Coordination of zinc tetraphenylporphyrin with pyridine derivatives in chloroform solution and in the solid phase

Article abstract of DOI:10.1134/S1070363217070210

Coordination of zinc tetraphenylporphyrin with 2-,3-, and 4-halopyridines, pyridin-2-amine, and pyrimidin-2-amine in chloroform has been studied by spectrophotometry. Protonation and complexation of halopyridines and haloanilines with zinc tetraphenylporp

Full text of DOI:10.1134/S1070363217070210

ISSN 1070-3632, Russian Journal of General Chemistry, 2017, Vol. 87, No. 7, pp. 1572–1579. © Pleiades Publishing, Ltd., 2017.
Original Russian Text © V.P. Andreev, P.S. Sobolev, V.A. Tafeenko, 2017, published in Zhurnal Obshchei Khimii, 2017, Vol. 87, No. 7, pp. 1179–1187.
Coordination of Zinc Tetraphenylporphyrin with Pyridine
Derivatives in Chloroform Solution and in the Solid Phase
V. P. Andreeva, P. S. Soboleva*, and V. A. Tafeenkob
a Petrozavodsk State University, ul. Lenina 33, Petrozavodsk, 185910 Russia
b Faculty of Chemistry, Moscow State University, Moscow, 119991 Russia
*e-mail: 16862.10.ns@gmail.com
Received March 16, 2017
Abstract—Coordination of zinc tetraphenylporphyrin with 2-,3-, and 4-halopyridines, pyridin-2-amine, and
pyrimidin-2-amine in chloroform has been studied by spectrophotometry. Protonation and complexation of
halopyridines and haloanilines with zinc tetraphenylporphyrin are discussed. According to the X-ray diffraction
data, enhanced stability of the 2:2 zinc tetraphenylporphyrin complex with pyrimidin-2-amine in the solid
phase and in chloroform solution is likely to be determined by hydrogen bonding between the two ligand
molecules involving nitrogen atoms in the pyrimidine ring and amino group.
Keywords: coordination, zinc tetraphenylporphyrin, pyridine derivatives, pyrimidin-2-amine, aniline derivatives,
X-ray analysis
DOI: 10.1134/S1070363217070210
Unlike other aniline derivatives, 3- and 4-halo-
anilines behave unusually in the complexation with
zinc tetraphenylporphyrin (Zn-TPP) in chloroform
[1, 2]. For example, the ΔH0 values of aniline
derivatives (except for 4-haloanilines and 2,6-dichloro-
and pKa and Hammett σ-constants, on the other (r =
0.99–0.999) [2, 3]. We have found that the change of
ΔH0 upon coordination of Zn-TPP to pyridine
derivative is linearly related to the ligand basicity and
Hammett constant σ (ΔH0 = 1895pKa – 27000, r =
0.99; ΔH0 = –10580σ – 17085; r = 0.994) and that the
absolute value of ΔH0 increases as pKa of the ligand
decreases. The ΔS0 values are also linear in pKa of the
ligands and Hammett constants (ΔS0 = 9.77pKa – 40.2,
r = 0.99; ΔS0 = –54.68σ + 10.79, r = 0.994). Unlike
aniline derivatives, the complexation of Zn-TPP with
substituted pyridines is isoequilibrium or isothermo-
dynamic (ΔH0 = 194ΔS0 – 19190, r = 0.9997). The
new data obtained in this work for halogen-substituted
pyridines are given in Table 1.
anilines) are fairly similar (ΔH0 = –14.7±0.1 kJ/mol;
av
n = 20); i.e., their coordination with Zn-TPP (including
3- and 2-haloanilines) is an isenthalpic process, and
ΔS0 is linearly related to logK where K is the stability
constant of the complex (Fig. 1a). Of particular interest
is the behavior of 4-haloanilines, for which ΔH0
changes from –13.47 to –15.62 kJ/mol upon complexa-
tion with Zn-TPP. These ligands (Fig. 1) show no
linear correlation between ΔS0 and substituent con-
stants σ+ or between ΔS0 and logK (ΔG0), though such
correlations are typical of other aniline derivatives.
The ΔS0–σ+ correlation for 3-haloanilines (Fig. 1b) also
deviates from linearity, though to a lesser extent.
NH2
X
N
N
N
2a, 2b
N
3
NH2
We have compared peculiar features of Zn-TPP
coordination with halopyridines 1a–1i, pyridine (1j),
pyridin-2- and -4-amines 2a and 2b, and pirimidin-2-
amine (3) in chloroform. The coordination of Zn-TPP
with 3- and 4-halopyridines was characterized by good
linear correlations between logK and Δλ (shift of the
absorption maximum of Zn-TPP due to coordination
with n-donor ligand in chloroform), on the one hand,
1a_1j
1, X = 4-Cl (a), 4-I (b), 3-F (c), 3-Cl (d), 3-Br (e), 3-I (f),
2-F (g), 2-Cl (h), 2-Br (i), H (j); 2, X = 4-NH2 (a), 2-NH2 (b).
Unlike aniline derivatives, the complexation of Zn–
TPP with 2-halopyridines showed no linear ΔS0–logK
correlation (Fig. 2a). This may be accounted for by
1572

COORDINATION OF ZINC TETRAPHENYLPORPHYRIN WITH PYRIDINE DERIVATIVES
(a) (b)
1573
σ+
log K
Fig. 1. Plots of ΔS0 versus (a) logK and (b) substituent constants σ+ for the complex formation of Zn-TPP with substituted anilines in
chloroform at 25°C; ΔS0 = 19.46logK – 50.07; n = 14, r = 0.99 (X = H, 3-Me, 4-Me, 3-MeO, 4-MeO, 4-NH2, 3-NO2, 3-F, 3-Cl, 3-Br,
2-F, 2-Cl, 2-Br, 2-I); ΔS0 = –11.56σ+ – 9.15; n = 7, r = 0.98 (X = H, 3-Me, 4-Me, 3-MeO, 4-MeO, 4-NH2, 3-NO2) [1, 2].
greater steric hindrances created by the α-substituent
for coordination to the pyridine nitrogen atom in
comparison to the NH2 group in substituted anilines.
Likewise, no linear correlation was observed between
the thermodynamic parameters for coordination of 3-
halopyridines and logK, though steric effect of the β-
or γ-substituent on the coordination to Zn–TPP should
be insignificant (anomalous behaviors of 4-halo-
pyridines and 4-haloanilines are similar). As with
aniline derivatives, the points for 3- and 4-halopyri-
dines deviate from the ΔS0–σ straight line (Fig. 2b)
(2-halopyridines are not discussed since there are no
appropriate constants σ).
Both 2-haloanilines and 2-halopyridines do not fit
linear correlations logK–Δλ and logK–pKa typical of
all 4- and 3-substituted derivatives for which the logK–σ,
Δλ–σ, and pKa–σ correlations are also linear. This may
be due to steric factors; however, the gas-phase
basicities [5, 6] (GB) of 3- and 4-substituted anilines
Table 1. Stability constants (K), thermodynamic parameters (ΔH0, ΔS0) for the formation of Zn-TPP complexes with pyridine
derivatives 1a–1j, aminopyridines 2a and 2b, and pyrimidin-2-amine (3) in chloroform at 25°C, shifts of the absorption
maxima (Δλ) in the electronic spectra of Zn-TPP upon complex formation, and substituent constants σ
Ligand
K298, L mol–1
σ [4]
ΔλSoret
ΔλII
ΔλI
–ΔH0, kJ/mol
ΔS0, J mol–1 K–1
1a
6495±40
0.227
10.5
14.1
16.8
22.02±1.60
–0.9±5.5
1b
1c
1d
1e
1f
2105±45
1065±15
1010±13
967±30
0.18
0.337
0.373
0.391
0.352
–
9.4
8.8
8.7
8.5
9.1
–
14.5
13.8
13.6
13.9
14.4
12.8
12.4
11.7
15.0
17.5
14.2
11.6
17.0
14.9
15.7
16.0
16.5
14.9
14.5
14.0
18.2
20.7
15.8
11.8
14.91±0.11
20.88±0.07
17.48±0.1
13.6±0.5
–12.1±0.3
–1.37
15.76±0.15
14.28±0.13
13.89±0.76
15.42±0.35
9.54±0.13
4.35±0.9
13.8±0.3
–32.1±1.7
–39.4±1.5
–27.1±0.6
8.9±0.6
1680±25
5.7±0.16
4.5±0.1
1g
1h
1i
–
7.2
–
1.71±0.7
3520±150
17460±380
670±30
–
1j
0
9.8
12.1
–
17.29±0.17
10.50±0.44
17.81±0.36
17.33±0.72
2a
2b
3
–0.66
–
46±2
–5.5±1.5
–1.5±2.3
910±30
–
–
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1574
ANDREEV et al.
(a)
(b)
σ
log K
Fig. 2. Plots of ΔS0 versus (a) logK and (b) substituent constants σ+ for the complex formation of Zn-TPP with substituted pyridines
in chloroform at 25°C; ΔS0 = 53.85logK – 180.74; n = 9, r = 0.998; ΔS0 = –51.36σ – 12.5; n = 9, r = 0.98; X = 4-NH2, 4-NMe2, 4-
Me, H, 4-CN, 4-COMe, 3-Me, 3-CONH2, 3-COOEt.
(a)
(b)
pKa
pKa
Fig. 3. Plots of the gas-phase basicities (GB) of (a) aniline (triangles, X = H, 4-F, 4-Cl, 3-F, 3-Cl, 3-Br, 3-I); circles (X = 4-Me,
4-OMe, 4-NH2, 3-Me, 3-NO2, 2-Me) and (b) pyridine derivatives (triangles, X = 3-Cl, 3-Br, 3-I, 2-F, 2-Cl, 2-Br; circles, X = H,
4-NH2, 4-Me, 3-Me, 3-CONH2) versus pKa in water at 25°C; (a) GB = 7.80pKa + 826; r = 0.998; n = 6; (b) GB = 11.2 pKa + 845;
r = 0.99; n = 5) [5, 6].
(Fig. 3a; no data for 2-substituted derivatives are
given, except for 2-methylaniline) and, to a lesser
extent, of 2- and 3-halopyridines (Fig. 3b; the data for
4-halopyridines are not given) also displayed no linear
correlation with pKa.
2-Cl) fit well the linear correlation Δλ–pKa (anilines:
ΔλII = 0.99pKa + 9.72; n = 17, r = 0.96; pyridines: ΔλII =
0.58pKa + 12.3; n = 17, r = 98), though the Δλ values
were measured in chloroform while pKa values were
determined in water. Presumably, both these solvents
essentially and similarly level unusual properties
(static polarization effect) of halogen atoms via
dynamic polarization of base molecules.
Taking into account the lack of steric effect of
3- and 4-substituents and of essential intermolecular
interactions in the gas phase, the electronic factors of
halogens are determined by specific rules depending
on the solvent.
The thermodynamic behaviors of the two ligand
series demonstrated considerably stronger differences:
the complexation of Zn-TPP with aniline derivatives
(except for 4-haloganilines) is an isenthalpic process,
whereas the complexation with pyridine derivatives
(except for 2-, 3-, and 4-halopyridines) is isothermo-
dynamic, and all halopyridines do not fit linear correla-
All monosubstituted anilines (X = 4-NH2, 4-OMe,
4-Me, 4-F, 4-Cl, 4-Br, 4-I, H, 3-Me, 3-OMe, 3-NO2,
3-F, 3-Cl, 3-Br, 2-F, 2-Cl, 2-Br) and pyridines (X =
4-NMe2, 4-NH2, 4-Me, 4-CN, 4-COMe, 4-Cl, 4-I, H,
3-Me, 3-CONH2, 3-COOEt, 3-F, 3-Cl, 3-Br, 3-I, 2-F,
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 87 No. 7 2017

COORDINATION OF ZINC TETRAPHENYLPORPHYRIN WITH PYRIDINE DERIVATIVES
1575
Table 2. Basicity constants of haloanilines and halopyridines in water (pKa) and stability constants of their complexes with
Zn-TPP in chloroform (K, 25°C)
Haloanilines, pKa (H2O) [2, 9], KZn-TPP [2]
Halopyridines pKa (H2O) [10, 11], KZn-TPP [2]
Halogen
position
F
Cl
Br
I
F
Cl
Br
I
4
3
2
4.65,
164
3.57,
59
3.20,
41
3.98,
138
3.57,
72
2.64,
36
3.88,
109
3.53,
89
2.53,
33
3.79,
124
3.61,
–
2.55,
31
–
–
2.97,
1065
0.44,
57
3.83,
6495
2.84,
1010
0.72,
4.5
3.78,
–
2.84,
967
0.90,
1.71
4.06,
2105
3.25,
1680
1.82,
–
tions ΔH–ΔS, as well as linear correlations of ΔH and
ΔS with logK, Δλ, pKa, and σ.
4-haloanilines but also 4-halopyridines in chloroform
(Tables 1, 2). Exceptions are 4-iodoaniline (for which
the stability constant K is higher than for 4-bromo-
aniline) and 4-iodopyridine (maximum pKa value). The
K values (Tables 1, 2) for 4-fluoroaniline (164 L/mol)
and 4-chloropyridine (6495 L/mol) are higher than
those for aniline (141 L/mol [2]) and pyridine (3520 L/mol
[2]), respectively. In the case of 2-haloanilines and
2-halopyridines, the stability constants change in
keeping with the general trend (F > Cl > Br > I).
Analysis of a few published and our own X-ray
diffraction data [2, 7] on 1:1 molecular complexes of
Zn-TPP with pyridine, phenol, aniline, pyridine N-
oxide, and quinoline N-oxide derivatives allowed us to
divide these complexes into two groups. The crystal
structure of n,ν-complexes derived from pyridine is
characterized by almost orthogonal orientation of the
pyridine ring with respect to the macrocycle plane (the
corresponding dihedral angle is 80°–89°), whereas
other ligands are oriented at an angle of 24° to 34°.
Probably, just these structural features are responsible
for the specific thermodynamic and kinetic behaviors
of pyridine derivatives (isoequilibrium process), as
well as of anilines and heteroaromatic N-oxides
(isenthalpic process), upon coordination to Zn-TPP.
However, there are also other differences in the
behaviors of halogen-substituted anilines and pyri-
dines. The orders of variation of pKa and KZn-TPP for
2- and 4-substituted anilines (+M effect is the major
factor), depending on the halogen nature (except for
4-iodo- and 4-bromoanilines), are almost similar.
3-Iodoaniline has the maximum basicity among
3-haloanilines (no +M effect), but the basicity order of
the other compounds remains almost unchanged.
However, the order is reversed upon coordination to
Zn-TPP (data for 3-iodoaniline are lacking).
Unusual behavior of halogen derivatives is likely to
be related in part to the fact that, unlike carbon,
nitrogen, and oxygen atoms constituting other sub-
stituents on the pyridine ring and belonging to the
same period of the Periodic Table, halogen atoms
belong to different periods of the Periodic Table
(though derivatives with fluorine atom of the second
Period also behave unusually; Figs. 1–3). Differences
in the size of halogen orbitals are considerably larger;
therefore, peculiarities of static (electronic effects) and
dynamic polarization [solvation with water (pKa) and
chloroform (logKZn-TPP)] of molecules containing
halogen atoms cannot be rationalized in a simple
manner. For example, the unusual basicity order of 4-
haloanilines (Table 2; F > Cl > Br > I, where the
fluorine atom is the strongest electron donor) in water
is explained assuming greater contribution of the +M
effect than of the –I effect which decreases in the
opposite direction [8]. In fact, this order is generally
retained for the complexation of Zn-TPP with not only
Substituted anilines:
pKa (H2O)
KZn-TPP,
4-F > 4-Cl > 4-Br > 4-I 4-F > 4-Cl > 4-I > 4-Br
3-I > 3-F = 3-Cl > 3-Br 3-Br > 3-Cl > 3-F
2-F > 2-Cl > 2-Br = 2-I 2-F > 2-Cl > 2-Br > 2-I
There are some peculiarities in the halopyridine
series. All iodopyridines are the most basic (no pKa
value of 4-fluoropyridine is available), while the
basicity and stability constant orders for the other
derivatives are similar. Exceptions are pKa values of 2-
halopyridines (reverse order) and stability constants
KZn-TPP for 3-halopyridines (the highest value is
observed for 3-iodopyridine).
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ANDREEV et al.
Table 3. Bond lengths and dihedral angles in Zn-TPP complexes 4–6 with pyrimidin-2-amine, acetone, and water
Parameter
Zn–N (Zn–O) bond length, Å
4
5
6
2.252
2.249
2.439
Deviation of the zinc atom from the porphyrin plane, Å
0.341
85.50
0.353
83.07
–
Dihedral angle between the porphyrin and extra ligand planes, deg
90
Substituted pyridines:
interact with the benzene π-system. One endocyclic
nitrogen atom of pyrimidin-2-amine forms a dative
bond with the zinc atom, so that the latter deviates by
0.341 Å from the porphyrin macrocycle plane (Table 3).
The Zn–N bond length is 2.252 Å, and the porphyrin
macrocycle and pyrimidine ring form a dihedral angle
of 85.50°. The other endocyclic pyrimidine nitrogen
atom and the amino group are involved in inter-
molecular hydrogen bonding to form a centro-
symmetric dimer (Fig. 4a) through N–H···N hydro-
gen bonds (N···N 2.061 Å). The pyrimidine rings in
the dimer lie in one plane, and the amino group is
turned through an angle of 8.91° with respect to the
pyrimidine ring.
pKa (H2O)
KZn‒TPP
4-I > 4-Cl > 4-Br
4-Cl > 4-I
3-I > 3-F > 3-Cl = 3-Br 3-I > 3-F > 3-Cl > 3-Br
2-I > 2-Br > 2-Cl > 2-F 2-F > 2-Cl > 2-Br
Thus, static polarization (electronic effects) cannot
completely rationalize variation of the stability
constants and thermodynamic parameters determined
by us. We plan to contunue studying anomalous
behavior of halogen derivatives of pyridine, aniline,
phenol, and heteroaromatic N-oxides.
We attempted to elucidate peculiar features of the
coordination of Zn-TPP with pyridin-2-amine (2b) and
pyrimidin-2-amine (3) that are key intermediate
products in the synthesis of many biologically active
compounds and medicinals. The stability constants and
thermodynamic parameters for the complexation of
Zn-TPP with ligands 2b and 3 are given in Table 1.
The X-ray diffraction data (Fig. 4a) suggest that, as
in the crystalline state, the formation of centrosym-
metric dimer is responsible for the enhanced stability
of complex 4 in chloroform. Analogous intermolecular
hydrogen bonds are formed in nature between
complementary base pairs in DNA helix. Such
dimerization via hydrogen bonding is impossible for
the Zn-TPP complex with pyridin-2-amine since the
latter lacks second endocyclic nitrogen atom.
The stability constants of the complexes formed by
Zn-TPP with pyridin-2-amine (2b) and pyrimidin-2-
amine (3) were much higher than those found for
2-halopyridines, and the complexation with these
ligands was characterized by more negative ΔH0 values
and less negative values. The ΔS0 values were positive
for pyridine (1i) and, especially for pyridin-4-amine
(2a) (Table 1) having higher pKa values (5.29 and 9.17 [2]).
We failed to isolate a complex of Zn-TPP with
pyridin-2-amine from acetone solution; instead,
crystalline 1:1 adduct 5 of Zn-TPP with acetone was
formed (Fig. 4b). The crystal packing of 5 is
represented by a two-layer structure like cell mem-
brane, where weakly polar metal porphyrin molecules
are linked through H25 aromatic hydrogen atoms of one
layer and C9 and N3 of the other layer. More polar
acetone molecules are located at the outer side of the
porphyrin systems and are coordinated to zinc, thus
forcing the latter out of the porphyrin macrocycle by
0.353 Å. The Zn–O bond length is 2.249 Å, and the
dihedral angle between the macrocycle and acetone
planes is 83.07°.
Pyridin-2-amine (2b), in keeping with its higher
basicity {pKa 6.86 (5.23) [12]} relative to pyrimidin-2-
amine (3) {(pKa 3.54 (1.30) [12]}, showed higher
nucleophilicity in the coordination to metal porphyrins.
However, the stability constant of the Zn-TPP complex
with pyrimidin-2-amine (3) is slightly higher. In order
to rationalize these findings, the structure of crystalline
Zn-TPP adduct 4 was studied by X-ray analysis.
According to the X-ray difraction data (Fig. 4a, Table 3),
isolated complex 4 contains solvent (acetone) molecule
and has the composition Zn-TPP–pyrimidin-2-amine–
acetone 1:2:1. Protons of the acetone molecule
In view of the above stated, of particular interest is
ligand competition for coordination sites in the
complexation with Zn-TPP. Therefore, while studying
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 87 No. 7 2017

COORDINATION OF ZINC TETRAPHENYLPORPHYRIN WITH PYRIDINE DERIVATIVES
1577
Fig. 4. (a) Structure of complex 4 formed by zinc tetraphenylporphyrin with pyrimidin-2-amine according to the X-ray diffraction
data (black circles indicate nitrogen atoms; acetone molecule is shown at the top) and (b) steric arrangement of molecules 4 and
acetone molecules in the crystal packing (black circles indicate nitrogen atoms, and white circles indicate acetone oxygen atoms).
complex formation of Zn-TPP with n-donor ligands in
solution and obtaining crystalline complexes for X-ray
analysis, we selected chloroform as solvent incapable
of participating in strong specific interaction.
Nevertheless, even low-boiling chloroform can be
included into crystals, as it was observed, e.g., for the
2:1 complex of Zn-TPP with p-phenylenediamine [1].
elucidate mechanisms of interaction of pyrimidine
drugs with heme-containing proteins, as well as
coordination processes in vivo involving metal
porphyrins used as photosensitizers in photodynamic
therapy of cancer.
EXPERIMENTAL
The use of acetone which always contains some
water (if no special purification was performed) makes
the situation more complicated. As stated above, from
a solution in acetone we isolated crystalline complex 4
of Zn-TPP with pyrimidin-2-amine, whereas acetone
complex 5 with Zn–O dative bond was isolated in the
presence of pyridin-2-amine. Our attempts to obtain
Zn-TPP complexes with 4-aminobenzaldehyde and
ethyl 4-dimethylaminobenzoate from acetone solution
in both cases resulted in the isolation of previously
unknown adduct 6 of Zn-TPP with water at a ratio of
1:1 (Fig. 5, Table 3). Unlike the complex with acetone,
complex 6 in crystal has a multilayer structure where
the porphyrin units are linked not only directly to each
other (Fig. 5) but also to water molecules located on
the fourfold inversion axis and statistically positioned
below or above the porphyrin plane, so that a pseudo
symmetry center appears.
The electronic absorption spectra were measured on
an SF 2000-02 spectrophotometer. The stability constants
of Zn-TPP complexes with pyridine derivatives and
pyrimidin-2-amine in chloroform were determined
according to the procedure described in [1]. The
thermodynamic complex formation constants were
determined by the graphical method using formula (1)
(first Ulich approximation) [13] and assuming that ΔH
Thus, neither the basicity of halogen-substituted
anilines and pyridines in water or gas phase nor their
coordination to Zn-TPP in chloroform can be
interpreted with the aid of only electronic factors. The
anomalous behavior of these ligands is essentially
determined by solvation. Unlike aminopyridines, amino-
pyrimidines are capable of forming H-bonded as-
sociates in the complexation with metal porphyrins
both in the solid phase and in solution. This may
Fig. 5. Structure of complex 6 formed by zinc tetraphenyl-
porphyrin and water according to the X-ray diffraction data.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 87 No. 7 2017

1578
ANDREEV et al.
Table 4. Crystallographic parameters of Zn-TPP complexes 4–6
Parameter
4
5
6
Formula
C48H33N7Zn·C3H6O
C47H34N4OZn
C44H30N4OZn
Molecular weight
831.26
0.12×0.08×0.05
295
736.15
0.18×0.14×0.12
295
696.09
0.10×0.08×0.04
295
Crystal dimensions, mm
Temperature, K
Crystal system
Space group
a, Å
Triclinic
P-1
Monoclinic
P21C
Tetragonal
I-4
11.0531(4)
11.6587(5)
17.6689(8)
96.684(3)
93.792(3)
107.994(3)
2138.22
2
14.8542(6)
17.5725(6)
14.3296(7)
90
13.3969(3)
13.3969(3)
9.6671(2)
90.00
b, Å
c, Å
α, deg
β, deg
96.646(4)
90
90.00
γ, deg
V, Å3
90.00
3715.26
4
1735.02
2
Z
d
calc, g/cm3
μ, mm–1
max, deg
1.291
1.316
1.332
1.161
1.242
1.298
Θ
72.8
69.2
72.0
h, k, l ranges
–12.3, –13.14, –21.11
7979
–17.17, –21.17, –7.11
6840
–15.16, –7.16, –11.11
3735
Number of independent reflections
Number of reflections with I > 2σ(I)
Number of variables
R(F2)
5058
2931
1252
560
480
120
0.037
0.052
0.047
Rw(F2)
0.078
0.11
0.124
Goodness of fit
0.89
0.81
1.016
Δρmax/Δρmin (ē/Å3)
0.25/–0.34
0.30/–0.28
0.33/–0.45
and ΔS remain constant in the examined narrow
temperature range (273–313 K).
Complexes 5 and 6 were synthesized in a similar
way using pyridine-2-amine and 4-aminobenzaldehyde
or ethyl 4-(dimethylamino)benzoate, respectively.
ln KT = –ΔH0298/RT + ΔS0298/R.
(1)
The X-ray diffraction data for complexes 4–6 were
obtained on a STOE StadiVariPilatus 100K diffracto-
meter (CuKα radiation, GeniX3DCuHF generator,
microfocus X-ray tube, Xenocs FOX3D HF multilayer
thin film ellipsoid monochromator). The data were
collected and processed using STOEX-Area software.
The principal crystallographic parameters of com-
plexes 4–6 are given in Table 4. The structures were
(Pyrimidin-2-amine)(5,10,15,20-tetraphenylpor-
phyrinato)zinc(II) (4). A hot saturated acetone solu-
tion (10 mL) containing 10 mg (1.47×10–5 mol) of Zn-
TPP was mixed with a solution of pyrimidin-2-amine
(1.55×10–5 mol) in the same solvent, and the mixture
was left to stand at room temperature in the dark on
exposure to air. The crystals were filtered off, washed
with acetone (3×2 mL), and dried in air.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 87 No. 7 2017

COORDINATION OF ZINC TETRAPHENYLPORPHYRIN WITH PYRIDINE DERIVATIVES
1579
3. Andreev, V.P., Sobolev, P.S., Larkina, E.A., and
Tkachevskaya, E.P., Chem. Heterocycl. Compd., 2012,
vol. 48, no. 3, p. 497. doi 10.1007/s10593-012-1022-2
4. Becker, H., Einführung in die Elektronentheorie
organisch–chemischer Reaktionen, Berlin: Wissen-
schaften, 1974, 3rd ed. Translated under the title
Vvedenie v elektronnuyu teoriyu organicheskikh reaktsii,
Moscow: Mir, 1977, p. 87.
5. Hunter, E.P.L. and Lias, Sh.G., J. Phys. Chem. Ref.
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6. Andreev, V.P., Sobolev, P.S., and Zachinyaeva, A.V.,
Uch. Zap. Petrozavod. Gos. Univ., Ser. Fiz.-Khim. Biol.,
2016, no. 6 (159), p. 92.
solved by the direct method implemented in SHELXS-
97 [14]. The positional and thermal parameters of non-
hydrogen atoms were refined in full-matrix anisotropic
approximation. The positions of hydrogen atoms were
calculated and refined in isotropic approximation
according to the riding model. The molecular struc-
tures were plotted using DIAMOND [15]. The X-ray
diffraction data were deposited to the Cambridge
Crystallographic Data Centre [CCDC entry nos.
1521215 (4), 1521213 (5), 1521216 (6)].
ACKNOWLEDGMENTS
7. Allen, F.H., Acta Crystallogr., Sect. B, 2002, vol. 58,
The X-ray analysis was performed in the frame-
work of the Association Agreement between the
Faculty of Chemistry of the Moscow State University
and Medical Institute of the Petrozavodsk State
University using the equipment provided by the
Program for the Development of Moscow State University.
p. 380.
8. Reutov, O.A., Kurts, A.L., and Butin, K.P.,
Organicheskaya khimiya (Organic Chemistry), Moscow:
Mosk. Gos. Univ., 2004, vol. 1, p. 103.
9. Pankratov, A.N., Uchaeva, I.M., Doronin, S.Yu., and
Chernova, R.K., J. Struct. Chem., 2001, vol. 42, no. 5,
p. 739.
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