IBN AL- HAITHAM J. FOR PURE & APPL. S CI. VOL. 24 (3) 2011
Synthesis and Characterisation of a Novel 2,3-O-di Acetyl-
5,6-O-Benzylidene - L -Ascorbic Acid and its Complexes of
Cr(III), Co(II), Ni(II),Cu(II) and Zn(II)
I. Sh. Abdul Razzaq Al - Kadi
Departme nt of Chemistry, College of Education, I bn Al-Haitham, Unive rsity
of Baghdad
Received in : 11 May 2011
Accepete d in : 20 September 2011
Abstract
A new ligand ty p e (O2) [2,3-O-diacety l-5,6-O-benzy lidene L- ascorbic acid] [L] and its
comp lexes of general formula [M (L)2(X)(Y)]Cln (where: M =Cr
II I
,X=Y=H2O, n=3; Co
II
, X = Y =
0, n= 2; Ni
II
and
Cu
II
, X = Cl, Y = H2O, n= 1; Zn
II
, X = Y = H2O,n = 2) are reported. The ligand
was p repared in two st eps; first st ep involved the sy nthesis of [5,6-O-benzy lidene-L-ascorbic
acid] (A). In second st ep derivative-A was then reacted with acety l chloride and anhydrous
p y ridine as a base to give the titled ligand. M etal comp lexes of the ligand with Cr
II I
,Co
II
,Ni
II
,Cu
II
and Zn
II
were sy nthesised by direct reaction of the corresp onding metal chloride with the
ligand[L] in a 2L:1M mole ratio. The ligand and its comp lexes were characterised by
sp ectroscop ic methods
1
H NM R, FT IR, (UV-Vis), atomic absorp tion, microanaly ses, chloride
content, melting p oint and conductance measurements . These st udies revealed that t he geometry
about Cr
II I
, Ni
II
,Cu
II
and Zn
II
is octahedral while the comp lex of Co
II
adopts a tetrahedral
geometry .
Keywords: Ester, Benzy lidene, L-Ascorbic acid, M etal Ascorbate Complexes, Ant icancer
effect.
Introduction
Vitamin C is the L-enantiomer of ascorbic acid (meaning “without scurvy ”, the disease
caused by a vitamin C deficiency )[1]. The effect of ascorbic acid (AA) on cancer has been a
subject of great controversy [2]. The derivatives of L-ascorbic acid (AA) (5,6-O-Cy clic acetal)
p ossess p harmaceutical activity similar to L- ascorbic acid, sup erior in cry st allinty , st ability , and
antioxidant effect [3,4]. These derivatives have been shown to exert anticancer effect [5-7], they
are free radical scavengers, and have anti-scorbutic activities [8], and reduce the arterial blood
IBN AL- HAITHAM J. FOR PURE & APPL. S CI. VOL. 24 (3) 2011
p ressure and regulates heart rate [9,10]. Sodium 5,6-O-benzy lidene-L-ascorbate(SBA) is a
conjugate of ascorbic acid with benzaldehy de. It has been found that the antioxidant activity of
(SBA) is more st able and has a longer lifetime in living cells and organs than (AA) [11,12,13]. In
addition it has been shown to exert anticancer effect in p atients without causing side effects [6].
The PKa value of (AA) and 5,6-O-benzy lidene L-ascorbic acid was exceedingly decreased by
esterification of 2-OH and 3-OH slightly by that of the 5-OH and 6-OH in L-ascorbic acid [14].
The (AA) est ers in 2, 3, 6 positions are more st able than (AA). The introduction of the est er in 2,
3-p ositions p rotected the molecule from break-up of the enediol sy st em, these esters as a very
st able derivatives of (AA) that may be easily used in various ty p es of cosmetics p roducts and
drugs[15,16]. The interaction of (AA) with metal ions p lay an imp ortant role in the reversible
oxidation of (AA) in living cells [17]. (AA) has several donor atoms cap able of metal comp lex
formation, and comp lexes of metal ascorbate are generally assumed to be a chelate in the
cryst alline solid, but chelate formation was suggested to be weak in aqueous solution [18]. The
p reparation of st able metal-ascorbate comp lexes is of considerable imp ortance not only for their
chemical but also biological and medical asp ects [19]. In view of these observations, this p aper
deals with the sy nthesis and characterisation of a new ligand derived from vitamin C [2,3-O-di
acety l-5,6-O-benzy lidene-L-ascorbic acid] and its metal comp lexes with Cr
II I
, Co
II
, Ni
II
, Cu
II
and
Zn
II
ions.
Experime ntal
Reagents were p urchased from Fluka and Riedal–Dehaën Chemical Co. The Thin Lay er
Chromatography (TLC) was p erformed on aluminum p lates coated with (0.25mm) lay er of silica
gel F254 (Fluka), the sp ot was detected by iodine vapor. IR sp ectra were recorded as (KBr) discs
using a Shimadzu 8400S FT IR sp ectrop hotometer in the range (4000– 400) cm
-1
. Electronic
sp ectra of the p repared comp ounds was measured in the region (200– 1100) nm for (10
-3
M )
solution in (DM F) at 25C by using a Shimadzu 160 sp ectrop hotometer with 1.000+0.001cm
matched quartz cell.
1
H NM R sp ectrum was acquired in DM SO solution using Brucker 300 M Hz
sp ectrometer at Al-al-Bayt University , Jordan. The (C.H.N.) of the ligand [L] was recorded using
(EURO EA, Elemental Analysis) at College of Science – University of Babylon. M etal contents
of the comp lexes were determined by atomic absorp tion (A.A) technique by using a Shimadzu
A.A 680G atomic absorp tion sp ectrop hotometer. The Chloride contents for comp lexes were
determined using p otentiometric titration method on 686–Titro p rocessor Dosimat–M etrahm–
Swiss. Electrical conductivity measurements of the comp lexes were recorded at 25C for (10
-3
M )
solutions of the samp les in (DM F) by using a PW 9526 digital conductivity meter.
IBN AL- HAITHAM J. FOR PURE & APPL. S CI. VOL. 24 (3) 2011
S ynthesis
The ligand was p repared in two st ep s:
S tep (1): p rep aration of the derivative (A) 5,6-O-Benzylidene-L-Ascorbic acid
Anhy drous Z inc chloride (3.86 g, 28.32 mmol) was added to a solution of benzaldehy de (15
mL, 174.56 mmol ). The mixture was allowed to st ir for one hour at room temperature, and then
L-ascorbic acid (5.00 g, 28.38 mmol) was added and the reaction mixture was stirred overnight at
room temperature until the solution became emulsion. A solution of p otassium carbonate (7.84 g,
56.72 mmol) was added to the emulsion solution and the mixture was st irred through it became-
milky, and then extracted with chloroform (50 mL). Aft er solvent was removed under reduced
p ressure, and a sy rup residue was left which then treated with a few drop s of p etroleum ether to
give the title derivative-A as a pale yellow solid. Yield (2.93 g, 39 %). Rf = 0.69, m.p = 163C.
S tep (2): p reparation of the ligand [L] 2,3-O-di Acety l-5,6-O-Benzy lidene L-Ascorbic acid
To a mixture of comp ound-A (5.00 g, 18.93 mmol) in a dried p y ridine (25 mL) was added
acety l chloride (4 mL, 56.81 mmol). The reaction mixture was st irred at room temp erature for
two hours, and then st ored in a dark p lace for 22 hours. A distillated ice-water (400 mL) was
added and the organic lay er was extracted with chloroform (2 × 50 mL), washed with distillated
water (3 × 100 mL), and then dried over anhydrous magnesium sulfate (M gSO4), filtered and
solvent removed under reduced pressure, and a sy rup residue was left which then treated with a
few drop s of p etroleum ether to give (3.78 g, 57%) of the ligand as a y ellow solid. Rf =0.42. m.p
= 124C. (C.H.N); Found (Calc.): C% = 57.48(58.62), H% = 3.97(4.59), N%= 0.
S ynthesi s of complexes
General me thod
To an ethanolic solution of ligand (2 mmol) in ethanol (15 mL) was added with st irring an
ethanolic solution (10 mL) of the metal salt (1 mmol). The reaction mixture was allowed to reflux
for 4 h, resulting in the formation of coloured p recipitate. This was t hen collected by filteration,
and washed with (5 mL) diethy l ether and dried at room temperature. Table (1) shows t he st ated
weight of st arting materials, y ield and some phy sical prop erties of the prepared comp lexes.
Re sults and Discussion
The derivative-A 5,6-O-benzy lidene L-ascorbic acid (scheme1) was obtained from the
reaction of L-ascorbic acid with (two mole) of benzaldehy de and anhydrous Zinc chloride. The
comp ound was characterised by IR and
1
H NM R sp ectra. The IR sp ectrum shows characterist ic
two bands at (1739, 1604) cm
-1
due to (C=O) and (C=C) lactone, resp ectively. The four bands
in the free L-ascorbic acid which assigned to the hydroxy l group s are no longer exist in
IBN AL- HAITHAM J. FOR PURE & APPL. S CI. VOL. 24 (3) 2011
comp ound-A. The sp ectrum shows two bands at (3448) and (3445)cm
-1
assigned to (O–H) at
p ositions (C3) and (C2), resp ectively. Also the sp ectrum shows two bands at (3066)cm
-1
and
(1408)cm
-1
assigned to (C–H) and (C=C) aromatic ring, resp ectively. This is due to block of
the hydroxy l group s at (C5) and (C6) p ositions by benzaldehy de and forming 5,6-O-cy clic acety l
derivative [20,21,22]. Fig (1) exhibits the (IR) sp ectrum for the derivative-A. The
1
H NM R
sp ectrum of (A) shows the following signals: doublet at δ(3.9- 4.0) p p m assigned to the p rotons
of (–CH2) at (C6) p osition, quartet at δ(4.1 - 4.4) p p m assigned to t he proton of the (–CH) of (C5)
p osition, doublet at δ(5.6 - 5.7) p p m assigned to the p roton of (-CH) at (C4) p osition. The
chemical shift at δ (10) p p m assigned to the p roton of the hy droxy l group at (C2) and (C3)
p ositions, these p rotons shifted to a lower frequency (deshielding) due to the resonance between
the (-OH) group at (C2) and (C3) with the (C=O) lactone ring. The singlet at δ(6.2) p p m was
assigned to the proton of a cyclic ring at (C7) p osition. This p roton shifted to a lower frequency
due to the bonded with the two oxy gen atoms. The chemical shifts at δ(7.3 - 7.9) p p m were
assigned to the p rotons of the aromatic ring, equivalent to 5 p rotons. The app earance of the
p rotons at (C7) p osition and aromatic ring as a result to the blocking of the two hy droxy l group s
at (C5) and (C6) p ositions by benzaldehy de to form the derivative-A [23,24]. Fig.(2) exhibits the
(
1
H NM R) for the derivative-A.
S cheme(1):The sy nthesis route of the derivative 5,6-O-benzy lidene-L-ascorbic acid (A)
The reaction of the derivative-A 5,6-O-benzy lidene-L-ascorbic acid dissolving in anhydrous
p y ridine with the acety l chloride offered the new ester [2,3-O-diacety l-5,6-O-benzy lidene-L-
ascorbic acid][L] (scheme 2). The ligand was characterised by elemental analysis (Table 1), IR
(Table 2), UV-Vis (Table 3) and
1
H NM R (Table 4) sp ectroscop y . The IR sp ectrum of the ligand
Fig.(3) shows characterist ic bands at (1739,1627 and 1496) cm
-1
due to the (C=O) lactone,
(C=C) aliphatic and (C=C) aromatic functional group resp ectively. The new band at (1670)
cm
-1
due to the est er group . The ap p earance of this new band as a result to the formation of the
ester at (C2) and (C3) p ositions by acety l chloride. The two bands in the derivative (A) at (3445
and 3448) cm
-1
which are due to the hy droxy l group at (C2) and (C3), these two bands
disapp eared in the new ligand due to the formation of ester[20,21,22]. The (UV-Vis) sp ectrum of
the ligand [L] Fig.(4) exhibits an intense absorp tion p eak at (274) nm, assigned to ( → *). A
hump at (370) nm assigned to (n → *) transition[25]. The
1
H NM R sp ectrum of the ligand [L]
Fig.(5) shows a new p eak at δ(1.7-2.3) p p m assigned to t he protons of (-CH3) in the ester. This is
equivalent t o six p rotons. T he ap p earance of a new p eak indicating to the formation of ester at
OHO
H O
O H
O
C
H
O
Zn Cl2
OO
O
OH
O
H
1
23
4
5
6
7
HOHO
IBN AL- HAITHAM J. FOR PURE & APPL. S CI. VOL. 24 (3) 2011
(C2) and (C3) p ositions by acety l chloride. In addition the chemical shift at δ(10) p p m in the
derivative [A] which is assigned to t he proton of (-OH) group at (C2) and (C3) p ositions, this p eak
disapp earance in the
1
H NM R sp ectrum of the new ligand as a result to the formation of
ester[23,24].
S cheme(2): The sy nthesis route of the ligand [L] 2,3-O-diacety l-5,6-O-benzy lidene-L-ascorbic
acid
All complexes were p repared by similar methods from the reaction of the ligand [L] with the
metal chloride salts at reflux in ethanol medium and p ure comp lexes were formed. The (IR)
sp ectrum of the comp lexes Cr
II I
,Co
II
,Ni
II
,Cu
II
and Zn
II
are shown in Figures 6, 7, 8, 9, 10,
resp ectively. The absorp tion bands at the range (3383-3456) cm
-1
and (819-925) cm
-1
were
assigned to the H2O aqua for the comp lexes Cr
II I
,
Ni
II
, Cu
II
and
Zn
II
,indicating to the
coordination of the H2O molecule with the metal ion . The absorp tion band at (1670) cm
-1
in the
free ligand which was assigned to the (C=O) ester, was shifted to a lower frequency in the
comp lexes and ap p eared at t he range (1624 - 1635) cm
-1
, indicating a reduction in the bond order.
This can be attributed to the delocalization of metal electronic density at (t 2g) in the - sy st em of
the ligand. In addition, the comp lexes showed new bands in the region (418 - 493)cm
-1
which are
due to the formation of M –O bonds, indicating that the oxy gen of ester group is involved in
coordination with metal ions [26]. Ot her bands of the (IR) sp ectral data are summarized in Table
(2). The molar conductance of the comp lexes in (DM F) Table (3) laid in the range (77.5-84.6
S.cm
2
.mole
-1
) for comp lexes Ni
II
and Cu
II
, indicating their electrolytic nature with (1:1) ratio. The
conductance measurements in the range (146.2-152.8 S.cm
2
mole
-1
) for comp lexes Co
II
and Zn
II
,
indicating their electrolytic nature with (1:2) ratio. While the molar conductance of the comp lex
Cr
II I
was (231.5 S.cm
2
.mole
-1
), indicating its electrolytic nature with (1:3) raito [27]. The
electronic absorp tion sp ectra Figures 11, 12, 13, 14 and 15 of the complexes Cr
II I
, Co
II
, Ni
II
, Cu
II
and Zn
II
, resp ectively were recorded at room temp erature using (DM F) solutions. T he absorp tion
sp ectra for these comp lexes show intense p eaks in the range (274-281) nm, which may be related
to the ligand field, while the p eaks in the range (350-372) nm, assigned to charge transfer. The
(UV-Vis) sp ectra of Cr
II I
and Cu
II
exhibited another p eaks at visible region at (873 and 825) nm,
resp ectively. These p eaks were assigned to (
4
A2g→
2
T2g) and (
2
B2g →
2
A1g) (d-d) transitions for
comp lexes Cr
II I
and Cu
II
resp ectively, confirming a distorted octahedral geometries. The (UV-
Vis) sp ectra of Ni
II
comp lex exhibited another two p eaks in the visible region at (677 and 833)
nm. These p eaks were assigned to (
3
A2g →
1
Eg) (d-d) transition, confirming octahedral st ructure.
OO
O
OH
OH
H 3C
C
Cl
O
Pyridine
OO
O
O
O
O
H
C
CH 3
C
H3C
O
1
23
4
5
6
7
OHO
IBN AL- HAITHAM J. FOR PURE & APPL. S CI. VOL. 24 (3) 2011
The (UV-Vis) sp ectra of Co
II
comp lex exhibited two p eaks at visible region at (608 and 672)
nm. These p eaks were assigned to (
4
A2 →
4
T1(p)) (d-d) transitions, confirming tetrahedral
geometry [25]. At last the (UV-Vis) sp ectra of Zn
II
disp lay ed peak at (276) nm assigned to ligand
field transition, since the metal ion of the comp ound belong to d
10
sy st em. The suggested
st ructure of the comp lexes are shown in the (scheme 3). The results are summarized in Table
(3).
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Organic Compounds” 4
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IBN AL- HAITHAM J. FOR PURE & APPL. S CI. VOL. 24 (3) 2011
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Table (1) :some physical propertie s of the complexes and its reactants quanti ties
Compound
m.
p
C
M .
wt
Color
Weight of metal
chloride( g)=(0.1
1)mmole
Weight
of
p roduct
(g)
Yield
%
Chlori
de
conten
t
M etal ion
%
Prac.(The
o.)
Derivative - A
16
3
264
Pa
Pale
y ellow
-
2.93
39%
-
-
[L] 12
4
348 Yello
w
- 3.78 57% - -
[Cr(L)2(H2O)2
]Cl3
10
8
890
.35
Green
0.030
0.15
73%
11.6
(11.9)
5.60
(5.83)
[Co(L)2]Cl2
10
7
825
.83
Dark
Brown
0.027
0.13
68%
8.41
(8.58)
6.97
(7.13)
[Ni(L)2(Cl)(H
2O)]Cl
10
4
843
.60
Green 0.027 0.10 51% 7.91
(8.40)
6.63
(6.95)
[Cu(L)2(Cl)(H
2O)]Cl
10
2
848
.40
Brown 0.019 0.17 87% 8.19
(8.35)
7.36
(7.48)
[Zn(L)2(H2O)2
]Cl2
10
4
868
.31
Yello
w
0.015 0.11 55% 8.07
(8.16)
7.40
(7.53)
IBN AL- HAITHAM J. FOR PURE & APPL. S CI. VOL. 24 (3) 2011
Table (2) :IR spectral data of the ligand and its complexes
Compound
(C=O)
lactone
(C=O)
ester
(C=C)
lactone
(C=C)
aromatic
M -
O
Ot her bands
Derivative - A
1739
-
1604
1408
-
2981(C-
H)alip ha
3066(C-
H)aroma
3445(C(2)-OH)
3448(C(3)-OH)
[L] 1739 1670 1627 1496 - 2927(C-
H)alip ha
3066(C-
H)aroma
[Cr(L)2(H2O)2]Cl3 1732 1635 1608 1417 486 2935(C-
H)alip ha
3010(C-
H)aroma
3404, 898 H2O
aqua
[Co(L)2]Cl2 1732 1635 1616 1456 487 2926(C-
H)alip ha
3197(C-
H)aroma
[Ni(L)2(Cl)(H2O)]Cl 1732 1624 1622 1406 470 2852(C-
H)alip ha
2926(C-
H)aroma
3383, 920 H2O
aqua
[Cu(L)2(Cl)(H2O)]Cl 1732 1635 1618 1409 493 2927(C-
H)alip ha
2983(C-
H)aroma
3456, 819 H2O
aqua
[Zn(L)2(H2O)2]Cl2 1734 1635 1618 1456 418 2997(C-
H)alip ha
3147(C-
H)aroma
3456, 925 H2O
aqua
IBN AL- HAITHAM J. FOR PURE & APPL. S CI. VOL. 24 (3) 2011
Table (3): Electroni c S pectral data and Conductance measurements of the ligand
and its complexes
Compound λ(nm)
εmax (molar
-1
cm
-1
)
Λm
(S.cm
2
. mol
-1
)
Ratio
Prop osed
Structure
[L] 274
370
1887
870
- - -
[Cr(L)2(H2O)2]C
l3
274
350
873
1852
581
6
231.5 1:3
Octahedral
[Co(L)2]Cl2
281
360
608
672
2350
562
82
103
146.2 1:2
Tetrahedral
[Ni(L)2(Cl)(H2O
)]Cl
281
372
677
833
2409
570
22
9
77.5 1:1
Octahedral
[Cu(L)2(Cl)(H2
O)]Cl
281
353
825
2428
522
28
84.6 1:1
Octahedral
[Zn(L)2(H2O)2]
Cl2
276 1920 152.8 1:2 Octahedral
IBN AL- HAITHAM J. FOR PURE & APPL. S CI. VOL. 24 (3) 2011
Table (4):
1
H NMR data for the ligand measured in DMSO and che mical shift in ppm(δ)
O
O
O
O
O
O
H
C
H3C
C
H3C
O
O
O
O
O
O
O
O
H
C
CH3
C
CH3
O
O
M
X
Y
Cln
Octahedral
M= Cr
III
, X=Y=H2O,n=3
Ni
II
and
Cu
II
, X=Cl, Y=H2O,n=1
Zn
II
, X=Y=H2O,n=2
comp ound
δ(C(6) -
H)
δ (C(5)-
H)
δ (C(4)-
H)
δ (C(7)-H)
δ (-CH3)
δ (C-H)
aromatic
δ (O-
H)
Derivative -
A
3.9- 4.0 4.1 - 4.4 5.6 - 5.7 6.2 - 7.3 -7.9 10
Ligand [L] 4.0 - 4.1 4.3 - 5.1 5.4 - 5.7 6.1 1.7 - 2.3 7.4 - 8.5 -
IBN AL- HAITHAM J. FOR PURE & APPL. S CI. VOL. 24 (3) 2011
O
O
O
O
O
O
H
C
H3C
C
H
3
C
O
O
O
O
O
O
O
O
H
C
CH3
C
CH3
O
O
Co Cl2
Tetrahedral
S cheme (3) :The suggested structure for the complexes
IBN AL- HAITHAM J. FOR PURE & APPL. S CI. VOL. 24 (3) 2011
Fig.(1): The IR. S pectrum of the Derivative [A]
Fig.(2): The
1
H NMR S pectrum of the De rivative [A]
Fig.(3): The IR. S pectrum of the Ligand [L]
Fig.(4) :The
1
H NMR S pectrum of the Ligand [L]
Fig.(5): The UV-Vis S pectrum of the ligand [L]
IBN AL- HAITHAM J. FOR PURE & APPL. S CI. VOL. 24 (3) 2011
Fig.(6) :The IR. S pectrum for [Cr(L)2(H2O)2]Cl
Fig.(7) :The IR. S pectrum for [Co(L)2]Cl 2
Fig.(8) :The IR. S pectrum for [Ni(L)2(Cl )(H2O)]Cl
Fig.(9):The IR. S pectrum for [Cu(L)2(Cl )(H2O)]Cl
Fig.(10): The IR. S pectrum for [Zn(L)2(H2O)2]Cl 2
IBN AL- HAITHAM J. FOR PURE & APPL. S CI. VOL. 24 (3) 2011
Fig.(11): The UV-Vis S pectrum for [Cr(L)2(H2O)2]Cl 3
Fig.(12) :The UV-Vis S pectrum for [Co(L)2]Cl 2
Fig.(13): The UV-Vis S pectrum for [Ni (L)2(Cl )(H2O)]Cl
IBN AL- HAITHAM J. FOR PURE & APPL. S CI. VOL. 24 (3) 2011
Fig.(14): The UV-Vis S pectrum for [Cu(L)2(Cl )(H2O)]Cl
Fig.(15): The UV-Vis S pectrum for [Zn( L)2(H2O)2]Cl 2
2011) 3( 24المجلد مجلة ابن الهیثم للعلوم الصرفة والتطبیقیة
ند جدیداتشخیص لیكتحضیر و
2,3-O-di Acetyl-5,6-O-Benzylidene - L -Ascorbic Acid
أیونات العناصرومعقداته مع
Cr(III), Co(II), Ni(II),Cu(II),Zn(II)
أسراء شكیب عبد الرزاق القاضي
بن الهیثم، جامعة بغدادا ة، كلیة التربیقسم الكیمیاء
الخالصة
O2([2,3-O-di Acety( ند جدید من نوعاتضمن البحث تحضیر لیك l-5,6-O-Benzy lidene-L-AscorbicAcid]
M]الصیغة يومعقداته ذ (L)2(X)(Y)]Cln حضر المشتق الخطوة االولى، حضر بخطوتین نداهذا اللیك
[5,6-O-benzy lidene-L-ascorbic acid] (A) . المشــتق(A) والبریـــدین یلاتفاعــل بـــالخطوة الثانیــة مــع كلوریـــد االســت
تــم Zn(II) و Cr(III), Co(II), Ni(II),Cu(II)معقـدات العناصــر . نــد المطلــوباللحصــول علـى اللیك الالمـائي كقاعــده
االشـعة (ق الطیفیـة ائـالطر المعنـد ومعقداتـه باسـتاشـخص اللیك. نـد اتحضیرها من التفاعل المباشر بین ملح كلوریـد الفلـز مـع اللیك
التحلیــل الـــدقیق للعناصــر والتوصـــیلیة ). [A]وللمشـــتق [L]نــد افـــوق البنفســجیة والـــرنین النــووي المغناطیســـي للیك، تحــت الحمــراء
,Cr(III)ومـن النتـائج اعـاله فـأن الشــكل الفراغـي للعناصـر . نــداللیك (C.H.N)االنصـهار وقیـاس قیـاس درجـات، الكهربائیـة
Ni(II),Cu(II)و Zn(II) هي ثمانیة السطوح بینما معقدCo(II) كان الشكل الفراغي هو رباعي السطوح.
.ر المضاد للسرطانالتأثی، معقدات األسكوربیت، حامض األسكوربیك، بنزالیدین، أستر :الكلمات المفتاحیة