Crystal and molecular structures of tetraaqua(di-para-oxybenzoato)iron(II) tetrahydrate

Article abstract of DOI:10.1134/S1070328410010124

The new complex [(p-HOC₆H₄CO₂) ₂Fe(H₂O)₄] ? 4H₂O is synthesized and studied by X-ray diffraction analysis. The Fe(II) cation is coordinated by two para-hydroxybenzoate anions through the mono-dentate mode. Four oxygen atoms of the water molecules complete the coordination polyhedron of the central atom to an octahedron. Four molecules of water of crystallization cross-link the monomers to form a polymeric structure.

Full text of DOI:10.1134/S1070328410010124

ISSN 1070ꢀ3284, Russian Journal of Coordination Chemistry, 2010, Vol. 36, No. 1, pp. 73–75. © Pleiades Publishing, Ltd., 2010.
Original Russian Text © A.T. Mamedova, M.F. Rzaeva, E.M. Movsumov, V.S. Sergienko, 2010, published in Koordinatsionnaya Khimiya, 2010, Vol. 36, No. 1, pp. 74–76.
Crystal and Molecular Structures
of Tetraaqua(diꢀparaꢀoxybenzoato)iron(II) Tetrahydrate
A. T. Mamedovaa, M. F. Rzaevaa, E. M. Movsumova,*, and V. S. Sergienkob
a Azerbaijan State Agrarian University, Gyandzha, Azerbaijan
b Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences,
Leninskii pr. 31, Moscow, 119991 Russia
*Eꢀmail: ElmanI@mai.ru
Received June 16, 2009
Abstract—The new complex [(
p
ꢀHOC6H4CO2)2Fe(H2O)4] 4H2O is synthesized and studied by Xꢀray difꢀ
⋅
fraction analysis. The Fe(II) cation is coordinated by two paraꢀhydroxybenzoate anions through the monoꢀ
dentate mode. Four oxygen atoms of the water molecules complete the coordination polyhedron of the cenꢀ
tral atom to an octahedron. Four molecules of water of crystallization “crossꢀlink” the monomers to form a
polymeric structure.
DOI: 10.1134/S1070328410010124
INTRODUCTION
size (Mo
μ
K
radiation,
λ
= 0
.
71073
Å,
θ
= 9.92°−18.12
°,
α
= 10.73 mm–1).
The simplest representative of aromatic hydroxyacꢀ
ids, paraꢀhydroxybenzoic acid (pꢀHOC6H4COOH), is
The structure of complex
I
was determined by the
met in soils [1], sea water [2], various organs of plants,
grape leaves and berries [3], and sweet beet [4] and is
introduced into food products as a preserving agent
[5]. This acid composes a number of pharmaceuticals
that stimulate inotropic effects of human heart and is
active against arrhythmia [6].
heavy atom method [7]. The coordinates of atoms are
given in Table 1 (the values of the thermal parameters
Table 1. Coordinates of atoms (×104) in structure I
Atom
x
y
z
Based on the aforesaid, it seems interesting to synꢀ
thesize and study by Xꢀray diffraction analysis comꢀ
plexes of hydroxybenzoic acid with microelements,
namely, with iron(II), which is in the composition of
hemoglobin.
Fe
500
500
0
O(1)
O(2)
O(3)
O(4)
O(5)
C(1)
C(2)
C(3)
C(4)
C(5)
C(6)
C(7)
9659(7)
8987(8)
9225(9)
2271(5)
8409(7)
9325(8)
9268(9)
8519(9)
8449(8)
9216(8)
10012(11)
1002(1)
4627(5)
2702(4)
3745(3)
5828(4)
4519(4)
3675(7)
3679(6)
2749(7)
2753(8)
3688(9)
4629(7)
4632(8)
831(2)
830(3)
EXPERIMENTAL
3416(3)
116(4)
Single crystals of HOC6H4COO)2Fe(H2O)4]
for Xꢀray diffraction analysis was prepared by the
reaction of aqueous solutions of iron(II) sulfate and
sodium ꢀhydroxybenzoate taken in a ratio of 1 : 2.
⋅
4H2O
(I)
869(2)
p
1092(4)
1698(5)
2561(4)
2554(5)
2861(4)
2563(4)
2005(4)
The mixture of the solutions heated to boiling was
cooled to room temperature. After several days, brown
crystals of I precipitated from the mixture.
The Xꢀray diffraction analysis was carried out on an
EnrafꢀNonius CADꢀ4 automated diffractometer.
The crystals are orthorhombic:
225(5), = 24.152(5)
= 2099(1) Å3
ρcalcd = 1.498 g/cm3,
= 4, space group Pcab
0.027, = 295 K.
The intensities of 2835 independent reflections
were measured for the crystal 0.14 0.18 0.21 mm in
а
= 7.758(3),
b = 11.
c
Å,
V
, M
= 464,
Z
, R =
T
×
×
73

74
MAMEDOVA et al.
O(2)
C(3)
O(5)
C(4)
C(1)
O(3)
O(4)
C(2)
C(5)
C(6)
Fe
O(1)
C(7)
O(6)
O(7)
Fig. 1. Structure of [(
p
ꢀHOC H CO ) Fe(H O) ]
⋅
4H O.
6
4
2 2
2
4
2
x
y
2
1
15
5
25
24
4
1
14
3
13
′
17
7
6
16
′
27
26
Fig. 2. Projection of the fragment of the structure of complex I on the plane [001].
Table 2. Selected bond lengths and bond angles in structure I
Bond
Fe–O(1)
d
, Å
Bond
d
, Å
Bond
d, Å
2.162(5)
O(1)–C(1)
O(2)–C(1)
O(3)–C(5)
C(1)–C(2)
O(3)–H(13)
1.243(2)
1.268(5)
1.352(2)
1.472(4)
1.02(3)
C(2)–C(3)
C(3)–C(4)
C(4)–C(5)
C(5)–C(6)
C(6)–C(7)
1.40(1)
1.36(1)
1.40(1)
1.41(1)
1.37(1)
Fe–O(4)
Fe–O(5)
2.284(3)
2.287(5)
Angle
ω
,
deg
Angle
ω
,
deg
Angle
ω
, deg
O(1)FeO(4)
O(1)FeO(7)
O(7)FeO(6)
O(1)C(1)O(2)
O(2 C(1)C(2)
92.41(2)
90.02(2)
89.87(3)
121.72(3)
119.16(3)
C(1)C(2)C(3)
C(1)C(2)C(7)
O(3)C(5)C(4)
O(3)C(5)C(6)
C(3)C(2)C(7)
121.67(4)
121.12(3)
122.54(7)
118.65(4)
118.19(4)
C(2)C(3)C(4)
C(3)C(2)C(1)
C(5)C(6)C(7)
C(6)C(7)C(2)
122.25(7)
119.81(7)
119.34(4)
122.81(3)
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 36
No. 1
2010

CRYSTAL AND MOLECULAR STRUCTURES OF TETRAAQUA
75
are available from the authors). Selected bond lengths
REFERENCES
and bond angles are listed in Table 2.
1. Tsareva, R.I. and Semenova, T.A., Pletidnyi apparat i
zhiznedeyatelnost’ rastenii (Plastid Apparatus and Vital
Activity of Plants), Minsk, 1971.
RESULTS AND DISCUSSION
2. Degens, E.T., Reuter, J.N., and Shaw, K.N.F.,
In the centrosymmetric molecule of complex
I
Geochim. Cosmochim. Acta, 1964, vol. 28, no. 1, p. 45.
(Fig. 1), the Fe2+ ion is coordinated by four oxygen
atoms of the water molecules [8]. The iron atom is
completed to the octahedral coordination by two oxyꢀ
gen atoms of the carboxylate groups of two monodenꢀ
tate paraꢀhydroxybenzoate anions. Four molecules of
water of crystallization “crossꢀlink” the monomers to
form the polymeric structure (Fig. 2).
3. RibereauꢀGayon, P., Compt. Rend., 1963, vol. 256,
no. 19, p. 4108.
4. Obala, Y., Senla, Y., and Coshika, M., Agr. Biol. Chem.
(Tokyo), 1963, vol. 27, p. 340.
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1978, vol. 89, no. 209282.
,
ACKNOWLEDGMENTS
7. Fair, C.K., Molen. An Interactive Intelligent System for
Crystal Stucture Analysis, Delft: EnrafꢀNonius, 1990.
The authors are grateful to the coworkers of the
Faculty of Physics of the Hacettepe University
(Ankara, Turkey) for performing the Xꢀray diffraction
8. Johnson, S.K., ORTER II. Report ORNLꢀ5138, Tennesꢀ
analysis of crystal I.
see (USA): Oak Ridge Natiinal Labiratiro, 1976.
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 36
No. 1
2010