10;

angles between Ag–C vectors and phenyl mean planes, 82°

and 83° respectively; τ parameters 0.72 and 0.61 at Ag(1)

and Ag(3) respectively]. The central Ag^Iion [Ag(2)] is in

a five coordinate N₂SO₂environment arising from an N,S

bidentate arm from one ligand, just the pyrazolyl N-donor

from the other ligand, and two oxygen atoms from one of

the perchlorate anions [Ag–O distances, 2.85 and 2.87 Å].

The remaining non-coordinated S atom, S(103), is 3.82 Å

away from Ag(2).

Table 9. Selected bond lengths [Å] and angles [°] for [AgL⁵](ClO₄).

Ag(1)–N(4)

Ag(1)–N(2)

Ag(1)–S(1)

Ag(1)–S(2)

2.3172(19)

2.436(2)

2.5201(7)

2.8347(7)

2.701(2)

151.66(7)

124.95(5)

79.22(5)

69.23(5)

90.61(5)

107.53(2)

Ag(1)–C(2)

N(4)–Ag(1)–N(2)

N(4)–Ag(1)–S(1)

N(2)–Ag(1)–S(1)

N(4)–Ag(1)–S(2)

N(2)–Ag(1)–S(2)

S(1)–Ag(1)–S(2)

Despite the asymmetry of the complex in the solid state,

the ¹H NMR spectrum of [AgL⁵](ClO₄) showed that all

three arms of the ligand are equivalent in solution, indicat-

ing that the silver() ion is coordinated by all three arms or,

more likely, that the structure is fluxional in solution.

The structure of [Ag(L⁵)](ClO₄) suggested that the pen-

dant arm would be able to coordinate a second metal ion,

but only after the conformation of L⁵alters such that the

pendant arm is rotated away from the metal ion. Reaction

of L⁵with a 10 fold excess of AgClO₄·H₂O in dry acetoni-

trile under nitrogen resulted in a colourless solution. Di-

ethyl ether vapour diffusion into this solution gave crystals

of unreacted [Ag(CH₃CN)₄]ClO₄in addition to crystals of

the trinuclear complex [Ag₃(L⁵)₂](ClO₄)₃. The FAB mass

spectrum of these latter crystals shows a peak at m/z = 835

for {Ag(L⁵)}⁺and additional peaks at m/z = 1041 for

{Ag₂(L⁵)(ClO₄)}⁺and 1768 for {Ag₂(L⁵)₂(ClO₄)}⁺. No

peaks were observed for intact trinuclear {Ag₃(L⁵)₂-

The two ligands are arranged such that the silver ions

form a rough triangle. The inter-metallic distances between

silver ions linked by the same ligand are 8.72 Å [Ag(1)···

Ag(2)] and 7.47 Å [Ag(2)···Ag(3)]; the Ag(1)···Ag(3) separa-

tion is 9.58 Å. The bidentate arms show twist angles of

11.2–49.3° between pyrazolyl and methylsulfanylphenyl

rings, whereas the arm where only the pyrazolyl donor is

coordinated shows a larger twist angle of 78.2° in order to

avoid unfavourable steric interactions between the thioether

group and the nearby bidentate arm from the other ligand.

The reaction of L⁵with [Cu(CH₃CN)₄]BF₄in a 2:3 ratio

in dry ethanol resulted in an off-white precipitate which was

isolated by filtration. The elemental analysis of the powder

Figure 13. Molecular structure of the metal complex unit of [Ag₃(L⁵)₂](ClO₄)₃; one ligand is shown with hollow bonds for clarity. The

Ag···C interactions to the phenyl rings are shown with dashed lines.

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T. K. Ronson, H. Adams, M. D. Ward

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Table 10. Selected bond lengths [Å] and angles [°] for [Ag₂- η¹π-type Ag···C(phenyl) interactions which do not occur

(L⁵)₃](ClO₄)₃.

with Cu^I.

Ag(1)–N(4)

Ag(1)–N(2)

Ag(1)–S(1)

Ag(1)–S(2)

Ag(1)–C(2)

Ag(2)–N(106)

Ag(2)–N(6)

Ag(2)–S(3)

Ag(2)–O(11)

Ag(2)–O(12)

Ag(3)–N(104)

Ag(3)–N(102)

Ag(3)–S(101)

Ag(3)–S(102)

Ag(3)–C(102)

N(4)–Ag(1)–N(2)

N(4)–Ag(1)–S(1)

N(2)–Ag(1)–S(1)

N(4)–Ag(1)–S(2)

N(2)–Ag(1)–S(2)

S(1)–Ag(1)–S(2)

N(106)–Ag(2)–N(6)

N(106)–Ag(2)–S(3)

N(6)–Ag(2)–S(3)

N(104)–Ag(3)–N(102)

N(104)–Ag(3)–S(101)

N(102)–Ag(3)–S(101)

N(104)–Ag(3)–S(102)

N(102)–Ag(3)–S(102)

S(101)–Ag(3)–S(102)

2.308(6)

2.439(6)

2.586(2)

2.626(2)

2.785(6)

2.154(6)

2.336(6)

2.539(2)

2.848(7)

2.871(7)

2.375(6)

2.385(6)

2.603(2)

2.667(2)

2.823(6)

168.2(2)

114.18(16)

71.62(15)

78.16(16)

109.53(14)

113.54(7)

129.7(2)

152.01(16)

72.58(15)

162.7(2)

120.34(15)

75.28(14)

72.05(15)

109.47(15)

115.13(6)

Experimental Section

General Details: 2Ј-(Methylthio)acetophenone,^[14]3,3Ј-bis(bromo-

methyl)biphenyl^[15]and [Cu(CH₃CN)₄]X (X = PF₆, BF₄)^[16]were

prepared according to literature methods. All other organic rea-

gents and metal salts were purchased from Aldrich or Avocado and

used as received. ¹H NMR spectra were recorded with a Bruker

AC 250 or Bruker AMX2 400 spectrometer, and all mass spectra

(FAB and EI) with a VG AutoSpec magnetic sector instrument. IR

spectra were recorded with a Perkin–Elmer Spectrum One instru-

ment. Samples for elemental analysis were vacuum-dried.

Preparation of 1,8-Bis(bromomethyl)naphthalene: This is a slight

variant of a literature method.^[17]PBr₃(6.0 cm³, 0.064 mol) was

added to

a suspension of 1,8-bis(hydroxymethyl)naphthalene

(3.93 g, 0.0209 mol) in dry dichloromethane (50 cm³) under nitro-

gen. The resulting clear solution was stirred at room temperature

for 5 h. After this period water was carefully added dropwise until

the evolution of gas ceased. The organic layer was separated,

washed with water and dried (MgSO₄). Removal of the solvent af-

forded the crude product as an off-white solid. Recrystallisation

from dichloromethane/hexane gave 5.29 g of off-white crystals

(81%). All analytical data match those previously published.^[17]

Preparation of 3-[(2-Methylthio)phenyl]pyrazole: This is a slight

variant of the method published earlier.^[5]A solution of 2Ј-(meth-

ylthio)acetophenone (4.28 g, 0.0257 mol) in dimethylformamide–

dimethylacetal (10 cm³, a large molar excess) was refluxed for

3 days under nitrogen to yield a dark brown solution. Removal of

excess dimethylformamide-dimethylacetal in vacuo gave crude 3-

(dimethylamino)-1-[2-(methylthio)phenyl]-2-propen-1-one as an

orange/brown oil. To this was added ethanol (60 cm³) and hydra-

zine hydrate (10 cm³, a large molar excess), and the mixture re-

fluxed in air for 2 h. The pale yellow solution was cooled and added

to ice/water (300 cm³) resulting in a pale yellow precipitate. The

mixture was refrigerated overnight to complete the precipitation of

the product. The solid was filtered off, washed with cold water

(50 cm³) and hexane (50 cm³) and dried in vacuo. Subsequent

recrystallisation from dichloromethane/hexane afforded 3-[(2-meth-

ylthio)phenyl]pyrazole as pale yellow needle crystals (4.35 g, 89%).

was consistent with a 1:1 metal/ligand ratio suggesting that

the product is a mononuclear complex similar in structure

to [AgL⁵](ClO₄). The IR spectrum is consistent with the

–

presence of the BF₄anion with a broad band centred

around 1064 cm^–1. The FAB mass spectrum shows a main

peak at 789 for {CuL⁵}⁺but also very weak peaks for 1006

({Cu₂(L⁵) + NOBA}⁺), 1515 ({Cu(L⁵)₂}⁺) and 1669

({Cu(L⁵)₂+ NOBA}⁺) suggesting that a complex of higher

nuclearity could have formed. The poor solubility of this

complex did not permit study by NMR spectroscopy. All

attempts to crystallise this complex have been unsuccessful.

1

EI MS: m/z = 190 [M⁺]. H NMR (250 MHz): CDCl₃: δ (ppm) =

7.63 (d, 1 H, pyrazolyl H⁵), 7.50 (m, 1 H, phenyl H³), 7.31–7.36

(m, 2 H, phenyl H⁵, phenyl H⁶), 7.21 (m, 1 H, phenyl H⁴), 6.62 (d,

1 H, pyrazolyl H⁴), 2.41 (s, 3 H, SCH₃). C₁₀H₁₀N₂S (190.27): calcd.

C 63.1, H 5.3, N, 14.7; found C 62.7, H 5.2, N 14.7.

Conclusions

Reaction of the bidentate N,S-donor fragment 3-[2-

(methylsulfanyl)phenyl]pyrazole with a range of aromatic

groups having two or three bromomethyl substituents al-

lows two or three N,S-donor units to be linked to a central

Preparation of L¹: A two-phase mixture of 3-[(2-methylthio)phenyl]-

pyrazole (1.26 g, 6.60 mmol), α,αЈ-dibromo-p-xylene (0.711 g,

2.70 mmol), toluene (90 cm³), nBu₄NOH (0.10 cm³) and aqueous

aromatic spacer. Depending on the separation between the 10  NaOH (15 cm³) was heated to 75 °C and stirred vigorously at

this temperature for 24 h. After cooling the mixture was diluted

with water (100 cm³) and the aqueous layer extracted with toluene

(2×100 cm³). The combined organic layers were washed with water

and dried (MgSO₄). The solvent was removed in vacuo and the

crude product was purified by column chromatography (alumina,

dichloromethane) to give 0.767 g of pale yellow solid (59%). FAB

MS: m/z = 483 [MH⁺]. ¹H NMR (250 MHz, CDCl₃): δ (ppm) =

7.55 (dd, 2 H, methylthiophenyl H³), 7.38 (d, 2 H, pyrazolyl H⁵),

7.23–7.35 (m, 8 H, phenyl, methylthiophenyl H⁵, H⁶), 7.17 (dd, 2

H, methylthiophenyl H⁴), 6.63 (d, 2 H, pyrazolyl H⁴), 5.36 (s, 4 H,

N,S-donor units they can either each bind to a separate me-

tal ion, giving one-dimensional (helical or zig-zag) chains

with Ag^Iand Cu^I, or can chelate to a single metal centre

giving smaller mononuclear (metal/ligand, 1:1) or trinuclear

(metal/ligand, 3:2) complexes. Whereas the Cu^Icentres in

these complexes are all four coordinate from two N,S-donor

units, the Ag^Icentres are sometimes three-coordinate due

to incomplete coordination of the N,S-donor units. An ad-

ditional factor responsible for the differences between Cu^I

and Ag^Icomplexes with the same ligand is the presence of CH₂), 2.42 (s, 6 H, SCH₃) ppm. ¹³C NMR (100 MHz, CDCl₃): δ =

Eur. J. Inorg. Chem. 2005, 4533–4549

Mononuclear and Polynuclear Chain Complexes of Multinucleating N/S Donor Ligands

FULL PAPER

150.6, 137.3, 136.5, 132.4, 129.7 (two closely spaced signals), 128.2,

128.1, 125.2, 124.6, 106.9, 55.7, 16.1 ppm. IR (KBr disk): ν = 2916

ane/hexane to give 0.86 g of off-white needle crystals. A second

crop of 1.17 g of off-white powder was obtained from the

˜

(w), 2854 (w), 1588 (w), 1514 (m), 1489 (m), 1426 (m), 1355 (m), recrystallisation filtrates by column chromatography (alumina,

1322 (w), 1304 (w), 1261 (m), 1217 (w), 1065 (m), 1051 (s), 1000

20% hexane in dichloromethane). Total yield: 2.03 g (60%). FAB

(w), 952 (w), 861 (w), 777 (w), 754 (s), 722 (m), 705 (m), 946 (w), MS: m/z = 533 [MH⁺]. ¹H NMR (500 MHz, CDCl₃): δ (ppm) =

629 (w), 521 (w) cm^–1. C₂₈H₂₆N₄S₂(482.67): calcd. C 69.7, H 5.4, 7.89 (dd, 2 H, napthyl H⁴), 7.57 (ddd, 2 H, methylthiophenyl H³),

N 11.6; found C 69.6, H 5.4, N 11.2. X-ray quality crystals of L¹

were grown from slow evaporation of an acetonitrile solution.

7.45 (dd, 2 H, napthyl H³), 7.24–7.32 (m, 4 H, methylthiophenyl

H⁵, H⁶), 7.23 (dd, 2 H, naphthyl H²), 7.20 (d, 2 H, pyrazolyl H⁵),

7.16 (ddd, 2 H, methylthiophenyl H⁴), 6.59 (d, 2 H, pyrazolyl H⁴),

5.93 (s, 4 H, CH₂), 2.39 (s, 6 H, SCH₃) ppm. ¹³C NMR (100 MHz,

CDCl₄): δ (ppm) = 150.9, 137.4, 135.8, 132.4, 131.8, 130.8, 130.5,

130.4, 130.1, 129.7, 128.2, 125.5, 125.3, 124.5, 106.7, 56.7, 16.1. IR

Preparation of L²: A two-phase mixture of 3-[(2-methylthio)phenyl]-

pyrazole (1.00 g, 5.26 mmol), α,αЈ-dibromo-m-xylene (0.630 g,

2.39 mmol), toluene (100 cm³), nBu₄NOH (0.10 cm³) and aqueous

10  NaOH (15 cm³) was heated to 65 °C and stirred vigorously at

this temperature for 24 h. After cooling the mixture was diluted

with water (100 cm³) and the aqueous layer extracted with toluene

(2×100 cm³). The combined organic layers were washed with water

and dried (MgSO₄). The solvent was removed in vacuo and the

crude product was purified by column chromatography (alumina,

dichloromethane) to give 0.691 g of colourless oil (60%). EI MS:

m/z = 483 [MH⁺]. ¹H NMR (500 MHz, CDCl₃): δ = 7.54 (dd, 2

H, methylthiophenyl H³), 7.39 (d, 2 H, pyrazolyl H⁵), 7.25–7.34

(m, 5 H, phenyl H⁵, methylthiophenyl H⁵, H⁶), 7.15–7.22 (m, 5 H,

phenyl H², H⁴, methylthiophenyl H⁴), 6.62 (d, 2 H, pyrazolyl H⁴),

5.36 (s, 4 H, CH₂), 2.42 (s, 6 H, SCH₃) ppm. ¹³C NMR (125 MHz,

CDCl₃): δ = 150.5, 137.4, 137.2, 132.3, 129.8 (two closely spaced

signals), 129.2, 128.2, 127.3, 126.9, 125.2, 124.6, 106.9, 55.8,

(KBr disk): ν 3117 (w), 2918 (w), 1586 (w), 1562 (w), 1509 (m),

˜

1489 (m), 1454 (s), 1440 (m), 1399 (w), 1331 (m), 1258 (m), 1213

(m), 1170 (w), 1107 (w), 1052 (s), 976 (w), 960 (w), 944 (w), 844

(w), 782 (s), 769 (m), 753 (s), 737 (m), 676 (m), 622 (w) cm^–1.

C₃₂H₂₈N₄S₂(532.73): calcd. C 72.1, H 5.3, N 10.5; found C 72.0,

H 5.3, N 10.5. X-ray quality crystals were grown from diethyl ether

diffusion into an NMR sample of L⁴in CDCl₃.

Preparation of L⁵: A two-phase mixture of 3-[(2-methylthio)phenyl]-

pyrazole (1.54 g, 8.09 mmol), 2,4,6-tris(bromomethyl)mesitylene

(0.981 g, 2.46 mmol), toluene (70 cm³), nBu₄NOH (0.10 cm³) and

aqueous 10  NaOH (25 cm³) was heated to 70 °C and stirred vig-

orously at this temperature for 24 h. After cooling the mixture was

diluted with water (100 cm³) and the aqueous layer extracted with

toluene (2×100 cm³). The combined organic layers were washed

with water and dried (MgSO₄). The solvent was removed in vacuo

and the crude product was purified by column chromatography

(alumina, 1% methanol in dichloromethane) to give 0.551 g of off-

white foam (31%). EI MS: m/z = 726 [M⁺], 536 {M⁺-[3-(2-methyl-

thiophenyl)pyrazole]}, 347 {M⁺– 2[3-(2-methylthiophenyl)pyr-

azole]}. ¹H NMR (250 MHz, CDCl₃): δ (ppm) = 7.56 (dd, 3 H,

methylthiophenyl H³), 7.23–7.35 (m, 6 H, methylthiophenyl H⁵,

H⁶), 7.17 (ddd, 3 H, methylthiophenyl H⁴), 7.09 (d, 3 H, pyrazolyl

H⁵), 6.56 (d, 3 H, pyrazolyl H⁴), 5.54 (s, 6 H, CH₂), 2.47 (s, 9 H,

CH₃), 2.42 (s, 9 H, SCH₃) ppm. ¹³C NMR (100 MHz, CDCl₃): δ

(ppm) = 150.4, 139.7, 137.3, 132.2, 131.3, 129.6, 128.4, 128.2,

16.0 ppm. IR (neat): ν = 3111 cm^–1(w), 3052 (w), 2979 (w), 2920

˜

(m), 2854 (w), 1610 (w), 1591 (w), 1563 (w), 1516 (m), 1490 (s),

1453 (s), 1436 (s), 1400 (s), 1335 (s), 1259 (s), 1221 (s), 1164 (w),

1106 (w), 1064 (m), 1052 (s), 1002 (w), 967 (w), 947 (w), 753 (s),

710 (m), 654 (w) cm^–1. C₂₈H₂₆N₄S₂(482.67): calcd. C 69.7, H 5.4,

N 11.6; found C 69.4, H 5.8, N 11.4.

Preparation of L³: A two-phase mixture of 3-[(2-methylthio)phenyl]-

pyrazole (1.23 g, 6.46 mmol), 3,3Ј-bis(bromomethyl)biphenyl

(1.00 g, 2.94 mmol), toluene (55 cm³), nBu₄NOH (0.03 cm³) and

aqueous 10  NaOH (12 cm³) was heated to 70 °C and stirred vig-

orously at this temperature for 24 h. After cooling the mixture was

diluted with water (100 cm³) and the aqueous layer extracted with

toluene (2×100 cm³). The combined organic layers were washed

with water and dried (MgSO₄). The solvent was removed in vacuo

and the crude product was purified by column chromatography

(alumina, 20% hexane in dichloromethane) to give 0.701 g of white

foam (43%). EI MS: m/z = 558 [M⁺]. ¹H NMR (250 MHz, CDCl₃):

δ (ppm) 7.50–7.59 (m, 6 H), 7.43 (d, 2 H, pyrazolyl H⁵), 7.23–7.42

(m, 8 H), 7.17 (ddd, 2 H, methylthiophenyl H⁴), 6.62 (d, 2 H, pyr-

azolyl H⁴), 5.43 (s, 4 H, CH₂), 2.39 (s, 6 H, SCH₃) ppm. ¹³C NMR

(100 MHz, CDCl₃): δ = 150.6, 141.2, 137.4, 137.2, 132.4, 129.8 (two

closely spaced signals), 129.2, 128.2, 126.8 (two closely spaced sig-

125.2, 124.6, 106.2, 50.9, 16.5, 16.1. IR (KBr disk): ν 3050 (w),

˜

2977 (w), 2916 (m), 1589 (w), 1562 (w), 1514 (w), 1488 (m), 1453

(s), 1436 (s), 1398 (m), 1323 (m), 1256 (m), 1215 (s), 1106 (w), 1063

(m), 1051 (s), 998 (w), 944 (m), 752 (s), 732 (s), 654 (w), 618 (w)

cm^–1. C₄₂H₄₂N₆S₃(727.03): calcd. C 69.4, H 5.8, N 11.6; found C

69.2, H 5.9, N 11.5. X-ray quality crystals were grown from the

diffusion of pentane vapour into an acetonitrile solution of L⁵.

Preparation of {[CuL¹](PF₆)}_ϱ: A solution of [Cu(CH₃CN)₄]PF₆

(62 mg, 0.17 mmol) in MeCN (5 cm³) was added to a solution of

L¹(80 mg, 0.17 mmol) in MeCN (20 cm³). The colourless solution

was stirred for 4 h and the volume reduced to ca. 10 cm³. Diethyl

ether diffusion into the solution gave off-white crystals of

{[CuL¹](PF₆)}_ϱwhich were suitable for X-ray crystallography.

Yield: 86 mg, 75%. ES MS: m/z = 545 [CuL¹]⁺. ¹H NMR

(250 MHz, CDCl₃): δ (ppm) = 7.69 (d, 2 H, pyrazolyl H⁵), 7.48 (m,

2 H, methylthiophenyl H³), 7.30-7.75 (m, 4 H, methylthiophenyl

H⁵, H⁶), 7.18–7.25 (m, 2 H, methylthiophenyl H⁴), 7.12 (s, 4 H,

phenyl), 6.62 (d, 2 H, pyrazolyl H⁴), 5.27 (s, 4 H, CH₂), 2.32 (s, 6

H, SMe). ¹³C NMR (100 MHz, CD₃CN): δ (ppm) = 151.4, 137.8,

136.2, 132.8, 132.5, 131.1 129.7, 128.6, 127.8, 126.7, 107.6, 55.9,

nals), 126.6, 125.2, 124.6, 106.9, 56.0, 16.0 ppm. IR (KBr disk): ν

˜

3050 (w), 2917 (m), 2853 (w), 1603 (w), 1588 (w), 1515 (w), 1488

(m), 1453 (m), 1434 (s), 1399 (m), 1334 (m), 1257 (m), 1220 (m),

1105 (w), 1063 (m), 1050 (m), 1000 (w), 946 (w), 751 (s), 732 (m),

695 (m), 654 (w) cm^–1. C₃₄H₃₀N₄S₂(558.77): calcd. C 73.1, H 5.4,

N 10.0; found C 72.8, H 5.6, N 9.6.

Preparation of L⁴: A two-phase mixture of 3-[(2-methylthio)phenyl]-

pyrazole (2.50 g, 13.1 mmol), 1,8-bis(bromomethyl)naphthalene

(1.99 g, 6.34 mmol), toluene (120 cm³), nBu₄NOH (0.20 cm³) and

aqueous 10  NaOH (26 cm³) was heated to 65 °C and stirred vig-

orously at this temperature for 24 h. After cooling the mixture was

diluted with water (100 cm³) and the aqueous layer extracted with

toluene (2×100 cm³). The combined organic layers were washed

with water and dried (MgSO₄). The solvent was removed in vacuo

and the crude product was recrystallised twice from dichlorometh-

17.3 ppm. IR (KBr disk): ν 3156 (w), 3138 (w), 3052 (w), 2997 (w),

˜

2925 (w), 1631 (w), 1589 (w), 1564 (w), 1518 (s), 1501 (s), 1462 (w),

1425 (s), 1401 (w), 1357 (s), 1325 (s), 1277 (w), 1225 (m), 1075 (s),

1020 (w), 971 (m), 954 (m), 879 (m), 839 (s), 786 (s), 760 (s), 729

(m), 649 (w), 619 (w), 558 (s) cm^–1. C₂₈H₂₆CuF₆N₄PS₂(691.18):

calcd. C 48.7, H 3.8, N 8.1; found C 48.8, H 3.7, N 8.0.

Eur. J. Inorg. Chem. 2005, 4533–4549

www.eurjic.org

4545

T. K. Ronson, H. Adams, M. D. Ward

FULL PAPER

Preparation of {[AgL¹](NO₃)}_ϱ: A solution of AgNO₃(29 mg, (500 MHz, CD₃CN): δ (ppm) = 7.71 (br. s, 2 H, pyrazolyl H⁵),

0.17 mmol) in H₂O (3 cm³) was added to a solution of L¹(81 mg, 7.46–7.55 (m, 6 H), 7.41 (t, 2 H), 7.27–7.35 (m, 4 H), 7.25 (d, 2 H),

0.17 mmol) in hot MeOH (10 cm³). The colourless solution was

stirred for 4 h and the volume reduced to ca. 5 cm³. The mixture

was filtered to give {[AgL¹](NO₃)}_ϱas a white powder. Yield:

71 mg, 65%. X-ray quality crystals were obtained from slow evapo-

7.21 (m, 1 H), 6.58 (d, 2 H, pyrazolyl H⁴), 5.40 (s, 4 H, CH₂), 2.28

(s, 6 H, SCH ) ppm. IR (KBr disk): ν = 3143 (w), 2925 (w), 1602

˜

3

(w), 1519 (w), 1502 (m), 1435 (m), 1412 (m), 1360 (w), 1329 (w),

1232 (m), 1083 (s, br), 1060 (s), 785 (m), 771 (m), 756 (s), 732 (w),

699 (m), 623 (w), 520 (w) cm^–1. C₃₄H₃₀BCuF₄N₄S₂(709.12): calcd.

C 57.6, H 4.3, N 7.9; found C 57.3, H 4.2, N 7.9. X-ray quality

crystals were grown from diethyl ether diffusion into an acetonitrile

ration of the filtrate. FAB MS: m/z

=

591 [AgL¹], 651

[Ag(L¹)(NO₃)], 697 [Ag₂(L¹)], 760 [Ag₂(L¹)(NO₃)], 850 [Ag₂(L¹) +

NOBA], 1179 [Ag₂(L¹)₂], 1242 [Ag₂(L¹)₂(NO₃)], 1333 [Ag₂(L¹)₂+

NOBA]. ¹H NMR (250 MHz, CD₃CN): δ (ppm) = 7.69 (d, 2 H, solution of the complex.

pyrazolyl H⁵), 7.42 (dd, 2 H, methylthiophenyl H³), 7.33 (ddd, 2

Preparation of {[AgL³](BF₄)}_ϱ: [Ag(CH₃CN)₄]BF₄(61 mg,

H, methylthiophenyl H⁵), 7.25 (dd, 2 H, methylthiophenyl H⁶), 7.19

(td, 2 H, methylthiophenyl H⁴), 7.10 (s, 4 H, phenyl), 6.56 (d, 2 H,

pyrazolyl H⁴), 5.22 (s, 4 H, CH₂), 2.28 (s, 6 H, SMe); (500 MHz,

CD₃NO₂): δ (ppm) = 7.80 (d, 2 H, pyrazolyl H⁵), 7.37–7.42 (m, 4

H, methylthiophenyl H³, H⁵), 7.29 (td, 2 H, methylthiophenyl H⁴),

7.28 (d, 2 H, methylthiophenyl H⁶), 6.86 (s, 4 H, phenyl), 6.61 (d,

2 H, pyrazolyl H⁴), 5.17 (s, 4 H, CH₂), 2.24 (s, 6 H, SMe). IR (KBr

0.17 mmol) was added to a suspension of L³(95 mg, 0.17 mmol)

in dry MeCN (20 cm³). The colourless solution was protected from

light and stirred overnight. The volume was then reduced to ca.

10 cm³in vacuo. Diethyl ether diffusion into the resulting solution

gave off-white crystals of {[AgL³](BF₄)}_ϱwhich were suitable for

X-ray crystallography. Yield: 114 mg, 89%. FAB MS: m/z = 667

[Ag(L³)], 1225 [Ag(L³)₂], 1332 [Ag₂(L³)₂], 1378 [Ag(L³)₂+ NOBA],

disk): ν 3108 (w), 2920 (w), 1624 (w), 1590 (w), 1519 (m), 1495 (m),

˜

1419 [Ag₂(L³)₂(BF₄)], 1485 [Ag₂(L³)₂

+

NOBA]. ¹H NMR

1430 (s), 1384 (s), 1339 (s), 1321 (s), 1259 (m), 1226 (m), 1065

(m), 1038 (w), 963 (m), 948 (m), 758 (s), 734 (m), 705 (w) cm^–1.

C₂₈H₂₆AgN₅O₃S₂(652.54): calcd. C 51.5, H 4.2, N 10.7; found C

51.4, H 4.1, N 10.6.

(500 MHz, CD₃CN): δ (ppm) = 7.78 (d, 2 H, pyrazolyl H⁵), 7.43–

7.47 (m, 4 H), 7.40 (ddd, 2 H), 7.37 (td, 2 H), 7.30 (ddd, 2 H), 7.22

(td, 2 H), 7.18 (ddd, 2 H), 7.09 (dd, 2 H), 6.51 (d, 2 H, pyrazolyl

H⁴), 5.30 (s, 4 H, CH ), 2.04 (s, 6 H, SMe). IR (KBr disk): ν =

˜

2

Preparation of {[CuL²](BF₄)}_ϱ: [Cu(CH₃CN)₄]BF₄(61 mg,

0.19 mmol) was added to a solution of L²(94 mg, 0.19 mmol) in

dry MeCN (20 cm³). The colourless solution was stirred overnight

under nitrogen and the volume reduced to ca. 10 cm³. Diethyl ether

diffusion into the solution gave off-white crystals of [CuL²](BF₄)

which were suitable for X-ray crystallography. Yield: 70 mg, 56%.

ES MS: m/z = 545 [CuL²]⁺. ¹H NMR (500 MHz, CD₃CN): δ =

7.68 (br. s, 2 H, pyrazolyl H⁵), 7.47 (d, 2 H), 7.29–7.36 (m, 5 H),

7.11–7.23 (m, 4 H), 7.07 (s, 1 H), 6.61 (br. s, 2 H, pyrazolyl H⁴),

3139 (w), 2924(w), 1604 (w), 1589 (w), 1519 (w), 1497 (m), 1432

(m), 1410 (m), 1356 (m), 1324 (w), 1262 (w), 1220 (m), 1061 (s, br),

786 (m), 757 (s), 728 (m), 703 (w), 520 (w) cm^–1. C₃₄H₃₀AgBF₄N₄S₂

(753.43): calcd. C 54.2, H 4.0, N 7.4; found C 54.1, H 3.9, N 7.4.

Preparation of [CuL⁴](PF₆): [Cu(CH₃CN)₄]PF₆(57 mg, 0.15 mmol)

was added to a suspension of L⁴(82 mg, 0.15 mmol) in dry MeCN

(20 cm³) and the colourless solution was stirred overnight. The vol-

ume was then reduced to ca. 10 cm³in vacuo and the solution

filtered to remove a small amount of solid. Diethyl ether diffusion

into the resulting solution gave off-white crystals of [CuL⁴](PF₆)

which were suitable for X-ray crystallography. Yield: 57 mg, 50%.

FAB MS: m/z = 595 [Cu(L⁴)]. ¹H NMR (500 MHz, CD₃CN): δ

(ppm) = 8.17 (dd, 2 H), 7.75 (dd, 2 H), 7.60–7.70 (m, 6 H), 7.42–

7.49 (m, 6 H), 6.72 (d, 2 H, pyrazolyl H⁴), 5.64 (s, 4 H, CH₂), 2.42

5.32 (s, 4 H, CH ), 2.34 (br. s, 6 H, SMe) ppm. IR (KBr disk): ν =

˜

2

3135 (w), 3057 (w), 2975 (w), 2924 (w), 1610 (w), 1590 (w), 1567

(w), 1518 (m), 1500 (m), 1433 (s), 1406 (m), 1385 (w), 1356 (m),

1327 (w), 1280 (w), 1223 (w), 1169 (w), 1056 (s), 951 (w), 877 (w),

757 (s), 729 (m), 709 (w), 651 (w), 631 (w), 520 (w) cm^–1.

C₂₈H₂₆BCuF₄N₄S₂(633.02): calcd. C 53.1, H 4.1, N 8.9; found C

52.7, H 4.3, N 8.7.

(s, 6 H, SMe). IR (KBr disk): ν = 2923 (w), 1624 (w), 1515 (w),

˜

1499 (w), 1487 (w), 1431 (m), 1371 (m), 1325 (m), 1211 (m), 1065

(m), 841 (s), 781 (m), 760 (s), 685 (w), 557 (s) cm^–1.

C₃₂H₂₈CuF₆N₄PS₂(741.24): calcd. C 51.9, H 3.8, N, 7.6; found C

51.5, H 3.8, N, 7.7.

Preparation of [AgL²](BF₄): [Ag(CH₃CN)₄]BF₄(71 mg, 0.20 mmol)

was added to a solution of L²(96 mg, 0.20 mmol) in dry MeCN

(20 cm³). The colourless solution was stirred overnight protected

from light and the volume reduced to ca. 10 cm³. Diethyl ether

diffusion into the solution gave off-white crystals of [AgL²](BF₄)

which were suitable for X-ray crystallography. Yield: 98 mg, 73%.

ES MS: m/z = 589 [AgL²]⁺. ¹H NMR (500 MHz, CD₃CN): δ =

7.88 (d, 2 H, pyrazolyl H⁵), 7.70 (s, 1 H, phenyl H²), 7.45–7.49 (m,

4 H), 7.34–7.39 (m, 4 H), 7.28 (td, 2 H), 6.95 (dd, 2 H), 6.53 (d, 2

H, pyrazolyl H⁴), 5.38 (s, 4 H, CH₂), 1.89 (s, 6 H, SMe) ppm. IR

Preparation of [AgL⁴](BF₄): [Ag(CH₃CN)₄]BF₄(137 mg,

0.38 mmol) was added to a suspension of L⁴(204 mg, 0.38 mmol)

in EtOH (20 cm³) protected from light and the mixture was stirred

overnight. The off-white solid was collected by filtration and dried

in vacuo. Yield: 247 mg, 89%. FAB MS: m/z = 641 [Ag(L⁴)]. ¹H

NMR (400 MHz, CD₃CN): δ (ppm) = 8.15 (dd, 2 H), 7.69 (dd, 2

H), 7.63 (dd, 2 H), 7.49 (m, 2 H), 7.41–7.45 (m, 4 H), 7.31 (m, 2

H), 7.16 (d, 2 H, pyrazolyl H⁵), 6.47 (d, 2 H, pyrazolyl H⁴), 5.78

(s, 4 H, CH₂), 2.50 (s, 6 H, SMe). ¹³C NMR (100 MHz, CD₃CN):

δ (ppm) = 152.6, 137.6, 135.7, 135.4, 133.3, 132.1, 131.7 (2 closely

spaced signals), 131.1, 130.3, 129.8, 127.0 (2 closely spaced signals),

(KBr disk): ν = 3140 (w), 3127 (w), 3054 (w), 3007 (w), 2926 (w),

˜

1590 (w), 1566 (w), 1516 (m), 1497 (s), 1456 (m), 1431 (s), 1410

(m), 1366 (w), 1351 (m), 1296 (w), 1273 (w), 1260 (w), 1217 (s),

1050 (s), 949 (m), 896 (m), 777 (m), 760 (s), 740 (s), 707 (m), 650

(w), 620 (w), 521 (s) cm^–1. C₂₈H₂₆AgBF₄N₄S₂(677.34): calcd. C

49.7, H 3.9, N 8.3; found C 49.6, H 3.6, N 8.2.

126.7, 107.9, 57.7, 16.9. IR (KBr disk): ν = 3144 (w), 2924 (w),

˜

1590 (w), 1515 (w), 1496 (w), 1485 (w), 1429 (m), 1362 (w), 1324

(m), 1212 (m), 1103 (m), 1070 (s, br), 1048 (s), 849 (w), 825 (w),

779 (m), 765 (s), 684 (w), 520 (w) cm^–1. C₃₂H₂₈AgBF₄N₄S₂

(727.40): calcd. C 52.8, H 3.9, N 7.7; found C 52.3, H 3.8, N 7.6.

X-ray quality crystals were obtained from slow evaporation of the

filtrate when the reaction was carried out in methanol.

Preparation of {[CuL³](BF₄)}_ϱ: [Cu(CH₃CN)₄]BF₄(50 mg,

0.16 mmol) was added to a suspension of L³(89 mg, 0.16 mmol)

in dry MeOH (20 cm³). The resulting suspension was sonicated for

10 min then stirred overnight under nitrogen. Filtration gave

{[CuL³](BF₄)}_ϱas an off-white solid which was dried in vacuo.

Yield: 86 mg, 76%. FAB MS: m/z = 621 [CuL³], 1179 [Cu(L³)₂],

Preparation of [CuL⁵](BF₄): [Cu(CH₃CN)₄]BF₄(54 mg, 0.17 mmol)

1331 [Cu₂(L³)₂(BF₄) and/or Cu(L³)₂

+

NOBA]. ¹H NMR was added to a suspension of L⁵(84 mg, 0.12 mmol) in dry and

4546

www.eurjic.org

Eur. J. Inorg. Chem. 2005, 4533–4549

Mononuclear and Polynuclear Chain Complexes of Multinucleating N/S Donor Ligands

FULL PAPER

degassed EtOH (20 cm³) and the suspension was stirred overnight

under nitrogen. The volume was then reduced to ca. 10 cm³in

vacuo and the off-white powder filtered off. Yield: 90 mg, 89%.

FAB MS: m/z = 789 [Cu(L⁵)], 1006 [Cu₂(L⁵) + NOBA], 1515

Preparation of [AgL⁵](ClO₄): Caution: Perchlorate salts are poten-

tially explosive and should only be prepared in small quantities and

handled with care! AgClO₄·H₂O (38 mg, 0.18 mmol) was added to

a suspension of L⁵(90 mg, 0.12 mmol) in dry MeCN (20 cm³) and

the colourless solution was stirred overnight while protected from

[Cu(L⁵)₂], 1669 [Cu(L⁵)₂+ NOBA]. IR (KBr disk): ν =3134 (w),

˜

2978 (w), 2918 (w), 1630 (w), 1588 (w), 1563 (w), 1486 (m), 1454 light. The volume was then reduced to ca. 10 cm³in vacuo. Diethyl

(m), 1433 (s), 1399 (m), 1326 (m), 1256 (w), 1216 (m), 1083 (s), ether diffusion into the resulting solution gave colourless crystals of

1064 (s), 1048 (s), 945 (w), 753 (s), 733 (m), 652 (w), 617 (w) cm^–1. [AgL⁵](ClO₄) which were suitable for X-ray crystallography. Yield:

1

C₄₂H₄₂BCuF₄N₆S₃(877.38): calcd. C 57.5, H 4.8, N 9.6; found C

57.2, H 5.0, N 9.4.

93 mg, 80%. FAB MS: m/z = 835 {Ag(L⁵)}. H NMR (250 MHz,

CD₃CN): δ (ppm) 7.79 (d, 3 H, pyrazolyl H⁵), 7.44 (dd, 3 H, meth-

Table 11. Crystallographic data for the ligands L¹, L⁴and L⁵.

Ligand

L¹

L⁴

L⁵

Formula

Formula weight

C₂₈H₂₆N₄S₂

482.65

C₃₂H₂₈N₄S₂

532.70

C₄₂H₄₂N₆S₃

727.00

T [K]

150(2)

triclinic, P1

¯

Crystal system, space group

a [Å]

b [Å]

c [Å]

α [°]

β [°]

orthorhombic, Pbcn

30.251(5)

8.8015(14)

9.2578(15)

90

2464.9(7)

4

1.301

monoclinic, P2/c

12.548(4)

8.423(2)

12.579(4)

90

94.604(5)

90

1325.3(6)

2

8.5155(11)

15.452(2)

16.190(2)

62.058(2)

82.603(2)

84.463(2)

1864.7(4)

2

γ [°]

V [Å³]

Z

D_calcd.[mg/m³]

1.335

0.231

1.295

0.238

µ [mm^–1]

0.240

Crystal size [mm]

Reflections collected

Independent reflections

0.50×0.48×0.39

25818

2821

[R(int) = 0.0283]

2821/0/155

R₁= 0.0377

wR₂= 0.1138

0.228 and –0.233

0.50×0.41×0.07

14511

3018

[R(int) = 0.0521]

3018/0/174

R₁= 0.0413

wR₂= 0.1009

0.273 and –0.282

0.41×0.20×0.10

21704

8385

[R(int) = 0.0434]

8385/2/467

R₁= 0.0590

wR₂= 0.1677

1.857 and –0.585

Data/restraints/parameters

Final R indices^[a]

Largest diff. peak and hole [e·Å^–3]

[a] The value of R₁is based on selected data with I Ͼ 2σ(I); the value of wR₂is based on all data.

Table 12. Crystallographic data for Cu⁺and Ag⁺complexes with L¹and L².

Ligand

{[Cu(L¹)](PF₆)}_ϱ{[AgL¹](NO₃)·

{[CuL²](BF₄)}_ϱ·

1.5MeCN·0.5Et₂O

[AgL²](BF₄)

MeOH}_ϱ

Formula

Formula weight

T [K]

C₂₈H₂₆CuF₆N₄PS₂C₂₉H₃₀AgN₅O₄S₂C₃₃H₃₇BCuF₄N_5.5O_0.5S₂C₂₈H₂₆AgBF₄N₄S₂

691.16

150(2)

684.57

150(2)

733.15

150(2)

677.33

150(2)

Crystal system, space group

a [Å]

b [Å]

c [Å]

monoclinic, C2/c monoclinic, P21/c orthorhombic, Pmna

orthorhombic, P2(1)2(1)2(1)

14.310(3)

21.062(5)

11.250(3)

90

12.963(3)

12.529(3)

17.935(4)

90

21.129(2)

13.7026(15)

11.7024(13)

90

12.794(3)

18.763(4)

23.184(5)

90

α [°]

β [°]

121.070(4)

90

2904.2(12)

4

1.581

1.016

93.948(4)

90

2906.0(11)

4

1.565

0.882

90

3388.1(6)

4

1.437

90

5566(2)

8

1.617

0.928

γ [°]

V [Å³]

Z

D_calcd.[mg/m³]

µ [mm^–1]

0.824

Crystal size [mm]

Reflections collected

Independent reflections

0.48×0.38×0.30

16217

3322

[R(int) = 0.0649]

3322/0/192

R₁= 0.0403

wR₂= 0.1025

0.36×0.24×0.10

17458

4043

[R(int) = 0.1387]

4043/0/375

R₁= 0.0555

wR₂= 0.1489

0.41×0.20×0.20

36991

4034

[R(int) = 0.0725]

4034/7/242

R₁= 0.0456

wR₂= 0.1340

0.23×0.22×0.10

62930

12643

[R(int) = 0.0544]

12643/26/722

R₁= 0.0360

wR₂= 0.0777

0.942 and –0.490

Data/restraints/parameters

Final R indices^[a]

Largest diff. peak and hole [e·Å^–3] 0.519 and –0.408 1.926 and –1.375 0.597 and –0.315

[a] The value of R₁is based on selected data with I Ͼ 2σ(I); the value of wR₂is based on all data.

Eur. J. Inorg. Chem. 2005, 4533–4549

www.eurjic.org

4547

T. K. Ronson, H. Adams, M. D. Ward

FULL PAPER

ylthiophenyl H³), 7.32 (td, 3 H, methylthiophenyl H⁵), 7.23 (td, 3

H, methylthiophenyl H⁴), 6.83 (dd, 3 H, methylthiophenyl H⁶), 6.55

(d, 3 H, pyrazolyl H⁴), 5.58 (s, 6 H, CH₂), 2.47 (s, 9 H, CH₃), 1.77

the tip of a glass fibre and transferred to Bruker-SMART dif-

fractometer under a stream of cold N₂. Data were collected using

a Siemens SMART CCD area diffractometer (graphite-monochro-

mated Mo-K_αradiation, λ = 0.71073 Å) with an Oxford Cryosys-

(s, 9 H, SCH ) ppm. IR (KBr disk): ν = 3127 (w), 3112 (w), 2970

˜

3

(w), 2911 (w), 1625 (w), 1589 (w), 1563 (w), 1515 (w), 1492 (m), tems low temperature system. The data were corrected for Lorentz

1440 (m), 1429 (s), 1409 (m), 1348 (m), 1270 (w), 1258 (w), 1210

and polarisation effects and for absorption by semi-empirical meth-

(s), 1091 (s, br), 980 (w), 961 (w), 946 (w), 802 (m), 754 (s), 733 ods (SADABS)^[18]based on symmetry-equivalent and repeated re-

(m), 623 (s), 613 (m) cm^–1. C₄₂H₄₂AgClN₆O₄S₃(934.35): calcd. C flections. The structures were solved by direct methods or heavy

54.0, H 4.5, N 9.0; found C 53.9, H 4.3, N 8.9.

atom Patterson methods and refined by full-matrix least-squares

methods on F². Hydrogen atoms were placed geometrically and

X-ray Crystallography: X-ray crystallographic data are summarised refined with a riding model and with U_isoconstrained to be 1.2 (1.5

in Table 11, Table 12, Table 13 and Table 14. For each compound

a suitable crystal was coated with hydrocarbon oil and attached to

for methyl groups) times U_eqof the carrier atom. Structures were

solved and refined using the SHELX suite of programs.^[19]Selected

Table 13. Crystallographic data for Cu⁺and Ag⁺complexes with L³and a Cu⁺complex with L⁴.

Complex

{[CuL³](BF₄)}_ϱ·1.53CH₃CN·0.47Et₂O {[AgL³](BF₄)}_ϱ

[CuL⁴](PF₆)·2MeCN·2H₂O

Formula

Formula weight

C_38.95H_39.33BCuF₄N_5.53O_0.47S₂

806.90

C₃₄H₃₀AgBF₄N₄S₂

753.42

C₃₆H₃₈CuF₆N₆O₂PS₂

859.35

T [K]

Crystal system

a [Å]

b [Å]

c [Å]

α [°]

β [°]

150(2)

triclinic, P1

150(2)

¯

monoclinic, P21/n

11.607(3)

10.649(2)

31.565(6)

90

97.547(5)

90

3867.6(14)

4

1.386

monoclinic, Cc

17.757(3)

22.728(4)

13.059(2)

90

132.495(2)

90

3886.0(12)

4

1.469

11.666(2)

11.973(2)

24.485(5)

89.231(4)

81.743(4)

71.756(3)

3212.6(11)

4

γ [°]

V [Å³]

Z

D_calcd.[mg/m³]

1.558

0.812

µ [mm^–1]

0.729

0.781

Crystal size [mm]

Reflections collected

Independent reflections

0.38×0.21×0.06

18589

6456

[R(int) = 0.1053]

6456/4/477

R₁= 0.0647

wR₂= 0.1790

0.45×0.38×0.23

36999

14378

[R(int) = 0.0543]

14378/78/817

R₁= 0.0516

wR₂= 0.1298

1.076 and –0.661

0.38×0.32×0.21

21450

4408

[R(int) = 0.0321]

4408/74/549

R₁= 0.0337

wR₂= 0.0894

0.575 and –0.328

Data/restraints/parameters

Final R indices^[a]

Largest diff. peak and hole [e·Å^–3] 0.630 and –0.896

[a] The value of R₁is based on selected data with I Ͼ 2σ(I); the value of wR₂is based on all data.

Table 14. Crystallographic data for Ag⁺complexes with L⁴and L⁵.

Ligand

[Ag(L⁴)](BF₄)

[AgL⁵](ClO₄)

[Ag₃(L⁵)₂](ClO₄)₃

Formula

Formula weight

C₃₂H₂₈AgBF₄N₄S₂

727.38

C₄₂H₄₂AgClN₆O₄S₃

934.32

C₈₄H₈₅Ag₃Cl₃N₁₂O₁₂S₆

2076.96

T [K]

150(2)

120(2)

triclinic, P1

¯

Crystal system, space group

a [Å]

b [Å]

c [Å]

α [°]

β [°]

orthorhombic, P2(1)2(1)2(1)

orthorhombic, Pbca

12.3282(14)

21.611(3)

30.241(3)

90

8056.7(16)

8

1.541

11.430(4)

21.880(8)

23.840(8)

90

5962(4)

8

1.621

11.666(4)

15.388(5)

25.033(9)

72.435(8)

89.156(7)

85.591(7)

4272(3)

γ [°]

V [Å³]

Z

2

D_calcd.[mg/m³]

1.615

0.990

µ [mm^–1]

0.872

0.774

Crystal size [mm]

Reflections collected

Independent reflections

0.20×0.17×0.08

58451

10523

[R(int) = 0.2292]

10523/0/799

R₁= 0.0816

wR₂= 0.2343

0.41×0.32×0.21

87723

9248

[R(int) = 0.0479]

9248/0/520

R₁= 0.0345

wR₂= 0.0943

1.016 and –0.705

0.32×0.21×0.12

41978

15010

[R(int) = 0.1254]

15010/0/1093

R₁= 0.0569

wR₂= 0.1193

0.860 and –1.212

Data/restraints/parameters

Final R indices^[a]

Largest diff. peak and hole [e·Å^–3] 1.506 and –1.323

[a] The value of R₁is based on selected data with I Ͼ 2σ(I); the value of wR₂is based on all data.

Eur. J. Inorg. Chem. 2005, 4533–4549

Mononuclear and Polynuclear Chain Complexes of Multinucleating N/S Donor Ligands

FULL PAPER

Japan 2002, 75, 1611; i) I. Vargas-Baca, T. Chivers, Phosphorus,

Sulfur, Silicon and the Related Elements 2000, 164, 207; j) R. M.

Minyaev, V. I. Minkin, Can. J. Chem. 1998, 76, 776.

bond lengths and angles for the structures of the metal complexes

are in Tables 1–10.

[8] K. Nakamoto, Infrared and Raman Spectra of Inorganic and

Coordination Compounds, 4^thed., Wiley, New York, 1986.

[9] a) Y.-P. Cai, H.-X. Zhang, A.-W. Xu, C.-Y. Su, C.-L. Chen, H.-

Q. Liu, L. Zhang, B.-S. Kang, J. Chem. Soc., Dalton Trans.

2001, 2429; b) E. Psillakis, J. C. Jeffery, J. A. McCleverty, M. D.

Ward, J. Chem. Soc., Dalton Trans. 1997, 1645; c) X. Meng, B.

Xiao, Y. Fan, H. Hou, G. Li, Inorg. Chim. Acta 2004, 357,

1471; d) L. Carlucci, G. Ciani, D. W. von Gudenberg, D. M.

Proserpio, Inorg. Chem. 1997, 36, 3812; e) R. Horikoshi, T.

Mochida, H. Moriyama, Inorg. Chem. 2002, 41, 3017; f) P. L.

Caradoc-Davies, L. R. Hanton, Chem. Commun. 2001, 1098;

g) Y. Kang, S. S. Lee, K.-M. Park, S. J. Lee, S. O. Kang, J. Ko,

Inorg. Chem. 2001, 40, 7027.

Acknowledgments

We thank the New Zealand Tertiary Education Commission for a

Top Achiever Doctoral scholarship to T. K. R.

[1] a) D. L. Caulder, K. N. Raymond, Acc. Chem. Res. 1999, 32,

975; b) G. F. Swiegers, T. J. Malefetse, Chem. Eur. J. 2001, 7,

3637; c) B. J. Holliday, C. A. Mirkin, Angew. Chem. Int. Ed.

2001, 40, 2022; d) D. Philp, J. F. Stoddart, Angew. Chem. Int.

Ed. Engl. 1996, 35, 1155; e) S. Leininger, B. Olenyuk, P. J.

Stang, Chem. Rev. 2000, 100, 853; f) S. R. Seidel, P. J. Stang, [10] a) C. Piguet, G. Bernardinelli, G. Hopfgartner, Chem. Rev.

Acc. Chem. Res. 2002, 35, 972; g) L. K. Thompson, Coord.

Chem. Rev. 2002, 233, 193.

1997, 97, 2005; b) E. C. Constable, Prog. Inorg. Chem. 1994,

42, 67; c) M. Albrecht, Chem. Rev. 2001, 101, 3457.

[2] a) M. D. Ward, J. A. McCleverty, J. C. Jeffery, Coord. Chem. [11] a) J. M. Baumeister, R. Alberto, K. Ortner, B. Spingler, P. A.

Rev. 2001, 222, 251; b) R. L. Paul, S. P. Argent, J. C. Jeffery,

L. P. Harding, J. M. Lynam, M. D. Ward, Dalton Trans. 2004,

3453; c) Z. R. Bell, L. P. Harding, M. D. Ward, Chem. Com-

mun. 2003, 2432; d) Z. R. Bell, J. C. Jeffery, J. A. McCleverty,

M. D. Ward, Angew. Chem. Int. Ed. 2002, 41, 2515; e) R. L.

Paul, Z. R. Bell, J. C. Jeffery, J. A. McCleverty, M. D. Ward,

Proc. Natl. Acad. Sci. USA 2002, 99, 4883.

Schubiger, T. A. Kaden, J. Chem. Soc., Dalton Trans. 2002,

4143; b) H. C. Kang, A. W. Hanson, B. Eaton, V. Boekelheide,

J. Am. Chem. Soc. 1985, 107, 1979; c) Y.-B. Dong, G.-X. Jin,

M. D. Smith, R.-Q. Huang, B. Tang, H.-C. zur Loye, Inorg.

Chem. 2002, 41, 4909; d) D. Song, S. Wang, Eur. J. Inorg.

Chem. 2003, 3774; e) Y.-B. Dong, Z. Zhao, G.-X. Jin, R.-Q.

Huang, M. D. Smith, Eur. J. Inorg. Chem. 2003, 4017; f) J.

Budka, P. Lhotak, I. Stibor, J. Sykora, I. Cisarova, Supramol.

Chem. 2003, 15, 353; g) C.-W. Tsang, Q. Yang, E. T.-P. Sze,

T. C. W. Mak, D. T. W. Chan, Z. Xie, Inorg. Chem. 2000, 39,

5851.

[3] a) M. C. Hong, W. P. Su, R. Cao, M. Fujita, J. X. Lu, Chem.

Eur. J. 2000, 6, 427; b) C. Y. Su, S. Liao, H. L. Zhu, B. S. Kang,

X. M. Chen, H. Q. Liu, J. Chem. Soc., Dalton Trans. 2000,

1985; c) S. Liao, C. Y. Su, H. X. Zhang, J. L. Shi, Z. Y. Zhou,

H. Q. Liu, A. S. C. Chan, B. S. Kang, Inorg. Chim. Acta 2002,

336, 151; d) S. Tavacoli, T. A. Miller, R. L. Paul, J. C. Jeffery,

M. D. Ward, Polyhedron 2003, 22, 507; e) Y. Zheng, M. Du, J.-

R. Li, R.-H. Zhang, X.-H. Bu, Dalton Trans. 2003, 1509; f) M.

Oh, C. L. Stern, C. A. Mirkin, Chem. Commun. 2004, 2684; g)

Y.-B. Xie, C. Zhang, J.-R. Li, X.-H. Bu, Dalton Trans. 2004,

562; h) D. A. McMorran, C. M. Hartshorn, P. J. Steel, Polyhe-

dron 2004, 23, 1055.

[12] a) D. Eisler, R. J. Puddephatt, Inorg. Chem. 2005, 44, 4666; b)

W. Xu, R. J. Puddephatt, K. W. Muir, A. A. Torabi, Organome-

tallics 1994, 13, 3054; c) M. Munakata, L. P. Wu, T. Kuroda-

Sowa, M. Maekawa, Y. Suenaga, G. L. Ning, T. Kojima, J. Am.

Chem. Soc. 1998, 120, 8610.

[13] A. W. Addison, T. N. Rao, J. Reedijk, J. van Rijn, G. C. Ver-

schoor, J. Chem. Soc., Dalton Trans. 1984, 1349.

[14] a) S. H. Pines, J. Org. Chem. 1976, 41, 884; b) D. V. Griffiths,

P. A. Griffiths, K. Karim, B. J. Whitehead, J. Chem. Res. 1996,

176, 901.

[4] T. K. Ronson, H. Adams, M. D. Ward, Inorg. Chim. Acta 2005,

358, 1943.

[5] E. R. Humphrey, K. L. V. Mann, Z. R. Reeves, A. Behrendt,

J. C. Jeffery, J. P. Maher, J. A. McCleverty, M. D. Ward, New J.

Chem. 1999, 23, 417.

[6] a) E. C. Constable, S. M. Elder, J. V. Walker, P. D. Wood, D. A.

Tocher, J. Chem. Soc., Chem. Commun. 1992, 229; b) K. T.

Potts, K. A. G. Rayford, M. Keshavarz-K, J. Am. Chem. Soc.

[15] M. Asakawa, P. R. Ashton, S. E. Boyd, C. L. Brown, S.

Menzer, D. Pasini, J. F. Stoddart, M. S. Tolley, A. J. P. White,

D. J. Williams, P. G. Wyatt, Chem. Eur. J. 1997, 3, 463.

[16] G. J. Kubas, Inorg. Synth. 1976, 19, 90.

[17] U. Azzena, S. Demartis, L. Pilo, E. Piras, Tetrahedron 2000, 56,

8375.

1993, 115, 2793; c) R. L. Cleary, D. A. Bardwell, M. Murray, [18] G. M. Sheldrick, SADABS, A program for absorption correc-

J. C. Jeffery, M. D. Ward, J. Chem. Soc., Perkin Trans. 2 1997,

tion with the Siemens SMART area-detector system; Univer-

sity of Göttingen, 1996.

2179.

[7] a) A. M. W. Cargill Thompson, D. A. Bardwell, J. C. Jeffery, [19] a) Siemens SHELXTL, An integrated system for solving and

L. H. Rees, M. D. Ward, J. Chem. Soc., Dalton Trans. 1997,

721; b) R. E. Rosenfeld, Jr., R. Parthasarathy, J. D. Dunitz, J.

Am. Chem. Soc. 1977, 99, 4860; c) F. T. Burling, B. M.

Goldstein, J. Am. Chem. Soc. 1992, 114, 2313; d) F. T. Burling,

B. M. Goldstein, Acta Crystallogr., Sect. B 1993, 49, 738; e)

G. R. Desiraju, V. Nalini, J. Mater. Chem. 1991, 1, 201; f) D.

Britton, J. D. Dunitz, Helv. Chim. Acta 1980, 63, 1068; g) M.

Iwaoka, S. Tomoda, J. Am. Chem. Soc. 1996, 118, 8077; h) M.

Iwaoka, S. Takemoto, M. Okada, S. Tomoda, Bull. Chem. Soc.

refining crystal structures from diffraction data, revision 5.1;

Siemens Analytical X-ray Instruments Ltd, Madison, WI,

1996; b) G. M. Sheldrick, SHELXS-97, a Program for Auto-

matic Solution of Crystal Structures; University of Göttingen,

Göttingen, Germany, 1997; c) G. M. Sheldrick, SHELXL-97,

a Program for Crystal Structure Refinement; University of

Göttingen, Göttingen, Germany, 1997.

Received: August 4, 2005

Published Online: October 4, 2005

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www.eurjic.org

4549

Article Doi

Mononuclear and polynuclear chain complexes of a series of multinucleating N/S donor ligands

DOI: 10.1002/ejic.200500704

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Article abstract of DOI:10.1002/ejic.200500704

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