Syntheses, crystal structures and thermal decomposition kinetics of Ni(II) and Cu(II) complexes with dpa and dca: [Ni(dpa)2(dca)2] and [Cu(dpa)2(dca)2] (dpa = 2, 2′-dipyridylamine, dca = sodium dicyanamide) ligands

Article abstract of DOI:10.1080/15533170600910355

The syntheses, crystal structures, luminescence properties and thermal decomposition kinetics of Ni(II) and Cu(II) complexes with dpa and dca, [Ni(dpa)₂ (dca)₂] (I) and [Cu(dpa)₂(dca) ₂] (II) (dpa = 2, 2′-dipyridylamine, dca = sodium dicyanamide) are described. I crystallizes in Monoclinic cells with c2c space groups; the center metal ion Ni^II lies in a distorted octahedron environment, and the endmost nitrogen atom of dca with a V model coordinates to Ni^II. Though the chemical formula of II is similar to I, II crystallizes in triclinic cells with a Pi space group. The center Cu ^II ion has an octahedral-coordinated environment. Copyright

Full text of DOI:10.1080/15533170600910355

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Synthesis and Reactivity in Inorganic, Metal-Organic,
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Syntheses, Crystal Structures and Thermal
Decomposition Kinetics of Ni(II) and Cu(II) Complexes
with dpa and dca: [Ni(dpa)2(dca)2] and [Cu(dpa)2(dca)2]
(dpa=2, 2′‐Dipyridylamine, dca=Sodium Dicyanamide)
Ligands
Hui Wang a , Xian‐Fu Zheng b , Xiao‐Qing Shen a , Hong‐Yun Zhang a , Rui Yang a , Hong‐Wei
Hou a & Yu Zhu a
a Department of Chemistry , Zhengzhou University , Zhengzhou, P. R. China
b College of Science , Henan Agricultural University , Zhengzhou, P. R. China
Published online: 15 Feb 2007.
To cite this article: Hui Wang , Xian‐Fu Zheng , Xiao‐Qing Shen , Hong‐Yun Zhang , Rui Yang , Hong‐Wei Hou & Yu Zhu
(2006) Syntheses, Crystal Structures and Thermal Decomposition Kinetics of Ni(II) and Cu(II) Complexes with dpa and dca:
[Ni(dpa)2(dca)2] and [Cu(dpa)2(dca)2] (dpa=2, 2′‐Dipyridylamine, dca=Sodium Dicyanamide) Ligands, Synthesis and Reactivity
in Inorganic, Metal-Organic, and Nano-Metal Chemistry, 36:8, 609-616
To link to this article: http://dx.doi.org/10.1080/15533170600910355
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Synthesis and Reactivity in Inorganic, Metal-Organic and Nano-Metal Chemistry, 36:609–616, 2006
Copyright # 2006 Taylor & Francis Group, LLC
ISSN: 0094-5714 print/1532-2440 online
DOI: 10.1080/15533170600910355
Syntheses, Crystal Structures and Thermal Decomposition
Kinetics of Ni(II) and Cu(II) Complexes with dpa
and dca: [Ni(dpa)2(dca)2] and [Cu(dpa)2(dca)2] (dpa 5 2,
20-Dipyridylamine, dca 5 Sodium Dicyanamide) Ligands
Hui Wang
Department of Chemistry, Zhengzhou University, Zhengzhou, P. R. China
Xian-Fu Zheng
College of Science, Henan Agricultural University, Zhengzhou, P. R. China
Xiao-Qing Shen, Hong-Yun Zhang, Rui Yang, Hong-Wei Hou, and Yu Zhu
Department of Chemistry, Zhengzhou University, Zhengzhou, P. R. China
aromatic amine has the ability both to form a hydrogen bond
The syntheses, crystal structures, luminescence properties and network by active amine hydrogens (-NH-) and to show p-p
thermal decomposition kinetics of Ni(II) and Cu(II) complexes
with dpa and dca, [Ni(dpa)2 (dca)2] (I) and [Cu(dpa)2(dca)2] (II)
interactions through pyridine planes. As far as our knowledge
goes, many metal complexes with dpa are reported, including
(dpa 5 2, 20-dipyridylamine, dca 5 sodium dicyanamide) are
described. I crystallizes in Monoclinic cells with c2c space
elements of metal, namely Co(II), Ni(II), Zn(II),[4] Pt(II),[5]
Pd(II),[6] Re(I),[7] Ru(II),[8] Au(I), Ag(I),[9] Fe(II),[10]
groups; the center metal ion NiII lies in a distorted octahedron
environment, and the endmost nitrogen atom of dca with a “V” Mn(II),[11] Cu(II).[12] In this work, we have reported the synth-
eses, crystal structures, fluorescence and thermal analysis prop-
model coordinates to NiII. Though the chemical formula of II is
similar to I, II crystallizes in triclinic cells with a Pı space
¯
erties of [Ni(dpa)2(dca)2] (I) and [Cu(dpa)2(dca)2] (II). Based on
the result of thermal analysis, the kinetic parameters for the
thermal decomposition of I and II have been calculated by the
OFW method.
group. The center CuII ion has an octahedral-coordinated
environment.
Keywords synthesis, crystal structure, fluorescence property,
non-isothermal kinetics of decomposition
EXPERIMENTAL
Materials and Physical Measurements
The 2,20-dipyridylamine, sodium dicyanamide and other
chemicals employed (Zhengzhou Chemical Reagent Company)
were commercial products and used without further purification.
Crystal structure was measured on a Rigaku-Raxis-IV X-ray
diffractometer. Thermal analysis was measured on NETZSCH
TG209 instrument. The IR spectrum was recorded on a Nicolet
IR-470 spectrometer using KBr pellets in the range of 4000–
400 cm21. Liquid fluorescence measurements were made
with Hitachi F-4500 spectrophotometer at room temperature.
INTRODUCTION
Recently, many researchers are focusing their attention on the
construction of supramolecular architectures organized through
coordinate covalent bonding or hydrogen bonding and p-p
stacking interactions[1] in organic-inorganic hybrid molecules
because of potential applications as functional materials.[2]
Bidentate ligands containing pyridine units, especially, have
attracted much attention.[3] 2,20-Dipyridylamine (dpa) as an
Preparation of the Complexes
Received 25 May 2006; accepted 2 June 2006.
We gratefully acknowledge financial support from the National
Natural Science Foundation of China (20501017).
Address correspondence to Hong-Yun Zhang, Department of
Chemistry, Zhengzhou University, Zhengzhou 450052, P. R. China.
E-mail: wzhy917@zzu.edu.cn
Synthesis of [Ni(dpa)2(dca)2] (I)
10 mL acetonitrile solution containing 0.034 g (0.2 mmol)
of dpa was added to the solution of 0.0242 g (0.1 mmol) of
.
NiSO4 6H2O in methanol (10 mL) and was stirred. The
solution of 0.0178 g (0.2 mmol) NaN(CN)2 in acetonitrile
609

610
H. WANG ET AL.
(10 mL) was added dropwise to the above-mentioned solution,
again while stirring. The mixture was refluxed for 30 min,
cooled to room temperature, and filtered. The filtrate was
allowed to stand evaporation at the ambient temperature. The
amethyst crystals of I were obtained after 2 months with the
yields of 68%. IR (KBr, cm21): y(N-H) 3444 m; y(C55N)
1644 s, 1477 s; y(C55C) 1530 s, 1587 s; y(N(CN)22 ) 2165 m.
TABLE 1
Crystallographic data for complexes I and II
II1
II2
Empirical formula
Formula weight
Crystal system
Space group
C24 H18 N12 Ni
533.21
C24 H18 Cu N12
538.04
Monoclinic
C2C
Triclinic
P¯ı
Synthesis of [Cu(dpa)2(dca)2] (II)
Crystal size (mm)
0.20 ꢀ
0.20 ꢀ
Except for replacing 10 ml acetonitrile solution containing
.
0.0120 g (0.1 mmol) of Cu(CH3COO)2 H2O, the synthesis
0.18 ꢀ 0.17
291.2
0.18 ꢀ 0.17
291.2
Temperature(K)
˚
of II is similar to the procedure of I. The grass-green
crystals of [Cu(dpa)2(dca)2] were obtained after 3 months
with the yields of 62%. IR (KBr, cm21): y(N-H) 3429 m;
y(C55N)1647 s, 1477 s; y(C55C) 1530 m, 1587 m;
y(N(CN)22 ) 2135 s, 2238 m.
a/A
˚
8.6627(17)
13.746(3)
21.463(4)
90
7.5188(15)
8.6084(17)
9.5067(19)
72.86(3)
88.12(3)
80.01(3)
579.0(2)
1
b/A
˚
c/A
a/8
b/8
g/8
94.23(3)
90
X-ray Crystallographic Analyses
3
˚
V/A
2548.9(9)
4
1.390
An amethyst prismatic single crystal of I (0.20 mm ꢀ
0.18 mm ꢀ 0.17 mm) and a grass-green prismatic single
crystal of II (0.20 mm ꢀ 0.18 mm ꢀ 0.17 mm) were mounted
on a Rigaku-Raxis-IV X-ray diffractometer using graphite
Z
23
.
Dc/g cm
Reflens collected
1.543
1793/
3880/
2185[R(int) ¼
1793[R(int)
¼0.0000]
1793/0/174
0.1019, 0.2648
0.1106, 0.2778
1.181
˚
monochromated Mo Ka radiation (l ¼ 0.71073 A) at
0.0285]
291(2) K. 3880 reflections were measured over the ranges
1.908 ꢁ 2u ꢁ 24.998, 210 ꢁ h ꢁ 8, 28 ꢁ k ꢁ 16, 225 ꢁ
l ꢁ 25, yielding 2185 unique reflections for I. 1793 reflections
were measured over the ranges 2.248 ꢁ 2u ꢁ 25.008,
28 ꢁ h ꢁ 8, 210 ꢁ k ꢁ 0, 211 ꢁ l ꢁ 10, all of which being
unique for II. The raw data were corrected and the structure
was solved using the SHELX-97 program. Non-hydrogen
atoms were located by direct phase determination and subjected
to anisotropic refinement. The full matrix least-squares calcu-
lations on F2 were applied to the final refinement. The refine-
ment converged at R1 ¼ 0.0369 and wR2 ¼ 0.0895 values for
reflections with I .2s(I) for I, and R1 ¼ 0.1019 and
wR2 ¼ 0.2648 values for reflections with I .2s(I) for II. The
crystal data and data collection parameters of I and II are sum-
marized in Table 1. Full atomic data are available as files in CIF
format deposited with the Cambridge Crystallographic Data
Center (CCDC 269645 and CCDC 250102, respectively).
Data/restraints
2185/0/173
0.0369, 0.0895
0.0424, 0.0923
1.062
R1, wR2[I . 2s(I)]
R1, wR2(all data)
Good of fit on F2
23
˚
Drmin, Drmax/e A
0.8761, 0.8565
0.8504, 0.8274
that of I, II crystallizes in a triclinic cell with the P¯ı space
group. Figures 1 and 2 show the ORTEP drawing and 2D
network formed by the hydrogen bonds for I. Figures 3 and 4
show the ORTEP diagram, essentially a 1D double-chain helix
Thermal Analysis
Thermal decomposition experiments in nitrogen atmosphere
with the flow rate of 20 mL min21 were carried out using a
NETZSCH TG 209 instrument. In these experiments the com-
plexes I and II were pre-triturated. The employed heating rate
for thermal decomposition was 10 8C min21, and the rates
.
21
.
for kinetic analysis of I and II were 10, 20, 25 8C min and
15, 20, 30 8C min21 respectively.
.
RESULTS AND DISCUSSION
Structural Description of the Complexes I and II
Complex I crystallizes in a monocline cell with the c2c
FIG. 1. X-ray crystal structure of I showing the structure unit (H atoms are
space group. Though the chemical formula of II is similar to not shown which have neither part nor lot in forming hydrogen bonding).

EFFECT OF DPA AND DCA ON NI AND CU COMPLEXES
611
FIG. 4. 1D double-chain helix structure by hydrogen bond in II.
“V,” the center bond angle [C11-N5-C12] is 123.638. The
joined pyridine rings via the NH group are not planar, invol-
ving two dihedral angles (N1, C1 ! C5 and N3, C6 ! C10;
N1A, C1A ! C5A and N3A, C6A ! C10A) of 26.28,
which are similar to other Ni(II) complex formats.[13] There
are two types of hydrogen bonds (shown in Figure 2) in the
solid structure of I, one is the imine group and the endmost
N atom of the dca in the other coordinate structure unit link
FIG. 2. Two-dimensional reticulate structure of the I by hydrongen bonding.
structure via hydrogen bonding for II. Selected bond distances
and angles relevant to both the Ni coordination spheres for I
and the Cu coordination spheres for II are given in Tables 2
and 3. The significant hydrogen bond parameters are shown in
Table 4.
In I, the NiII atom was coordinated with six nitrogen atoms
from two dpa and two dca in a distorted octahedron environ-
ment (shown in Figure 1), four N atoms (N1A, N3A, N4,
N3) respectively come from one dca unit and two dpa units
lay in the equatorial plane (mean deviation from plane is
˚
by hydrogen bonding [N(2D)-H(2EG) . . . N(6A) ¼ 2.916(3)A,
/N(2D)-H(2EG) . . . N(6A) ¼ 178.38], which form 1D chains.
These 1D chains are connected with the 2D network through
the other hydrogen bonding [C(1C)-H(1AE) . . . N(5AD) ¼
˚
3.396A, /C(1C)-H(1AE) . . . N(5AD) ¼ 154.48] between the
˚
0.0111 A). One dca and one dpa respectively provided one N
C-H group of the pyridine rings and the imine N atom of dca
in proximate structure unit. Weak p-p interaction comes from
between the pyridine planes.
atom that occupied the trans axial sites (N4A, N1). All the
six Ni-N bond lengths lie within a close range [2.0933(19)-
The ORTEP drawing of II shows that CuII centers can be
described as a octahedral (CuN6) environment (show as
Figure 3). Four N atoms (N3, N3A, N4, N4A) of the equatorial
plane are provided by two dpa and the end-cap N atom of the
two dca, respectively. The trans axial sites are occupied by
two nitrogen atoms (N1, N1A) from two dpa. 2,20-Dipyridyla-
mine as a chelate ligand connect with CuII atom by cis-format,
forming six-membered ring (Cu1, N1, C5, N2, C6, N3) of
˚
2.123(2) A]. These values are very similar to dpa complexes
with Ni-N systems.[13] The axial bond angle [N1-Ni1-N4A]
is 175.8288, making it almost linear. The endmost N atom of
the two dca ligands compound with Ni(II) in the form of
˚
non-coplane (mean deviation from plane is 0.2362A). The
axial bond angle (N1-Cu1-N1A) [180.000(0)8] and two bond
angles (N3-Cu1-N3A [180.000(1)8] and N4-Cu1-N4A [180.0
(3)8]) of the equatorial plane are linear. The two pyridine rings
joined via the NH group are not planar, involving a dihedral
angle of 139.68. Two dihedral angles via the pyridine rings
from different dpa in axial and in equatorial plane are all 0.08.
˚
˚
The Cu-Ndpa bond lengths are 2.0106A and 2.0176A, respect-
ively. These values are very similar to dpa complexes with Ni-
N systems.[13] The Cu-Ndca bond length is 2.4807A, which is
˚
longer than that of MII(dca)2(M ¼ transition metal).[14]
It is seen from Figure 4 that the ligand dca only forms one
hydrogen bond (N2-H2E . . . N6 ¼ 0.2956 nm) by a weak
interaction from the end-cap Ndca and the imine (N2-H)
group in adjacent structure unit. The hydrogen bond
FIG. 3. X-ray crystal structure of II showing the structure unit (pyridine rings
of hydration not shown).

612
H. WANG ET AL.
TABLE 2
˚
Selected bond lengths (A) and angles (8) for I
Ni(1)-N(3)
Ni(1)-N(1)
Ni(1)-N(4)
2.123(2)
2.0933 (19)
2.103(2)
Ni(1)-N(3A)
Ni(1)-N(1A)
Ni(1)-N(4A)
2.123(2)
2.0933(19)
2.103(2)
90.71(11)
84.92(8)
95.50(8)
91.24(8)
88.33(8)
84.92(8)
91.24(8)
—
N(1A)-Ni(1)-N(1)
N(1A)-Ni(1)-N(4)
N(1)-Ni(1)-N(4)
N(1A)-Ni(1)-N(4A)
N(1)-Ni(1)-N(4A)
N(1A)-Ni(1)-N(3)
N(4)-Ni(1)-N(3)
N(3A)-Ni(1)-N(3)
94.45(11)
175.82(8)
87.54(8)
N(4)-Ni(1)-N(4A)
N(1A)-Ni(1)-N(3A)
N(1)-Ni(1)-N(3A)
N(4)-Ni(1)-N(3A)
N(4A)-Ni(1)-N(3A)
N(1)-Ni(1)-N(3)
N(4A)-Ni(1)-N(3)
—
87.54(8)
175.82(8)
95.50(8)
88.33(8)
179.39(12)
Symmetry operations A: 2x, y, 2 z þ (3/2).
(N2-H2E . . . N6) makes Cu atoms into 1D double-chain helix to the ligand types. Hydrogen bonding can enhance the intension
structure. The distance (Cu . . . Cu) is 0.8608 nm in the chain. of fluorescence so that complex I is stronger than complex II.
Face-to-face p-p weak interaction between pyridine rings
results in the structure units forming a 3D continuum as a solid.
Thermal Analyses
The TG and DTG curve of I are shown in Figure 6. The
thermal decomposition starts at 314.2 8C (on TG curve) and
Luminescence Spectra
The luminescence spectra of the ligand dpa and I and II in the main process ends before 500 8C. One maximum rate of
DMF(1 ꢀ 1025M) solution has been determined at room temp- weight loss appears at 341.2 8C(on DTG curve). Furthermore,
erature (shown in Figure 5). 2, 20-Dipyridylamine has been the sub-process of the thermal decomposition appears between
excited at 332 nm, an intense absorption appearing at 500–600 8C, with the peak at 548.6 8C. The total mass loss up
346.8 nm. The peak shape of I and II is almost the same as to 600 8C(on TG curve) is only 68.6%, which is due to the
that of dpa, when it was have been excitated under each carbon deposition resulted products in N2 atmosphere. The
maximal wavelength, which indicate that the luminescence of final product may be nickel.
I and II are assigned to the type of p-pꢂ(C55C)and p-pꢂ
The TG and DTG curve of II are shown in Figure 7. The
(C55N) of the ligand. The fluorescent absorption of the com- thermal decomposition of II starts at 213.1 8C (on TG curve)
plexes I and II appeared to shift to length wave-length and two similar transitions can be seen from the DTG curve.
compared with dpa, which is due to the metallic ions perturbing The two maximum rates of weight loss appear at 225.2 8C
TABLE 3
˚
Selected bond lengths (A) and angles (8) for II
Cu(1)-N(3)
Cu(1)-N(3)A1
0.2010(6)
0.2010(6)
0.2480(7)
180.000(1)
85.8(2)
Cu(1)-N(1)
Cu(1)-N(1)A1
0.2017(6)
0.2017(6)
0.2480(7)
94.2(2)
Cu(1)-N(4)A2
Cu(1)-N(4)A3
N(3)-Cu(1)-N(3)A1
N(3)-Cu(1)-N(1)
N(3)-Cu(1)-N(4)A2
N(1)-Cu(1)-N(4)A2
N(1)-Cu(1)-N(4)A3
C(5)-N(1)-Cu(1)
C(10)-N(3)-Cu(1)
N(3)A1-Cu(1)-N(1)A1
N(1)A1-Cu(1)-N(4)A2
N(4)A2-Cu(1)-N(4)A3
N(3)-Cu(1)-N(1)A1
N(3)A1-Cu(1)-N(1)
N(3)A1-Cu(1)-N(4)A2
N(3)-Cu(1)-N(4)A3
N(1)A1-Cu(1)-N(4)A3
C(1)-N(1)-Cu(1)
C(11)-N(4)-Cu(1)A4
N(1)A1-Cu(1)-N(1)
N(3)A1-Cu(1)-N(4)A3
C(6)-N(3)-Cu(1)
94.2(2)
87.3(2)
92.7(2)
90.2(2)
89.8(2)
87.3(2)
90.2(2)
121.0(4)
121.9(5)
85.8(2)
121.1(5)
136.5(7)
180.000(0)
92.7(2)
89.8(2)
180.0(3)
120.3(5)
Symmetry operations A1: 2x, 2y þ 2, 2z; A2: x, y þ 1, z; A3: 2x, 2y þ 1, 2z; A4: x, y 2 1, z.

EFFECT OF DPA AND DCA ON NI AND CU COMPLEXES
613
TABLE 4
˚
Hydrogen bond distances (A) and angles (8)
˚
D-H . . . A
d(D . . . A)/A 8; DHA/8
C(1C)-H(1A1E) . . . N(5A1D)(I)
N(2)-H(2E) . . . N(6)A2 (I)
N(2)-H(2E) . . . N(6) (II)
3.396
2.9163
2.9569
154.4
178.3
172.5
Symmetry operations A1: 2x, 2y þ 2, 2z; A2: (2x 2 1)/2,
(2y þ 1)/2, 2z þ 1.
and 249.0 8C. The value of total mass loss is only 56.37% to
600 8C, the reasoning being the same as that of complex I.
The final product may be copper.
FIG. 7. TG-DTG curves of II.
presuppose a certain model. Figure 8 shows the TG curves of
complex I decomposition from 200 to 450 8C with heating
Non-Isothermal Kinetics Studies
rates of 10, 20 and 25 8C min21. Figure 9 shows the TG
A series of dynamic scans with different heating rates results
in a set of data that exhibits the same degree of conversion (s)
at different temperatures. Based on this, two methods are
developed by Friedman as well as Ozawa-Flynn-Wall(OFW)
to determine the kinetic parameters without having to
.
curves of complex II decomposition from 120 to 320 8C
with heating rates of 15, 20 and 30 8C min21. The base data
.
FIG. 8. TG curves of I with different heating rates (8C/min).
FIG. 5. The emission spectra of the complexes I, II and dpa.
FIG. 6. TG-DTG curves of I.
FIG. 9. TG curves of II with different heating rates (8C/min).

614
H. WANG ET AL.
FIG. 10. The OFW analysis of I.
(b, s, T ) taken from the TG curves of the complexes I and II of these straight lines are directly proportional to the reaction
are used in the equations that follow.
The Friedman equation[15] is
activation energy (E). Figure 10 shows these lines at different
a by means of OFW method for I and the calculated results
using both Eq. (1) and Eq. (2) are shown in Table 5. Table 6
shows the calculated results using both Eq. (1) and Eq. (2) of
complex II.
E
lnðda=dtÞa¼aj ¼ ln½A†f ðaÞjꢃ ꢄ
ð1Þ
RT
where da/dt is the rate of conversion, and f (a) mechanism
function, E activation energy, A pre-exponential factor and R
gas constant.
From Table 5 it is seen that the values of E and lgA calcu-
lated by using different methods are comparable, which indi-
cates that the kinetic parameters thus obtained are
reasonable. Table 5 shows that the activation energy is not a
constant and two maximums appear at a ¼ 0.05 and 0.9,
which indicates that the thermal decomposition of complex I
is not a one-step reaction.[18,19] Furthermore, the two
methods obtained activation energies and pre-exponential
factors which are of good pertinence. Kinetic parameters of
this reaction can be estimated from the maximums of the
Friedman method or OFW method or also from averaging
The Ozawa-Flynn-Wall equation[16,17] is
ꢀ
ꢁ
AE
R
E
ln b ¼ ln
ꢄ ln fðaÞ ꢄ 5:3305 ꢄ 1:052 ꢅ
ð2Þ
RT
where b is the heating rate, a the degree of conversion.
It is seen from Eqs (1) and (2) that the graphs ln(da/dt)
versus 1/T and lnb versus 1/T both show straight lines with
slopes m(1) ¼ 2 (E/R) and m(2) ¼ 21.052 E/R. The slopes
TABLE 5
Parameters Ea (kJmol21) and lgA (s21) for the thermal decomposition of I
Ozawa-Flynn-Wall analysis Friedman analysis
Partial mass loss
Ea (kJmol21
)
lgA (s21
)
Ea (kJmol21
)
lgA (s21
)
0.02
0.05
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
0.95
0.98
64.73 + 107.30
185.26 + 56.01
190.82 + 39.52
198.38 + 40.68
203.91 + 42.77
204.06 + 40.86
203.42 + 36.57
205.93 + 31.10
214.48 + 23.71
216.92 + 8.70
199.63 + 16.39
317.36 + 89.31
873.14 + 304.02
2.38
13.99
14.39
14.97
15.40
15.37
15.28
15.46
16.14
16.27
14.68
23.73
65.68
142.82 + 45.24
179.05 + 34.84
191.38 + 37.83
210.41 + 45.07
208.19 + 44.11
199.75 + 35.85
199.51 + 24.59
213.54 + 13.81
227.55 + 6.33
196.37 + 31.00
206.84 + 52.07
457.60 + 116.41
1168.10 + 318.20
9.93
13.27
14.31
15.90
15.66
14.90
14.84
15.95
17.03
14.35
14.84
33.78
86.93

EFFECT OF DPA AND DCA ON NI AND CU COMPLEXES
615
TABLE 6
Parameters Ea (kJmol21) and lgA (s21) for the thermal decomposition of II
Ozawa-Flynn-Wall analysis
Friedman analysis
Partial mass loss
Ea (kJmol21
)
lgA (s21
)
Ea (kJmol21
)
lgA (s21
)
0.02
0.05
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
0.95
0.98
90.25 + 12.03
119.06 + 3.04
124.08 + 2.30
109.44 + 2.72
94.69 + 6.08
86.42 + 8.27
87.86 + 8.19
94.35 + 7.22
94.66 + 7.32
89.94 + 7.04
81.22 + 5.76
69.86 + 2.86
54.76 + 3.95
6.66
9.90
10.48
8.95
7.42
6.57
6.74
7.43
7.49
7.04
6.18
5.01
3.41
112.24 + 7.01
141.04 + 9.11
114.74 + 1.53
69.77 + 14.53
57.27 + 20.58
72.65 + 16.23
109.67 + 13.29
108.38 + 17.26
82.43 + 10.48
63.55 + 6.79
47.41 + 4.03
34.34 + 4.71
32.42 + 9.06
9.07
12.27
9.56
4.94
3.69
5.27
8.99
8.89
6.39
4.58
2.96
1.46
1.11
values from each of the two methods.[20] According to
OFW method, the activation energies and pre-exponential
2. Bose, D.; Rahaman, S. H.; Mostafa, G.; Walsh, R. D. B.;
Zaworotko, M. J.; Ghosh, B. K. Synthesis, structure and proper-
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¯
factors of thermal decomposition of I are, E1 ¼ 203.77 +
32.29 kJmol21
,
lgA1 ¼ 154.28 s21
;
E2max ¼ 873.14 +
304.02 kJmol21, lgA2 ¼ 65.68 s21, respectively.
From Table 6 it can be seen that the values of lgA calcu-
lated by using Friedman method (0.02 , a , 0.98) are
smaller than the values of lgA calculated by using OFW
method (0.02 , a , 0.98), and the values of E calculated
by using Friedman method are very different, which may be
due to the analytic method effected in the experiment.
According to OFW method, the activation energies and
pre-exponential factors of thermal decomposition of II
4. Wang, C.-C.; Yang, C.-H; Lee, G.-H; Tsai, H.-L. Syntheses,
structures, and magnetic properties of two 1D, mixed-ligand,
metal coordination polymers, [M(C4O4)(dpa)(OH2)] (M ¼ CoII,
NiII, and ZnII; dpa ¼ 2,20-dipyridylamine) and [Cu(C4O4)
are, E1max ¼ 124.08 + 2.30 kJmol21, lgA=10.48 s21; E2 ¼
¯
90.00 + 7.28 kJmol21, lgA ¼ 6.99 s21, respectively.
.
(dpa)(H2O)]2 (H2O). Eur. J. Inorg. Chem. 2005, 7, 1334–1342.
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smaller than that of complex I, which may be because structure
I is more stable due to the two types of hydrogen bond action.
5. Romeo, R.; Nastasi, N.; Scolaro, L. M.; Plutino, M. R.;
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and kinetic behavior of the cationic complex (Methyl)(dimethyl
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SUPPLEMENTARY MATERIAL
Supplementary crystallographic data have been deposited
with the Cambridge Crystallographic Data Center, CCDC No.
269645 for complex I and 273706 for complex II. Copies of
this information may be obtained free of charge from The
Director, CCDC, 12 Union Road, Cambridge CB21EZ, UK
(fax: þ 44 – 1223 – 336 – 033; E-mail: deposit@ccdc.cam.
ac.uk or kwww:http:// www.ccdc.cam.ac.ukl).
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C(Aryl)-Cl activation catalysts. Angew. Chem. Int. Ed. 2002,
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osmium carbonyl complexes. Organometallics 2003, 22 (24),
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