Preparation of complexes of 1-amino-6,7-O-cyclohexylidene-4-azaheptane with transition metal acetates

Article abstract of DOI:10.1134/S1070363206010075

1-Amino-6,7-O-cyclohexylidene-4-azaheptane (L) has been synthesized starting from 1-chloro-2,3-O-cyclohexylidenepropane prepared by the reaction of epichlorohydrin with cyclohexanone, catalyzed by BF₃OEt₂. Complexes of this ligand with Co(II), Ni(II) and Cu(II) acetates were prepared. The structures of the ligand and its complexes are proposed based on the elemental analyses, IR, UV-VIS, and ¹H and ¹³C NMR spectra, magnetic susceptibilities, and conductomety data. Pleiades Publishing, Inc. 2006.

Full text of DOI:10.1134/S1070363206010075

ISSN 1070-3632, Russian Journal of General Chemistry, 2006, Vol. 76, No. 1, pp. 33 36.
Pleiades Publishing, Inc., 2006.
Original Russian Text
O.F. Oztirk, M. Sekerci, E. Ozdemir, 2006, published in Zhurnal Obshchei Khimii, 2006, Vol. 76, No. 1, pp. 36 40.
,
Preparation of Complexes
of 1-Amino-6,7-O-Cyclohexylidene-4-Azaheptane
with Transition Metal Acetates
O. F.Oztirk*, M.Sekerci**, and E.Ozdemir*
,
* C, anakkale 18 Mart University of Arts and Sciences, C, anakkale, 17100 Turkey
** Firat University, Elazig, 23119 Turkey
Received February 6, 2004
Abstract 1-Amino-6,7-O-cyclohexylidene-4-azaheptane (L) has been synthesized starting from 1-chloro-
2,3-O-cyclohexylidenepropane prepared by the reaction of epichlorohydrin with cyclohexanone, catalyzed by
BF3OEt2. Complexes of this ligand with Co(II), Ni(II) and Cu(II) acetates were prepared. The structures of
the ligand and its complexes are proposed based on the elemental analyses, IR, UV-VIS, and 1H and 13C NMR
spectra, magnetic susceptibilities, and conductomety data.
DOI: 10.1134/S1070363206010075
Complexes formed by reactions of diamines with
transition metals have a wide range of applications
[1 7]. For instance, they are used in the determination
of mercury in natural waters, production of colored
thermoplastic resins and cross-linked epoxy resins,
determination of selenium by instrumental methods,
prevention of corrosion, pressure-sensitive color
imaging technologies, powdered hair dyes, cation-
exchange copolymerizations, and some antiallergenes
of medical use [8].
Proceeding with our research into the coordination
activity of various diamines containing an oxolane
group toward transition metal ions, in the present
work we synthesized three new complexes of 1-amino-
6,7-O-cyclohexylidene-4-azaheptane (L) with Co(II),
Ni(II) and Cu(II) acetates.
1-Amino-6,7-O-cyclohexylidene-4-azaheptane (L)
was prepared by a two-step procedure (Scheme 1).
The first step was the synthesis of 1-chloro-2,3-O-
cyclohexylidenepropane (I) from of cyclohexanone
and epichlorohydrin. In this reaction, BF3 OEt2 was
used as catalyst. In the second step, 1-chloro-2,3-O-
cyclohexylidenepropane was reacted with 1,3-diamino-
propane to obtain the target product. The structures of
L was determined by a combination of elemental
1,3-Dioxolane complexes are also used as mono-
mers for homo- or copolymer synthesis. Oguchi et al.
have studied the semiconducting properties and bio-
logic activity of 1,3-dioxolane vinyl polymers [9].
Finally, 1,3-dioxolane complexes can be used as sol-
vents, additives, and corrosion-preventing materials
[10].
1
analyses, IR, UV-VIS, and H NMR spectroscopy,
magnetic susceptibility measurements, and conduc-
tometry (see Experimental).
Scheme 1.
CH2 Cl
O
O
O
BF3 OEt2
H2C CH CH2 Cl +
O
I
CH2 NH (CH2)3 NH2
O
O
I + NH2(CH2)3NH2
L
33

34
OZTIRK et al.
Table 1. Yields, colors, elemental analyses, and molecular weights of ligands and complexes
Found, %
H
Calculated, %
Yield,
%
mp,
C
Compound
Color
Formula
M
C
N
C
H
N
I
75
65
75
Colorless
Dark red
C9H15ClO2
C12H24N2O2
50.50 8.74 8.15 C28H56CoN4O5 51.54
190.50
228.00
8.61 586.93
Ligand
[Co(L)2(OAc)2]
H2O
210
8.59
[Ni(L)2(OAc)2]
[Cu(L)2(OAc)2]
55
75
Claret red
Parliament
blue
240
220
53.69 7.68 8.64 C28H54N4NiO4 53.11
51.22 7.68 8.12 C28H54CuN4O4 52.70
8.54
8.47
8.86 568.71
8.78 573.54
1
Table 2. Characteristic IR bands (cm ) of complexes in KBr
Compound
OH (H2O)
3444
N H
C Haliph
C O C
C N
C=O (OAc)
[Co(L)2(OAc)2] H2O
[Ni(L)2(OAc)2]
[Cu(L)2(OAc)2]
3300 3270, 1610
3310, 3265, 3200, 1610 2985 2882
3265, 3214, 3180, 1610 2983 2910
2982 2880
1114
1114
1114
1035 1583 as, 1389 s
1035 1597 as, 1417 s
1038 1603 as, 1451 s
The IR spectrum of I contains characteristic bands
Scheme 2.
M(OAc)2 mH2O + 2L
at 2959 2877 [ (CHaliph)], 1114 [ (COC)], and
1
1
760 cm [ (CCl)] [11]. The characteristic H NMR
signals appear at 1.70 (ring CH2), 3.54 (OCH2), 3.92
(CH2Cl), and 4.30 pm (OCH).
abs. EtOH/abs. CHCl3
[M(L)2(OAc)2] nH2O
+ zH2O,
M = Cu(II), Ni(II), Co(II); L = C12H24N2O2.
m 6 5 6
The IR spectrum of L contains characteristic bands
1
1
at 3330 3275 cm [ (NH) and (NH2)]and 1114 cm
[ (COC)] and lacks C Cl bands. The 1H NMR spectra
of L displays a multiplet at 2.66 ppm (NCH2) and a
singlet at 1.18 ppm (NH, NH2). The NH and NH2
signals disappear on addition of D2O [12]. On the
n
1
z 6 5 5
shift of the N H band to lower frequencies (3330
1
other hand, the H NMR spectra of L contains multi-
1
3180 cm ) is due to N,N-metal coordination. At the
plets at 4.19 ppm (OCH). Based on the elemental
1
same time, the band at 1650 cm in the free ligand
1
analyses and IR and H and 13C NMR spectra, we
assigned to (NH2) is shifted to lower frequencies
(1610 cm ) in the complexes. This fact suggests that
both the primary and secondary amino groups are in-
volved in complex formation [13]. The new absorp-
tion bands at 1583 1603 and 1389 1451 cm in the
assigned to the ligand the structure shown in
Scheme 1.
1
The ligand L reacts with Cu(II), Ni(II) and Co(II)
acetates to form complexes of the general formula
[M(L)2(OAc)2] H2O (M = Cu(II), Ni(II), Co(II);
n = 1). Analytical data for all the complexes are
presented in Tables 1 3.
1
spectra of the complexes provide evidence to show
that the CH3COO group is coordinated to the metal
ion. The IR spectra of [Cu(L)2(OAc)2], [Ni(L)2(OAc)2],
and [Co(L)2(OAc)2] H2O show two new bands at
The complexes were prepared by Scheme 2.
1
1583 1603 and 1389 1451 cm assignable to acetate
The metal-to-ligand ratios in the Co(II) and Ni(II)
complexes were found to be 1:2; in addition, the com-
plexes contain two acetate ligands. The Co(II) com-
plexes has one additional moilecule of water of crys-
tallization. The IR absorption band near 3330
as(C O) and s(C O), respectively. The acetate
group in [Cu(L)2(OAc)2], [Ni(L)2(OAc)2], and
[Co(L)2(OAc)2] H2O acts as monodentate ligand, as
evidenced by the great difference between the
as(C O) and s(C O) frequencies (1603 1451 = 152;
1
1
3275 cm can be assigned to (NH2) of the intramo-
1597 1417 = 180, and 1583 1389 = 194 cm , res-
lecularly H-bonded 1,3-diaminopropane moiety. The
pectively) [14, 15].
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 76 No. 1 2006

PREPARATION OF COMPLEXES OF 1-AMINO-6,7-O-CYCLOHEXYLIDENE-4-AZAHEPTANE
35
Table 3. Characteristic UV-VIS bands of complexes in C2H5OH
1
Compound
, nm ( , l mol 1 cm )
[Co(L)2(OAc)2] H2O
420.0 463.0 (1200)
4T1g(F) 4T1g(P)
485 550 (2400)
4T1g(F)
4A2g(F)
[Ni(L)2(OAc)2]
[Cu(L)2(OAc)2]
430.0 460.0 (1900)
3A2g 3T1g(P)
545 (1700)
3A2g 3T1g(F)
578 610 (1800)
3A2g
3T2g(F)
538.0 588.0 (1450)
2Eg 2T2g
1
The Co(II), Ni(II) and Cu(II) complexes are para-
magnetic, and their magnetic suscuptibilities 5.28,
2.89, and 1.80 BM, respectively. Based on the data
in Tables 1 3, the complexes were assigned a distorted
octahedral high-spin geometry [16 18]. The suggested
structures of the complexes are shown in Scheme 3.
Since all the metal complexes are paramagnetic, their
1H NMR spectra could not be obtained.
7.80, 8.40, and 6.50 1 cm2 mol for the the Co(II),
Ni(II), and Cu(II) complexes, respectively [21].
EXPERIMENTAL
The IR spectra were recorded on an Ati-Lnicom
Mattson 1000 FT-IR spectrometer in KBr pellets. The
13C and H NMR spectra were recorded on a Bruker
1
DPX-400 (400 MHz) or a JEOL FX 90QFT spectro-
meter. The magnetic susceptibilities were determined
on a Christon balance at room temperature (20 C);
the diamagnetic corrections were calculated from
Gouy’s constants [24]. The molar conductivities were
determined on a CMD 750WPA conductometer. The
elemental analyses were performed at the TUBITAK
Laboratory (Scientific and Technical Research
Council of Turkey).
Scheme 3.
O
O
CH2 NH (CH2)3 NH2
nH2O
H3CCOO M OOCCH3
Reagent grade chemicals were used. Epichlorohyd-
rin and cyclohexanone were purchased from Merck
(Pure) and (Sigma), respectively, and used as received.
1-Chloro-2,3-O-cyclohexylidinepropane (I) and 1-
amino-6,7-O-cyclohexylidene-4-azaheptane (L) were
synthesized as described in [22, 23].
H2N (CH2)3 NH H2C
O
O
Synthesis of 1-chloro-2,3-O-cyclohexylidine-
propane (I). In a three-necked flask with a thermo-
meter, a CaCl2 drying tube, and a dropping funnel,
14.7 g (0.15 mole) cyclohexanone and 15 20 drops
of boron trifuoride ether complex were mixed. This
mixture was cooled to 10 17 C. While maintaining
the mixture at this temperature, 34.5 g (0.38 mole) of
epichlorohydrin was added dropwise with continuous
stirring over the course of 20 min. The reaction mix-
ture was further stirred for 2 h at 40 C under nitrogen.
The product was distilled 105 110 C (37 mm Hg).
M = Co(II), n = 1; M = Ni(II), Cu(II), n = 0.
The electronic spectra of the complexes contain
strong n
* and n
* bands around 220 295 nm
[19,20], as well as absorption bands of the ligand and
the acetate groups, as well as those formed by weak
d d transitions in the Co(II), Ni(II), and Cu(II) com-
plexes at 420.0 463 and 485 550; 430 460, 545 and
578 610; 538 588 nm, respectively.
1
Yield 22.69 g (75%). IR spectrum, , cm : 2959
2877 (CHaliph), 1114 (COC), 760 (CCl). Character-
istic H NMR signals (400 MHz, CDCl3, , ppm):
The complexes are nonelectrolytes, as shown by
their molar conductivities ( M) in absolute ethanol:
1
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 76 No. 1 2006

36
OZTIRK et al.
1.70 d (8H, CH2); 3.54 m (2H, CH2O); 3.92 m (2H,
CH2Cl); 4.30 m (1H, CHO). The product is soluble in
ordinary solvents, such as chloroform, benzene, di-
ethyl ether, or ethanol.
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Synthesis of 1-amino-6,7-O-cyclohexylidene-4-
azaheptane (II). In a reaction flask with a thermo-
meter, a CaCl2 drying tube, and a dropping funnel,
18.42 ml (0.22 mol) of 1,3-diaminopropane, 8.0 ml
(0.057 mol) of triethylamine, and 60 ml of absolute
xylene were mixed. To this solution, a solution of
13.3 g (0.07 mol) of 1-chloro-2,3-O-cyclohexylidene-
propane in 25 ml of xylene was added dropwise with
continuous strirring. After this, the mixture was re-
fluxed at 122 130 C for 30 h and cooled to room
temperature under nitrogen. The precipitated triethyl-
ammonium salts were filtered off, and the filtrate was
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1
10.82 g (65%). Characteristic IR bands, , cm
(NaCl cell): 3330 3275; 1650 (NH and NH2), 2980
10. Rahmankulov, D.L., Karahanov, R.H., Zlotskiy, S.S.,
Kantar, E.A., Imasev, U.B., and Syrkin, A.M., Itogi
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1
2880 (CHaliph), 1114 (COC), 1038 (CN). H NMR
spectrum (CDCl3), , ppm): 4.19 pm (1H, CHO),
3.57 4.14 t (2H, CH2O), 2.66 m (6H, CH2NHCH2
CH2CH2NH2), 1.57 m (10H, cyclo-CH2) 1.35 s (2H,
CH2CH2CH2), 1.18 s (3H, NH and NH2). 13C NMR
spectrum (CDCl3), C, ppm: 23.87, 23.73, 25,16,
33.82, and 35.17 (5C, cyclo-CH2), 109.56 (1C, cyclo-
CH2), 67.39 (CH2O), 75.82 (CHO), 52.81 (CH2NH
CH2CH2CH2NH2), 48.12 (NHCH2CH2CH2NH2),
36.64 (NHCH2CH2CH2NH2), 40.50 (NHCH2CH2CH2
NH2). The product is soluble in ordinary solvents,
such as chloroform, benzene, water, xylene, or ethanol.
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Synthesis of the Co(II), Cu(II) and Ni(II) com-
plexes. The ligand, 0.457 g was dissolved in 10 ml of
absolute ethanol in a 50-ml round-bottom flask. A
solution of 1 mmol of metal acetate [Co(CH3COO)2
6H2O (0.498 g), Ni(CH3COO)2 5H2O (0.130 g). or
Cu(CH3COO)2 6H2O (0.254 g)] in 5 ml of absolute
ethanol and chloroform was added dropwise with
continuous strirrring over the course of 15 min at
room temperature. The reaction mixture was then
stirred for 1 h at room temperature. The resulting
precipitates were filtered off and washed with
absolute ether. The products were dissolved in
chloroform and precipitated with n-hexane (1:5).
The crystals were filtered and dried at room tempera-
ture. Yield 0.18 g (75%) for Co(II), 0.033 g (55%)
for Ni(II), and 0.18 g (75%) for Cu(II).
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ACKNOWLEDGMENTS
23. Tas, E., Cand. Sci. (Chem.) Dissertation, Elazig
,
(Turkey), 1995.
We are very greatful to the Research Council of
the C, anakkale 18 Mart University for financial
support.
24. Earnshaw, A., Introduction to Magnetochemistry,
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RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 76 No. 1 2006