Flexidentate behaviour of 2-pyridylsulfonamides - Direct electrochemical synthesis and spectroscopic and x-ray characterisation of neutral copper(II) complexes of N-(2-pyridyl)sulfonamides

Article abstract of DOI:10.1002/ejic.200300338

Copper complexes with potentially bidentate N-(2-pyridyl)-sulfonylamide ligands have been synthesised by the electrochemical oxidation of the metal in an acetonitrile solution of the neutral amide and additional bidentate N-N coligands. The compounds have been characterised by microanalysis and EPR, vibrational and electronic spectroscopy. In representative cases the structures were also determined by X-ray diffraction methods. Various coordination behaviour is found for the ligands, which act in a N, N′-bidentate or N, O-bidentate manner, the latter giving abnormally short Cu-O bonds. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.

Full text of DOI:10.1002/ejic.200300338

FULL PAPER
Flexidentate Behaviour of 2-Pyridylsulfonamides ؊ Direct Electrochemical
Synthesis and Spectroscopic and X-ray Characterisation of Neutral Copper(II
)
Complexes of N-(2-Pyridyl)sulfonamides
[a]
[b]
[a]
[c]
´
´
´
´
´
´
Inmaculada Beloso, Joaquın Borras, Jesus Castro,* Jose A. Garcıa-Vazquez,
[a]
[c]
[c]
´
Paulo Perez-Lourido, Jaime Romero, and Antonio Sousa*
Dedicated to the memory of Professor D. G. Tuck
Keywords: Copper / S ligands / Electrochemical synthesis / N ligands
Copper complexes with potentially bidentate N-(2-pyridyl)- entative cases the structures were also determined by X-ray
sulfonylamide ligands have been synthesised by the electro-
chemical oxidation of the metal in an acetonitrile solution of
the neutral amide and additional bidentate N−N coligands.
The compounds have been characterised by microanalysis
and EPR, vibrational and electronic spectroscopy. In repres-
diffraction methods. Various coordination behaviour is found
for the ligands, which act in a N,NЈ-bidentate or N,O-bident-
ate manner, the latter giving abnormally short Cu−O bonds.
( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2004)
Introduction
gands, Scheme 2, contain a bulky sulfonyl group as a sub-
stituent of the exocyclic nitrogen atom. In addition, its elec-
tron-withdrawing effect increases the acid character of the
NH group and makes ligand deprotonation easier.[4]
Metal complexes containing amide ligands are of great
recent interest[1Ϫ4] because they are easily made, and the
substituents can be readily amended so as to tune their bite
angle and steric hindrance. The chemistry of metal com-
plexes containing pyridine-functionalised amido ligands of
the type shown in Scheme 1 has received much
attention.[5Ϫ9] The bulky substituents on these ligands
stabilise the metal complexes.
Scheme 2
These ligands can coordinate to the metal in several dif-
ferent ways (Scheme 3).
Scheme 1
Consequently, it was decided to study the chemistry of
the metal complexes of sulfonyl-2-pyridine-amines. These li-
[a]
´
´
Departamento de Quımica Inorganica, Universidade de Vigo,
36200 Vigo, Spain
Fax: (internat.) ϩ 34-986-813-798
E-mail: fojo@uvigo.es
[b]
[c]
´
´
Departamento de Quımica Inorganica. Fac. Farmacia, Univ.
Valencia
´
´
Vicent Andres Estelles s/n, 46100 Burjassot, Valencia, Spain.
´
´
Departamento de Quımica Inorganica, Universidade de
Santiago de Compostela,
15782 Santiago, Spain
Fax: (internat.) ϩ 34-981-597-525
E-mail: qiansoal@usc.es
Scheme 3
Eur. J. Inorg. Chem. 2004, 635Ϫ645
DOI: 10.1002/ejic.200300338
 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
635

J. Castro, A. Sousa et al.
FULL PAPER
Coordination modes I and II have been found in zinc mechanism involving the anodic oxidation to copper() and
compounds. For complexes showing coordination mode I, the deprotonation of the ligand at the cathode.
a weak interaction between the metal and the exocyclic ni-
trogen atom is present,[10] while mode II exhibits a weak
interaction between the zinc and the pyridine nitrogen
atom.[11] Coordination mode III is the most common, and
has been found in cobalt(),[12] nickel(),[13] and cad-
mium()[14,15] complexes. Coordination mode IV has only
been found in copper()[9] and silver()[9,16] complexes, and
coordination mode V has only been found in zinc()[11] and
cadmium()[15] complexes. Coordination modes VI and VII
have been found in a polymer compound of cadmium()[14]
and the coordination mode VIII only occurs in silver()
complexes.[16]
Coordination mode IV appears to have only been found
with copper() and silver(). When the ligand has no sub-
stituent on the pyridine ring (R ϭ H) the compound is di-
nuclear.[9] To check if the nuclearity and the coordination
mode could be modified, we introduced a methyl group at
position 3 or 6 on the pyridine ring to determine the influ-
ence of the steric hindrance produced by such substitution
on the coordination of the pyridine and the sulfonamide
nitrogen atoms. Substitution at position 4 does not influ-
ence the coordination mode and a dinuclear compound is
again obtained.[16] Therefore, and to continue similar stud-
ies on ZnII [11] and CdII,[15] we report here the electrochemi-
cal synthesis and characterisation of several heteroleptic
copper() complexes with a number of benzenesulfonyl-2-
pyridineamide ligands. The pyridine ring contains one
methyl group and the benzene ring also contains one methyl
group (p-toluene group) or, alternatively, three methyl
groups (mesitylene group) (Scheme 4).
Anode: Cu ϩ LϪ Ǟ [CuL] ϩ eϪ
Cathode: HL ϩ eϪ Ǟ LϪ ϩ 1/2 H2
[CuL] ϩ HL ϩ LЈǞ [CuL2LЈ] ϩ 1/2 H2
The oxidation of copper() by another HL molecule has
been observed in other electrochemical processes involving
copper anodes.[17]
Description of the Structures
The crystal and molecular structures of several complexes
and the ligand HMs3mepy have been determined by single
crystal XRD. The crystal data are collected in Tables 12
and 13.
Structure of HMs3mepy
HMs3mepy crystallizes in the monoclinic C2/c space
group, Z ϭ 4, and consists of molecules of [(2,4,6-trimethyl-
phenyl)sulfonyl]imino-1H-3-methyl-2-pyridine associated
two-by-two by intermolecular hydrogen bonds established
between the pyridine nitrogen atom of one molecule and
two sulfonamide oxygen atoms, one of which forms an in-
tramolecular contact while the other is involved in an inter-
molecular contact with a neighbouring molecule. The imine
nitrogen is not implicated in these bonds. This arrangement
contrasts with the hydrogen network found in HTspy[13] and
HTs6mepy,[15] where the hydrogen bonds involve the Npy
and the Nsulfonamide atoms. The methyl group in position 3
of the pyridine ring precludes the use of the Nsulfonamide
atom with HTs3mepy for steric reasons. This explanation is
supported by the observed ligational mode of HTs3mepy
(vide infra).
The structure of HTs3mepy and the atomic numbering
scheme (Figure 1), and selected bond lengths and angles
and hydrogen bond parameters (Table 1 and Table 2), are
given here.
Scheme 4. The sulfonamide ligands
Results and Discussion
Anodic oxidation of copper metal in a non-aqueous solu-
tion containing a weakly acidic ligand alone or as a mixture
with a coligand, such as 2,2Ј-bipyridine (bipy) or 1,10-phen-
anthroline (phen), yields the products [CuL2H2O] or
[CuL2LЈ], respectively, were L is the deprotonated form of
the parent ligand and LЈ the coligand (i.e. bipy or phen)
(see Exp. Sect.). The compounds are obtained by air con-
centration of the resulting solution as green air-stable crys-
talline products. They are insoluble in water and in most
common organic solvents.
Figure 1. Structure of HMs3mepy
The electrochemical efficiency, defined as the amount of
The bond lengths and bond angles are similar to those in
metal dissolved per number of Faradays, was close to 1.0 other N-2-pyridinyl benzenesulfonamide derivatives.[11,13,15]
mol·FϪ1 in all cases. This fact, along with the evolution The hydrogen atom on the N-pyridine ring shows that the
of hydrogen at the cathode, is compatible with a reaction free ligand is the imido tautomer (I) rather than the amido
636
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Eur. J. Inorg. Chem. 2004, 635Ϫ645

Flexidentate Behaviour of 2-Pyridylsulfonamides
FULL PAPER
˚
The crystal structure can be described as discrete mol-
ecules of [Cu(Ts3mepy)2H2O] associated by intermolecular
interactions. The hydrogen atoms of the coordinated water
molecule are involved in hydrogen bonds with the amide
nitrogen atoms that are not coordinated to the metal in
such a way that infinite chains are formed parallel to the b
axis (Figure 3). Selected bond lengths and angles are given
in Table 3 and Table 4.
Table 1. Slected bond lengths [A] and angles [°] for HMs3mepy
SϪO(12)
SϪN(12)
N(11)ϪC(15)
N(11)ϪH(1)
1.4345(14) SϪO(11)
1.5937(14) SϪC(17)
1.4517(12)
1.7821(16)
1.364(2)
1.359(2)
0.945(19)
N(11)ϪC(11)
N(12)ϪC(15)
1.326(2)
O(12)ϪSϪO(11) 114.30(9)
O(11)ϪSϪN(12) 113.04(7)
O(11)ϪSϪC(17) 107.47(8)
O(12)ϪSϪN(12) 108.89(8)
O(12)ϪSϪC(17) 109.76(8)
N(12)ϪSϪC(17) 102.71(7)
Table 2. Hydrogen bonds and short contacts for HMs3mepy
(i: symmetry transformations used to generate equivalent atoms:
Ϫx, y, 0.5 Ϫ z)
DϪH···A
d(DϪH) d(H···A) d(D···A) Ͻ(DHA)
N(11)ϪH(1)···O(11)
N(11)ϪH(1)···O(11i)
C(113)ϪH(11A)···N(12) 0.96
C(113)ϪH(11B)···O(11) 0.96
C(115)ϪH(11E)···O(12) 0.96
0.945(19) 2.00(2) 2.7209(18) 131.6(16)
0.945(19) 2.124(19) 2.8858(19) 136.7(16)
2.61
2.47
2.40
3.102(3)
3.086(3)
2.747(2)
112.2
121.8
100.9
Figure 3. Supramolecular structure of [Cu(Ts3mepy)2H2O]
˚
Table 3. Selected bond lengths [A] and angles [°] for [Cu-
tautomer (II). This situation is similar to that described for
related compounds (Scheme 5).[11,13,15]
(Ts3mepy)2(H2O)]
CuϪN(21)
CuϪO(11)
CuϪO(1)
1.974(2)
2.0018(18) CuϪO(22)
2.160(2) S(1)ϪO(21)
CuϪN(11)
1.980(2)
2.0130(18)
1.428(2)
N(21)ϪCuϪN(11) 164.73(9)
N(11)ϪCuϪO(11) 89.81(8)
N(11)ϪCuϪO(22) 89.72(8)
N(21)ϪCuϪO(11) 88.69(8)
N(21)ϪCuϪO(22) 88.86(8)
O(11)ϪCuϪO(22) 168.98(8)
N(21)ϪCuϪO(1)
O(11)ϪCuϪO(1)
97.00(9)
95.88(10)
N(11)ϪCuϪO(1)
O(22)ϪCuϪO(1)
98.27(10)
95.08(10)
˚
Table 4. Hydrogen bonds for [Cu(Ts3mepy)2(H2O)] (A and °).
(i: symmetry transformations used to generate equivalent atoms:
x, y Ϫ 1, z)
Scheme 5
Structure of [Cu(Ts3mepy)2H2O]
DϪH···A
d(DϪH) d(H···A) d(D···A) Є(DHA)
This compound crystallizes in the monoclinic P21/c space
group, Z ϭ 4. Its structure is shown in Figure 2 together
with the atomic numbering scheme.
O(1)ϪH(1)···N(12)i 0.81(3)
O(1)ϪH(2)···N(22)i 0.85(3)
2.11(3)
2.14(3)
2.917(3)
2.984(3)
175(3)
179(3)
The copper atom is coordinated by a molecule of water
and two monoanionic (N,O)-bidentate ligands through the
nitrogen of the pyridine ring and one oxygen atom of a
sulfonic group. The sulfonamide nitrogen atoms are
˚
3.039(2) and 3.093(2) A, respectively, away from the copper
atom, and so they are not bonded. Consequently, the coor-
dination around the metal can be described as [CuN2O3].
This is quite surprising as sulfonyl oxygen atoms are not
good donors, and copper() complexes containing ligands
bonded through the sulfonamide oxygen donors are
scarce.[18,19] The environment around the central atom is
square pyramidal with a very small distortion towards a
Figure 2. Molecular structure of [Cu(Ts3mepy)2H2O]
Eur. J. Inorg. Chem. 2004, 635Ϫ645
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J. Castro, A. Sousa et al.
FULL PAPER
trigonal bipyramidal geometry (τ ϭ 0.07).[20] The apical po-
sition of the pyramid is occupied by the oxygen atom of the
water molecule and the base consists of an (N2O2) arrange-
ment in a trans disposition. This base is almost planar
˚
(rms ϭ 0.0353). The copper atom is 0.2273(11) A above
the plane.
The CuϪN bond lengths are in the normal range found
for CuϪNpy bonds.[4,21] However, the CuϪO bonds
[CuϪOwater ϭ 2.160(2); CuϪO(11) ϭ 2.0018(18) and
˚
CuϪO(22) ϭ 2.0130(18) A] are unusually short for such O-
donor atoms.[21,22] Firstly, the apical CuϪOwater in pentaco-
ordinate copper complexes are normally much longer than
the CuϪO bonds in the basal plane.[23,24] In addition, the
CuϪOsulfonamide bond is the shortest found so far in sulfon-
amide copper complexes.
Figure 5. Molecular structure of [Cu(Ts3mepy)2phen]
Structures of the Complexes [Cu(Ts3mepy)2bipy],
[Cu(Ts3mepy)2phen], [Cu(Ms3mepy)2bipy] and
[Cu(Ts3mepy)2phen]
Complexes [Cu(Ts3mepy)2bipy] and [Cu(Ts3mepy)2phen]
¯
crystallize in the triclinic P1 space group, Z ϭ 2. Complexes
[Cu(Ms3mepy)2bipy] and [Cu(Ms3mepy)2phen] crystallize
in the monoclinic P21/c space group, Z ϭ 4. The com-
pounds consist of discrete molecules without relevant inter-
molecular interactions.
The molecular structures are shown in Figures 4Ϫ7, to-
gether with the atomic numbering schemes. Selected bond
lengths and angles are given in Table 5.
In all the compounds, one of the sulfonamide ligands be-
haves in a (N,O)-bidentate manner and the other one is N-
monodentate. The coligand (2,2-bipyridine or 1,10 phen-
anthroline) acts as an (N,NЈ)-bidentate ligand. The different
Figure 6. Molecular structure of [Cu(Ms3mepy)2bipy]
Figure 7. Molecular structure of [Cu(Ms3mepy)2phen]
coordination behaviour of the two tosylamide ligands is the
most significant feature of the structures.
The copper atom is in a pentacoordinate environment
˚
with four CuϪN bonds close to 2.0 A, CuϪO bonds rang-
˚
ing from 2.209(6) to 2.291(2) A and with another
CuϪNsulfonamide interaction, not considered as a bond,
˚
ranging from 2.592(7) A for [Cu(Ts3mepy)2bipy] to 2.726(3)
˚
A for [Cu(Ms3mepy)2phen] (Table 5).
The coordination polyhedron is best described as square
pyramidal with a distortion towards a trigonal bipyramidal
Figure 4. Molecular structure of [Cu(Ts3mepy)2bipy]
638
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Flexidentate Behaviour of 2-Pyridylsulfonamides
FULL PAPER
˚
Table 5. Selected bond lengths [A] and angles [°] for the pentacoordinate compounds [CuL2LЈ], LЈ ϭ bipy or phen
[Cu(Ts3mepy)2bipy]
[Cu(Ts3mepy)2phen]
[Cu(Ms3mepy)2bipy]
[Cu(Ms3mepy)2phen]
Cu(1)ϪO(11)
Cu(1)ϪN(11)
Cu(1)ϪN(21)
Cu(1)ϪN(31)
Cu(1)ϪN(32)
Cu(1)ϪN(22)
2.209(6)
2.019(8)
2.020(7)
1.999(8)
2.023(8)
2.592(7)
2.244(3)
2.004(4)
2.003(4)
2.039(4)
2.029(4)
2.665(4)
2.2914(18)
2.0259(19)
1.984(2)
2.0355(19)
2.005(2)
2.263(2)
2.032(3)
1.994(3)
2.018(3)
2.039(3)
2.726(3)
2.620(2)
N(11)ϪCu(1)ϪN(21)
N(11)ϪCu(1)ϪN(32)
N(11)ϪCu(1)ϪN(31)
N(11)ϪCu(1)ϪO(11)
N(21)ϪCu(1)ϪN(31)
N(21)ϪCu(1)ϪN(32)
N(21)ϪCu(1)ϪO(11)
N(31)ϪCu(1)ϪO(11)
N(32)ϪCu(1)ϪO(11)
N(31)ϪCu(1)ϪN(32)
89.9(3)
96.0(3)
175.8(3)
90.4(3)
92.4(3)
158.8(3)
103.7(3)
92.4(3)
96.6(3)
80.6(3)
92.77(14)
175.90(17)
94.91(15)
87.64(14)
165.11(17)
90.98(16)
92.07(16)
100.97(14)
93.88(14)
81.07(17)
93.61(8)
93.86(8)
173.69(9)
92.59(7)
92.63(8)
163.31(9)
104.56(8)
84.91(7)
89.98(8)
80.36(8)
94.01(12)
172.36(13)
93.93(12)
86.77(10)
164.93(12)
92.38(12)
93.38(11)
99.84(10)
88.69(10)
80.79(12)
Table 6. Environment around the metal
˚
Table 7. Some short contacts between rings [A] (stacking) for the pentacoordinate compounds [CuL2LЈ], LЈ ϭ bipy or phen
[Cu(Ts3mepy)2phen]
[Cu(Ms3mepy)2phen]
[Cu(Ms3mepy)2bipy]
N(31)ϪC(28)
C(29)ϪC(31)
3.607(6)
3.652(7)
3.599(8)
3.477(8)
3.705(8)
3.508(8)
3.599(7)
3.600(7)
3.471(7)
3.555(8)
N(31)ϪC(212)
N(32)ϪC(27)
C(2)ϪC(311)
C(2)ϪC(312)
C(28)ϪC(311)
C(29)ϪC(37)
C(210)ϪC(34)
C(211)ϪC(312)
C(212)ϪC(31)
3.585(6)
3.680(5)
3.651(4)
3.663(4)
3.679(6)
3.683(6)
3.729(7)
3.611(6)
3.968(7)
N(31)ϪC(37)
N(32)ϪC(212)
N(32)ϪC(27)
C(210)ϪC(37)
C(210)ϪC(38)
C(211)ϪC(39)
C(212)ϪC(310)
3.680(4)
3.446(4)
3.752(3)
3.386(4)
3.697(5)
3.681(5)
3.680(4)
C(33)ϪC(210)
C(34)ϪC(211)
C(37)ϪC(212)
C(34)ϪC(210)
C(211)ϪC(312)
C(212)ϪC(312)
C(212)ϪC(311)
C(35)ϪC(211)
between 12 and 28% (τ ϭ 0.12Ϫ0.28, see Table 6).[20] The CuϪO(apical) distances normally found in copper()
oxygen atom occupies the apical position of the pyramid square-pyramid complexes.[18,23] This distance is remark-
and the four nitrogen atoms of the three ligands form the able since the sulfonamide groups are not good O-donors.
basal plane. The copper atoms lies 0.203(2), 0.122(2),
0.114(1), and 0.069(2) A out of this basal plane, respec- crystallize in the same space group, but their molecular ar-
Complexes [Cu(Ts3mepy)2bipy] and [Cu(Ts3mepy)2phen]
˚
tively.
rangements are different due to a twist around the
The CuϪN bond lengths are as expected for such com- S(2)ϪN(22) bond (Figure 4 and Figure 5). Thus, in [Cu(Ts-
plexes and do not warrant further comment. However, the 3mepy)2phen], the planes of the 1,10-phenanthroline and
˚
CuϪO bonds [2.209(6) to 2.291(2) A], although slightly the benzene ring of the monoanionic monodentate sulfona-
longer than in [Cu(Ts3mepy)2H2O], are shorter than the mide ligand are almost parallel, with a dihedral angle of
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J. Castro, A. Sousa et al.
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˚
˚
5.3(2)° and distances between rings of 3.471(7) A. This dis-
position produces an intramolecular π,π-stacking interac-
tion that stabilises the structure.[24] This interaction does
not seem to be present at an intermolecular level. Some
short distances between rings are indicated in Table 7.
Table 8. Selected bond lengths [A] and angles [°] for [Cu-
(Ms6mepy)2phen]
Cu(1)ϪN(11)
Cu(1)ϪN(21)
Cu(1)ϪN(12)
Cu(2)ϪN(41)
Cu(2)ϪN(62)
Cu(2)ϪN(42)
1.985(6) Cu(1)ϪN(31)
2.023(6) Cu(1)ϪN(32)
2.357(6) Cu(1)ϪN(22)
1.983(6) Cu(2)ϪN(51)
2.001(6) Cu(2)ϪN(61)
2.413(6) Cu(2)ϪN(52)
2.015(6)
2.035(6)
2.506(5)
2.000(6)
2.016(5)
2.503(6)
Conversely,
complexes
[Cu(Ms3mepy)2bipy]
and
[Cu(Ms3mepy)2phen] crystallize in the same space group,
P21/c, and a intramolecular π,π-stacking interaction is
found in both cases; the dihedral angles between rings are
3.2(1) and 1.41(8)°, respectively. However, the complexes
are not identical, showing differences related to the spatial
position of the mesitylene group, which is directed towards
the π,π-stacking axis, or is twisted outward (Figure 8).
Other parameters are also indicated in Table 7.
N(11)ϪCu(1)ϪN(31) 160.4(2) N(11)ϪCu(1)ϪN(21) 94.3(2)
N(31)ϪCu(1)ϪN(21) 97.3(2) N(11)ϪCu(1)ϪN(32) 96.1(2)
N(31)ϪCu(1)ϪN(32) 80.9(3) N(21)ϪCu(1)ϪN(32) 152.0(2)
N(11)ϪCu(1)ϪN(12) 61.5(2) N(31)ϪCu(1)ϪN(12) 99.3(2)
N(21)ϪCu(1)ϪN(12) 112.4(2) N(32)ϪCu(1)ϪN(12) 95.5(2)
N(11)ϪCu(1)ϪN(22) 113.6(2) N(31)ϪCu(1)ϪN(22) 86.0(2)
N(21)ϪCu(1)ϪN(22) 58.1(2) N(32)ϪCu(1)ϪN(22) 93.9(2)
N(12)ϪCu(1)ϪN(22) 169.8(2)
N(41)ϪCu(2)ϪN(51) 93.1(2) N(41)ϪCu(2)ϪN(62) 158.9(3)
N(51)ϪCu(2)ϪN(62) 97.6(2) N(41)ϪCu(2)ϪN(61) 95.6(2)
N(51)ϪCu(2)ϪN(61) 156.5(3) N(62)ϪCu(2)ϪN(61) 81.7(2)
N(41)ϪCu(2)ϪN(42) 60.0(2) N(51)ϪCu(2)ϪN(42) 115.1(3)
N(62)ϪCu(2)ϪN(42) 99.0(2) N(61)ϪCu(2)ϪN(42) 88.1(2)
N(41)ϪCu(2)ϪN(52) 115.4(2) N(51)ϪCu(2)ϪN(52) 58.3(3)
N(62)ϪCu(2)ϪN(52) 85.6(2) N(61)ϪCu(2)ϪN(52) 98.3(2)
N(42)ϪCu(2)ϪN(52) 172.7(2)
The coordination behaviour of the anionic ligands in this
complex is quite different from the other systems described
here as the sulfonamide anionic ligands behave as (N,N)-
bidentate ligands. A neutral 1,10-phenanthroline molecule
acting as an (N,N)-donor completes the coordination
sphere of the metal. Consequently, the coordination poly-
hedron around the copper() is best described as a highly
distorted octahedron, CuN6. There are several sources of
distortion: Two CuϪN bond lengths are longer than the
Figure 8. Spatial differences between [Cu(Ms3mepy)2bipy] (left)
and [Cu(Ms3mepy)2phen] (right)
Structure of [Cu(Ms6mepy)2phen]
¯
This compound crystallizes in the triclinic P1 space
group with two chemically equivalent molecules in the
asymmetric unit. Only one of the molecules is represented
in Figure 9 (together with the atomic numbering pattern).
Selected bond lengths and angles are given in Table 8.
˚
others, with a maximum of 2.506(5) A. In addition, the
anionic ligands form a four-membered chelate ring with
angles of only 58.1(2) to 61.5(2)°. The theoretical equatorial
plane is also highly distorted in that the dihedral angle be-
tween the planes formed by the central atom and the donors
NphenϪCuϪNphen and NpyϪCuϪNpy is 32.66° [average val-
ues for the two molecules: 33.85(26) and 31.48(38)°].
Once again, significant intramolecular π,π stacking
stabilisation is produced between the 1,10-phenanthroline
unit and the benzene rings of the two sulfonamide ligands.
This interaction does not seem to continue on an intermo-
lecular level. The dihedral angles between the rings involved
in this interaction are Є6.2(4)° (average 3.6°). The centres
˚
of the three rings are ca. 3.704 and 3.651 A apart. Some
short distances between rings are indicated in Table 9.
Spectroscopic and Magnetic Studies
The IR spectra of the complexes do not show the band
attributable to ν(NϪH), which in the free ligand appears at
3248Ϫ3222 cmϪ1. This change confirms that the hydrogen
atom of the amide group is lost during electrolysis. The
bands in the spectra of the ligands in the range 1594Ϫ1612
cmϪ1, due to the ν(CϭN) absorption, appear in similar po-
Figure 9. Molecular structure of [Cu(Ms6mepy)2phen]
640
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Eur. J. Inorg. Chem. 2004, 635Ϫ645

Flexidentate Behaviour of 2-Pyridylsulfonamides
FULL PAPER
˚
Table 9. Selected short contacts between rings [A] (stacking) for
[Cu(Ms6mepy)2phen]
Table 10. EPR and RD parameters for the complexes (sh: shoulder)
Compound
g||
gЌ
A||
ν˜ [cmϪ1
]
N(31)ϪC(18)
N(31)ϪC(212)
N(32)ϪC(112)
C(18)ϪC(36)
C(111)ϪC(34)
C(112)ϪC(35)
C(28)ϪC(35)
C(211)ϪC(37)
N(62)ϪC(47)
C(48)ϪC(610)
C(49)ϪC(68)
C(410)ϪC(612)
C(412)ϪC(65)
C(511)ϪC(63)
C(510)ϪC(64)
3.775(10)
3.895(9)
3.623(9)
N(31)ϪC(17)
N(31)ϪC(27)
N(32)ϪC(17)
C(19)ϪC(37)
C(110)ϪC(312)
C(111)ϪC(35)
C(29)ϪC(312)
C(29)ϪC(311)
C(210)ϪC(311)
N(61)ϪC(512)
N(62)ϪC(48)
C(410)ϪC(67)
C(59)ϪC(612)
C(511)ϪC(64)
C(510)ϪC(611)
3.798(10)
3.916(8)
3.888(9)
[Cu(Ts3mepy)2(H2O)]
[Cu(Ts3mepy)2bipy]
[Cu(Ts3mepy)2phen]
[Cu(Ms3mepy)2bipy]
[Cu(Ms3mepy)2phen]
[Cu(Ts6mepy)2bipy]
[Cu(Ts6mepy)2phen]
[Cu(Ms6mepy)2bipy]
[Cu(Ms6mepy)2phen]
2.25
2.26
2.21
2.23
2.26
2.26
2.26
2.26
2.26
2.11
2.06
2.07
2.07
2.07
2.08
2.08
2.06
2.08
140
150
156
150
155
Ϫ
Ϫ
163
166
15800
15975
16315
16130
16315
13515
13280
14165
14430
11820(sh)
10640
12195
11765
12300
9320
10640
11200
10955
3.655(10)
3.521(11)
3.634(10)
3.667(10)
3.692(11)
3.706(9)
3.625(10)
3.559(13)
3.688(14)
3.630(10)
3.616(13)
3.548(11)
3.530(14)
3.597(13)
3.656(11)
3.613(11)
3.664(11)
3.624(12)
3.726(10)
3.647(9)
3.537(12)
3.616(13)
3.546(12)
3.523(12)
sitions in the complexes except when the ligands Ts6mepyϪ
and Ms6mepyϪ are present, in which case the bands are
shifted to lower frequencies due to coordination through
the sulfonamide nitrogen atom. The bands of the ligands at
1338Ϫ1369 cmϪ1, attributable to νas(S ϭO), are also seen
for the complexes with Ts3mepyϪ and Ms3mepyϪ but in
these cases they are shifted to slightly lower frequencies due
to the coordination.
In addition, the IR spectra of the mixed complexes show
absorptions that are typical of coordinated 2,2Ј-bipyridine
(764 and 736 cmϪ1) and 1,10-phenanthroline (1520, 850,
and 720 cmϪ1).
The electronic reflectance spectrum of the pentacoordi-
nate complex [Cu(Ts3mepy)2H2O] shows a very broad
band, probably a multicomponent band, at 15800 with a
shoulder at ca. 11800 cmϪ1, a situation in accord with a
pseudo-square planar pyramidal environment forming a
[CuN2O3] chromophore.[25]
Figure 10. EPR Spectra in X-band of the complex [Cu(Ms6me-
py)2phen] (solid line) and its simulation (dotted line) as a powder
at room temperature
mide ligands and the bipy and phen. Bertini[29] has sug-
gested that A|| may be a measure of the coordination poly-
hedron around copper(). Accordingly A|| from 120 to 150
G indicates a square-pyramidal geometry while values of
160Ϫ200 G correspond to a square planar or six-coordinate
stereochemistry. The A||s of[Cu(Ts3mepy)2(H2O)], [Cu(Ts3-
mepy)2bipy] and [Cu(Ms3mepy)2bipy] suggest a square-
pyramidal arrangement, in agreement with their crystal
structures. The A||s of [Cu(Ms6mepy)2phen] indicate a six-
coordinate geometry, which agrees with the crystal struc-
ture. The complexes [Cu(Ts3mepy)2phen] and [Cu(Ms3me-
py)2phen] are in the limit between the pentacoordinate and
the six-coordinate environment; their crystal structures
both show a distorted square-pyramidal geometry. From
the A||s of [Cu(Ms6mepy)2bipy] we propose a six-coordinate
around copper(). Similar conclusions were obtained from
the spectroscopic data.
The electronic reflectance spectra of [Cu(Ts3me-
py)2phen], [Cu(Ts3mepy)2bipy], [Cu(Ms3mepy)2phen], and
[Cu(Ms3mepy)2bipy] show two broad bands in the range
16300Ϫ15900 cmϪ1 and 12300Ϫ10600 cmϪ1. This is similar
to the spectra of copper() complexes involving
a
[CuN4O] chromophore.[26]
The electronic reflectance spectrum of [Cu(Ms6me-
py)2phen] shows two bands at 14430 and 10955 cmϪ1
,
which are similar to those found for [Cu(Ms6mepy)2bipy],
[Cu(Ts6mepy)2bipy], and [Cu(Ts6mepy)2phen], suggesting
an octahedral [CuN6] chromophore for all these com-
pounds.[27]
The magnetic moments at room temperature are close to
1.8 B.M. in all cases, as expected for d9 systems.
The X-band spectra of polycrystalline samples of the
complexes were recorded at room temperature. Table 10
show the EPR parameters of the ternary complexes ob-
tained by simulation.[28] As an example, Figure 10 shows
Conclusion
The most important feature of these complexes is the co-
both the obtained and simulated EPR spectrum of ordinative behaviour of the anionic ligand and the presence
[Cu(Ms6mepy)2phen].
or absence of π,π-stacking (Table 11).
All the spectra are axial with similar EPR parameters so
The ligands behave in a (N,O) bidentate way with a sub-
that it can be predicted due to the similarity of the sulfona- stituent at position 3. However, for a substituent in position
Eur. J. Inorg. Chem. 2004, 635Ϫ645
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641

J. Castro, A. Sousa et al.
FULL PAPER
Table 11. Conclusions
Complex
Behaviour of the ligands
L1 L2
Environment
around Cu atom
Geometry
π-π stacking
Coligand
[Cu(Ts3mepy)2(H2O)] bidentate-(N,O) bidentate-(N,O) monodentate-O [CuN2O3]
[Cu(Ts3mepy)2bipy] monodentate-N bidentate-(N,O) bidentate-(N,N) [CuN4O]
[Cu(Ts3mepy)2phen] monodentate-N bidentate-(N,O) bidentate-(N,N) [CuN4O]
[Cu(Ms3mepy)2phen] monodentate-N bidentate-(N,O) bidentate-(N,N) [CuN4O]
[Cu(Ms3mepy)2bipy] monodentate-N bidentate-(N,O) bidentate-(N,N) [CuN4O]
Square pyramid (τ ϭ 0.07) no
Square pyramid (τ ϭ 0.28) no
Square pyramid (τ ϭ 0.18) yes
Square pyramid (τ ϭ 0.12) yes
Square pyramid (τ ϭ 0.18) yes
Octahedral
[Cu(Ts6mepy)2bipy]
bidentate-(N,N) bidentate-(N,N) bidentate-(N,N) [CuN6]
[Cu(Ts6mepy)2phen] bidentate-(N,N) bidentate-(N,N) bidentate-(N,N) [CuN6]
[Cu(Ms6mepy)2phen] bidentate-(N,N) bidentate-(N,N) bidentate-(N,N) [CuN6]
[Cu(Ms6mepy)2bipy] bidentate-(N,N) bidentate-(N,N) bidentate-(N,N) [CuN6]
Octahedral
Octahedral
Octahedral
yes
ppm): δ ϭ 2.24 [s, 3 H, CH3(p-mesityl)]; 2.37 [s, 3 H, CH3(py)];
2.69 [s, 6 H, CH3(o-mesityl)]; 6.55 (d, 1 H, py); 6.74 (d, 1 H, py);
6.88 (s, 2 H, tolyl); 7.37 (t, 1 H, py); 9.40 (b, 1 H, NH). IR (KBr,
cmϪ1): 3236 (w), 2931 (w), 1617 (s), 1533 (m), 1457 (m), 1363 (vs),
1290 (m), 1136 (s), 1063 (w), 834 (m), 656 (m). EI MS: m/z (%):
291(4) [Mϩ]; 108 (13) [Mϩ Ϫ {O2S-mesityl}].
6, they behave in a (N,N) bidentate way. Probably, the dif-
ference can be traced to a steric effect. A substituent in
position 3 pushes the sulfonyl group towards the metal, and
induces (N,O) bidentate behaviour.
In addition, when the coligand is 1,10-phenanthroline the
third ring allows a π,π-stacking, either with the toluene ring
or the mesytilene ring. When the coligand is 2,2Ј-bipyridine,
π,π-stacking is only produced when the benzene ring is sub-
stituted by three methyl groups. This could be due to the
electron-releasing effect of the three methyl groups in the
ring, together with the increasing size of the group.
HTs3mepy: Yield 26.7%. C13H14N2O2S (%): calcd. C 59.5, H 5.4,
N 10.7, S 12.2; found C 58.7, H 5.7, N 10.2, S 11.8. 1H NMR
(CDCl3, ppm): δ ϭ 2.15 [s, 3 H, CH3(py)]; 2.35 [s, 3 H, CH3(tolyl)];
6.50 (t, 2 H, tolyl); 7.21 (d, 1 H, py); 7.40 (d, 1 H, py); 7.49 (d, 1
H, py); 7.85 (d, 2 H, tolyl); 12.14 (b, 1 H, NH). IR (KBr, cmϪ1):
3248 (m), 2920 (w), 1593 (s), 1543 (s), 1399 (m), 1371 (m), 1342 (s),
1255 (m), 1126 (s), 1080 (m), 963 (m), 767 (w), 683 (m), 570 (w).
EI MS: m/z (%): 262 (8) [Mϩ]; 108 (20) [Mϩ Ϫ {O2S-tolyl}].
Experimental Section
HTs6mepy: Yield 37.5%. C13H14N2O2S (%): calcd. C 59.5, H 5.4,
N 10.7, S 12.2; found C 58.8, H 5.6, N 10.6, S 12.3. 1H NMR
(CDCl3, ppm): δ ϭ 2.36 [s, 3 H, CH3(tolyl)]; 2.41 [s, 3 H, CH3(py)];
6.60 (d, 1 H, py); 7.06 (d, 1 H, py); 7.22 (d, 2 H, tolyl); 7.46 (t, 1
H, py); 7.79 (d, 2 H, tolyl); 9.95 (b, 1 H, NH). IR (KBr, cmϪ1):
3231 (w), 3052 (w), 2958 (w), 1613 (vs), 1534 (m), 1369 (s), 1252
(m), 1135 (s), 1089 (m), 855 (m), 787 (m), 661 (m), 572 (m). EI MS:
m/z (%): 262 (6) [Mϩ]; 108 (3) [Mϩ Ϫ {O2S-tolyl}].
Acetonitrile, dichloromethane, 2-amino-3-picoline, 2-amino-6-pico-
line, p-toluenesulfonyl chloride, 2-mesitylenesulfonyl chloride, 2,2Ј-
bipyridine, 1,10-phenanthroline monohydrate, sodium carbonate,
magnesium sulfate, and all other reagents were commercial prod-
ucts and were used as supplied. Copper (Aldrich) was used as 2 ϫ
2 cm plates.
Preparation of the Ligands
Preparation of Complexes. General Procedure: The complexes were
obtained by an electrochemical procedure.[30] The cell consisted of
a tall-form beaker (100 mL) fitted with a rubber bung through
which the electrochemical leads entered. An acetonitrile solution
of either the ligand or the ligand/coligand (1,10-
phenanthroline·monohydrate or 2,2Ј-bipyridine) mixture contain-
ing tetraethylammonium perchlorate (ca. 20 mg) as electrolyte was
electrolysed using a platinum wire as the cathode and a copper
plate as the sacrificial anode. Direct current was supplied by a pur-
pose-built d.c. power supply. The applied voltages (5Ϫ15 V) al-
lowed sufficient current flow for smooth dissolution of the copper
metal. The current was maintained at 10 mA for one hour. In all
cases, hydrogen was evolved at the cathode. These cells can be sum-
marised as Cu(ϩ)/CH3CN ϩ HL ϩ LЈ/Pt(Ϫ) where LЈ is 2,2Ј-bipyri-
dine or 1,10-phenanthroline.
Ligands were prepared by reaction of the corresponding amine and
the sulfonyl chloride in a 1:1 ratio. Details are given for a represen-
tative example.
HMs3mepy: An aqueous solution of sodium carbonate (1.95 g,
18.4 mmol in 20 mL) was added dropwise to a solution of 2-amino-
3-picoline (2.0 g, 18.4 mmol) and 2-mesitylenesulfonyl chloride
(4.05 g, 18.4 mmol) dissolved in dichloromethane. The reaction
mixture was then stirred overnight and water (100 mL) was added.
The organic layer was then separated and dried over anhydrous
magnesium sulfate. The solvent was evaporated and the crude prod-
uct, an oil, was treated with ethanol. The resulting white solid was
isolated by filtration and identified as HMs3mepy; yield 16.7%.
C15H18N2O2S (%): calcd. C 62.1, H 6.2, N 9.6, S 11.0; found C
1
61.3, H 6.0, N 9.3, S 11.2. H NMR (CDCl3, ppm): δ ϭ 2.15 [s, 3
H, CH3(py)]; 2.25 [s 3 H, CH3(p-mesityl)]; 2.71 [s, 6 H, CH3(o-
mesityl)]; 6.47 (t, 1 H, py); 6.89 (s, 2 H, tolyl); 7.36 (d, 1 H, py);
7.42 (d, 1 H, py; 12.33 (b, 1 H, NH). IR (KBr, cmϪ1): 3222 (m),
2940 (w), 1633 (w), 1595 (s), 1544 (s), 1375 (w), 1338 (s), 1259 (m),
1098 (s), 1047 (m), 780 (m), 676 (m). EI MS: m/z (%): 291 (100)
[Mϩ]; 108 (10) [Mϩ Ϫ {O2S-mesityl}].
After one hour of electrolysis, the resultant clear green solutions
were filtered to remove any particles of metal and then left to con-
centrate. This procedure afforded crystalline products in good
yield. The solids were then washed with acetonitrile and diethyl
ether and dried at room temperature.
[Cu(Ts3mepy)2H2O]: Electrochemical oxidation of a copper anode
in a solution of the ligand N-(3-methyl-2-pyridyl)-p-toluenesulfon-
HMs6mepy: Yield 42.1%. C15H18N2O2S (%): calcd. C 62.1, H 6.2,
N 9.6, S 11.0; found C 61.3, H 6.4, N 9.5, S 10.9. 1H NMR (CDCl3, amide, (0.19 g, 0.75 mmol) in acetonitrile (50 cm3), at 12 V and
642
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Eur. J. Inorg. Chem. 2004, 635Ϫ645

Flexidentate Behaviour of 2-Pyridylsulfonamides
FULL PAPER
10 mA for 1 h, dissolved copper (25 mg), Ef ϭ 1.05 mol·FϪ1
.
[Cu(Ms3mepy)2phen]: Electrochemical oxidation of a copper anode
C26H28CuN4O5S2 (%): calcd. C 51.7, N 9.3, H 4.7, S 10.6; found in a solution of the ligand (0.22 g, 0.75 mmol) and 1,10-phen-
C 51.2, N 9.4, H 4.5, S 10.3. IR (KBr, cmϪ1): 3444 (m), 2922 (w), anthroline (0.07 g, 0.37 mmol) in acetonitrile (50 cm3), at 14 V and
1593 (s), 1419 (s), 1336 (w), 1265 (m), 1133 (s), 1090 (m), 853 (w),
814 (w), 665 (m), 587 (m), 546 (m).
10 mA for 1 h dissolved copper (22 mg), Ef ϭ 0.93 mol·FϪ1
.
C42H42CuN4O4S2 (%): calcd. C 61.1, N 10.2, H 5.1, S 7.8; found
C 61.1, N 10.4, H 5.2, S 7.6. IR (KBr, cmϪ1): 3425 (m), 2930 (w),
1594 (m), 1512 (m), 1416 (s), 1319 (m), 1121 (s), 845 (m), 724 (m),
683 (w), 593 (w), 532 (w).
[Cu(Ts3mepy)2bipy]: Electrolysis of a solution of the ligand (0.19 g,
0.75 mmol) and 2,2Ј-bipyridine (0.58 g, 0.37 mmol) in acetonitrile,
(50 cm3) at 10 V and 10 mA for 1 h dissolved copper (26 mg) from
the anode, Ef ϭ 1.10 mol·FϪ1. C36H34CuN4O4S2 (%): calcd. C 58.3,
N 11.3, H 4.6, S 8.6; found C 57.8, N 11.3, H 4.8, S 8.4. IR (KBr,
cmϪ1): 3441 (m), 2922 (w), 1606 (m), 1445 (w), 1416 (s); 1327 (m),
[Cu(Ts6mepy)2bipy]: A similar experiment to those described above
(10 V, 10 mA, 1 h) with N-(6-methyl-2-pyridyl)-p-toluenesulfon-
amide (0.19 g, 0.75 mmol) and 2,2Ј-bipyridine (0.58 g, 0.37 mmol)
1247 (m), 1128 (m), 1085 (m), 772 (m), 737 (w), 659 (m), 587 (m), in acetonitrile (50 cm3) led to the dissolution of 25 mg of metal,
550 (m).
Ef ϭ 1.05 mol·FϪ1. C36H34CuN4O4S2 (%): calcd. C 58.3, N 11.3,
H 4.6, S 8.6; found C 57.9, N 11.6, H 4.4, S 8.5. IR (KBr, cmϪ1):
3445 (m), 2922 (w), 1596 (m), 1457 (s), 1339 (s), 1135 (s), 1097 (m),
855 (m), 769 (w), 731 (w), 660 (w), 577 (w), 550 (w).
[Cu(Ts3mepy)2phen]: A solution of the ligand (0.19 g, 0.75 mmol)
and 1,10Ϫphenanthroline (0.07 g, 0.37 mmol) in acetonitrile (50
cm3) was electrolyzed at 8 V and 10 mA for 1 hour; copper metal
(22 mg) was dissolved from the anode, Ef ϭ 0.93 mol·FϪ1
.
[Cu(Ts6mepy)2phen]: A similar experiment to those described above
C38H34CuN4O4S2 (%): calcd. C 59.4, N 10.9, H 4.7, S 8.3; found
(12 V, 10 mA, 1 h) with HTs6mepy (0.19 g, 0.75 mmol) and 1,10-
C 59.5, N 11.1, H 4.7, S 8.3. IR (KBr, cmϪ1): 34445 (m), 2918 (w), phenanthroline (0.07 g, 0.37 mmol) in acetonitrile (50 cm3) led to
1592 (m), 1414 (s), 1326 (m), 1243 (m), 1126 (m), 1096 (m), 988
(m), 848 (w), 720 (w), 588 (m), 545 (m).
the dissolution of metal (22 mg), Ef
ϭ
0.93 mol·FϪ1
.
C38H34CuN4O4S2 (%): calcd. C 59.4, N 10.9, H 4.7, S 8.3; found
C 58.8, N 11.4, H 4.5, S 7.9. IR (KBr, cmϪ1): 3441 (m), 2924 (w),
1596 (m), 1518 (w), 1457 (m), 1339 (m), 1266 (m), 1134 (m), 1096
(m), 852 (w), 723 (w), 665 (m), 578 (m), 551 (w).
[Cu(Ms3mepy)2bipy]: A solution of the ligand N-(3-methyl-2-pyrid-
yl)mesitylenesulfonamide (0.22 g, 0.75 mmol) and 2,2Ј-bipyridine
(0.58 g, 0.37 mmol) in acetonitrile (50 cm3) was electrolyzed at 14
V and 10 mA for 1 hour; copper (27 mg) was dissolved from the
anode, Ef ϭ 1.13 mol·FϪ1. C40H42CuN4O4S2 (%): calcd. C 60.1, N
[Cu(Ms6mepy)2bipy]: In similar fashion to above (12 V, 10 mA,
1 h),
N-(6-methyl-2-pyridyl)-2-mesitylenesulfonamide
(0.22 g,
10.5, H 5.3, S 8.0; found C, 59.5, N 10.2, H 5.3, S 8.1. IR (KBr, 0.75 mmol) and 2,2Ј-bipyridine (0.58 g, 0.37 mmol) in acetonitrile
cmϪ1): 3443 (m), 2931 (w), 1605 (m), 1416 (s), 1327 (m), 1228 (m),
1117 (s), 1057 (w), 770 (m), 728 (w), 687 (m), 593 (w), 521 (w).
(50 cm3) led to the dissolution of 28 mg of metal, Ef ϭ 1.18
mol·FϪ1. C40H42CuN4O4S2 (%): calcd. C 60.1, N 10.5, H 5.3, S
Table 12. Summary of crystal data and structure refinement
Identification code:
HMs3mepy
[Cu(Ts3mepy)2H2O]
[Cu(Ts3mepy)2bipy].
[Cu(Ts3mepy)2phen]
Empirical formula
Molecular mass
Temperature
Wavelength
Crystal system,
space group
C30H36N4O4S2
580.75
C26H28N4O5S2Cu
604.18
C36H34N6O4S2Cu
742.35
C38H34N6O4S2Cu
766.37
293(2) K
0.71073 A
293(2) K
0.71073 A
293(2) K
0.71073 A
293(2) K
0.71073 A
¯
triclinic, P1
˚
˚
˚
˚
¯
Monoclinic, C2/c
monoclinic, P21/c
triclinic, P1
˚
˚
˚
˚
˚
˚
Unit cell dimensions
a ϭ 15.069(2) A
b ϭ 8.0862(11) A
c ϭ 24.651(3) A
a ϭ 16.6262(15) A
a ϭ 17.346(3) A
a ϭ 10.7185(12) A
˚
˚
˚
b ϭ 6.0343(5) A
b ϭ 9.2519(14) A
b ϭ 10.9915(13) A
˚
˚
˚
c ϭ 27.530(3) A
c ϭ 24.083(3) A
c ϭ 17.6002(19) A
α ϭ 90°
α ϭ 90°
α ϭ 90°
α ϭ 106.300(2)°
β ϭ 102.900(3)°
γ ϭ 97.734(2)°
β ϭ 102.765(3)°
γ ϭ 90°.
β ϭ 103.112(2)°
γ ϭ 90°
β ϭ 114.640(8)°
γ ϭ 90°
3
3
3
3
˚
˚
˚
˚
Volume
2929.5(7) A
2690.0(4) A
3513.0(9) A
1896.3(4) A
Z, calculated density
Absorption coefficient
F(000)
4, 1.317 Mg/m3
4, 1.492 Mg/m3
2, 1.404 Mg/m3
2, 1.342 Mg/m3
0.733 mmϪ1
794
0.224 mmϪ1
1.011 mmϪ1
0.789 mmϪ1
1232
1252
1540
Crystal size
Theta range for data
collection
0.41 ϫ 0.47 ϫ 0.50 mm
2.77 to 28.05°.
0.8 ϫ 0.46 ϫ 0.62 mm
1.52 to 28.01°
0.03 ϫ 0.10 ϫ 0.14 mm
1.29 to 28.09°.
0.9 ϫ 0.1 ϫ 0.16 mm
1.97 to 28.05°
Index ranges
Ϫ19 Յ h Յ 18,
Ϫ9 Յ k Յ 10,
Ϫ32 Յ l Յ 28
Ϫ21 Յ h Յ 21,
Ϫ7 Յ k Յ 6,
Ϫ29 Յ l Յ 36
Ϫ22 Յ h Յ 22,
Ϫ12 Յ k Յ 12,
Ϫ31 Յ l Յ 18
Ϫ13 Յ h Յ 14,
Ϫ13 Յ k Յ 14,
Ϫ23 Յ l Յ 17
Reflections collected/unique 8866/ 3441 [R(int) ϭ 0.0279] 14844/6056 [R(int) ϭ 0.0364] 17080/7613 [R(int) ϭ 0.1615] 11011/7676 [R(int) ϭ 0.0600]
Completeness to 2θ
Data/restraints/parameters 3441/0/209
Goodness-of-fit on F2
1.043
96.5%
93.3%
6056/0/355
0.923
83.9%
7613/0/426
0.697
83.4%
7676/0/464
0.740
Final R indices [I Ͼ 2σ(I)] R1 ϭ 0.0446, wR2 ϭ 0.1174 R1 ϭ 0.0404, wR2 ϭ 0.0911 R1 ϭ 0.0570, wR2 ϭ 0.1005 R1 ϭ 0.0572, wR2 ϭ 0.0900
R indices (all data) R1 ϭ 0.0590, wR2 ϭ 0.1240 R1 ϭ 0.0797, wR2 ϭ 0.1017 R1 ϭ 0.3440, wR2 ϭ 0.1974 R1 ϭ 0.1689, wR2 ϭ 0.1089
Largest diff. peak and hole 0.256 and Ϫ0.422 e·A
Ϫ3
Ϫ3
Ϫ3
Ϫ3
˚
˚
˚
˚
0.266 and Ϫ0.269 e·A
0.397 and Ϫ0.312 e·A
0.426 and Ϫ0.343 e·A
Eur. J. Inorg. Chem. 2004, 635Ϫ645
www.eurjic.org
 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
643

J. Castro, A. Sousa et al.
[Cu(Ms6mepy)phen]2
FULL PAPER
Table 13. Summary of crystal data and structure refinement
Identification code:
[Cu(Ms3mepy)2bipy]
[Cu(Ms3mepy)2phen]
Empirical formula
Molecular mass
C40H42N6O4S2Cu
798.46
C42H42N6O4S2Cu
822.48
C42H42N6O4S2Cu
822.48
Temperature
Wavelength
293(2) K
0.71073 A
293(2) K
0.71073 A
293(2) K
0.71073 A
˚
˚
˚
¯
Crystal system, space group
Unit cell dimensions
monoclinic, P21/c
monoclinic, P21/c
triclinic, P1
˚
˚
˚
˚
˚
a ϭ 17.1798(11) A
a ϭ 16.2855(12) A
a ϭ 15.370(5) A
b ϭ 16.143(5) A
c ϭ 17.532(5) A
˚
˚
˚
b ϭ 15.6081(10) A
b ϭ 15.8753(11) A
˚
c ϭ 15.5389(9) A
c ϭ 15.0249(11) A
α ϭ 90°
α ϭ 90°.
α ϭ 109.564(5)°.
β ϭ 92.724(5)°
γ ϭ 98.831(5)°.
β ϭ 105.6420(10)°
γ ϭ 90°
β ϭ 96.897(2) deg.
γ ϭ 90°.
3
3
3
˚
˚
˚
Volume
4012.4(4) A
3856.4(5) A
4027(2) A
Z, calculated density
Absorption coefficient
F(000)
4, 1.322 Mg/m3
4, 1.417 Mg/m3
2, 1.357 Mg/m3
0.696 mmϪ1
0.726 mmϪ1
0.695 mmϪ1
1668
1716
1716
Crystal size
Theta range for data collection
Index ranges
0.15 ϫ 0.23 ϫ 0.54 mm
1.79 to 28.02°
Ϫ22 Յ h Յ 22,
Ϫ20 Յ k Յ 20,
Ϫ14 Յ l Յ 20
23177/9157 [R(int) ϭ 0.0578]
94.3%
0.44 ϫ 0.12 ϫ 0.12 mm
1.80 to 28.02°
Ϫ20 Յ h Յ 21,
Ϫ20 Յ k Յ 19,
Ϫ19 Յ l Յ 15
0.31 ϫ 0.25 ϫ 0.22 mm
1.24 to 26.48°
Ϫ17 Յ h Յ 19,
Ϫ20 Յ k Յ 17,
Ϫ21 Յ l Յ 21
Reflections collected/unique
Completeness to 2θ
22031/8786 [R(int) ϭ 0.0599]
94.3%
33835/16311 [R(int) ϭ 0.0788]
97.9%
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [I Ͼ 2σ(I)]
R indices (all data)
9157/0/486
0.862
R1 ϭ 0.0443, wR2 ϭ 0.0893
8786/0/496
0.871
R1 ϭ 0.0528, wR2 ϭ 0.1023
R1 ϭ 0.1505, wR2 ϭ 0.1222
0.448 and Ϫ0.291 e·AϪ3
16311/5/1007
0.934
R1 ϭ 0.0703, wR2 ϭ 0.1779
R1 ϭ 0.2359, wR2 ϭ 0.2432
0.891 and Ϫ0.628 e·AϪ3
R1 ϭ 0.0991, wR2 ϭ 0.1009
Ϫ3
˚
0.392 and Ϫ0.264 e·A
Largest diff. peak and hole
8.0; found C 59.7, N 10.4, H 5.2, S 7.8. IR (KBr, cmϪ1): 3443 (m),
2931 (w), 1598 (s), 1457 (s), 1343 (s), 1251 (m), 1125 (s), 1083 (m),
843 (m), 768 (w), 732 (w), 671 (w), 587 (w), 535 (w).
HMs3mepy the hydrogen atoms (except those of the methyl groups)
were located on a difference electron density map and refined with
isotropic displacement parameters. For the complexes, hydrogen
atoms were included in idealised positions and refined with iso-
tropic displacement parameters, except for those of the water mol-
ecule of [Cu(Ts3mepy)2H2O], which were located and refined with
isotropic displacement parameters. Atomic scattering factors and
anomalous dispersion corrections for all atoms were taken from
International Tables for X-ray Crystallography.[33] Details of crystal
data and structural refinements are given in Tables 12 and 13.
[Cu(Ms6mepy)2phen]: By a similar procedure (15 V, 10 mA, 1 h),
HMs6mepy, (0.22 g, 0.75 mmol) and 1,10-phenanthroline (0.07 g,
0.37 mmol) in acetonitrile (50 cm3) led to the dissolution of metal
(25 mg), Ef ϭ 1.05 mol·FϪ1. C42H42CuN4O4S2 (%): calcd. C 61.1,
N 10.2, H 5.2, S 7.8; found C 60.8, N 10.1, H 5.2, S 7.6. IR (KBr,
cmϪ1): 3445 (m), 2931 (w), 1594 (m), 1519 (w), 1457 (m), 1344 (m),
1250 (w), 1124 (s), 1082 (m), 845 (m), 722 (w), 689 (w), 588 (w),
533 (w).
CCDC 187516 and 209128Ϫ209133 contain the supplementary
crystallographic data for this paper. These data can be obtained
free of charge at www.ccdc.cam.ac.uk/conts/retrieving.html [or
from the Cambridge Crystallographic Data Centre, 12 Union
Road, Cambridge CB2 1EZ, UK; Fax: (internat.) ϩ 44-1223-336-
033; E-mail: deposit@ccdc.cam.ac.uk].
Physical Measurements: The C, N, H, and S contents of the com-
pounds were determined on a CarloϪErba EA 1108 microanalyser.
IR spectra in the solid state were recorded as KBr mulls on a
1
Bruker Vector-22 spectrophotometer. The H NMR spectra of the
ligands were recorded on a Bruker ARX-400 MHz spectrometer
using CDCl3 as solvent. Solid-state electronic spectra were recorded
on a Shimadzu UV 3101 PC. Magnetic measurements were made
using a DMS VSM 1160. EI (70 eV, 250 °C), and LSI mass spectra
were recorded on a VG Autospec-M Micromass, using 2-nitro-
benzyl alcohol (2-NBA) as matrix material. EPR measurements on
solid samples were recorded on a Bruker EMX spectrometer, using
frequencies between 9400 and 9800 MHz (X-band).
Acknowledgments
This work was supported by the fl  , under the
grant PGIDT00PXI20305PR, the Ministerio de Ciencia y Tecnolo-
´
gıa (Spain), under grant BQU2002Ϫ01819, and the Universidade
de Vigo, under grant C221 122F 64102.
[1]
[1a] G. Wilkinson, R. D. Gillard, J. A. McCleverty; Comprehen-
X-ray Crystallographic Study: Data collections were taken on a
SIEMENS Smart CCD area-detector diffractometer with graphite-
monochromated Mo-Kα radiation. Absorption corrections were
carried out using SADABS.[31]
sive Coordination Chemistry, Ed. Pergamon Press, Oxford,
[1b]
1987.
H. E. Bryndza, W. Tam, Chem. Rev. 1988, 88,
[1c]
1163Ϫ1188.
M. D. Fryzuk, C. D. Montgomery, Coord.
Chem. Rev. 1989, 95, 1Ϫ40.
[2] [2a]
´
J. Casanova, G. Alzuet, J. Borras, O. Carugo, J. Chem. Soc.,
Dalton Trans. 1996, 2239Ϫ2244. [2b] L. Gutierrez, G. Alzuet, J.
All the structures were solved by direct methods and refined by
full-matrix least-squares based on F2.[32] All non-hydrogen atoms
were refined with anisotropic displacement parameters. For
´
´
A. Real, J. Cano, J. Borras, A. Castin˜eiras, Inorg. Chem. 2000,
39, 3608Ϫ3614. [2c] L. Gutierrez, G. Alzuet, J. Borras, A. Casti-
´
´
644
 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org Eur. J. Inorg. Chem. 2004, 635Ϫ645

Flexidentate Behaviour of 2-Pyridylsulfonamides
FULL PAPER
G. B. Gavioli, M. Borsari, L. Menabue, M. Saladini, J. Chem.
Soc., Dalton Trans. 1991, 2961Ϫ2965.
[21]
[22]
´
n˜eiras, A. Rodrıguez-Fortea, E. Ruiz, Inorg. Chem. 2001, 40,
[2d]
´
L. Gutierrez, G. Alzuet, J. A. Real, J. Cano, J.
3089Ϫ3096.
´
Borras, A. Castin˜eiras, Eur. J. Inorg. Chem. 2002, 2094Ϫ2102.
D. Iacopino, L. Menabue, M. Saladini, Aust J. Chem. 1999, 52,
741Ϫ748 and references cited therein.
P. Comba, P. Jurisic, Y. D. Lampeka, A. Peters, A. I. Prikh-
od’ko, H. Pritzkow, Inorg. Chim. Acta 2001, 324, 99Ϫ107.
[3]
[4]
[23] [23a]
R. L. Chapman, F. S. Stephens, R. S. Vagg, Inorg. Chim.
[23b]
Acta 1980, 43, 29Ϫ33.
M. Mulqi, F. S. Stephens, R. S.
C. A. Otter, S. M. Couchman, J. C. Jeffery, K. L. V. Mann, E.
Psillakis, M. D. Ward, Inorg. Chim. Acta 1998, 278, 178Ϫ184,
and references cited therein.
R. Kempe, Eur. J. Inorg. Chem. 2003, 791Ϫ803, and references
cited therein.
R. Clerac, F. A. Cotton, K. R. Dunbar, C. A. Murillo, I. Pas-
cual, X. Wang, Inorg. Chem. 1999, 38, 2655Ϫ2657.
L. M. Engelhardt, M. G. Gardiner, C. Jones, P. C. Junk, C. L.
Raston, A. H. White, J. Chem. Soc., Dalton Trans. 1996,
3053Ϫ3057.
[23c]
Vagg, Inorg. Chim. Acta 1981, 51, 9Ϫ14.
M. Mulqi, F. S.
Stephens, R. S. Vagg, Inorg. Chim. Acta 1981, 52, 177Ϫ182.
[23d]
[5]
[6]
[7]
F. S. Stephens, R. S. Vagg, Inorg. Chim. Acta 1982, 57,
43Ϫ49.
[24]
C. Janiak, J. Chem. Soc., Dalton Trans. 2001, 3885Ϫ3896.
[25] [25a]
S. Ferrer, J. G. Haasnoot, J. Reedijk, E. Müller, M. B.
Cingi, M. Lanfranchi, A. M. M. Lanfredi, J. Ribas, Inorg.
[25b]
´ ´
P. G o mez-Sainz, J. Garcıa-
Chem. 2000, 39, 1859Ϫ1867.
´
´
Tojal, M. A. Maestro, J. Mahıa, F. J. Arnaiz, T. Rojo, Poly-
hedron 2002, 21, 2257Ϫ2263.
[8]
C. L. Raston, B. W. Skelton, V. A. Tolhurst, A. H. White, Poly-
[26] [26a]
Z. He, P. J. Chaimungkalanont, D. C. Craig, B. Colbran,
J. Chem. Soc., Dalton Trans. 2000, 1419Ϫ1429. [26b] G. Murphy,
C. Murphy, B. Murphy, B. Hathaway, J. Chem. Soc., Dalton
Trans. 1997, 2653Ϫ2660.
hedron 1998, 17, 935Ϫ942.
[9] [9a]
C.-F. Lee, S.-M. Peng, J. Chin. Chem. Soc., (Taipei) 1991,
[9b]
38, 559Ϫ564.
H.-Y. Cheng, P.-H. Cheng, C.-F. Lee, S.-M.
Peng, Inorg. Chim. Acta 1991, 181, 145Ϫ147.
[27] [27a]
J. R. Hartman, R. W. Vachet, W. Pearson, R. J. Wheat, J.
[10]
´
´
´
´
S. Cabaleiro, J. Castro, E. Vazquez-Lopez, J. A. Garcıa-Vaz-
quez, J. Romero, A. Sousa, Acta Cristallogr. 1999, C56,
293Ϫ295.
[27b]
H. Callahan, Inorg. Chim. Acta 2003, 343, 119Ϫ132.
I.
Riggio, G. A. van Albada, D. D. Ellis, A. L. Spek, J. Reedijk,
Inorg. Chim. Acta 2001, 313, 120Ϫ124.
WINEPR-Simfonia 1.25. Bruker Analytik GmbH, Kalrsruhe,
FRG, 1994؊1996.
[11]
[12]
[13]
[14]
´
´
´
I. Beloso, J. Castro, J. A. Garcıa-Vazquez, P. Perez-Lourido, J.
[28]
[29]
Romero, A. Sousa, Polyhedron 2003, 22, 1099Ϫ1111.
S. Cabaleiro, J. Castro, J. A. Garcıa-Vazquez, J. Romero, A.
Sousa, Polyhedron 2000, 19, 1607Ϫ1614.
S. Cabaleiro, J. Castro, E. Vazquez-Lopez, J. A. Garcıa-Vaz-
quez, J. Romero, A. Sousa, Polyhedron 1999, 18, 1669Ϫ1674.
S. Cabaleiro, J. Castro, E. Vazquez-Lopez, J. A. Garcıa-Vaz-
quez, J. Romero, A. Sousa, Inorg. Chim. Acta 1999, 294,
87Ϫ94, and references cited therein.
´
´
I. Bertini, in: ESR and NMR of Paramagnetic Species in Bio-
logical and related Systems (Eds.: I. Bertini, R. S. Drago), D.
Reidel Publishing Co. Dordrecht (Holland), 1980, chapter 11.
´
´
´
´
[30] [30a] M. C. Chakravorti, G. V. B. Subrahmanyam, Coord. Chem.
´
´
´
´
[30b]
Rev. 1994, 135/136, 65Ϫ92.
A. M. Vecchio-Sadus, J. Appl.
[30c]
Electrochem. 1993, 23, 401Ϫ416.
Chem. 1979, 51, 2005Ϫ2018.
D. G. Tuck, Pure Appl.
[30d]
J. A. Davies, C. M. Hok-
[15]
[16]
[17]
´
´
´
I. Beloso, J. Castro, J. A. Garcıa-Vazquez, P. Perez-Lourido, J.
ensmith, V. Yu Kukushkin, Yu N. Kukushkin, in: Synthetic
Coordination Chemistry. Principles and Practice. Word Scien-
tific Publishing Co. Pte. Ltd., 1996, chapter 7.
G. M. Sheldrick, SADABS, An empirical absorption correction
program for area detector data, University of Göttingen, Ger-
many, 1996.
G. M. Sheldrick, SHELX-97, Program for the solution and
refinement of crystal structures. University of Göttingen, Ger-
many, 1997.
Romero, A. Sousa, Z. Anorg. Allg. Chem. 2003, 629, 275Ϫ284.
´
´
´
I. Beloso, J. Castro, J. A. Garcıa-Vazquez, P. Perez-Lourido, J.
[31]
[32]
[33]
Romero, A. Sousa, unpublished results.
J. Castro, J. Romero, J. A. Garcıa-Vazquez, A. Castin˜eiras, M.
L. Duran, A. Sousa, Z. Anorg. Allg. Chem. 1992, 615,
´
´
´
155Ϫ160.
[18]
A. Nanthakumar, J. Miura, S. Diltz, C.-K. Lee, G. Aguirre, F.
Ortega, J. W. Ziller, P. J. Walsh, Inorg. Chem. 1999, 38,
3010Ϫ3013.
L. P. Battaglia, A. B. Corradi, L. Menabue, M. Saladini, M.
Sola, J. Chem. Soc., Dalton Trans. 1987, 1333Ϫ1339.
A. W. Addison, T. N. Rao, J. van Reedijk, J. Van Rijn, G. C.
Verschoor, J. Chem. Soc., Dalton Trans. 1984, 1349Ϫ1356.
International Tables for X-ray Crystallography, Vol C, Ed.
Kluwer, Dordrecht, 1992.
[19]
[20]
Received June 4, 2003
Early View Article
Published Online December 19, 2003
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www.eurjic.org
 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
645