1D hydrogen-bonded infinite chains from tetraaza macrocycle nickel(II) complexes and ligands

Article abstract of DOI:10.1016/j.poly.2017.02.024

The reaction of square planar complex [Ni(L2)]Cl₂·2H₂O (L2?=?3,14-diethyl-2,6,13,17-tetraazatricyclo[14,4,0^1.18,0^7.12]docosane) with ligands KNCS and H₂cpdc generates 1D hydrogen-bonded infinite chains [Ni(L2)(NCS)₂] (1) and [Ni(L2)(H-cpdc)₂] (2) (H₂cpdc?=?cyclopropanedicarboxylic acid). These compounds have been characterized by X-ray crystallography, spectroscopic, cyclic voltammetry and thermogravimetry. The crystal structures of compounds 1 and 2 show that each nickel(II) centre has an elongated distorted octahedral geometry with the axial ligands. Electronic spectra and redox potentials of the complexes 1 and 2 exhibit a high-spin octahedral environment, which is reflected by the nature of the axial ligands. The TGA behaviors of two compounds 1 and 2 are also significantly affected by the nature of the axial ligands.

Full text of DOI:10.1016/j.poly.2017.02.024

Accepted Manuscript
1D Hydrogen-bonded infinite chains from tetraaza macrocycle nickel(II) com-
plexes and ligands
In-Taek Lim, Ki-Young Choi
PII:
S0277-5387(17)30144-4
DOI:
http://dx.doi.org/10.1016/j.poly.2017.02.024
POLY 12491
Reference:
Polyhedron
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15 February 2017
15 February 2017
Please cite this article as: I-T. Lim, K-Y. Choi, 1D Hydrogen-bonded infinite chains from tetraaza macrocycle
nickel(II) complexes and ligands, Polyhedron (2017), doi: http://dx.doi.org/10.1016/j.poly.2017.02.024
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1D Hydrogen-bonded infinite chains from tetraaza macrocycle nickel(II)
complexes and ligands
In-Taek Lima, Ki-Young Choia*
a Department of Chemistry Education, Kongju National University, Kongju 314-701, Korea
Abstract
The reaction of square planar complex [Ni(L2)]Cl2·2H2O (L2
= 3,14-diethyl-2,6,13,17-
tetraazatricyclo[14,4,01.18,07.12]docosane) with ligands KNCS and H2cpdc generates 1D hydrogen-bonded
infinite chains [Ni(L2)(NCS)2] (1) and [Ni(L2)(H-cpdc)2] (2) (H2cpdc = cyclopropanedicarboxylic acid).
These compounds have been characterized by X-ray crystallography, spectroscopic, cyclic voltammetry
and thermogravimetry. The crystal structures of compounds 1 and 2 show that each nickel(II) centre has
an elongated distorted octahedral geometry with the axial ligands. Electronic spectra and redox potentials
of the complexes 1 and 2 exhibit a high-spin octahedral environment, which is reflected by the nature of
the axial ligands. The TGA behaviors of two compounds 1 and 2 are also significantly affected by the
nature of the axial ligands.

2
Keywords: Crystal structures; Nickel(II) complexes; Tetraaza macrocycle; Sodium thiocynate;
Cycopropanedicarvoxylic acid; 1D Hydrogen-bonded infinite chains.
* Corresponding author. Tel.: +82-41-850-8284; fax: +82-41-850-8347.
E-mail address: kychoi@kongju.ac.kr (K.-Y. Choi).
1. Introduction
The self-assembly of transition metal(II) macrocyclic complexes and aromatic polycarboxylate ligands
have received considerable current interest owing to their interesting structures and potential applications
[1-5]. Macrocyclic complexes with multi-connecting ligands such as aromatic polycarboxylate ligands
have been proved to be good building blocks for the construction of coordination polymers [6-12].
Especially, hydrogen bonding is one of the key interactions for the process of molecular aggregation and
recognition in nature, which creates novel structures of molecular assemblies [10]. For example, the
compound
[Ni(L1)(H2O)2]0.5[Ni(L1)(WO4)2]0.5
(L1
=
3,14-dimethyl-2,6,13,17-
tetraazatricyclo[14,4,01.18,07.12]docosane) assembles in the solid state to form a 1D chain linked by
intermolecular hydrogen bond [13]. The reaction of [Ni(L1)]Cl2•2H2O [14] with 1,1-
cyclobutanedicarboxylic acid(H2cbdc) generates 1D hydrogen polymer [Ni(L1)(Hcbdc)2] [15]. In
addition, the compound [Ni(cyclam)(H2O)2]3[(btc)3]2⋅24H2O (cyclam = 1,4,8,11-tetraazacyclotetradecane;

3
btc = 1,3,5-benzenetricarboxylate) was assembled by [Ni(cyclam)(H2O)2]2+ and btc3- ligand in water via
hydrogen bonds, which can be regarded as a molecular floral lace [2]. Recently, we reported the synthesis
and crystal structures of [Ni(Me4cyclam)(H2O)2](tp)⋅4H2O (Me4cyclam = 2,5,9,12-tetramethyl-1,4,8,11-
tetraazacyclotetradecane, tp = terephthalate) and [Ni(Me4cyclam)(H2O)2](pdc)⋅4H2O (pdc = 2,5-
pyridinedicarboxylate) [16], in which the coordinated water molecules are linked to the carboxylate
oxygen atoms of tp and pdc ligands to give a 1D polymer through the intermolecular hydrogen bonding
interaction. The hydrogen bonding interactions, therefore, play a significant role in aligning the molecules
and polymer stands in the crystalline solids.
To further investigate the coordination behavior, we have prepared and characterized 1D hydrogen-
bonded infinite chains [Ni(L2)(NCS)2] (1) [Ni(L2)(H-cpdc)2] (2) (L1 = 3,14-diethyl-2,6,13,17-
tetraazatricyclo[14,4,01.18,07.12]docosane; H2cpdc = cyclopropanedicarboxylic acid), which are prepared
by the reaction of [Ni(L2)]Cl2·2H2O with the NaNCS and H2cpdc ligand.
L1
L2

4
2. Experimental
2.1. Materials and physical methods
All chemicals used in syntheses were of reagent grade and were used without further purification. The
macrocycle 3,14-diethyl-2,6,13,17-tetraazatricyclo[14,4,01.18,07.12]docosane (L2) and [Ni(L2)]Cl2·2H2O
were prepared according to the literature method [17]. IR spectra were recorded as KBr pellets on a
Perkin-Elmer Paragon 1000 FT-IR spectrometer. The solution electronic and diffuse reflectance spectra
were obtained on a Jasco V-550 spectrophotometer. Electrochemical measurements were accomplished
with a three electrode potentiostat BAS-100BW system. A 3-mm Pt disk was used as the working
electrode. The counter electrode was a coiled Pt wire and a Ag/AgCl electrode was used as a reference
electrode. Cyclic voltametric data were obtained in DMSO solution using 0.1 M tetraethylammonium
perchlorate (TEAP) as supporting electrolyte at 20.0 0.1 ˚C. The solution was degassed with high purity
N2 prior to carrying out the electrochemical measurements. DSC and TGA were performed under flowing
nitrogen at a heating rate of 10°C mim-1 using an SDT 2960 Thermogravimetric Analyzer. 13C NMR
spectra were recorded at room temperature on a Bruker AVANCE II 500 spectrometer. Elemental analyses
(C, H, N) were performed on a Perkin-Elmer CHN-2400 analyzer.
2.1. Synthesis of [Ni(L2)(NCS)2] (1)
To a methanol solution (20 ml) of [Ni(L2)]Cl2·2H2O (265 mg, 0.5 mmol) was added an aqueous

5
solution (10 ml) of KSCN (97 mg, 1.0 mmol) and the mixture was stirred for 30 min at room temperature.
The solution was filtered and left at room temperature until the purple crystals formed. The product was
recrystallized from a hot water/acetonitrile (1:1 v/v, 10 ml) mixture. Yield: 73%. Anal. Found: C, 53.51; H,
8.30; N, 15.47. Calc. for C22H44N6NiS2: C, 53.43; H, 8.22; N, 15.58 %. IR (KBr, cm-1): 3,240(m),
2,946(m), 2,066(s), 1,458(m), 1,381(m), 1,154(m), 1,097(m), 1,021(m), 1,005(m), 977(m), 942(m),
894(w), 871(w), 781(w).
2.2. Syntheses of [Ni(L2)(H-cpdc)2] (2)
To a methanol solution (20 ml) of [Ni(L2)]Cl2·2H2O (265 mg, 0.5 mmol) was added an aqueous
solution (10 ml) of H2-cpdc (130 mg, 1.0 mmol). The mixture was heated to reflux for 30 mim and then
cooled to room temperature. The solution was filtered and left at room temperature until purple crystals
formed. The product was recrystallized from a hot water/acetonitrile (1:1 v/v, 10 ml) mixture. Yield: 68%.
Anal. Found: C, 56.51; H, 8.07; N, 8.14. Calc. for C32H54N4NiO8: C, 56.40; H, 7.99; N, 8.22 %. IR (KBr,
cm-1): 3,434(m), 3,261(m), 2,947(m), 1,655(s), 1,579(m), 1,476(w), 1,450(w), 1,398(m), 1,305(w),
1,273(w), 1,167(w), 1,104(m), 963(m), 898(w), 806(m), 748(w).
2.3. X-ray crystal structure analysis
The single crystals of 1 and 2 were mounted on a Bruker Apex II CCD diffractometer. X-ray data were

6
collected using graphite-monochromated Mo-Kα radiation (λ = 0.71073 Å) at room temperature.
Accurate cell parameters and an orientation matrix were determined by the least-squares fit of 7482
(compound 1) and 3031 (compound 2) reflections. The intensity data were collected by the π-ω scan and
corrected for Lorentz and polarization effects. An empirical absorption correction was applied with the
(multiple scan) SADABS program [18]. The structure was solved by direct methods [19] and the least-
squares refinement of the structure was performed by the SHELXL-97 program [20]. All atoms except for
all hydrogen atoms were refined anisotropically. Hydrogen atoms were placed in calculated positions,
allowing them to ride on their parent C or N atoms with Uiso(H) = 1.2Ueq(C or N). Crystal parameters and
details of the data collections and refinement are summarized in Table 1.
3. Results and discussion
3.1. Crystal structures
3.1.1. Description of the Structure
The macrcyclic ligand skeleton of the present compounds contains the most stable trans-III (R,R,S,S)
configuration with two gauche five-membered and two chair six-membered chelate rings. The N-Ni-N
angles of the six-membered chelate rings for the complexes are larger than those of the five-membered
chelate rings. The ethyl group on a six-membered chelate ring is anti with respect to the N4 plane.
An ORTEP drawing of [Ni(L3)(NCS)2] (1) with the atomic numbering scheme is shown in Fig. 1

7
and the selected bond lengths and angles are listed in Table 2. The crystal structure of 1 shows that the
nickel(II) ion is coordinated by the secondary amines of the macrocyclic ligand and that the axial position
bonded by two nitrogen atoms of the thiocynate ligands. The average Ni-N (secondary amines) distance
of 2.086(5) Å is significantly longer than in the square-planar geometry of [Ni(L1)]Cl2·2H2O [1.948(4)
Å] [15], but is similar to that observed for high-spin octahedral nickel(II) complexes with 14-membered
tetraaza macrocyclic ligands [21-25]. The axial Ni-N distance of 2.152(5) Å is longer than the equatorial
Ni-N distances, giving an axially elongated octahedral environment and comparable to the previously
reported values in the related systems {[Ni(L1)(NCS)2] [22]: Ni-N = 2.115(3) ; [Ni(2,7,9,14-
cyclam)(NCS)2] (2,7,9,14-cyclam = 2,7,9,14-tetramethyl1,4,8,11-tetraazacyclotetradecane) [26]: Ni-N =
2.108(4)
[Ni(2,5,9,12-cyclam)(NCS)2]
(2,5,9,12-cyclam
=
2,5,9,12-tetramethyl1,4,8,11-
tetraazacyclotetradecane) [27]: Ni-N = 2.109(7) and 2.100(7) Å}. Also, The axial Ni-N(5) and Ni-N(6)
linkages are bent slightly off the perpendicular to the NiN4 plane by 1.3-5.5° and 2.1-5.6°, respectively.
The Ni-N(5)-C(23) and Ni-N(6)-C(24) angles related to the thiocynate ligand are 177.1(5) and 176.1(5)°,
respectively. Interestingly, uncoordinated sulfur atoms, S(1) and S(2), of the thiocynate ligands form the
intermolecular hydrogen bonds to an adjacent secondary of the macrocycle [N(2)…S(2)#1 3.834(5) Å,
147.8°; N(4)…S(1)#2 3.846(5) Å, 147.9°; symmetry codes: (#1) x, y+1, z; (#2) x, y−1, z] This interaction
gives rise to an one-dimensional hydrogen-bonded infinite chain (Fig. 2 and Table 3).
An ORTEP drawing of [Ni(L3)(H-cpdc)2] (2) with the atomic numbering scheme is shown in Fig. 3

8
and the selected bond lengths and angles are listed in Table 4. The coordination environment around
nickel(II) ion shows a six-coordinated octahedron with four secondary amines of macrocycle and two
oxygen atoms of H-cpdc ligands. The average Ni-N (secondary amines) distance of 2.075(7) Å is similar
to that found in [Ni(L1)(NCS)2] (1) (2.085(5) Å) and shorter than the average Ni-O distance of 2.179(7)
Å, giving an axially elongated octahedral geometry. The axial Ni-O bond distances and Ni-O-C angles
[133.4(6) and 136.9(6)°] are similar to the observed for [Ni(L1)(H-cpdc)2] [28]. The axial Ni-O(1) and
Ni-O(5) linkages are bent slightly off the perpendicular to the NiN4 plane by 3.7-7.4 and 1.5-6.4°,
respectively. Interestingly, the uncoordinated oxygen atoms, O(2) and O(6) of the H-cpdc ligand form the
intramolecular hydrogen bonds with the secondary amines N(4) and N(2) of the macrocycle [N(2)…O(6)
2.967(12) Å, 151.7°; N(4)…O(2) 2.948(12) Å, 155.4°]. In addition the protonated oxygen atom O(3) is
intramoleculary hydrogen bonded to the uncoordinated oxygen atom O(2) of the H-cpdc ligand.
Furthermore, uncoordinated oxygen atoms, O(4) and O(7), of the H-cpdc ligand form the intermolecular
hydrogen bonds to an adjacent secondary of the macrocycle [N(1)…O(7)#3 3.139(11) Å, 143.4°;
N(3)…O(4)#4 3.146(11) Å, 148.0°; symmetry codes: (#3) x, y, z+1; (#4) x, y, z−1]. This interaction gives
rise to an one-dimensional hydrogen-bonded infinite chain (Fig. 4 and Table 5).
3.2. Characterization of the complexes
The IR spectra of these complexes show bands at 3,240-3,261 cm-1, which is assigned to the ν(NH) of

9
the coordinated secondary amines. A single very strong band at 2,066 cm-1 of 1 is associated with the
thiocynate stretching mode, which is agree with the crystal structure of 1. For 2, two strong bands exhibit
νas(COO) stretching frequency at 1,655 cm-1 and νsym(COO) at 1,398 cm-1, respectively. The value of ∆ν
(257 cm-1) indicates that the carboxylate groups coordinated to the nickel(II) ion only as a monodentate
ligand [29,30]. In addition, the sharp band ν(OH) at 3,434 cm-1 in 2 indicates that the complex contains
the hydroxyl group. The UV-Vis spectral data and solid state spectra of the complexes are shown in Table
6 and Fig. 5. The solid reflectance and CH3CN solution spectra of 1 and 2 shows absorption maxima in
the region 236-256 and 251-265 nm respectively, attributed to ligand-metal charge transfer transitions
associated with nitrogen and oxygen donors [30,31]. The solid state electronic spectra of 1 and 2 in the
3
visible region exhibit three absorption bands at 338-346, 516-526, and 718-706 nm assignable to the B1g
3
3
3
3
3
3
3
→ Ec , B1g → Eb , B1g → B2g + B1g → Aa transitions, which are the characteristic spectrum
g
g
2g
expected for a high-spin d8 nickel(II) ion in D4h environment [23,32]. However, the visible spectra of 1
and 2 in water solution displays the broad bands 462-463 nm, which have a low-spin d8 nickel(II) ion in a
square-planar environment of [Ni(L1)]Cl2·2H2O (λmax = 461 nm) [17]. This fact can be understood in
terms of dissociation of the thiocyanate and H-cpdc ligands at water solution
The compounds 1-2 were heated in the temperature range 30-1000°C under nitrogen gas. The TGA
diagrams of compounds 1-2 are shown in Fig. 6. TGA curve for 1 shows a first weight loss of 84.9%
(calculated 86.2%) over ca. 284-573°C, corresponding the macrocycle and two thiocyanate anions. A

10
final residue (observed 15.1%, calculated 13.8%) was remained above 573°C with NiO composition. For
2, the first weight loss is observed from 236 to 523°C, which is due to the loss of the macrocycle and two
nitrate anions (observed 89.5%, calculated 89.1%). A final residue (observed 10.5%, calculated 10.9%)
was remained above 523°C with NiO composition.
Cyclic voltammetric data and cyclic voltammograms for compounds 1 and 2 in 0.10 M TEAP-DMSO
solution are given in Table 7 and Fig. 7. The complex 1 reveals one one-electron wave corresponding to
NiII/NiI process. However, the complex 2 exhibits two one-electron waves corresponding to NiII/NiIII and
NiII/NiI processes. It is of interest to compare the redox potentials for the nickel(II) complexes with the
axial ligands. The reduction potentials for 1 and 2 are distinctly more positive than those of complex
[Ni(L2)]Cl2·2H2O. This may result from the structural geometry (octahedral and square-plane). This is
consistent with the crystal structures and spectroscopic data discussed previously.
Appendix A. Supplementary data
CCDC 1524580 and 1524582 contains the supplementary crystallographic data for 1 and 2. These data
can be obtained free of charge via http://www.ccdc. cam.ac.uk/conts/retrieving.html, or from the
Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge, CB2 1EZ, UK; fax: (+44) 1223-
336-033; or e-mail: deposit@ccdc.cam.ac.uk.

11
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12
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Germany, 2008.
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Table 1. Crystallographic data
1
2

14
Empirical formula
Formula weight
Temperature (K)
Crystal color/habit
Crystal system
Space group
Unit cell dimensions
a (Å)
C24H44N6NiS2
539.48
C32H54N4NiO8
681.50
296(2)
296(2)
purple/block
triclinic
P1
purple/block
triclinic
P1
8.7822(5)
9.1152(5)
9.3914(5)
74.398(2)
86.252(2)
67.172(3)
666.74(6)
1
9.789(4)
b (Å)
10.401(5)
c (Å)
10.608(4)
α (°)
105.69(3)
β (°)
105.15(3)
γ (°)
V (Å3)
114.79(3)
852.8(6)
Z
1
Dcalc (Mg m-3)
1.344
1.327
Absorption coefficient (mm-1)
0.908
0.623
F(000)
289
366
Crystal size (mm)
θ range (°)
0.36×0.26×0.12
2.25 to 28.42
-11≤h≤11, -11≤k≤12,
0≤l≤12
0.20×0.18×0.06
2.39 to 28.42
-13≤h≤12, -13≤k≤13,
0≤l≤14
Limiting indices
Reflection collected/unique (Rint)
Absorption correction
3312/3312 (0.0000)
SADABS
0.8988 and 0.7357
3312/3/300
1.053
4175/4175 (0.0000)
SADABS
Maximum and minimum transmission
Data/restraints/parameters
Goodness-of-fit on F2
0.9636 and 0.8856
4175/3/394
1.050
a
b
Final R indices (I>2σ(I))
R indices (all data)
R1 =0.0242, wR2 =0.0618
R1=0.0475, wR2=0.1218
R1=0.0626, wR2=0.1307
0.513 and -0.433
R1=0.0263, wR2=0.0633
Largest difference peak and hole (eÅ-3) 0.298 and -0.266
a R1 = || Fo |−| Fc ||/Σ| Fo |.
2
2 2
b wR2 = [Σ[w(Fo -Fc2)2]/Σ[w(Fo ) ]]1/2.
Table 2. Selected bond lengths (Å) and angles (°) for [Ni(L3)(NCS)2] (1)

15
Bond lengths (Å)
Ni-N(1)
2.111(4)
2.076(5)
2.168(4)
1.144(8)
1.169(8)
Ni-N(2)
2.067(5)
2.088(5)
2.135(5)
1.648(6)
1.619(6)
Ni-N(3)
Ni-N(4)
Ni-N(5)
Ni-N(6)
N(5)-C(23)
N(6)-C(24)
C(23)-S(1)
C(24)-S(2)
Bond angles (°)
N(1)-Ni-N(2)
N(1)-Ni-N(4)
N(2)-Ni-N(4)
N(1)-Ni-N(5)
N(3)-Ni-N(5)
N(1)-Ni-N(6)
N(3)-Ni-N(6)
N(5)-Ni-N(6)
Ni-N(6)-C(24)
N(6)-C(24)-S(2)
83.9(2)
95.3(2)
178.6(3)
95.5(2)
84.5(2)
84.5(2)
95.6(2)
179.2(3)
176.1(5)
178.3(5)
N(1)-Ni-N(3)
N(2)-Ni-N(3)
N(3)-Ni-N(4)
N(2)-Ni-N(5)
N(4)-Ni-N(5)
N(2)-Ni-N(6)
N(4)-Ni-N(6)
Ni-N(5)-C(23)
N(5)-C(23)-S(1)
179.8(3)
95.8(2)
84.9(2)
87.6(2)
91.3(2)
93.2(2)
87.9(2)
177.1(5)
177.5(5)
Table 3. Hydrogen bonding parameters (Å, °) for [Ni(L2)(NCS)2] (1)

16
D-H…A
D-H (Å)
H…A (Å)
D…A (Å)
D-H…A (°)
N(2)-HN(2)…S(2)#1
N(4)-HN(4))…S(1)#2
0.91
0.91
3.03
3.05
3.834(5)
3.846(5)
147.8
147.9
Symmetry codes: (#1) x, y+1, z; (#2) x, y−1, z.
Table 4. Selected bond lengths (Å) and angles (°) for [Ni(L2)(H-cpdc)2] (2)

17
Bond lengths (Å)
Ni-N(1)
2.093(6)
2.101(7)
2.191(7)
1.251(12)
1.240(10)
Ni-N(2)
2.067(6)
2.039(7)
2.167(7)
1.272(11)
1.241(10)
Ni-N(3)
Ni-N(4)
Ni-O(1)
Ni-O(5)
C(26)-O(1)
C(31)-O(5)
C(26)-O(2)
C(31)-O(6)
Bond angles (°)
N(1)-Ni-N(2)
N(1)-Ni-N(4)
N(2)-Ni-N(4)
N(1)-Ni-O(1)
N(3)-Ni-O(1)
N(1)-Ni-O(5)
N(3)-Ni-O(5)
O(1)-Ni-O(5)
Ni-O(5)-C(31)
O(5)-C(31)-O(6)
83.6(3)
96.5(2)
177.8(4)
83.2(2)
95.4(3)
96.4(3)
84.9(3)
178.9(3)
136.9(6)
121.5(8)
N(1)-Ni-N(3)
N(2)-Ni-N(3)
N(3)-Ni-N(4)
N(2)-Ni-O(1)
N(4)-Ni-O(1)
N(2)-Ni-O(5)
N(4)-Ni-O(5)
Ni-O(1)-C(26)
O(1)-C(26)-O(2)
178.6(4)
96.0(3)
83.8(3)
85.3(2)
92.6(3)
93.6(3)
88.5(3)
133.4(6)
127.3(8)
Table 5. Hydrogen bonding parameters (Å, °) for [Ni(L2)(H-cpdc)2] (2)

18
D-H…A
D-H (Å)
H…A (Å)
D…A (Å)
D-H…A (°)
N(1)-HN(1)…O(7)#3
N(3)-HN(3)…O(4)#4
N(2)-HN(2)…O(6)
N(4)-HN(4)…O(2)
O(3)-HO(3)…O(2)
0.91
2.36
3.139(11)
3.146(11)
2.967(12)
2.948(12)
2.491(12)
143.4
148.0
151.7
155.4
154(5)
0.91
2.34
0.91
2.13
0.91
2.10
0.86(6)
1.69(6)
Symmetry codes: (#3) x, y, z+1; (#4) x, y, z−1.
Table 6. Electronic spectral dataa

19
λmax / nm (ε / M-1 cm-1)
Complex
State
[Ni(L2)]Cl2·2H2Ob
Solid
252, 460
CH3CN
H2O
465(65)
461(68)
[Ni(L2)(NCS)2] (1)
Solid
256, 338, 516, 718
251(8.4×102) 521(8.7)
250(7.2×103), 462 (73)
236, 346, 526, 706
265(1.8×103), 531(9.1)
260(5.6×103), 463(75)
CH3CN
H2O
[Ni(L2)(H-cpdc)2] (2)
Solid
CH3CN
H2O
a Solution = CH3CN and H2O at 20 0.1 °C; Solid = diffuse reflectance.
b Ref [17].
Table 7. Cyclic voltammetric dataa

20
Potentials (V) versus Ag/AgCl
Ni(III)/Ni(II) Ni(II)/Ni(I)
Complex
[Ni(L2)]Cl2·2H2Ob
[Ni(L2)(NCS)2] (1)
[Ni(L2)(H-cpdc)2] (2)
+0.68
−1.54(i)c
−1.35
+0.70
−1.34
a Measured in 0.10 M TEAP-DMSO solution at 20.0 0.1 °C.
b Ref [17].
c i = irreversible.
Figure captions

21
Fig. 1. An ORTEP diagram of [Ni(L2)(NCS)2] (1) with the atom-numbering scheme (30% probability
ellipsoids shown). The hydrogen atoms and water molecules are omitted for clarity.
Fig. 2. Crystal packing of [Ni(L2)(NCS)2] (1), showing the hydrogen bonds as dotted lines.
Fig. 3. An ORTEP diagram of [Ni(L2)(H-cpdc)2] (2) with the atom-numbering scheme (30% probability
ellipsoids shown). The hydrogen atoms and water molecules are omitted for clarity.
Fig. 4. Crystal packing of [Ni(L2)(H-cpdc)2] (2), showing the hydrogen bonds as dotted lines.
Fig. 5. Solid state electronic absorption spectra [Ni(L2)(NCS)2] (2) and [Ni(L2)(H-cpdc)2] (3) by the
diffuse reflectance method at 20.0 0.1°C.
Fig. 6. Thermogravimetric curves of [Ni(L2)(NCS)2] (1) and [Ni(L2)(H-cpdc)2] (2).
Fig. 7. Cyclic voltammograms of of [Ni(L2)(NCS)2] (1) and [Ni(L2)(H-cpdc)2] (2) in 0.1M TEAP-
DMSO solution at 20.0 0.1℃. The scan rate is 100 mV/s.

22
Fig. 1

23
Fig. 2.

24
Fig. 3.

25
Fig. 4.

26
Fig. 5.

27
Fig. 6.

28
Fig. 7.
Pictogram and Synopsis

29
In-Taek Lim, Ki-Young Choi
1D Hydrogen-bonded infinite chains from tetraaza macrocycle nickel(II)
complexes and ligands
The reaction of [Ni(L2)]Cl2·2H2O (L1 = 3,14-diethyl-2,6,13,17-tetraazatricyclo[14,4,01.18,07.12]docosane)
with ligands generates 1D hydrogen-bonded infinite chains [Ni(L2)(NCS)2] (1) and [Ni(L2)(H-cpdc)2]
(2). The crystal structure of the compounds 1 and 2 exhibits a high-spin octahedral geometry with the
axial ligands.
2