4′-(2-Methylphenyl)-2,2′:6′,2″-terpyridine: coordination chemistry with Ni(II), Cu(II), Zn(II) and Ag(I)

Article abstract of DOI:10.1080/00958972.2019.1580698

The synthesis of 4′-(2-methylphenyl)-2,2′:6′,2″-terpyridine (L) has been improved. The coordination chemistry of the ligand was explored using Ni(II), Cu(II), Zn(II), and Ag(I) ions. X-ray crystallography, elemental analysis, NMR, and mass spectrometry we

Full text of DOI:10.1080/00958972.2019.1580698

Journal of Coordination Chemistry
ISSN: 0095-8972 (Print) 1029-0389 (Online) Journal homepage: https://www.tandfonline.com/loi/gcoo20
4′-(2-Methylphenyl)-2,2′:6′,2″-terpyridine:
coordination chemistry with Ni(II), Cu(II), Zn(II) and
Ag(I)
Gurpreet Kaur, Matthew I. J. Polson & Richard M. Hartshorn
To cite this article: Gurpreet Kaur, Matthew I. J. Polson & Richard M. Hartshorn (2019): 4′-(2-
Methylphenyl)-2,2′:6′,2″-terpyridine: coordination chemistry with Ni(II), Cu(II), Zn(II) and Ag(I),
Journal of Coordination Chemistry, DOI: 10.1080/00958972.2019.1580698
To link to this article: https://doi.org/10.1080/00958972.2019.1580698
View supplementary material
Accepted author version posted online: 12
Feb 2019.
Published online: 26 Feb 2019.
Submit your article to this journal
Article views: 29
View Crossmark data
Full Terms & Conditions of access and use can be found at
https://www.tandfonline.com/action/journalInformation?journalCode=gcoo20

JOURNAL OF COORDINATION CHEMISTRY
https://doi.org/10.1080/00958972.2019.1580698
40-(2-Methylphenyl)-2,20:60,200-terpyridine: coordination
chemistry with Ni(II), Cu(II), Zn(II) and Ag(I)
Gurpreet Kaur, Matthew I. J. Polson and Richard M. Hartshorn
School of Physical and Chemical Sciences, University of Canterbury, Christchurch, New Zealand
ABSTRACT
ARTICLE HISTORY
The synthesis of 40-(2-methylphenyl)-2,20:60,200-terpyridine (L) has been
improved. The coordination chemistry of the ligand was explored
using Ni(II), Cu(II), Zn(II), and Ag(I) ions. X-ray crystallography, elemental
analysis, NMR, and mass spectrometry were used to characterize the
13 new compounds that have been synthesized. Under different reac-
tion conditions, Ni(II), Cu(II), and Zn(II) produced discrete complexes,
sometimes containing more than one metal ion, while Ag(I) furnished
a polymeric spiral complex in which the central pyridine nitrogen of
each terpyridine ligand bridges two Ag(I) ions. Crystallographically
characterized complexes are [Ni(L)2]Cl2, [Ni2Cl4(L)2], [Ni(L)(OH2)3]Cl2,
[Ni(L)2]Br2, [Cu(L)(OH2)(OSO3)], [Cu3Cl6(L)2], [Cu(L)(OH)(OH2)2]PF6,
[Cu(L)2](OTf)2, [Cu(L)(OAc)2], [Zn(L)(OAc)2], [Zn(L)Cl2], [Zn(L)2](NO3)2,
[{Ag2(l-L)2(l-NO3)}n](NO3)n.
Received 25 June 2018
Accepted 18 January 2019
KEYWORDS
Terpyridine; coordination
equilibria; coordination
complexes; supramolecular
complexes; crystallography
1. Introduction
The tridentate chelating ligand 2,20:60,200-terpyridine (terpyridine) was first isolated by
Morgan and Burstall in 1932 [1], and since its discovery terpyridine and its many
CONTACT Richard M. Hartshorn
richard.hartshorn@canterbury.ac.nz
School of Physical and Chemical Sciences,
University of Canterbury, Christchurch, New Zealand
Supplemental data for this article can be accessed here.
ß 2019 Informa UK Limited, trading as Taylor & Francis Group

2
G. KAUR ET AL.
derivatives have been featured in a vast body of research, as evidenced by the large
number of review articles that have been published in the area. Terpyridine and its
complexes have been studied due to interest in their fluorescence, luminescence, elec-
tronic, photophysical, and biological properties [2–8]. It has also been exploited as a
component in building molecular devices and supramolecular assemblies [2, 9–20].
Many of these applications are based upon the ability to tune the electronic and spec-
troscopic properties of the terpyridine complexes. This can be achieved by introducing
substituents with different electron donating or withdrawing properties at different
positions onto the terpyridine ligands [9, 10, 21–24].
2,20:60,200-Terpyridines can be synthesized with substituents at many different posi-
tions. One of the most common substitution sites is the 40 position of the central pyri-
dine ring, due to their accessibility from the appropriate aldehyde [25]. There are two
main synthetic routes for the production of terpyridines, the cross-coupling method
and the ring assembly method, and numerous 40-substituted-2,20:60,200-terpyridine mol-
ecules have been synthesized via these paths [21]. Further functionalization is possible
on a pendant phenyl ring, and we have explored a particular example of that [26].
The particular ligand of interest in this article, 40-(2-methylphenyl)-2,20:60,200-terpyri-
dine (L), does not feature greatly in the literature, but has been used to explore the
photoluminescence of its platinum complexes [27]. We have used it as a basis on
which to build more elaborate structures that can bind more than one metal ion [28],
and as a preliminary part of that work, we explored some coordination chemistry of
L [29].
In this article, we further explore the coordination and supramolecular chemistry of
L and describe a variation on its synthesis. The new synthesis, based on that reported
by Constable et al. for the preparation of 40-pentafluorophenyl-2,20:60,200-terpyridine
[30], is an improvement on the previously reported method [29]. The terpyridine-type
ligand L was then used in an exploration of its coordination chemistry with Cu(II),
Zn(II), Ni(II), and Ag(I). The results of X-ray crystallographic studies and other data for
the complexes are reported in this article.
2. Results and discussion
2.1. Syntheses
The ligand 40-(2-methylphenyl)-2,20:60,200-terpyridine (L) forms a number of complexes
with divalent metal ions Ni(II), Cu(II), and Zn(II) under different reaction conditions. A
remarkable Ag(I)-L complex with an unusual coordination chemistry was also revealed
during this research. The coordination motifs found on binding L to Ni(II), Cu(II), or
Zn(II) are shown in Scheme 1.
The reaction conditions for the syntheses of twelve new complexes of Ni(II), Cu(II),
and Zn(II) are shown in Schemes 2–4, respectively. Structural studies reveal that in all
of the nickel complexes, the Ni(II) is six-coordinate and has an approximately octahe-
dral geometry. Cu(II) and Zn(II) gave five-coordinate and/or six-coordinate complexes,
depending on the reaction conditions.
In all the Ni(II) complexes obtained, three sites of the octahedral nickel center are
occupied by L, bound through its pyridine-type nitrogen atoms. The remaining

JOURNAL OF COORDINATION CHEMISTRY
3
Scheme 1. Coordination motifs found on binding L to Ni(II), Cu(II) or Zn(II); X ¼ anions/solvent,
R ¼ 2-methylphenyl.
octahedral sites are occupied either by neutral/anionic ligands such as chloride (2),
water (3) or by another L ligand, (1) and (4), as shown in Scheme 2.
The Cu(II) center is five-coordinate in three of the five structures and six-coordinate
in the remaining two, as shown in Scheme 3. In each complex, three coordination sites
of the copper are occupied by three pyridine nitrogens of L and the remaining sites
are occupied by other neutral or anionic ligands. The [Cu(L)2]2þ complex, 8, is octahe-
dral and the structure is very similar to that of the Ni compounds 1 and 4 and other
similar bis-terpyridine type metal complexes reported [31–37].
The Zn(II) compounds synthesized are shown in Scheme 4, including two five-
coordinate complexes, [Zn(L)(CH3COO)2] (10) and [Zn(L)Cl2] (11), and one six-coordin-
ate bis-terpyridine octahedral complex, [Zn(L)2](NO3)2 (12).
Overall, we believe that the synthetic results can be rationalized and controlled
based on equilibrium principles. For example, the initial syntheses of Ni(II) complexes
using a 1:1 Ni(II):L ratio gave mixtures of 1 and 2, which were identified and character-
ized by X-ray crystallography. Subsequently each of these complexes could be pre-
pared deliberately, in good yield, by adjusting the Ni(II):L ratio or adding a large
excess of NaCl to the reaction mixture.
When sufficient L is present in solution, the [Ni(L)2]2þ complex (1) is favored, owing
to higher stability of bis-terpyridine complexes in comparison to mono-terpyridine
complexes [21]. In contrast, the presence of a large excess of NaCl favored the forma-
tion of the 1:1 M:L complex 2.
In general, structural solutions for crystals obtained from reaction mixtures contain-
ing various different ratios of ligand L to Ni(II), Cu(II) or Zn(II) salts were used to guide
the optimization of the syntheses of each complex isolated.

4
G. KAUR ET AL.
Scheme 2. Syntheses of Ni(II)-L compounds 1-4, R ¼ 2-methylphenyl.
2.2. Crystallography and other characterization
2.2.1. M-bis(terpyridine) type octahedral complexes
The reaction of two equivalents of L with one equivalent of either NiCl2, NiBr2,
Cu(OTf)2, or Zn(NO3)2 resulted in formation of [M(L)2]2þ octahedral complexes,
[Ni(L)2]Cl2ꢀ4H2OꢀCH3OH (1), [Ni(L)2]Br2ꢀ3H2O (4), [Cu(L)2](OTf)2ꢀH2O (8), and
[Zn(L)2](NO3)2 (12). Mass spectra of these compounds each show m/z signals for the
[M þ 2L]2þ fragment. Both 1 and 4 give an m/z signal at 352.10 for [Ni þ 2L]2þ. The
m/z signal for [Cu þ 2L]2þ (8) and [Zn þ 2L]2þ (12) appears at 354.60 and 355.10,
respectively.
All four of these compounds were characterized by single crystal X-ray diffraction.
However, the refinements for 8 and 12 were poor, due to low quality crystals, and the
structural solutions must therefore be considered tentative, even if they are consistent
with both the mass spectrometry and elemental analysis results.
The syntheses of both 1 and 4 produced X-ray quality crystals by vapor diffusion of
diethyl ether into the methanolic reaction mixtures. 1 crystallized as orange-brown
cubes and the structure was solved in the monoclinic space group C2/c, Figure 1 (top).
The synthesis of 4 gave hexagonal plate-shaped crystals, with a similar orange-brown

JOURNAL OF COORDINATION CHEMISTRY
5
Scheme 3. Syntheses of Cu(II)-L compounds 5-9, R ¼ 2-methylphenyl.
color, and the crystal structure was solved in the monoclinic space group P21/n, as
shown in Figure 1 (bottom).
In both of these complexes, the nickel center coordinates in a meridional fashion to
two L ligands through six pyridine-type nitrogens. Two noncoordinating chlorides or
bromides were located around the cation in the asymmetric unit.
In 1, both of the ligands lie almost perpendicular to each other with central pyri-
dine plane-to-plane angle of 88.97(9)ꢁ. In 4, the ligands deviate more significantly
from orthogonality and the central pyridines plane-to-plane angle of 75.39(13)ꢁ. Both
complexes occupy a distorted octahedral geometry with approximate D2d symmetry
around the metal center, which is typical of bis-terpyridine-type metal complexes such
as [Fe(tpy)2]2þ, [Co(tpy)2]2þ, [Ni(tpy)2]2þ, and [Cu(tpy)2]2þ reported previously [31–37]

6
G. KAUR ET AL.
Scheme 4. Syntheses of Zn(II)-L compounds 10-12, R ¼ 2-methylphenyl.
and the other bis-L complexes, 8 and 12, reported here. The Ni-N bond lengths in 1
and 4 are consistent with those in the literature.
2.2.2. M-X-M bridging complexes
An excess of chloride in the reaction mixture containing NiCl2 or CuCl2 salts resulted
in the isolation of the metal-halide-metal bridged complexes [Ni2(L)2(l-
Cl)2Cl2]ꢀ2CH3OHꢀ4H2O (2) and [Cu2(L)2(l-Cl)2CuCl4]ꢀCH3OH (6), respectively. The crystal
structure of 2 was solved in the triclinic space group P1 and refined to give the struc-
ture shown in Figure 2.
The asymmetric unit of 2 contains half of the molecule and the two metal ions are
linked by two Ni-Cl-Ni bridges. Each of the nickel centers is bonded to the tridentate
terpyridine metal-binding domain of one L. The remaining coordination sites on each
Ni(II) are occupied by one terminal and two bridging chloride ligands. In the bridging
structural motif [38] each Ni(II) has one short Ni-Cl bond length and one longer one
(Table 1). The Ni-Cl bond to the terminal ligand falls between these two values. This
pattern is consistent with that seen in closely related complexes in which the methyl
group is in the para position of the pendant phenyl ring (40-(4-methylphenyl)-
2,20:60,200-terpyridine (pttp)) or absent (40-(phenyl)-2,20:60,200-terpyridine (phtpy)), see
Table 1. The NiꢀꢀꢀꢀNi distance is 3.5499(15) Å, which is comparable to the inter-metallic
distance observed in other similar di-nickel complexes [40–45]. One somewhat longer
NiꢀꢀꢀNi distance at 3.6421(8) Å was found in [Ni2(phtpy)2(l-Cl)2Cl2] [38].
The copper complex, [Cu2(L)2(l-Cl)2CuCl4]ꢀCH3OH (6), was synthesized by reacting
two equivalents of L with three equivalents of CuCl2ꢀ2H2O. Vapor diffusion of diethyl
ether into the reaction mixture produced X-ray quality needle crystals. The crystal
;
structure of 6, solved in the triclinic space group P1 is shown in Figure 3.

JOURNAL OF COORDINATION CHEMISTRY
7
Figure 1. The crystal structures of the [Ni(L)2]2þ complex as its chloride salt 1 (top) and bromide
salt 4 (bottom). Solvent molecules and hydrogen atoms have been omitted for clarity. Thermal
ellipsoids are shown at 50% probability.
The crystal structure contains a discrete trinuclear [Cu3(L)2Cl6] unit. Each complex
contains two L ligands, three Cu(II) ions and six chlorides. All of the Cu(II) centers have
different coordination environments. The two bound to L ligands are five-coordinate
and approximately square pyramidal (the values of the geometric parameter, s, as
defined by Addison et al. [46] are 0.126 and 0.003 for Cu3 and Cu2, respectively,
where a square pyramid gives a s value of 0 and a trigonal bipyramid gives a value
of 1).
The third copper center, Cu1, is coordinated to four chlorides in a distorted tetrahe-
dral geometry. The Cu(II) ions and chloride ions in the Cl6-Cu3-Cl5-Cu2-Cl4-Cu1-Cl3
chain are almost coplanar. The bond lengths and angles between copper and nitrogen
in 6 are similar to those found in a closely related mononuclear [Cu(L)Cl2] com-
plex [29].

8
G. KAUR ET AL.
Figure 2. The crystal structure of [Ni2(L)2(l-Cl)2Cl2] (2); solvent, hydrogen atoms and anion are
omitted for clarity. Thermal ellipsoids are shown at 50% probability.
Table 1. Ni-Cl bond lengths (Å) in 2 and two closely related complexes in which the methyl
group is in the para position (pttp) or absent (phtpy).
Bridge 1 (Å)
Bridge 2 (Å)
Terminal (Å)
[Ni2(L)2(l-Cl)2] (2)
[Ni2(pttp)2(l-Cl)2Cl2] [39]
[Ni2(phtpy)2(l-Cl)2Cl2] [38]
2.3421(11)
2.3449(7)
2.3666(11)
2.5715(13)
2.6231(8)
2.5309(12)
2.4558(13)
2.3980(8)
2.4082(12)
2.2.3. M(L)X2 five-coordinate complexes
Reaction of one equivalent of with one equivalent CuSO4, Cu(OCH3CO)2,
L
Zn(OCH3CO)2, or ZnCl2 resulted in formation of the [M(L)X2] five-coordinate complexes
[Cu(L)(OSO3)(OH2)]ꢀ3H2O (5), [Cu(L)(OCH3CO)2]ꢀ4H2O (9), [Zn(L)(OCOCH3)2]ꢀCH3CN (10),
and [Zn(L)Cl2] (11), respectively.
Vapor diffusion of diethyl ether into the reaction mixture of 5 produced blue nee-
dle-shaped crystals. The structure was solved in the orthorhombic chiral space group
Pna21. X-ray quality blue-green crystals of 9 were formed by slow evaporation of its
:
reaction mixture, and the structure was solved in the triclinic space group P1 The
crystal structures of 5 and 9 are shown in Figure 4.
The Cu(II) ion in 5 is five-coordinate and has an approximately square pyramidal
geometry (s = 0.13). The axial position of the square pyramidal geometry is occupied
by the water ligand. Each hydrogen of the coordinated water molecule is hydrogen
bonded to a sulfate oxygen.
The copper center in 9 is again five-coordinate and approximately square pyram-
idal, but more distorted, with a slightly larger s value of 0.22, indicating it has more
trigonal bipyramidal character than 5. The asymmetric unit contains a copper-bound
ligand L, two copper-bound acetate ions, one water molecule and one disordered
acetonitrile molecule. The axial Cu1-O2 bond is relatively long, at 2.203(6) Å, when
compared to the equatorial Cu1-O1 bond, at 1.9142(6) Å.
X-ray quality block-shaped crystals of [Zn(L)(CH3COO)2] (10) were formed by slow
evaporation of the reaction mixture. Crystals of [Zn(L)Cl2] (11) were formed as fragile

JOURNAL OF COORDINATION CHEMISTRY
9
Figure 3. The crystal structure of [Cu2(L)2(l-Cl)2CuCl4] (6). The hydrogen atoms and solvent mole-
cules have been omitted for clarity. Thermal ellipsoids are shown at 50% probability.
plates by vapor diffusion of di-isopropyl ether into a DMF solution of a crude white
precipitate of 11.
The crystal structure of 10 was solved in the monoclinic space group P21/c, and 11
was solved in the monoclinic space group C2/c. Both are shown in Figure 5. In both
complexes, the Zn(II) is five-coordinate and geometry lies between trigonal bipyrami-
dal and square pyramidal. The s values for 10 and 11 are 0.21 and 0.41, respect-
ively [46].
In each case three coordination sites of Zn(II) are occupied by terpyridine-type
nitrogen donor of L and the remaining coordination sites are occupied either by acet-
ate ions (complex 10) or chloride ions (complex 11). In 11, the toluyl ring is disor-
dered over two positions occupying each position approximately half of the time.
2.2.4. M(L)(X)3 octahedral complexes
Reaction of one equivalent of L with one equivalent of NiCl2 in water, or CuCl2 in the
presence of the noncoordinating anion PF6ꢂ, resulted in formation of M(L)(X)3 type
octahedral complexes [Ni(L)(OH2)3]Cl2ꢀH2O (3) and [Cu(L)(OH2)2(OH)]PF6ꢀ2H2O (7),
respectively, where X is either water or hydroxide.

10
G. KAUR ET AL.
Figure 4. The crystal structures of the Cu(II) complexes [Cu(L)(OSO3)(OH2)] (5), above, and
[Cu(L)(OCOCH3)2] (9), below. All the anions are ligands in these complexes, and the solvent mole-
cules not involved in hydrogen bonding to the complex have been omitted for clarity. Thermal
ellipsoids are shown at 50% probability.
Green-blue rectangular X-ray quality crystals of 3 were formed by slow evapor-
ation of the aqueous reaction mixture, and the structure, solved in the orthorhom-
bic space group P212121, is shown in Figure 6. The geometry around Ni(II) ion is a
distorted octahedron. The Ni-O distances vary from 2.059(2) to 2.115(2) Å, with Ni-
O2 being shortest. All the water molecules and chlorides present in the lattice are
involved in a hydrogen bonding network that runs along the a-axis of the
unit cell.

JOURNAL OF COORDINATION CHEMISTRY
11
Figure 5. The X-ray crystal structures of Zn(II) complex 10 (above) and 11 (below). The solvent
molecules and hydrogens have been omitted for clarity, and the second disorder position is shown
in white. Thermal ellipsoids are shown at 50% probability.

12
G. KAUR ET AL.
Figure 6. Crystal structures of octahedral complexes of Ni(II) 3 (above) and Cu(II) 7 (below).
Hydrogens, anions, and/or solvent have been omitted for clarity, if they are not connected to the
complex by hydrogen bonding networks. Thermal ellipsoids are shown at 50% probability.
X-ray quality blue crystals of 7 were formed by vapor diffusion of diethyl ether into
an acetonitrile solution of the precipitate of 7. The crystal structure of 7 was solved in
the monoclinic space group P21/c, Figure 6.
The Cu(II) is six-coordinate and is in the center of a distorted octahedron of three
terpyridine-type nitrogens, two water ligands, and one hydroxide ion. The crystal lat-
tice also contains two solvent water molecules, with some evaporation presumably

JOURNAL OF COORDINATION CHEMISTRY
13
Figure 7. Crystal structure of [{Ag2(l-L)2(l-NO3)}n](NO3)nꢀ(CH3CN)n, an infinite spiral oriented along
the c-axis. The solvent, nitrate anions and hydrogens have been omitted for clarity. Disorder shown
in white. Thermal ellipsoids are shown at 50% probability.
accounting for the elemental analysis being consistent with the presence of only one
water molecule. The Cu1-N2 and Cu1-O3 bond lengths are shorter than other Cu-N
and Cu-O bond lengths in 7.
2.2.5. The spiral shaped Ag(I) complex
A reaction of one equivalent of L in chloroform with one equivalent of AgNO3 in etha-
nol produced thin and long needle-shaped crystalline material. The X-ray diffraction
experiment revealed a fascinating Ag(I)-L polymeric complex (Figure 7) of stoichiom-
etry [{Ag2(l-L)2(l-NO3)}n](NO3)nꢀ(CH3CN)n that was solved in the hexagonal chiral space
group P6122.
The coordination environment of 13 is shown schematically in Figure 8. In this spi-
ral complex, one terpyridine ligand bridges symmetry related two Ag(I) ions, with the
central pyridine nitrogen atom being bound to both. A nitrate ion also bridges these
Ag(I) ions. A second terpyridine ligand bridges the disilver units, with a terminal pyri-
dine nitrogen being coordinated to each unit and the central pyridine not being coor-
dinated (or at least being beyond the 2.6 Å arbitrary cut-off for bonding).
The coordination environment shown in Figure 8 essentially requires that each kind
of terpyridine ligand, L, is nonplanar and twists around the mean spiral axis to bridge
the Ag(I) centers. Each silver center has a coordination number of six, including two
nitrogens from one terpyridine ligand, one from another terpyridine ligand, two
AgꢀꢀꢀAg interactions, and a bridging nitrate ligand. The alternating silver-silver distan-
ces are 3.1479(13) Å and 2.9958(14) Å which are, respectively, the bonds bridged by a
pyridine nitrogen of the ligand and a coordinating nitrate or by the ligand alone.
These AgꢀꢀꢀAg contacts are a common feature in Ag(I) coordination chemistry [47–49].
Binding to two silver ions is unusual behavior for sp2 nitrogens. The term
“hyperdentate” has been introduced recently for such a situation where an atom binds
to more metal ions than normal [50]. To the best of our knowledge, there are only

14
G. KAUR ET AL.
Figure 8. A schematic view of the repeating unit of the spiral polymer, with the terpyridine
ligands being represented by the nitrogens joined by curves. The bottom terpyridine ligand links
the units by coordination of its terminal pyridine ligands (and is split by delineation of the repeat-
ing unit).
five examples in the literature where pyridine nitrogen bridges between two metals:
Cs [51], Mo [52], Ti [53], and Ag [54, 55]. The latter Ag(I) complex, of 40-thiomethyl-
2,20:60,200-terpyridine, is also a spiral complex. In our structure, the silver atoms define a
deeper helical spiral about the axis of the array with a displacement of 1.611 Å from
the mean spiral axis, which is significantly greater than the 0.3–0.7 Å displacement
previously reported [55].
The key Ag-N bond lengths are 2.232(3) Å (Ag1-N1), 2.641(4) Å (Ag1-N2), 2.546(3) Å
(Ag1-N3), and 2.241(3) Å (Ag1-N4). All three pyridine rings have face-face p-p stacking
with the ligands both above and below in a range of 3.4 Å to 3.6 Å. The individual ter-
pyridine units are not planar, exhibiting a dihedral angle between the terminal rings
and the central ring of 38.4ꢁ. The infinite spiral polymers have a pitch of 35.3631(4) Å
and thirteen L ligands rotate around to complete one pitch.
The spiral polymer chains are packed together in a grid, leaving inter-chain voids
that contain the noncoordinating nitrate anions (Figure 9). The nitrates and acetonitrile
molecules make both inter- and intrachain short contacts with aromatic C-H hydrogen
atoms in the 2.3–2.6 Å range.
The overall structure of the spiral was well ordered, except for the toluyl ring of L,
which was disordered over two positions with 50% occupancy in each. Both the coor-
dinated and noncoordinated nitrate anions are also disordered over two sites. The
same disorder has been seen in previous reports of similar spirals [55]. Despite the
Flack parameter being very close to 0, –0.0.027(3), the low data parameter ratio means
that the absolute chirality of the crystal cannot be reliably determined.
The bulk crystals were examined under a microscope, with a view to achieving a
manual chiral resolution similar to that used by Louis Pasteur to separate both enan-
tiomers of sodium ammonium tartrate. In our case, we were not able to distinguish
different mirror image crystals due to their thin needle shape.
The elemental analysis was consistent with an empirical formulation of [Ag(L)(NO3)],
which is consistent with the structural result, except for loss of volatile solvent, and
the ESI-MS spectrum shows m/z peaks at 430.05, 753.19, and 922.08 corresponding to
[Ag þ L]þ, [Ag þ 2L]þ, and [2Ag þ 2L þ NO3]þ but no higher oligomers were
detected by mass spectroscopy.

JOURNAL OF COORDINATION CHEMISTRY
15
Figure 9. Packing of [{Ag2(l-L)2(l-NO3)}n](NO3)nꢀ(CH3CN)n . The hydrogens have been omitted for
clarity. Thermal ellipsoids are shown at 50% probability.
3. Conclusion
In an exploration of the coordination chemistry of divalent metal ions with 40-(2-meth-
ylphenyl)-2,20:60,200-terpyridine, L, 13 new complexes of Cu(II), Ni(II), Zn(II), and Ag(I)
have been prepared and characterized using X-ray crystallography. A variety of com-
plexes with different coordination geometries was observed. A remarkable spiral-
shaped Ag(I)-L complex [{Ag2(l-L)2(l-NO3)}n](NO3)nꢀ(CH3CN)n with unusual coordination
chemistry was also isolated and characterized during this research. The nature of the
isolated products has been rationalized based on equilibrium principles and the stabil-
ity of complexes.
4. Experimental
Experimental detail for the X-ray crystallographic studies can be found in the elec-
tronic Supporting Information, along with fully labeled structural diagrams and
related tables.
4.1. 40-(2-Methylphenyl)-2,20:60,200-terpyridine, L
2-Acetylpyridine (2.4 g, 20 mmol) was added to a solution of potassium t-butoxide
(3.36 g, 30 mmol) in freshly distilled dry THF (160 mL). The resultant creamy yellow
suspension was treated with o-tolualdehyde (1.2 g, 10 mmol), and the mixture was
stirred overnight at room temperature under nitrogen. A solution of dry ammonium
acetate (15.8 g) in 2:1 ethanol:acetic acid (190 mL) was then added, and the clear
brown mixture obtained was heated at reflux for 5 h. The resulting orange-yellow
reaction mixture was cooled to room temperature and treated with ice (500 g) and

16
G. KAUR ET AL.
water (2 L) to give a yellow precipitate. The precipitate was collected by filtration.
Recrystallization from ethanol gave pure L as pale yellow crystals. Yield: 2.5 g (68%).
1
ꢁ
m.p. 146–152 C. H NMR (CDCl3): d = 8.72 (d, 2H, H6,6"), 8.71 (d, 2H, H3,3"), 8.49 (s, 2H,
H3’,5’), 7.90 (t, 2H, H4,4"), 7.30–7.36 (m, 6H, H5,5",toluyl), 2.38 (s, 3H, CH3). 13C NMR (CDCl3):
156.5, 155.6, 152.2,149.4, 139.9, 137.1, 135.4, 130.7, 129.7, 128.5, 126.2, 124.1, 121.9,
121.6, 20.7 (CH3). ESI-MS m/z: [M þ H]þ 324.13. These data are consistent with previ-
ously published data [29].
4.2. [Ni(L)2]Cl2ꢀ3H2OꢀCH3OH (1), bis[40-(2-methylphenyl)-2,20:60,200-
terpyridine]nickel(II) chloride-trihydrate-monomethanol
L (0.010 g, 0.030 mmol) was dissolved in a methanol/DCM mixture (1:1, 1.00 mL) and
the solution was added to a 1.00 mL methanolic solution of NiCl2ꢀ6H2O (0.004 g, 0.015
mmol). The mixture was heated for 10 min to remove DCM from the mixture. Vapor
diffusion of diethyl ether into the resulting green methanolic solution produced hex-
agonal orange-brown X-ray quality block-shaped crystals. Yield: 0.015 g, 80%. m.p.
>300 ꢁC. Anal. Calcd for C44H34N6NiCl2ꢀ3H2OꢀCH3OH (%): C, 62.67; H, 5.14; N, 9.74.
Found (%): C, 62.52; H, 5.48; N, 9.71; IR (neat, cmꢂ1): 3352 w, 3050 w, 1599 m, 1544 sh,
1514 m, 1489 sh, 1473 m, 1415 m, 1344 s, 1218 s, 1158 m, 1111 w, 1097 w, 1081 w,
1014 m, 910 s, 849 m, 797 s,763 s, 749 s, 739 s, 725 sh, 654 m, 573 w, 532 w, 450 w,
419 s. ESI-MS (CH3OH): m/z [Ni þ 2L]2þ 352.10. Crystal data for 1: monoclinic, space
group C2/c (no. 15), a = 22.6980(4) Å, b = 9.7960(2) Å, c = 20.4797(4) Å, b =
95.3294(18)ꢁ, V = 4533.96(16) Å3, Z = 4, T = 120.01(10) K, l(Cu-Ka) = 2.141 mmꢂ1, Dcalc
= 1.337 g/cm3, 8667 reflections measured (7.824ꢁ ꢃ 2H ꢃ 147.538ꢁ), 4436 unique (Rint
= 0.0302, Rsigma = 0.0392) which were used in all calculations. The final R1 was 0.0413
(I > 2r(I)) and wR2 was 0.1118 (all data).
4.3. [Ni2(L)2(l-Cl)2Cl2]ꢀCH3OHꢀ4H2O (2), di-l-chloridodichloridobis{[40-(2-
methylphenyl)-2,20:60,200-terpyridine]nickel(II)}-tetrahydrate-monomethanol
L (0.010 g, 0.030 mmol) was dissolved in 1.00 mL methanol/DCM mixture and then a
1.00 mL methanolic solution of NiCl2ꢀ6H2O (0.007 g, 0.030 mmol) was added, followed
by two drops of saturated NaCl(aq). The mixture was heated to remove DCM. Slow
evaporation of the resulting green solution produced X-ray quality crystals as green
rectangular blocks. Yield: 0.009 g, 75%. m.p. >300 ꢁC. Anal. Calcd for
C44H34N6Ni2Cl4ꢀCH3OHꢀ4H2O (%): C, 53.51; H, 4.59; N, 8.32. Found (%): C, 53.37; H, 4.53;
N, 8.29. IR (neat, cmꢂ1): 3340 w, 3051 w, 1600 s, 1570 wsh, 1470 m, 1413 m, 1302 w,
1244 m, 1157 w, 1015 s, 897 w, 843 w, 797 s, 763, s, 739 m, 641 m, 556 w, 510 w, 452
w, 423 m. ESI-MS (CH3OH): m/z [Ni þ L]2þ 190.53. Crystal data for 2: triclinic, space
group P-1 (no. 2), a = 8.3231(6) Å, b = 8.4401(5) Å, c = 18.0115(13) Å, a = 96.932(6)ꢁ, b
= 95.135(6)ꢁ, c = 106.782(6)ꢁ, V = 1192.18(15) Å3, Z = 1, T = 120.01(10) K, l(Cu-Ka) =
3.446 mmꢂ1, Dcalc = 1.440 g/cm3, 7418 reflections measured (9.98ꢁ ꢃ 2H ꢃ 147.884ꢁ),
4481 unique (Rint = 0.0573, Rsigma = 0.0885) which were used in all calculations. The
final R1 was 0.0655 (I > 2r(I)) and wR2 was 0.1948 (all data).

JOURNAL OF COORDINATION CHEMISTRY
17
4.4. Alternative method for both complexes 1 and 2
L (0.010 g, 0.030 mmol) was dissolved in 2.00 mL methanol/DCM mixture and then a
2.00 mL methanolic solution of NiCl2ꢀ6H2O (0.007 g, 0.003 mmol) was added. The mix-
ture was heated for 10 min to remove DCM from the mixture. Vapor diffusion of
diethyl ether into the resulting green methanolic solution produced both hexagonal
orange-brown plates of 1 and green rectangular blocks of 2 that could be manu-
ally separated.
4.5. [Ni(L)(OH2)3]Cl2ꢀH2O (3), triaqua[40-(2-methylphenyl)-2,20:60,200-
terpyridine]nickel(II) trichloride—monohydrate
L (0.010 g, 0.030 mmol) was dissolved in a 1.00 mL methanol/DCM mixture and added
to a 1.00 mL aqueous solution of NiCl2ꢀ6H2O (0.007 g, 0.030 mmol). The green filtrate
was allowed to evaporate slowly, and pale green blue rectangular X-ray quality crystals
ꢁ
were formed over a period of 10 days. Yield: 0.008 g, 50%. m.p. 220 –225 C. Anal.
Calcd for C22H23N3NiO3Cl2ꢀH2O (%): C, 50.33; H, 4.80; N, 8.00. Found (%): C, 50.06; H,
4.87; N, 8.26. IR (neat, cmꢂ1): 3361 w, 3051 w, 1620 m, 1519 m, 1475 w, 1465 m, 1419
m, 1349 s, 1217 s, 1153 m, 1097 w, 1081 w, 1014 m, 910 s, 849 m, 797 s,763 s, 749 s,
739 s, 728 s, 657 m, 575 w, 535 w, 441 w, 413 m. ESI-MS (CH3CN): m/z [Ni þ L þ
CH3CN]2þ 211.05. Crystal data for 3: orthorhombic, space group P212121 (no. 19), a =
8.1847(2) Å, b = 16.6365(4) Å, c = 16.9751(4) Å, V = 2311.40(10) Å3, Z = 4, T =
120.01(10) K, l(Mo-Ka) = 1.105 mmꢂ1, Dcalc = 1.509 g/cm3, 13,909 reflections meas-
ured (5.388ꢁ ꢃ 2H ꢃ 70.24ꢁ), 9048 unique (Rint = 0.0251, Rsigma = 0.0472) which were
used in all calculations. The final R1 was 0.0361 (I > 2r(I)) and wR2 was 0.0801
(all data).
4.6. [Ni(L)2]Br2ꢀ3H2O (4), bis[40-(2-methylphenyl)-2,20:60,200-terpyridine]nickel(II)
bromide—trihydrate
L (0.010 g, 0.030 mmol) was dissolved in 1.00 mL methanol/DCM mixture and added
to a 1.00 mL methanolic solution of NiBr2ꢀ3H2O (0.004 g, 0.015 mmol). Vapor diffusion
of diethyl ether into the resulting green solution produced hexagonal orange-brown
X-ray quality plates. Yield: 0.020 g, 85%. m.p. >300 ꢁC. Anal. Calcd for
C44H34N6NiBr2ꢀ3H2O (%): C, 57.47; H, 4.38; N, 9.14. Found (%): C, 57.54; H, 4.50; N, 9.26.
IR (net) (m, cmꢂ1): 3383 w, 3050 w, 1598 m, 1543 sh, 1515 m, 1492 sh, 1472 m, 1415 s,
1348 m, 1245 m, 1156 m, 1112 m, 1096 w, 1052 w, 1013 m, 969 sh, 898 m, 797 s, 763
s, 738 s, 725 sh, 654 m, 629 m, 580 w, 556 w, 510 w, 452 w, 419 s. ESI-MS (CH3OH): m/
z [Ni þ 2L]2þ 352.10. Crystal data for 4: monoclinic, space group P21/n (no. 14), a =
12.51071(12) Å, b = 16.10999(19) Å, c = 21.8761(2) Å, b = 93.8168(10)ꢁ, V = 4399.30(8)
Å3, Z = 4, T = 120.02(10) K, l(Cu-Ka) = 3.035 mmꢂ1, Dcalc = 1.306 g/cm3, 44,242 reflec-
tions measured (6.82ꢁ ꢃ 2H ꢃ 147.554ꢁ), 8758 unique (Rint = 0.0385, Rsigma = 0.0240)
which were used in all calculations. The final R1 was 0.0538 (I > 2r(I)) and wR2 was
0.1587 (all data).

18
G. KAUR ET AL.
4.7. [Cu(L)(OSO3)(OH2)]ꢀ3H2O (5), aqua[40-(2-methylphenyl)-2,20:60,200-
terpyridine](sulfato)copper(II)—trihydrate
L (0.037 g, 0.11 mmol) was dissolved in 1.00 mL methanol/DCM mixture and added to
a 1.00 mL methanolic solution of CuSO4 (0.018 g, 0.11 mmol). The blue green solution
ꢁ
was heated for 10 min at 40 C. Vapor diffusion of diethyl ether into the filtered blue
green reaction mixture produced thin needle-shaped X-ray quality crystals. Yield: 0.055
ꢁ
g, 85%. m.p. 240–244 C. Anal. Calcd for C22H19N3CuSO5ꢀ3H2O (%): C, 47.61; H, 4.54; N,
7.57. Found (%): C, 47.60; H, 4.62; N, 7.23. IR (neat, cmꢂ1): 3050 w, 2160 w, 2080 w,
1687 m, 1604 m, 1462 m, 1433 m, 1245 w, 1145 m, 1108 w, 1051 w, 1028 m, 995 m,
838 s, 801 msh, 639 w, 556 s, 479 w, 419 m. ESI-MS (CH3OH): m/z [Cu þ L]2þ 193.04.
Crystal data for 5: orthorhombic, space group Pna21(no. 33), a = 16.4460(10) Å, b =
19.2279(13) Å, c = 7.3351(4) Å, V = 2319.5(2) Å3, Z = 4, T = 120.01(10) K, l(Cu-Ka) =
2.706 mmꢂ1, Dcalc = 1.641 g/cm3, 9959 reflections measured (7.072ꢁ ꢃ 2H ꢃ
148.238ꢁ), 4225 unique (Rint = 0.0527, Rsigma = 0.0494) which were used in all calcula-
tions. The final R1 was 0.0668 (I > 2r(I)) and wR2 was 0.2109 (all data).
4.8. [Cu2(L)2(l-Cl)2CuCl4]ꢀ2H2O (6), di-l-chlorido-1:2jCl,2:3jCl-tetrachlorido-
1jCl,3j3Cl-[40-(2-methylphenyl)-2,20:60,200-terpyridine-1j3N][40-(2-
methylphenyl)-2,20:60,200-terpyridine-2j3N]tricopper(II)—dihydrate
L (0.010 g, 0.030 mmol) was dissolved in a 1.00 mL methanol/DCM mixture and added
dropwise to 1.00 mL methanolic solution of CuCl2ꢀ2H2O (0.033 g, 0.020 mmol). The
resulting solution was heated at reflux for 30 min and then DCM was evaporated by
further heating. The methanolic green reaction mixture was cooled to room tempera-
ture and vapor diffusion of diethyl ether into the solution produced X-ray quality
green needle-shaped crystals. Slow evaporation of the resulting solution produced fur-
ꢁ
ther crystals over a period of two weeks. Yield: 0.020 g, 90%. m.p. 210 –213 C. Anal.
Calcd for C44H34N6Cu3Cl6ꢀ2H2O (%): C, 48.65; H, 3.53; N, 7.74. Found (%): C, 48.33; H,
3.26; N, 7.89. IR (neat, cmꢂ1): 3339 w, 3063 w, 1598 s, 1539 m, 1470 w, 1403 w, 1359
s, 1298 w, 1234 m, 1160 w, 1119 w, 1020 s, 906 w, 867 w, 761 s, 732 w, 694 w, 441 w,
418 m. ESI-MS (CH3OH): m/z [(Cu þ L þ Cl]þ 421.04, [Cu þ L]2þ 193.04. UV-vis
(CH3CN): kmax = 720, 435, 345, 330, 288, 278, 266, 220 nm. Crystal data for 6: triclinic,
space group P-1 (no. 2), a = 10.0354(4) Å, b = 11.0653(4) Å, c = 22.0881(7) Å, a =
98.167(3)ꢁ, b = 101.713(3)ꢁ, c = 98.340(3)ꢁ, V = 2338.77(14) Å3, Z = 2, T = 120.01(10) K,
l(Cu-Ka) = 5.711 mmꢂ1, Dcalc = 1.604 g/cm3, 18,915 reflections measured (8.206ꢁ ꢃ
2H ꢃ 147.462ꢁ), 9149 unique (Rint = 0.0534, Rsigma = 0.0567) which were used in all
calculations. The final R1 was 0.0669 (I > 2r(I)) and wR2 was 0.1999 (all data).
4.9. [Cu(L)(OH2)2(OH)]PF6ꢀH2O (7), diaquahydroxido[40-(2-methylphenyl)-
2,20:60,200-terpyridine]copper(II) hexafluoridophosphate—monohydrate
L (0.030 g, 0.10 mmol) was dissolved in a small amount of DCM/methanol mixture and
then a 1.00 mL methanolic solution of CuCl2ꢀ2H2O (0.015 g, 0.10 mmol) was added.
The mixture was heated to remove any DCM present. Addition of a few drops of satu-
rated aqueous ammonium hexafluoridophosphate resulted in formation of a green

JOURNAL OF COORDINATION CHEMISTRY
19
precipitate, which was filtered and washed with methanol and ether. Vapor diffusion
of ether to an acetonitrile solution of the precipitate produced X-ray quality crystals.
Yield: 0.019 g, 40%. m.p. 225–228 ꢁC. Anal. Calcd for C22H22N3CuO3PF6ꢀH2O (%): C,
43.82; H, 4.01; N, 6.97. Found (%): C, 43.82; H, 4.25; N, 7.10. IR (neat, cmꢂ1): 3501 w,
3083 w, 2163 w, 2083 w, 1608 s, 1573 m, 1557 w, 1478 m, 1420 m, 1247 m, 1021bs,
790 s, 632 w, 520 w, 419 m. ESI-MS (CH3OH): m/z [Cu þ L]2þ 193.04. Crystal data for 7:
monoclinic, space group P21/c (no. 14), a = 12.7656(3) Å, b = 7.53655(11) Å, c =
25.5833(4) Å, b = 94.4076(16)ꢁ, V = 2454.06(7) Å3, Z = 4, T = 120.0(2) K, l(Cu-Ka) =
2.669 mmꢂ1, Dcalc = 1.681 g/cm3, 17,298 reflections measured (6.93ꢁ ꢃ 2H ꢃ
147.706ꢁ), 4887 unique (Rint = 0.0324, Rsigma = 0.0266) which were used in all calcula-
tions. The final R1 was 0.0897 (I > 2r(I)) and wR2 was 0.2465 (all data).
4.10. [Cu(L)2](OTf)2ꢀH2O (8), bis[40-(2-methylphenyl)-2,20:60,200-
terpyridine]copper(II) bis(trifluoromethanesulfonate)—monohydrate
L (0.010 g, 0.030 mmol) was dissolved in 1.00 mL DCM/methanol mixture and then
Cu(OTf)2 (0.006 g, 0.015 mmol) was added slowly. The mixture was heated for 10
mins, filtered, and slow evaporation of solvent produced very thin overlapped plates
of crystals. X-ray quality crystals were carefully collected from the bulk. Yield: 0.013 g,
ꢁ
80%. m.p. >300 C. Anal. Calcd for C44H34N6Cu(CF3SO3)2ꢀH2O (%): C, 53.83; H, 3.53; N,
8.19. Found (%): C, 53.88; H, 3.50; N, 8.20. IR (neat, cmꢂ1): 3063 w, 2164 w, 1598 m,
1573 w, 1544 w, 1544 w, 1416 m, 1258 s, 1222 wsh, 1145 s, 1055 s, 929 w, 891 w, 844
m, 794 m, 632 s, 571 m, 515 m, 454 w, 413 m. ESI-MS (CH3OH): m/z [Cu þ 2L]2þ
354.60. UV-vis (CH3CN): kmax = 680, 285, 276, 267, 226, 213 nm. Crystal data for 8:
monoclinic, space group P21/c (no. 13), a = 12.8715(2) Å, b = 9.5562(2) Å, c =
35.9916(6) Å, b = 90.0382(19)ꢁ, V = 4427.04(15) Å3, Z = 4, T = 120.00(10) K, l(Cu-Ka) =
1.622 mmꢂ1, Dcalc = 1.288 g/cm3, 18,833 reflections measured (6.868ꢁ ꢃ 2H ꢃ
133.994ꢁ), 7215 unique (Rint = 0.0212, Rsigma = 0.0249) which were used in all calcula-
tions. The final R1 was 0.0701 (I > 2r(I)) and wR2 was 0.2243 (all data).
4.11. [Cu(L)(OAc)2]ꢀ4H2O (9), diacetato[40-(2-methylphenyl)-2,20:60,200-
terpyridine]copper(II)—tetrahydrate
L (0.016 g, 0.049 mmol) was dissolved in 1.00 mL chloroform and then added drop-
wise to a 1.00 mL methanolic solution of Cu(OCOCH3)2 (0.015 g, 0.049 mmol) while
ꢁ
stirring. The resulting blue green mixture was heated for 1 h at 35 C and then aceto-
nitrile (5 mL) was added. Slow evaporation of the solvent overnight produced X-ray
quality blue-green crystals. Yield: 0.020 g, 55%. m.p. 230–233 ꢁC. Anal. Calcd for
C26H23N3CuO4ꢀ4H2O (%): C, 54.11; H, 5.41; N, 7.28. Found (%): C, 54.34; H, 5.27; N, 7.30.
IR (neat, cmꢂ1): 3383 w, 3079 w, 2160 w, 1603 m, 1547 s, 1476 m, 1392 s, 1340 m,
1305 w, 1264 w, 1166 w, 1021 s, 1893 w, 763 s, 736 s, 640 m, 571 s, 421 w, 421 m.
ESI-MS (CH3CN): m/z [(Cu þ L þ CH3CN]þ 427.10, [Cu þ L þ CH3CN]2þ 213.54. UV-vis
(CH3CN): kmax = 680, 285, 275, 267, 226, 213 nm. Crystal data for 9: triclinic, space
group P-1 (no. 2), a = 7.9373(3) Å, b = 12.2403(5) Å, c = 15.0665(5) Å, a = 111.035(4)ꢁ,
b = 103.434(3)ꢁ, c = 92.943(3)ꢁ, V = 1314.15(9) Å3, Z = 2, T = 120.01(10) K, l(Mo-Ka) =

20
G. KAUR ET AL.
0.877 mmꢂ1, Dcalc = 1.426 g/cm3, 18,076 reflections measured (5.336ꢁ ꢃ 2H ꢃ
65.998ꢁ), 9892 unique (Rint = 0.0258, Rsigma = 0.0485) which were used in all calcula-
tions. The final R1 was 0.0474 (I > 2r(I)) and wR2 was 0.1257 (all data).
4.12. [Zn(L)(OAc)2]ꢀCH3CN (10), diacetato[40-(2-methylphenyl)-2,20:60,200-
terpyridine]zinc(II)—monoacetonitrile
L (0.013 g, 0.040 mmol) in 0.5 mL DCM was mixed with a methanol:acetonitrile solu-
tion (1:1, 2 mL) of Zn(OCH3CO)2ꢀ2H2O (0.0084 g, 0.040 mmol). The mixture was heated
for 15 mins and filtered. Slow evaporation of the solvents produced X-ray quality crys-
ꢁ
tals over a period of one week. Yield: 0.008 g, 50%. m.p. 258–261 C. Anal. Calcd for
C26H23N3O4ZnꢀCH3CN (%): C, 61.38; H, 4.78; N, 10.23. Found (%): C, 61.68; H, 4.62; N,
1
10.13. H NMR (CD3CN): 2.11 (s, 6H), 2.62 (s, 3H), 7.43 (m, 2H), 7.57 (m, 3H), 7.66 (d,
1H), 7.91 (d, 2H), 8.15 (t, 2H), 8.62 (d, 2H), 8.77 (s, 2H). 13C NMR (CD3CN): 158.03,
149.31, 148.13, 147.91, 141.27, 137.52, 135.71, 131.21, 129.99, 129.63, 127.52, 126.63,
124.22, 123.18, 29.89, 19.52. IR (neat, cmꢂ1): 3395 w, 3059 w, 2979 w, 2244 w, 1730 w,
1594 s, 1547 m, 1475 w, 1372 s, 1249 m, 1150 m, 1047 w, 1023 s, 922 w, 843 m, 795
m, 764 m, 692 s, 657 m, 637 msh, 452 w, 412 m. ESI-MS (CH3CN): m/z [Zn þ L]2þ
193.53. Crystal data for 10: monoclinic, space group P21/c (no. 14), a = 14.5206(3) Å, b
= 8.80580(10) Å, c = 21.2298(4) Å, b = 106.854(2)ꢁ, V = 2597.96(8) Å3, Z = 4, T =
119.99(10) K, l(Cu-Ka) = 1.625 mmꢂ1, Dcalc = 1.348 g/cm3, 27,187 reflections measured
(6.36ꢁ ꢃ 2H ꢃ 148.994ꢁ), 5231 unique (Rint = 0.0303, Rsigma = 0.0205) which were
used in all calculations. The final R1 was 0.0444 (I > 2r(I)) and wR2 was 0.1395
(all data).
4.13. [Zn(L)Cl2] (11), dichlorido[40-(2-methylphenyl)-2,20:60,200-
terpyridine]zinc(II)
L (0.106 g, 0.32 mmol) dissolved in 1.00 mL DCM/methanol was added dropwise to a
1.00 mL methanolic solution of ZnCl2ꢀ2H2O (0.044 g, 0.32 mmol). The mixture was
ꢁ
heated to 35 C for 5 min. A white precipitate formed upon cooling the mixture to
room temperature. The precipitate was filtered and dissolved in hot DMF. Over a
period of 2 days, vapor diffusion of di-isopropyl ether into the DMF solution produced
ꢁ
fragile X-ray quality colorless plates. Yield: 0.096 g, 65%. m.p. 272–275 C. Elemental
analysis: Anal. Calcd for C22H17N3ZnCl2 (%): C, 57.48; H, 3.73; N 9.14. Found (%): C,
1
57.46; H, 3.69; N, 9.24. H NMR (DMSO): 2.41 (s, 3H), 7.43 (m, 3H), 7.52 (d, 1H), 7.86 (t,
2H), 8.26 (t, 2H), 8.83 (d, 6H). IR (neat, cmꢂ1): 3453 w, 3070 w, 2163 w, 1655 s, 1611 w,
1597 s, 1570 m, 1547 m, 1494 m, 1457 m, 1437 s, 1410 s, 1387 m, 1292 s, 1245 w,
1162 w, 1096 m, 1011 s, 953 w, 798 m, 764 m, 733 w, 692 m, 657 m, 511 w, 412 m.
ESI-MS (CH3CN): m/z [Zn þ L þ Cl]þ 422.0397. Crystal data for 11: monoclinic, space
group C2/c (no. 15), a = 11.0423(6) Å, b = 13.5298(6) Å, c = 13.1986(7) Å, b =
100.126(5)ꢁ, V = 1941.15(18) Å3, Z = 4, T = 120.02(10) K, l(CuKa) = 4.385 mmꢂ1, Dcalc
= 1.573 g/cm3, 5785 reflections measured (10.44ꢁ ꢃ 2H ꢃ 148.818ꢁ), 1874 unique (Rint
= 0.0338, Rsigma = 0.0316) which were used in all calculations. The final R1 was 0.0492
(I > 2r(I)) and wR2 was 0.1357 (all data).

JOURNAL OF COORDINATION CHEMISTRY
21
4.14. [Zn(L)2](NO3)2 (12), bis[40-(2-methylphenyl)-2,20:60,200-
terpyridine]copper(II) bis(nitrate)
Zn(NO3)2ꢀ6H2O (0.004 g, 0.015 mmol) dissolved in 1.00 mL methanol was added drop-
wise to a 1.00 mL hot methanolic solution of L (0.010 g, 0.030 mmol). The resulting
ꢁ
solution was heated at 35 C to remove DCM. Vapor diffusion of diethyl ether to the
resulting solution produced a very small quantity of X-ray quality irregular shaped
crystals. IR (neat, cmꢂ1): 3455 w, 3069 w, 1625 s, 1558 s, 1493 s, 1328 s, 1248 m, 1163
s, 1100 m, 1017 s, 896 m, 790 m, 733 w, 511 w, 419 m. ESI-MS (CH3CN): m/z [Zn þ
2L]2þ 355.10. Crystal data for 12: orthorhombic, space group Fddd (no. 70), a =
8.8748(2) Å, b = 22.9788(5) Å, c = 48.4764(13) Å, V = 9885.9(4) Å3, Z = 8, T =
120.02(10) K, l(Cu-Ka) = 1.091 mmꢂ1, Dcalc = 1.124 g/cm3, 11411 reflections measured
(8.516ꢁ ꢃ 2H ꢃ 147.594ꢁ), 2474 unique (Rint = 0.0209, Rsigma = 0.0131) which were
used in all calculations. The final R1 was 0.0605 (I > 2r(I)) and wR2 was 0.1686
(all data).
4.15. [{Ag2(l-L)2(l-NO3)}n](NO3)n (13), poly{[l-40-(2-methylphenyl)-2,20:60,200-
terpyridine-1jN1:1jN2:2jN2:2jN3][l-40-(2-methylphenyl)-2,20:60,200-terpyridine-
10jN1:2jN3](l-nitrato-1jO1:2jO2)disilver(I) nitrate}
L (0.010 g, 0.030 mmol) was dissolved in 1.00 mL chloroform. Dropwise addition of an
ethanolic solution of AgNO3 (0.005 g, 0.030 mmol, 1.00 mL) under dark conditions pro-
duced a white fibrous precipitate. The precipitate was filtered and dissolved in 1 mL
of acetonitrile. Vapor diffusion of di-isopropyl ether into the resulting solution pro-
duced colorless needle-shaped crystals of the polymeric compound. Yield: 0.011 g,
ꢁ
70%. m.p. 123–125 C. Anal. Calcd for AgC22H17N4O3 (%): C, 53.57; H, 3.47; N, 11.36.
1
Found: C, 53.68; H, 3.50; N, 11.24. H NMR (CD3CN) 2.42 (s, 3H), 7.45 (m, 4H), 7.55 (t,
2H), 8.20 (t, 2H), 8.26 (s, 2H), 8.30 (d, 2H), 8.59 (d, 2H). IR (neat, cmꢂ1): 3439 w, 3018 w,
2251 w, 1754 s, 1602 w, 1567 w, 1539 w, 1518 m, 1333 bs, 1242 w, 1190 w, 1099 w,
1006 m, 885 w, 787 m, 745 s, 684 w, 633 w, 504 m, 419 m. ESI-MS (CH3CN): m/z [Ag þ
L]þ 430.05, [Ag þ 2L]þ 753.19, [2Ag þ 2L þ NO3]þ 922.08. Crystal data for 13: hex-
agonal, space group P6122 (no. 178), a = 14.82062(15) Å, c = 35.3631(4) Å, V =
6726.87(15) Å3, Z = 12, T = 120.01(10) K, l(Cu-Ka) = 7.519 mmꢂ1, Dcalc = 1.583 g/cm3,
34,286 reflections measured (6.886ꢁ ꢃ 2H ꢃ 148.824ꢁ), 4570 unique (Rint = 0.0372,
Rsigma = 0.0189) which were used in all calculations. The final R1 was 0.0223 (I > 2r(I))
and wR2 was 0.0604 (all data).
Disclosure statement
No potential conflict of interest was reported by the author(s).
References
[1] S.G. Morgan, F.H. Burstall. J. Chem. Soc., 20 (1932).
[2] H. Hofmeier, U.S. Schubert. Chem. Soc. Rev., 33, 373 (2004).
[3] U.S. Schubert, C. Eschbaumer, O. Hien, P.R. Andres. Tetrahedron Lett., 42, 4705 (2001).

22
G. KAUR ET AL.
€
[4] A. Wild, S. Hornig, F. Schlutter, J. Vitz, C. Friebe, M.D. Hager, A. Winter, U.S. Schubert.
Macromol Rapid Commun., 31, 921 (2010).
[5] J.K. Bashkin, L.A. Jenkins. J. Chem. Soc. Dalton Trans., 3631 (1993).
[6] L.A. Jenkins, J.K. Bashkin, J.D. Pennock, J. Florian, A. Warshel. Inorg. Chem., 38, 3215
(1999).
[7] C. Bazzicalupi, A. Bencini, A. Bianchi, A. Danesi, E. Faggi, C. Giorgi, S. Santarelli, B.
Valtancoli. Coord. Chem. Rev., 252, 1052 (2008).
[8] P.E. Jurek, A.E. Martell. Inorg. Chem., 38, 6003 (1999).
[9] E.C. Constable. Chem. Soc. Rev., 36, 246 (2007).
[10] E.C. Constable. Coord. Chem. Rev., 252, 842 (2008).
[11] E.C. Constable, A.H. Redondo, C.E. Housecroft, M. Neuburger. Inorg. Chem. Commun., 13,
70 (2010).
[12] J. Husson, M. Knorr. J. Heterocycl. Chem., 49, 453 (2012).
[13] A. Winter, S. Hoeppener, G.R. Newkome, U.S. Schubert. Adv. Mater. (Weinheim)., 23, 3484
(2011).
[14] C. Haensch, M. Chiper, C. Ulbricht, A. Winter, S. Hoeppener, U.S. Schubert. Langmuir, 24,
12981 (2008).
[15] I.M. Henderson, R.C. Hayward. Polym. Chem., 3, 1221 (2012).
[16] T. Konno, K. Koide, T. Ishida. Chem. Commun. (Camb.), 49, 5156 (2013).
[17] R. Siebert, F. Schluetter, A. Winter, M. Presselt, H. Goerls, U.S. Schubert, B. Dietzek, J.
Popp. Cent. Eur. J. Chem., 9, 990 (2011).
[18] N. Tuccitto, I. Delfanti, V. Torrisi, F. Scandola, C. Chiorboli, V. Stepanenko, F. Wuerthner, A.
Licciardello. Phys. Chem. Chem. Phys., 11, 4033 (2009).
[19] A. Winter, M.D. Hager, G.R. Newkome, U.S. Schubert, Adv. Mater. (Weinheim), 23, 5728
(2011).
[20] Y. Gao, D. Rajwar, A.C. Grimsdale. Macromol. Rapid Commun., 35, 1727 (2014).
[21] U.S. Schubert, H. Hofmeier, G.R. Newkome, Modern Terpyridine Chemistry, pp. 1–6, Wiley-
VCH Verlag GmbH & Co. KGaA, Hoboken, NJ (2006).
[22] C. Kaes, A. Katz, M.W. Hosseini. Chem. Rev., 100, 3553 (2000).
[23] B. Tang, F. Yu, P. Li, L. Tong, X. Duan, T. Xie, X. Wang. J. Am. Chem. Soc., 131, 3016
(2000).
[24] S. Wang, B.-D. Li, R.-Y. Wang, B.-L. Wu, H.-Y. Zhang. Synth. React. Inorg., Met. Org. Nano
Met. Chem., 39, 355 (2009).
[25] E.C. Constable, J.M. Holmes, R.C.S. McQueen. J. Chem. Soc. Dalton Trans., 5 (1987).
[26] R. Zibaseresht, R.M. Hartshorn. Dalton Trans., 3898 (2005).
[27] J.S. Field, R.J. Haines, D.R. McMillin, G.C. Summerton. J. Chem. Soc. Dalton Trans., 1369
(2002).
[28] G. Kaur, M.I.J. Polson, R.M. Hartshorn. Dalton Trans., 44, 4200 (2015).
[29] P.A. Thornley, J.C. Starkey, R. Zibaseresht, M.I.J. Polson, J.L. Wikaira, R.M. Hartshorn. J.
Coord. Chem., 64, 145 (2011).
[30] E.C. Constable, B. Kariuki, A. Mahmood. Polyhedron, 22, 687 (2003).
[31] E.C. Constable, J. Lewis, M.C. Liptrot, P.R. Raithby. Inorg. Chim. Acta, 178, 47 (1990).
[32] A.T. Baker, H.A. Goodwin. Aust. J. Chem., 38, 207 (1985).
[33] G.-J. Chen, Z.-G. Wang, Y.-Y. Kou, J.-L. Tian, S.-P. Yan. J. Inorg. Biochem., 122, 49 (2013).
[34] B.N. Figgis, E.S. Kucharski, A.H. White. Aust. J. Chem., 36, 1563 (1983).
[35] B.N. Figgis, E.S. Kucharski, A.H. White. Aust. J. Chem., 36, 1537 (1983).
[36] M.I. Arriortua, T. Rojo, J.M. Amigo, G. Germain, J.P. Declercq. Bull. Soc. Chim. Belg., 91, 337
(1982).
[37] K.V. Reddy, T. Satyanarayana, N.R. Anipindi, R.N. Reddy. Oxid. Commun., 34, 38 (2011).
[38] E.C. Constable, D. Phillips, P.R. Raithby. Inorg. Chem. Commun., 5, 519 (2002).
[39] Y.-L. Chen, B.-Z. Li, P. Yang, J.-Z. Wu. Acta Crystallogr., Sect. C, 65, m238 (2009).
[40] G. Aullon, D. Bellamy, A. Guy Orpen, L. Brammer, A.B. Eric. Chem. Commun., 653 (1998).
[41] N. Baidya, M. Olmstead, P.K. Mascharak. Inorg. Chem., 30, 929 (1991).

JOURNAL OF COORDINATION CHEMISTRY
23
ꢀ
ꢀ
[42] R. Cortes, M.I. Arriortua, T. Rojo, D. Beltran, T. Debaerdemaeker. Transit. Met. Chem., 11,
238 (1986).
[43] R. Cortes, M.I. Arriortua, T. Rojo, X. Solans, C. Miravitlles, D. Beltran. Acta Crystallogr., Sect.
C, 41, 1733 (1985).
[44] R. Cortes, L. Lezama, J.I.R. Larramendi, M. Insausti, J.V. Folgado, G. Madariaga, T. Rojo. J.
Chem. Soc. Dalton Trans., 2573 (1994).
[45] M. G. Barandika, R. Cortes, L. Lezama, M. K. Urtiaga, M. I. Arriortua, T. Rojo. J. Chem. Soc.
Dalton Trans., 2971 (1999).
[46] A.W. Addison, T.N. Rao, J. Reedijk, J. Van Rijn, G.C. Verschoor. J. Chem. Soc., Dalton Trans.,
1349 (1984).
[47] E.C. Constable, A.J. Edwards, G.R. Haire, M.J. Hannon, P.R. Raithby. Polyhedron, 17, 243
(1997).
[48] M. Munakata, L.P. Wu, K. Sugimoto, T. Kuroda-Sowa, M. Maekawa, Y. Suenaga, N. Maeno,
M. Fujita. Inorg. Chem., 38, 5674 (1999).
[49] M.A. Omary, T.R. Webb, Z. Assefa, G.E. Shankle, H.H. Patterson. Inorg. Chem., 37, 1380
(1998).
[50] R. Puttreddy, P.J. Steel. CrystEngComm, 16, 556 (2014).
[51] G.W. Rabe, H. Heise, G.P.A. Yap, L.M. Liable-Sands, I.A. Guzei, A.L. Rheingold. Inorg. Chem.,
37, 4235 (1998).
[52] M.G.B. Drew, P.C.H. Mitchell, A.R. Read. J. Chem. Soc. Chem. Commun., 238 (1982).
[53] T.J. Boyle, L.A.M. Ottley, S.M. Hoppe, C.F. Campana. Inorg. Chem., 49, 10798 (2010).
[54] G.A. Bowmaker, Effendy, P.J. Harvey, P.C. Healy, B.W. Skelton, A.H. White. J. Chem. Soc.
Dalton Trans., 2459 (1996).
[55] M.J. Hannon, C.L. Painting, E.A. Plummer, L.J. Childs, N.W. Alcock. Chemistry 8, 2225
(2002).