Preparation and spectroscopic characterization of novel cyclodiphosph(V)azane of N1-2-pyrimidinylsulfanilamide complexes. Magnetic, thermal and biological activity studies

Article abstract of DOI:10.1016/j.saa.2006.04.032

Hexachlorocyclophosph(V)azane of sulfadiazine, (sulfupyrimidine) [N¹-2-pyrimidinylsulfanilamide] (H₂L¹), was prepared and reacted with sulfur and glycine to give (H₂L²) and (H₂L³

Full text of DOI:10.1016/j.saa.2006.04.032

Spectrochimica Acta Part A 66 (2007) 935–948
Preparation and spectroscopic characterization of novel
cyclodiphosph(V)azane of N1-2-pyrimidinylsulfanilamide complexes
Magnetic, thermal and biological activity studies
Carmen M. Sharabya,∗, Gehad G. Mohamedb, M.M. Omarb
a Chemistry Department, Faculty of Science, Al-Azhar University (Girls), Nasr City, Cairo, Egypt
b Chemistry Department, Faculty of Science, Cairo University, Giza, Egypt
Received 5 January 2006; accepted 17 April 2006
Abstract
Hexachlorocyclophosph(V)azane of sulfadiazine, (sulfupyrimidine) [N1-2-pyrimidinylsulfanilamide] (H2L1), was prepared and reacted with
sulfur and glycine to give (H2L2) and (H2L3) ligands, respectively. The prepared ligands; H2L1, H2L2 and H2L3, react in 1:2 [ligands]:[metal
ions] molar ratio with transition metals to give coloured complexes in a relatively good yields. The complexes were characterized using different
physicochemical techniques, namely elemental analyses, IR, UV–vis, mass, 1H NMR, molar conductance, magnetic, solid reflectance and thermal
analysis. The spectral data reveal that all the ligands behave as neutral bidentate ligands and coordinated to the metal ions via pyrimidine-N
and enolic sulfonamide OH. The molar conductance data reveal that the complexes are non-electrolytes while UV–vis, solid reflectance and
magnetic moment data have been shown that the complexes have octahedral geometry. The thermal behaviour of the complexes is studied and the
thermodynamic activation parameters are calculated. The ligands and their complexes show high to moderate bactericidal activity.
© 2006 Elsevier B.V. All rights reserved.
Keywords: Sulfadiazine; Phosphorus pentachloride; Sulfur; Glycine; Transition metals; Thermal analysis; Biological activity
1. Introduction
cyclodiphosphazane had been prepared [5]. The cyclodiphos-
phazanes of sulfonamides had been prepared and their ability
to form more biologically active complexes had been studied
[6–9]. In continuation to our interest to prepare hexachlorocy-
clodiphosph(V)azane of sulfa drugs [6–9], the present paper
aims chiefly to prepare hexachlorocyclodiphosph(V)azane of
sulfadiazine H2L1 or its disulfo and diamino substituted hex-
achlorocyclodiphosph(V)azane, H2L2 and H2L3, respectively.
The behaviour of these three ligands towards transition metal
ions was studied. The characterization of the prepared com-
pounds was performed using different physicochemical meth-
ods. Also the biological activity of the prepared ligands and their
complexes were studied.
No congeners in the periodic table of the elements form
compoundsofagreaterstructuralvarietythannitrogenandphos-
phorus [1]. This was due in part to the ability of these nonmetals
to form single, double, and triple bonds with each other. It was,
however, also due to the strength of P N bonds, which render
most phosphorus–nitrogen compounds exceptionally thermally
stable [2]. While the unsaturated cylophosphazenes and their
polymeric products were of the oldest and best-known class
of P N compounds [3], the saturated phosphazanes also had
a well-established chemistry [4]. The reaction of cyclophosp-
hazenes [ClPNR]2 were interesting class of heterocycles with
two reactive phosphorus centers [5]. It was also interested in
designing compounds with multiple cycladiphosphazane unites
to be used as ligands for complexation. We needed the mono
substituted cyclodiphosphazanes to represent a few examples
of this type [5]. The bis-cyclodiphosphazane and tetrakis-
2. Experimental
2.1. Reagents
Chemicals were procured from Aldrich or BDH. They were
purifiedwhenrequired. Solventswerepurifiedaccordingtostan-
dard procedures.
∗
Corresponding author.
E-mail address: csharaby@hotmail.com (C.M. Sharaby).
1386-1425/$ – see front matter © 2006 Elsevier B.V. All rights reserved.
doi:10.1016/j.saa.2006.04.032

936
C.M. Sharaby et al. / Spectrochimica Acta Part A 66 (2007) 935–948
2.2. Synthesis of H2L1, H2L2 and H2L3 ligands
Shimadzu PC 3101 spectrophotometer. The magnetic suscep-
tibilities of the complexes in the solid state were recorded on
a Sherwood Scientific Magnetic Susceptibility Balance using
Faraday method. Thermogravimetric analysis was performed
under a nitrogen atmosphere using a Shimadzu TGA-50H with a
flow rate of 20 ml min−1. The UV–vis spectra were recorded on
a Perkin-Elmer Lambda 3B UV–vis spectrophotometer. Mass
spectra were recorded with the aid of a Shimadzu-Ge-Ms-QP
1,3-di-[N1-2-pyrimidinylsulfanilamide]-2,2,2.4,4,4-
hexachlorocyclodiphosph(V)azane (H2L1) was prepared
using the methods of Chapman et al. [10] and Zhumurova and
Kirzanov [10], sulfadiazine [N1-2-pyrimidinylsulfanilamide]
(0.1 mol, 25.0 g) in 100 ml cold dry benzene was added in
small portions to a well stirred cold solution of phosphorus
pentachloride (0.l mol, 20.95 g) in 100 ml cold dry benzene
during half an hour at ꢀ15 ◦C under dry conditions. After
completion of the reaction (HCl gas ceased to evolve), filtration
and removal of all solvent in vacuo, a residue was obtained
which on crystallization, yielded white crystals of (H2L1) (37 g,
80.5%) with mp = 162 ◦C.
100 EX mass spectrometer (Japan) using a direct insertion
◦
¨
probe (DIP) at temperature range 50–800 C. Mossbauer mea-
surements were performed at Physics Department, Faculty of
Science, Al-Azhar University, employing 57Co as a radioac-
tive source. The spectra were analyzed using a computer pro-
gram based on lorentzian distribution. The isomer shift were
expressed relative to a metallic iron absorber. Metal contents
were determined complexometerically using standard EDTA
titration [7]. The phosphorus content was determined gravimet-
rically as phosphoammoniummolybdate [7]. The Antimicrobial
activity was performed using DMF as solvent at Fermenta-
tion Biotechnology and Applied Microbiology (FERM-BAM)
Center, Al-Azhar University, Egypt. The test was done using
diffusion agar technique.
2.2.1. 1,3-di-[N1-2-pyrimidinylsulfanilamide]-2,4-disulfo-
2,4-dichlorocyclodiphosph(V)azane(H2L2)
The sulphur solid (0.7 g) was added in excess to a well stirred
solution of H2L1 (7.68 g, 0.1 mol) in 100 ml acetonitrile. After
the addition was completed, the reaction mixture was heated
under reflux for 1 h with continuous stirring under anhydrous
conditions. The reaction mixture was filtered while hot at vacuo,
a residue was obtained which on washing several times with ace-
tonitrile and dry diethyl ether, yielded yellow crystals of H2L2
(3 g, 35.80%), with mp = 192 ◦C.
3. Results and discussion
3.1. The ligands
2.2.2. 1,3-di-[N1-2-pyrimidinylsulfanilamide]-2,4-di-
[aminoacetic acid]-2,4-dichlorocyclodiphoph(V)azane
(H2L3)
In the present investigation, novel hexachlorocyclodi-
phosph(V)azane of sulfadiazine (H2L1) was prepared using the
methods of Chapman et al. [10] and Zhumurova and Kirzanov
[10]. Phosphorus pentachloride was reacted with sulfadiazine
in cold dry benzene to give 1,3-di-[N1-2-pyrimidinylsulfani-
lamide]-2,2,2,4,4,4-hexachlorocyclodiphosph(V)azane (H2L1)
in 80.5% yield. The reaction of solid sulfur with H2L1
in acetonitrile give 1,3-di-[N1-2-pyrimidinylsulfanilamide]-2,4-
disulfo-2,4-dichlorocyclodiphosph(V)azane (H2L2) in 35.80%
yield, while the reaction of glycine with H2L1 in acetoni-
trile gave a cyclosubstitution at the phosphorus atoms to
give 1,3-di-[N1-2-pyrimidylsulfanilamide]-2,4-(diaminoacetic
acid)-2,4-dichlorocyclodiphosph(V)azane (H2L3) in 60% yield.
The analytical data suggest the structures of the three pre-
pared ligands H2L1, H2L2 and H2L3 as given in Fig. 1.
Glycine (1.50 g, 0.02 mol) was added in small portions to a
well stirred solution of H2L1 (7.68 g, 0.01 mol) in 100 ml ace-
tonitrile during half hour. After the addition was completed,
the reaction mixture was heated under reflux for 3 h. After the
completion of the reaction (HCl gas ceased to evolve), the reac-
tion mixture was filtered while hot and the solid obtained was
washed several times with acetonitrile, diethyl ether and dried in
vacuo to give the corresponding aminoacyclodiphazane deriva-
tive (H2L3), (5.5 g, 60%) with mp = 210 ◦C.
2.3. Synthesis of the complexes
The structural elucidation of the ligands; H2L1, H2L2 and
A solution of metal salts (10 mmol) in 50 ml dry well stirred
ethanol was added dropwise to the solution of H2L1, H2L2 and
H2L3 (5 mmol) in 100 ml dry ethanol at room temperature. The
reaction mixture was heated under reflux for 2 h. The product
was separated and washed several times with ethanol and diethyl
ether and dried under vacuo.
H2L3, was accomplished on the basis of elemental analy-
1
ses (Table 1), UV–vis, IR, H NMR and mass spectroscopic
data. The UV spectra of the ligands in DMF solvent showed
absorption bands at 269, 270 and 270 nm, which are due to
the electron delocalization within the four membered ring of
the dimeric structure for the ligands H2L1, H2L2 and H2L3,
respectively [7,11]. The IR spectra for the ligands H2L1, H2L2
and H2L3 showed the characteristic bands of ν(P S), ν(P Cl),
ν(P N), ν(SO2), ν(C N) and ν(NH) which are summarized in
Table 2.
2.4. Instrumentation
Microanalytical determinations (C, H, N and S) were car-
ried out in the Microanalytical center, Cairo University. The
IR spectra were recorded on a Shimadzu FT-IR spectrometer
(KBr technique). 1H NMR spectra (DMSO-d6) were measured
on a Varian Gemini 200 MHz spectrometer, using TMS as inter-
nal standard. The electronic spectra were measured using a
Further the band at 623–625 cm−1 was characteristic to
ν(P S) for H2L2 and other bands characteristic to ν(P O C),
ν(C O) and ν(P N H), respectively, for H2L3 ligand are listed
1
in Table 2. H NMR (DMSO-d6), showed the characteristic

C.M. Sharaby et al. / Spectrochimica Acta Part A 66 (2007) 935–948
937
Fig. 1. The proposed structures for H2L1, H2L2 and H2L3 ligands.
of the complexes [(MXn)2 (H2L1 or H2L2 or H2L3) (H2O)z].
The formation of these complexes may proceed according to
the following equation:
proton signals, which are listed in Table 3. A broad signal
appeared between δ 6.28–7.3 ppm which is characteristic of
NH proton signal for H2L1, H2L2 and H2L3 ligands. Fur-
ther insight concerning the structures of the prepared ligands
were obtained from their mass spectra. The possible fragmenta-
tion pathways of H2L1, H2L2 and H2L3 ligands (Schemes 1–3)
showed a base peak at m/z 95, m/z 95 and m/z 186 (100%),
respectively. H2L1 ligand showed a peaks at m/z 673 (4%), m/z
580 (3.4%), m/z 384 (2.3%) and m/z 383 (2%) which confirm the
dimeric structure of H2L1 ligand (Fig. 1). H2L2 ligand showed
a peaks at m/z 578 (41%), m/z 379 (13.6%), m/z 346 (1.0%) and
m/z 342 (46%) which confirm the proposed structure of H2L2
ligand (Fig. 1). Also the mass fragmentation of H2L3 ligand
showed peaks at m/z 680 (47%) m/z 522 (8.24%) and m/z 388
(3.2%) which confirm the proposed structure of H2L3 ligand
(Fig. 1).
2MXn + H2L1orH2L2orH2L3 + zH2O
→ [(MXn)2(H2L1orH2L2orH2L3)(H2Oz)],
M = Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II),
X = Cl,n = 2,z = 4, M = Fe(II), X = SO4,n = 0,z = 4,
M = Fe(III), X = Cl,n = 2,z = 2,
M = UO2(II), X = NO3,n = 2,z = 0
3.2.1. Molar conductance
The molar conductance values in DMF at 25 ◦C (Table 1)
for the complexes were found to be in the range
7.85–18.30 ꢀ−1 mol−1 cm2. The relatively low values indicate
the non-electrolytic nature of these complexes [7,9]. This can
be accounted for by the satisfaction of the bi- or tri-valency of
the metal by the chloride, nitrate or sulphate. This implies the
coordination of the anions to the metal ion centers.
3.2. Metal complexes
The results of the elemental analyses listed in Table 1 are in
goodagreementwiththosecalculatedforthesuggestedformulae

Table 1
Analytical and physical data of H2L1, H2L2 and H2L3, ligands and their corresponding metal complexes
Compound
mp
(◦C)
Colour (% yield)
% Found (calcd.)
C
μeff.
(␮B)
Ωm (ꢀ−1
mol−1 cm2)
H
N
S
P
M
H2L1, (C20H16Cl6N8O4P2S2)
162
White (80.5)
31.62 (31.15)
2.48 (2.09)
1.83 (1.78)
2.71 (2.21)
2.32 (2.11)
2.27 (2.19)
2.04 (2.19)
2.24 (2.18)
2.53 (2.15)
2.06 (2.00
1.42 (1.03)
2.61 (2.33)
2.22 (1.91)
2.01 (2.14)
3.05 (2.86)
2.70 (2.31)
2.14 (2.49)
14.42 (14.53)
9.32 (9.90)
10.13 (10.23)
9.42 (9.77)
9.82 (10.16)
9.73 (10.16)
9.63 (10.08)
10.30 (10.50)
9.06 (9.26)
10.42 (10.78)
15.93 (16.16)
10.78 (10.63)
9.62 (9.90
8.40 (8.32)
7.87 (8.03)
5.90 (5.47)
6.03 (5.66)
4.98 (5.40)
5.87 (5.62)
6.03 (5.62)
5.77 (5.57)
5.63 (5.56)
4.93 (5.12)
3.67 (3.97)
8.53 (8.93)
5.48 (5.88)
–
–
–
[(FeCl3)2(H2L1)(H2O)2], C20H20Cl12Fe2N8O6P2S2
>300 Brownish yellow (58) 21.60 (21.23)
5.15 (5.67)
5.60 (5.86)
11.39 (11.18)
5.63 (5.82)
5.52 (5.82)
5.43 (5.77)
5.33 (5.74)
5.66 (5.30)
4.61 (4.11)
19.73 (18.49)
12.30 (12.17)
11.00 (11.33)
8.07 (8.27)
5.26 (5.65)
5.47 (5.28)
10.13 (9.87)
9.49 (10.03)
9.38 (9.74)
10.22 (10.65)
10.13 (10.65)
10.89 (11.43)
11.23 (11.66)
18.20 (18.58)
–
5.65
5.42
5.20
5.13
3.2
2.09
Diam.
Diam.
Diam.
–
5.82
Diam.
–
5.86
Diam.
18.30
9.58
10.50
12.40
11.30
7.85
11.30
14.22
12.5
–
13.95
11.85
–
14.50
9.76
[(MnCl2)2(H2L1)(H2O)4], C20H24Cl10Mn2N8O8P2S2 >300 Yellowish brown (52) 22.40 (21.94)
[(FeSO4)2(H2L1)(H2O)4], C2OH24Cl16Fe2N8O16P2S4 >300 Yellow (60)
20.35 (20.94)
21.73 (21.79)
21.99 (21.79)
21.16 (21.60)
21.89 (21.52)
20.38 (19.85)
[(CoCl2)2(H2L1)(H2O)4], C20H24Cl10Co2N8O8P2S2
[(NiCl2)2(H2L1)(H2O)4], C20H24Cl10N8Ni2O8P2S2
[(CuCl2)2(H2L1)(H2O)4], C20H24Cl10Cu2N8O8P2S2
[(ZnCl2)2(H2L1)(H2O)4], C20H24Cl10N8N8O8P2S2
[(CdCl2)2(H2L1)(H2O)4], C20H24Cd2Cl10N8O8P2S2
[(UO2)2(H2L1)(NO3)4], C20H16Cl6N12O20P2S2U2
H2L2, C20H20Cl2N8O4P2S2
[(FeCl3)2(H2L2)(H2O)2], C20H20Cl8Fe2N8O6P2S4
[(CdCl2)2(H2L2)(H2O)4], C20H24Cd2Cl6N8O8P2S4
H2L3, C24H22Cl2N10O8P2S2
[(FeCl3)2(H2L3)(H2O)2], C24H26Cl8Fe2N10O10P2S2
[(CdCl2)2(H2L3)(H2O)4], C24H30Cd2Cl6N10O12P2S2
>300 Brown (67)
>300 Brown (68)
>300 Yellow (70)
>300 White (73)
>300 Yellow (55)
>300 Brownish yellow (52) 15.00 (15.41
192 White (36) 34.24 (34.64)
>300 Yellowish brown (60) 22.54 (22.79)
>300 Yellowish white (63)
210 White (60)
>300 Yellow (58)
>300 White (60)
–
10.28 (10.60)
21.50 (21.22)
36.95 (37.17)
24.93 (25.38)
24.07 (23.74)
5.07 (5-47) 19.41 (19.86)
18.36 (18.06)
12.45 (12.33)
11.32 (11.54)
8.15 (7.99)
5.73 (5.45)
4.92 (5.10)
–
10.18 (9.83)
18.99 (18.52
Table 2
IR spectra (4000–400 cm−1) of the H2L1, H2L2 and H2L3 ligands and their metal complexes
Compound
ν(NH)
ν(P NH)
ν(C O)
ν(C N)
ν(SO2) (asym.)
ν(SO2) (sym.)
ν(P N)
ν(H2O) (coord.)
ν(P Cl)
ν(P S)
ν(M O)
ν(M N)
H2L1 [C20H16Cl6N8O4P2S2]
[(FeCl3)2(H2L1)(H2O)2]
[(MnCl2)2(H2L1)(H2O)4]
[(FeSO4)2(H2L1)(H2O)4]
[(CoCl)2(H2L1)(H2O)4]
[(NiCl2)2(H2L1)(H2O)4]
[(CuCl2)2(H2L1)(H2O)4]
[(CdCl2)2(H2L1)(H2O)4]
[(UO2)2((NO3)4(H2L1)]
H2L2 [C20H16Cl2N8O4P2S4]
[(FeCl3)2(H2L2)(H2O)2]
[(CdCl2)2(H2L2)(H2O)4]
H2L3[C24H22Cl2N10O8P2S2]
[(FeCl3)2(H2L3)(H2O)2]
[(CdCl2)2(H2L3)(H2O)4]
3368 br
3375 sh
3388 br
3372 br
3388 br
3378 br
3376 sh
3375 br
3375 br
3380 br
3385 br
3390 br
3375 br
3383 br
3386 br
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
1618 sh
1594 m
1600 m
1596 m
1600 m
1605 m
1594 m
1590 sh
1608 m
1618 sh
1595 m
1590 sh
1618 sh
1598 m
1596 m
1348 s
1084 m
10.92 m
1060 s
1156 sh
1158 sh
1170 w
1156 br
1188 br
1188 br
1156 sh
1168 sh
1168 br
1168 br
1158 sh
1150 m
1146 m
1160 m
1150 w
–
570 sh
574 sh
575 m
572 m
574 m
574 m
572 m
572 sh
566 m
572 sh
574 sh
572 w
572 w
575 sh
568 m
–
–
–
–
–
–
–
–
550 m
520 s
524 s
500 w
510 w
524 m
556 s
510 w
–
–
1326 sh
1332 sh
1322 w
1324 w
1320 w
1326 sh
1326 m
1325 w
1348 m
1326 w
1328 w
1342 sh
1324 w
1326 sh
844 m, 796 sh
820 s, 782 s
826 s, 790 s
850 m, 780 m
820 m, 780 m
842 m, 796 sh
812 m, 782 m
840 m, 795 m
–
810 s, 785 s
820 s, 794 m
–
830 s, 780 s
842 m, 796 sh
502 m
480 w
490 w
460 w
480 w
500 m
475 w
480 w
–
490 w
470 w
–
470 w
425 m
1090 s
1052 m
1046 m
1092 sh
1080 sh
1100 s
1086 m
1090 br
1086 m
1088 m
1092 br
1092 sh
–
625 m
625 m
623 m
–
–
–
–
530 w
584 m
–
550 s
485 m
2690 br
2700 br
2715 br
1650 m
1652 m
1652 m
sh: sharp, m: medium, s: small, w: weak, and br: broad.

C.M. Sharaby et al. / Spectrochimica Acta Part A 66 (2007) 935–948
939
Table 3
respectively. In the complexes, the asymmetric and symmetric
modes are shifted to 1320–1332 cm−1 and 1046–1100 cm−1
Characteristic 1H NMR spectra for the ligands H2L1, H2L2 and H2L3 and their
Cd(II) complex
,
respectively, upon coordination to the transition metals [6–9].
The blue shift of the SO2 stretching vibration to lower frequen-
cies may be attributed to the transformation of the sulfonamide
( SO2NH) to give the enol form ( SO(OH) N) as a result
of complex formation to give more stable six-membered ring
[6–9].
Compound
Chemical
shift, δ
(ppm)
Assignment
7.12
7.60
6.97
8.47
9.80
d, 4H, ArH’s, J = 8.80 Hz
d, 4H, ArH’s, J = 8.40 Hz
br, 2H, SO2NH
s, CH, hetero
br, H, heterocycle proton
H2L1
The strong and sharp bands at 1618 cm−1 of the pyrimidine-
N; ν(C N) in the free ligands are shifted to 1595–1605 cm−1
in the metal complexes. This indicates the participation of
the pyrimidine-N in complex formation. The presence of
medium-to-strong bands in the region between 810–850 and
769–780 cm−1 in the spectra of the metal complexes were
attributed to coordinated water molecules. New bands were
found in the spectra of the complexes in the regions 485–556 and
425–502 cm−1 which were assigned to ν(M O) and ν(M N)
stretching vibrations, respectively [12].
6.60
7.60
4.21
7.66
8.48
3.48
d, 4H, ArH’s, J = 8.60 Hz
d, 4H, ArH’s, J = 8.40 Hz
br, H, OH enolic
s, CH, hetero
br, 2H, heterocycle proton
br, 8H, coordinated H2O protons
[(CdCl2)2(H2L1)(H2O)4]
6.60
7.60
6.28
7.90
8.48
d, 4H, ArH’s, J = 8.90 Hz
d, 4H, ArH’s, J = 8.50 Hz
br, 2H, SO2NH
t, CH, hetero
br, 2H, heterocycle proton
H2L2
Therefore, the IR data reveal that H2L1, H2L2 and H2L3 lig-
ands behave as neutral bidentate ligands and bind to the metal
ions through enolic sulfonamide OH and pyrimidine-N.
6.50
7.00
5.80
7.00
8.40
3.45
d, 4H, ArH’s, J = 8.70 Hz
d, 4H, ArH’s, J = 8.40 Hz
br, H, OH enolic
t, CH, hetero
s, 2H, heterocycle proton
br, 8H, coordinated H2O protons
3.2.3. 1H NMR spectra
[(CdCl2)2(H2L2)(H2O)4]
The 1H NMR spectra of H2L1, H2L2 and H2L3 and their Cd
complexes were recorded in dimethylsulphoxide (DMSO-d6)
using trimethylsilane (TMS) as internal standard. The chemical
shifts of the different types of protons of H2L1, H2L2 and H2L3
ligands and their Cd complexes are listed in Table 3. It was found
thatthe SO2NHsignalisfoundatδ = 6.97, 6.28and7.30 ppmin
the spectra of H2L1, H2L2 and H2L3 ligands, respectively. This
signal is disappeared and a new signal was appeared at δ = 4.21,
5.80 and 5.97 ppm in the spectra of Cd complexes of H2L1,
H2L2 and H2L3 ligands, respectively. This was attributed to the
enolization of the SO2NH to SO(OH) N and coordination of
the enolized OH to the metal ions [6–9].
6.59
7.60
2.50
7.30
8.30
6.98
8.40
d, 4H, ArH’s, J = 8.90 Hz
d, 4H, ArH’s, J = 8.70 Hz
s, 2H, glycine CH2 protons
br, 2H, SO2NH
br, 2H, glycine NH protons
t, CH hetero
H2L3
s, 2H, CH heterocycle protons
6.50
7.60
2.50
5.97
8.30
6.99
8.40
3.49
d, 4H, ArH’s, J = 8.80 Hz
d, 4H, ArH’s, J = 8.80 Hz
s, 2H, glycine CH2 protons
br, H, OH enolic
br, 2H, glycine NH protons
t, CH hetero
[(CdCl2)2(H2L3)(H2O)4]
Also, the spectra of the complexes showed a broad signals at
δ 3.48, 3.45 and 3.49 ppm for Cd complexes with H2L1, H2L2
and H2L3 ligands, respectively, which attributed to the presence
of coordinated water molecules.
s, 2H, CH heterocycle protons
br, 8H, coordinated H2O protons
3.2.4. Electronic spectra and magnetic moment
3.2.2. IR spectra and mode of bonding
The UV–vis spectra of the ligands and the complexes were
recorded in DMF solution in the wavelength range from 200
to 800 nm. The spectra showed a sharp and intense band in
the 270 nm region, which is characteristic for phosphazo four-
membered rings of the ligands. The blue or red shifts of the band
in the region (267–276 nm) with respect to the ligands depend
on the type of metal ions coordinated to the ligand [6–9]. The
spectra of the complexes further display a band in the range
388–401 nm, which might be assigned to charge transfer transi-
tion from the ligand to metal ions (L → M) [9].
The IR spectra of the ligand and its metal complexes were car-
ried out in the range of 400–4000 cm−1 and the important bands
were listed in Table 2. The IR spectra of the complexes were
compared with those of the free ligands in order to determine
the possible coordination sites that may involved in chelation.
Thereweresomeguidepeaks, inthespectraoftheligands, which
were of good help for achieving this goal.
The stretching vibration band; ν(NH), of the sulfonamide
group, which found at 3368–3380 cm−1 in the free ligands, were
shifted to higher frequencies in the spectra of the isolated com-
plexes. The presence of coordinated water molecules renders it
difficult to confirm the enolization of the sulfonamide group. The
SO2 groupmodesoftheligandsappearasmediumtosharpbands
at 1348, 1348 and 1342 cm−1 (νasym(SO2)) and 1094, 1086
and 1088 cm−1 (νsym(SO2)) for H2L1, H2L2 and H2L3 ligands,
The diffuse reflectance spectrum of Mn(II) complex shows
three bands at 15,644, 22,222 and 26,455 cm−1 assignable to
6
4
6
4
6
4T1g → A1g, T2g (G) → A1g and T1g (D) → A1g transi-
tions, respectively [13]. The magnetic moment value is 5.42 ␮B.
which indicates the presence of Mn(II) complex in octahedral
structure.

940
C.M. Sharaby et al. / Spectrochimica Acta Part A 66 (2007) 935–948

C.M. Sharaby et al. / Spectrochimica Acta Part A 66 (2007) 935–948
941

942
C.M. Sharaby et al. / Spectrochimica Acta Part A 66 (2007) 935–948

C.M. Sharaby et al. / Spectrochimica Acta Part A 66 (2007) 935–948
943
It is observed from the diffuse reflectance spectra
of the Fe(III) complexes that they exhibit a band at
5
21,008–21,276 cm−1 whichmaybeassignedtothe6A1g → T2g
(G) transition in octahedral geometry [14,15]. The spectra also
show a spitted bands at 14,947–15,673 and 17,574–18,315 cm−1
6
5
which assigned to the A1g → T1g transition. The observed
magnetic moment of the Fe(III) complexes is 5.65, 5.82 and
5.86 ␮ for H2L1, H2L2 and H2L3 ligands, respectively, which
B
confirm the octahedral geometry. The bands observed at 29,154
and 24,937–26,041 cm−1 can be attributed to ligand-to-metal
charge transfer band for the Mn(II) and Fe(III) complexes,
respectively.
The diffuse reflectance spectrum of the Fe(II) complex dis-
plays two absorption bands at 13,157 and 17,636 cm−1 which
5
5
are assigned to T2g → Eg transitions [16]. Also the band at
28,735 cm−1 isassignedtoL → Mchargetransfer. Theobserved
magnetic moment of 5.2 ␮ is consistent with an octahedral
B
geometry [16].
The electronic spectrum of the Co(II) complex shows two
bands at 16,051 and 22,075 cm−1 assigned to the 4T1g → T1g
4
4
4
(P) and T1g → T2g (F) transitions, respectively, indicating
octahedral geometry. The band observed at 26,178 cm−1 refers
to L → Co charge transfer. The observed magnetic moment
value is 5.13 ␮ at room temperature which confirms the octa-
B
hedral geometry of this complex [16,17].
For Ni(II) complex, the electronic spectrum shows three
Fig. 2. Mo¨ssbauer spectra of iron complexes of H2L1, H2L2 and H2L3.
bands at 16,339, 17,636 and 20,964 cm−1, suggesting the exis-
3
3
3
3
3
3
tence of A2g → T1g (P), A2g → T1g (F) and A2g → T2g
transitions, respectively. The observed magnetic moment of the
complex is3.2 ␮B which confirmstheoctahedralstructureof this
complex[7,17]. Thespectrumalsodisplaysbandat26,315 cm−1
which assigned to L → M CT band.
those already present in the literature indicates the coordination
number of Fe(II) and Fe(III) complex are six. On the bases of
quadruple splitting data (QS), the iron complex exist in octahe-
dral configuration [20].
TheelectronicspectrumoftheCu(II)complexexhibitsaband
at 17,605 cm−1 which may be assigned to 2Eg → T2g transition
4. Thermal analysis (TGA)
3
[18]. The spectrum also displays and at 28,571 cm−1 refers to
L → M CT band. The observed magnetic moment of the Cu(II)
complex is 2.09 ␮B which confirms octahedral geometry around
the Cu(II) ion [18].
Table 5 shows the TGA results of the thermal decomposition
of the metal complexes of the ligands under study. While the
thermodynamic activation parameters are listed in Table 6.
[(FeSO4)2(H2L1)(H2O)4] complex was thermally decom-
posed in five decomposition steps within the temperature range
of 50–1100 ◦C. The first decomposition step with an estimated
mass loss of 6.83% (calcd. mass loss = 6.28%) within the tem-
perature range 50–200 ◦C, may be attributed to the liberation
of the four coordinated water molecules. The activation energy
was 63.60 kJ mol−1. The remaining decomposition steps (four
steps) found within the temperature range 200–1100 ◦C with
an estimated mass loss of 67.35% (calcd. mass loss = 67.22%)
which are reasonably accounted for by the removal of H2L1 lig-
and as gases. The activation energies were 92.04, 85.67, 136.80
and 185.7 kJ mol−1 for the second, third, fourth and fifth steps,
respectively. The thermograms of [(FeCl3)2(H2L1)(H2O)2],
[(CuCl2)2(H2L1),(H2O)4] and [(CdCl2)2(H2L1)(H2O)4] com-
plexes show five decomposition steps within the temperature
range 30–1000 ◦C. The first two steps of decomposition (in case
of Fe(III) and Cd(II) complexes) or three steps of decomposi-
tion (in case of Cu(II) complex) within the temperature range
30–350 ◦C corresponds to the loss of 4–6 HCl, 3H2O and O2
The Zn(II), Cd(II) and UO2(II) complexes are diamagnetic
and they proposed to have octahedral structure as those previ-
ously published [19,6–9].
3.2.5. Mo¨ssbauer measurement
1
¨
The Mossbauer spectra of iron complexes of ligands H2L ,
H2L2 and H2L3 were measured at room temperature (Table 4
and Fig. 2). The observed isomer shift values indicate the pres-
ence of iron in its +2 and +3 oxidation states. A comparative
study of the isomer shift values of these iron complexes with
Table 4
Mo¨ssbauer parameters of iron complexes of H2L1, H2L2 and H2L3 ligand
Complex compound
Isomer shift
(m/m/s) (IS)
Quadrupole splitting
(mm/S) (QS)
[(FeSO4)2(H2L1)(H2O)4]
[(FeCl3)2(H2L2)(H2O)2]
[(FeCl3)2(H2L2)(H2O)2]
1.39
0.48
0.47
2.7
0.58
0.56

944
C.M. Sharaby et al. / Spectrochimica Acta Part A 66 (2007) 935–948
Table 5
Thermogravimetric data of H2L1, H2L2 and H3L3 metal complexes
Complex
TG range (◦C) DTGmax (◦C)
na
% Found (calcd.)
Mass loss
Assignment
Metallic residue
Total mass loss
74.18 (73.50)
86.47 (86.05)
[(FeSO4)2(H2L1)(H2O)4]
[(FeCl3)2(H2L1)(H2O)2]
[(CuCl2)2(H2L1)(H2O)4]
50–200
120
1
4
6.73 (6.28)
67.35 (67.22)
Loss of 4H2O
Loss of H2L1
2FeSO4
Fe2O3
200–1100
275, 390, 660, 875
30–250
70, 210
2
3
22.68 (22.18)
63.79 (63.87)
Loss of 6HCl and O2
Loss of H2L1
250–1000
330, 560, 850
30–220
220–350
350–800
60, 185
290
490, 670
2
1
2
12.31 (12.86)
6.67 (6.56)
61.45 (61.88)
Loss of 2HCl, 3H2O and 1/2O2
Loss of 2HCl
Loss of H2L1
Cu2SO3
2CdO
2CdO
2CdO
80.43 (81.39)
78.79 (78.83)
77.50 (77.36)
78.32 (78.90)
[(CdCl2)2(H2L1)(H2O)4]
[(CdCl2)2(H2L2)(H2O)4]
30–180
180–260
260–600
120
230
290, 370, 510
1
1
3
11.54 (11.66)
6.68 (6.04)
60.75 (60.96)
Loss of 2HCl, 3H2O and 1/2O2
Loss of 2HCl
Loss of H2L1
30–200
200–360
360–1000
90
248
530, 850
1
1
2
11.98 (12.64)
6.70 (6.45)
58.82 (58.27)
Loss of 2HCl, 3H2O and 1/2O2
Loss of 2HCl
Loss of H2L2
[(CdCl2)2(H2L3)(H2O)4]
30–210
210–340
340–800
108
230
530
1
1
1
11.63 (11.79)
5.80 (6.02)
60.89 (61.09)
Loss of 2HCl, 3H2O and 1/2O2
Loss of 2HCl
Loss of H2L3
a
n: number of decomposition steps.
gases with a mass loss of 22.68% (calcd. mass loss = 22.18%),
18.98% (calcd. mass loss = 19.42%) and 18.22% (calcd. mass
loss = 17.87%) for Fe(III), Cu(II) and Cd(II) complexes, respec-
The last steps (250–1000 ◦C) correspond to the loss of the
organic ligand molecule (H2L1) leaving Fe2O3, Cu2SO3 and
CdO as a residue with an activation energies 99.86–152.3,
155.6–198.7 and 92.97–136.9 kJ mol−1 for Fe(III), Cu(II) and
tively. The activation energy values were 33.45–108.4 kJ mol−1
.
Table 6
Thermodynamic data of the thermal decomposition of H2L1, H2L2 and H2L3 metal complexes
Complex
Decomp. temp. (◦C)
E* (kJ mol−1
)
A (s−1
)
ꢁS* (kJ mol−1
)
ꢁH* (kJ mol−1
)
ꢁG* (kJ mol−1
)
50–150
220–300
340–460
570–760
830–960
63.60
92.07
85.67
136.8
185.7
1.67 × 107
3.04 × 1010
1.67 × 107
4.84 × 1012
6.53 × 109
−43.05
−72.22
−102.3
−98.87
−135.6
75.05
56.96
87.95
106.5
146.3
55.43
76.62
89.53
102.5
142.7
[(FeSO4)2(H2L1)(H2O)4]
30–100
150–250
280–380
500–670
780–900
64.73
108.4
152.3
99.86
145.6
3.67 × 109
2.67 × 105
4.59 × 1010
6.82 × 1011
7.14 × 109
1.98 × 1011
3.52 × 108
4.09 × 1012
2.51 × 106
7.08 × 1010
3.05 × 106
5.27 × 1011
4.49 × 109
6.08 × 1010
3.56 × 1013
−36.95
−65.97
−97.68
−112.6
−153.7
−39.85
−68.95
−97.85
−107.7
−154.3
−73.78
−98.77
−132.3
−163.4
−203.5
68.45
79.06
112.3
143.6
98.99
84.77
64.53
122.4
154.2
165.3
[(FeCl3)2(H2L1)(H2O)2]
[(CuCl2)2(H2L1)(H2O)4]
[(CdCl2)2(H2L1)(H2O)4]
30–90
49.85
97.65
84.89
155.6
198.7
52.73
95.53
143.6
193.2
223.6
38.66
87.55
135.4
168.3
200.1
100–220
220–400
460–530
600–750
50–150
180–250
250–320
320–430
440–600
33.45
75.02
117.7
92.97
136.9
67.96
86.15
76.87
145.3
165.2
58.69
90.67
103.4
87.45
115.6
50–180
200–300
400–600
750–900
53.26
77.95
94.82
175.2
2.83 × 108
3.49 × 1012
1.50 × 109
6.04 × 1013
2.95 × 109
4.19 × 107
5.65 × 1010
−29.78
−59.95
−88.66
−107.3
−56.44
−85.19
−106.7
45.13
95.26
176.3
203.6
38.56
67.53
125.4
95.67
[(CdCl2)2(H2L2)(H2O)4]
[(CdCl2)2(H2L3)(H2O)4]
30–150
200–290
450–650
48.69
75.23
152.6
38.46
79.98
100.5
34.62
61.52
95.96

C.M. Sharaby et al. / Spectrochimica Acta Part A 66 (2007) 935–948
945
On the other hand, [(CdCl2)2(H2L2)(H2O)4] and [CdCl2)2-
(H2L3)(H2O)4] complexes exhibit four and three decomposition
steps, respectively, within the temperature range 30–1000 ◦C.
The first decomposition step occurs within the temperature
Cd(II) complexes, respectively. The overall weigh loss amounts
to 86.47% (calcd. mass loss = 86.05%), 80.43% (calcd. mass
loss = 81.39%) and 78.79% (calcd. mass loss = 78.83%) for
Fe(III), Cu(II) and Cd(II) complexes, respectively.
Fig. 3. (a) Suggest structural formulae of H2L1 ligand. (b) Suggest structural formulae of H2L2 ligand. (c) Suggest structural formulae of H2L3 ligand.

Table 7
The antibacterial and antifungal activity of H2L1, H2L2, H2L3 ligands and their metal complexes
Test organisms
Conc. (mg/ml)
Compound
H2L1
[(FeCl3)2(H2L1)2(H2O2)
[(MnCl2)2(H2L1)(H2O)4]
[(FeSO4)2(H2L1)(H2O)4]
[(CoCl)2(H2L1)(H2O)4]
2.5
++ +++ +++
++ ++ +++
++ +++ +++
[(NiCl2)2(H2L1)(H2O)4]
St
1
1
2.5
5
1
2.5
5
1
2.5
5
1
2.5
5
1
5
1
2.5
5
2.5
5
Escherichia coli
++ ++
++ ++ ++
++
++
+
+
+
++ ++
++
++
++
+
+
+
+
+
+
+
0
0
++
++
+
+
0
++
++
++
+
0
0
++ ++
++
+
++
+++ +++
Staphylococcus aureus
Salmonella typhi
Bacillus subtillus
Aspergillus terreus
Aspergillus flavus
+
+
+
0
++
+
+
++
++
+
+
+
+
+
+
0
0
++
+
+
0
+
+
+
+
0
0
++
++
+
0
0
+
+
+++ +++ +++
++ +++ +++
++
++
++
++
+++
+
+
0
++
+
0
+++
++
+
+
0
0
+
0
0
+
0
0
+++ +++
+++ +++
0
+
+
+
0
+++ +++ +++
Test organisms
Compound
[(CuCl2)2(H2L1)(H2O)4]
[(CdCl2)2(H2L1)(H2O)4]
[(UO2)2((NO3)4(H2L1)]
H2L2
[(FeCl3)2(H2L2)(H2O)2]
[(CdCl2)2(H2L2)(H2O)4]
2.5
St.
Conc. (mg/ml)
1
2.5
5
1
2.5
5
1
2.5
5
1
2.5
5
1
2.5
5
1
5
1
2.5
5
E. coli
S. aureus
S. typhi
B. subtillus
Aspergillus terrens
A. flavus
++ ++
++
+
+++
+
+
+
++
++
++
++
+++
+++
+
+
+
+
0
0
++
+
+
+
0
++
+
+
+
+
++ ++
++ ++
++ ++
++
+++
+++
++
+
+
+
+
+
+
+
++
++
++
+
+
+
++
+++
++
+
+
+
++ +++ +++
++ +++ +++
++
+++ +++
+
+
+++ +++ +++
++ ++
+++ +++ +++
++
+
++ ++
++ ++
+++
++
++
++
++
++
+++
+
0
+
+
+
+
++
++
+
++
++
+
+
0
0
++
+
+
+++ +++
+++ +++
+
+
++
++
++
+++
+
0
0
+
+++ +++ +++
Test organisms
Compound
H2L3
1
[(FeCl3)2(H2L3)(H2O)2]
[(CdCl2)2(H2L3)(H2O)4]
St.
Conc. (mg/ml)
2.5
5
1
2.5
5
1
2.5
5
1
2.5
5
E. coli
S. aureus
S. typhi
B. subtillus
A. terreus
A. flavus
++
++
++
+
+
0
+++
++
++
+
+
0
+++
++
+++
+
++
+
++
+
+
+
0
++
+
++
+
+
0
++
++
++
+
+
+
++
++
++
+
+
+
++
++
++
++
++
+
++
++
+++
++
++
+
++
+++
++
++
++
+++
+++
++
+++
+++
+++
+++
+++
+++
+++
+++
+++
0
+++
St.: references standard; Chloramphenicol was used as a standard antibacterial agent and Grisofluvine was used as a standard antifungal agent; *tested was done the diffusion agar technique. Well diameter: 1 cm
(100 ␮l of each conc., was tested); +: inhibition values = 0.1–0.5 cm beyond control; ++: inhibition values = 0.6–1.0 cm beyond control; +++: inhibition values = 1.1–1.5 cm beyond control; 0: not detected.

C.M. Sharaby et al. / Spectrochimica Acta Part A 66 (2007) 935–948
947
range 30–210 ◦C and corresponds to the loss of 2HCl, 3H2O
and 1/2O2 gases with an estimated mass loss 11.98% (calcd.
mass loss = 12.64%) and 11.63% (calcd. mass loss = 11.79%) for
Cd(II)complexeswithH2L2 andH2L3 ligands, respectively. The
energy of activation was 53.26 and 48.69 kJ mol−1 for Cd(II)
complexes with H2L2 and H2L3 ligands, respectively. While, the
subsequent steps involve the loss of 2HCl and ligand molecules
within the temperature range 200–1000 ◦C with an estimated
mass loss 65.52% (calcd. mass loss = 64.72%) and 66.69%
(calcd. mass loss = 67.11%) for Cd(II) complexes with H2L2
and H2L3 ligands, respectively. The energies of activation were
77.95, 94.82 and 175.2 kJ mol−1 for the second, third and fourth
steps in case of [CdCl2)2(H2L2)(H2O)4] complex, respectively,
75.23and 152.6 kJ mol−1 for the second and third steps, respec-
tively, for the [(CdCl2)2, (H2L3) (H2O)4] complex. The overall
weight loss amounts to 77.50% (calcd. mass loss = 77.36%) and
78.32% (calcd. mass loss = 78.90%) for Cd(II) complexes with
H2L2 and H2L3 ligands, respectively.
The results showed that Co(II) and Cd(II) complexes
enhanced the activity towards E. coli more than the H2L1 free
ligand and the other metal complexes gave the same activity
as the H2L1 free ligand. Co(II), Ni(II) and Cd(II) complexes
showed a remarkable activity towards S. aureus than the H2L1
free ligand while the other tested metal complexes gave the same
or lower activity as the H2L1 free ligand.
Also Co(II), Ni(II), Cu(II) and Cd(II) complexes showed a
very high activity towards S. typhi than the H2L1 free ligand,
while the other metal complexes gave the same activity or lower
than the free ligand H2L1. Co(II) complex, enhanced the activity
towards B. subtillus than the free ligand H2L1.
Comparison of the biological activities of the synthesized
compounds and the standard antibiotic (Chloramphenicol)
showed that the free ligand H2L1 showed lower activity towards
the investigated bacterial than the standard.
The metal complexes of Co(II), Ni(II) and Cd(II) enhanced
the activity towards some investigated bacteria than the standard
antibiotic Chloramphenicol and in the same time they showed
the same activity towards some of the investigated bacteria as
the standard.
5. Kinetic data
The thermodynamic activation parameters such as activation
energy (E*), enthalpy of activation (ꢁH*), entropy (ꢁS*) and
free energy change of the decomposition (ꢁG*) were evaluated
graphically by employing the Coats–Redfern relation [21]. The
data are listed in Table 6. It was shown from the data that all the
complexes have negative entropy values, which indicate that the
activated complexes are formed spontaneously.
Ligand H2L2 showed a higher or the same activity towards
the investigated bacteria than the first ligand H2L1. This might
be due to the replacement of four chlorine atoms in H2L1 by
two sulphur atoms in H2L2 ligand. Also the free ligand H2L2
showed the same activity as Chloramphenicol towards S. aureus
and S. typhi and showed lower activity towards the investigated
fungi than the standard antibiotic Grisofluvine.
While Cd(II) complex enhanced the activity towards E. coli
and S. aureus than the free ligand H2L2 and this complex
showed the same activity as the standard antibiotic Chloram-
phenicol. Also Cd(II) complex showed a remarkable higher
activity towards A. terreus and A. flavus than the free ligand
H2L2 and the same activity towards E. coli, S. aureus, S. typhi
and Aspergillus ftavus as that of the standards Chloramphenicol
and Grisofluvine.
6. Structural interpretation
From the satisfactory microanalyses, magnetic, molar con-
ductance, thermal analysis and various spectral data, the struc-
ture can be interpreted in accordance with complexes of
ligands with the same coordination sites like hexachlorocy-
clodiphosph(V)azane of sulfadimidine [6], sulfameterol [7], sul-
famethoxazole [9] and sulfaguanidine [8]. It is concluded that
H2L1, H2L2 and H2L3 ligands act as a neutral bidentate ligands
coordinated to the metal ions through enolized SO(OH) N and
pyrimidine-N. The structures proposed are based on an octahe-
dral geometric structures. The molar conductance data reveal
that the complexes are non-electrolytes while the thermal analy-
sis (TGA) data show that the complexes decomposed in three to
five steps where the coordinated water and anions are removed
in the first steps followed by the ligands. Therefore, from the
above data and in accordance to those previously published, the
structures of the complexes are shown in Fig. 3.
H2L3 free ligand showed the same activity towardsE. coli and
A. terreus than the free ligands H2L1 and H2L2. This might be
reasonably accounted to the replacement of four chlorine atoms
in H2L1 ligand by two glycine molecules in H2L3 free ligand.
Cd(II) complex showed a remarkable higher activity towards
B. subtillus, A. terreus and A. flavus than the free ligand H2L3
and the standard Chloramphenicol.
From all of the above results we can conclude that some
metalcomplexesenhancedtheactivityoftheligandsandshowed
higher activity than the investigated standard antibiotics.
References
7. The antimicrobial activity
[1] (a) D.E.C. Corbridge, Phosphorus: An Outline of its Chemistry, Biochem-
istry and Technology, 5th ed., Elsevier, Amsterdam, 1995;
(b) N.N. Greenwood, A. Earnshaw, Chemistry of the Elements, 2nd ed.,
Butterworth-Heinemann, Oxford, 1998.
[2] S. Ingo, P. Luke, Grocholl, S. Lother, Inorg. Chem. 39 (2000) 3037.
[3] (a) J.E. Mark, H.R. Allcock, R. West, Inorganic Polymer, Englewood Cliffs,
Prentice Hall, NJ, 1992;
The synthesized compounds were tested against the bacte-
rial species namely Escherichia coli, Staphylococcus aureus,
Salmonella typhi and Bacillus subtillus. Also the antifungal
activity against Aspergillus terreus and Aspergillus flavus were
carried out. The organisms were tested against the activity of
different concentrations of the compounds, results are depicted
in Table 7.
(b) R.H. Neilson, P. Wisian-Neilson, Chem. Rev. 88 (1988) 541;
(c) C.E. Allen, Coord. Chem. Rev. 130 (1994) 137.

948
C.M. Sharaby et al. / Spectrochimica Acta Part A 66 (2007) 935–948
(b) I.M. Abd-Ellah, E.H.M. Ibrahim, A.N. El-Khazandar, J. Phosphorus
[4] (a) R.R. Holmes, J.A. Former, Inorg. Chem. 2 (1963) 380;
(b) T.G. Hill, R.C. Haltiwanger, M.L. Thompson, S.A. Katz, A.D. Norman,
Inorg. Chem. 33 (1994) 1770;
(c) O.J. Scherer, G. Schnable, Angew. Chem. Int. Ed. Engl. 15 (1976) 772;
(d) S.S. Kumaravel, S.S. Krishnamurthy, T.S. Gameron, A. Linden, Inorg.
Chem. 27 (1988) 4546;
Sulfur 31 (1987) 13.
[12] R.J. Ferraro, Low Frequency Vibrations of Inorganic and Coordination
Compounds, 1st ed., Plenum Publisher, New York, 1997, p. 168.
[13] G.M. Abu El-Reash, K.M. Ibrahim, M.M. Bekheit, Bull. Chem. Soc., Fr.
128 (1991) 149.
(e) A.R. Davies, A.I. Dronsfield, R.N. Haszeldin, D.R. Taylor, J. Chem.
Soc. Perkin Trans. 1 (1973) 379;
[14] G.G. Mohamed, N.E.A. El-Gamel, F.A. Nour El-Dien, Synth. React. Inorg.
Met.-Org. Chem. 31 (2) (2001) 347.
(f) W. Zeiss, W. Schwarz, H.Z. Hess, Naturforschung 33b (1980) 959;
(g) D. Dou, E.N. Duesler, R.T. Paine, Inorg. Chem. 38 (1999) 788.
[15] G.G. Mohamed, N.E.A. El-Gamel, Spectrochim. Acta (Part A) 61 (2005)
1089.
[5] J.J. Praveen Kommana, K.C. Vittal, Kumaraswamy, Polyhedron 22 (2003)
843.
[16] F.A. Cotton, G. Wilkinson, C.A. Murillo, M. Bochmann, Advanced Inor-
ganic Chemistry, 6th ed., Wiley, New York, 1999.
[6] C. Sharaby, Ph.D. Thesis, Faculty of Science, Al-Azhar University (Girls),
Cairo, Egypt, 1992.
[17] G.G. Mohamed, M.A. Zayed, N.E.A. El-Gamel, Spectrochim. Acta (Part
A) 58 (2002) 3167.
[7] C.M. Sharaby, Synth. React. Inorg. Met.-Org. Chem. 35 (2005) 133.
[8] C.M. Sharaby, Spectrochem. Acta (Part A) 62 (2005) 326.
[9] G.G. Mohamed, Phosphorus Sulfur Silicon Related Elements 180 (7)
(2005) 1569.
[10] I.N. Zhumurova, A.V. Kirzanov, Zh. Obshch. Khim. 32 (1962) 2576.
[11] (a) I.M. Abd Ellah, E.H.M. Ibrahim, A.N. El Khazandar, J. Phosphorus
Sulfur 29 (1987) 239;
[18] A.B.P. Lever, Inorganic Electronic Spectroscopy, 1st ed., Elsevier Pub-
lisher, London, New York, 1968, p. 267.
[19] Z.M. Zaki, Spectrosc. Lett. 31 (4) (1998) 757.
[20] N.N. Greenwood, T.C. Gibb, Mo¨ssbauer Spectroscopy, 1st ed., Chapman
and Hall Ltd. Publishers, London, 1671, p. 248.
[21] A.W. Coats, J.P. Redfern, Nature 201 (1961) 68.