Synthesis and spectroscopic characterization of ruthenium polypyridyl complexes containing 1,6-bis(Benzylidene)hexanediamine as Ligand

Article abstract of DOI:10.14233/ajchem.2017.20351

A novel bidentate ligand 1,6-bis(benzylidene)hexanediamine was synthesized and its eight ruthenium bis(bypyridine)sulphoxide complexes with the general formula [cis/trans-RuCl₂ (SO)₂ (N-N)](L); were SO = dimethyl sulphoxide (DMSO)/te

Full text of DOI:10.14233/ajchem.2017.20351

Asian Journal of Chemistry; Vol. 29, No. 5 (2017), 975-982
ASIAN JOURNAL OF CHEMISTRY
https://doi.org/10.14233/ajchem.2017.20351
Synthesis and Spectroscopic Characterization of Ruthenium Polypyridyl
Complexes Containing 1,6-bis(Benzylidene)hexanediamine as Ligand
1,*
2
2
1
ARCHANA CHOUBEY , SATYENDRA N. SHUKLA , PRATIKSHA GAUR and CHETNA ACHARYA
1
2
Department of Chemistry, Sagar Institute of Science Technology & Research, Sikandrabad, Ratibad, Bhopal-462 044, India
Coordination Chemistry Research Lab, Department of Chemistry, Government Model Science College, Jabalpur-482 001, India
*
Corresponding author: E-mail: choubey.a64@gmail.com
Received: 15 October 2016; Accepted: 13 January 2017;
Published online: 10 March 2017;
AJC-18284
A novel bidentate ligand 1,6-bis(benzylidene)hexanediamine was synthesized and its eight ruthenium bis(bypyridine)sulphoxide complexes
with the general formula[cis/trans-RuCl (SO) (N-N)](L); were SO = dimethyl sulphoxide (DMSO)/tetramethylene sulphoxide (TMSO),
N-N) = 1,10-phenanthroline/2,2'-bipyridyl, (L) = bridging ligand were synthesized. These complexes were characterized by elemental
2
2
(
1
13
analysis, IR, UV/visible, H NMR, C NMR and 2D NMR spectroscopy. All complexes were found to show antibacterial property against
E. coli and the pyridal ligands co-ordinate through a Ru–N bond in all cases.
Keywords: Ruthenium bypyridine, Hexanediamine, Sulphoxide, Phenanthroline.
RuCl (DMSO-S)(Him)] (Him = imidazole; DMSO = dimethyl
4
INTRODUCTION
sulfoxide), have shown to display an antimetastatic activity,
which has not been observed in the case of the routinely used
platinum compounds [8].
During the last decades, ruthenium(II)-based polypyridyl
complexes have been the object of an active field of research
1]. Ruthenium(II)-polypyridyl complexes belong to one of
[
1,6-Hexanediamine is a well known antimicrobial agent
the most thoroughly investigated classes of coordination
compounds, since they offer a variety of technologically relevant
properties, namely, photophysical, redox and charge transfer
characteristics [2]. These properties have prompted the use of
ruthenium(II) complexes as photosensitizers across diverse
light-driven applications such as artificial photosynthesis [3],
photocatalytic production of hydrogen [4], dye-sensitized solar
cells [5], photon-induced switches [6]and molecular machines
and devices [7].
and used in dye-sensitized cell [9,10]. Here it will be of interest
to synthesize some new molecule which has an excellent
tendency to inhibit the growth of pathogenic bacteria. Thus to
achieve this goal, we have coupled 1,6-hexanediamine with
benzaldehyde to give rise to a novel bidentate spacer. We have
explored the reaction of this novel spacer with different
ruthenium sulphoxide bipyridyl compounds, resulting in the
formation of dinuclear complexes with enhanced antibacterial
activity.
Recently, a large interest has grown in ruthenium polypyridyl
complexes as a possible alternative to the use of classical platinum
chemotherapy. Some examples of these compounds are
EXPERIMENTAL
13
1
2
1
13
Ru(tpy)Cl
Ru(tpy)Cl
exhibits antitumor activity. The compound α-[Ru(azpy)
3
and α-[Ru(azpy)
shows a pronounced in vitro cytotoxicity and
Cl
2
Cl
2
] (azpy = 2-phenylazopyridine).
{ C- H} D NMR, H NMR and C NMR spectra were
recorded on D6-DRX-300 MHz Bruker, spectrophotometer
with TMS as the internal standard. Chemical shifts are expressed
inparts per million FAB-Mass spectra of ligand and complexes
were recorded on JMS SX-102-Jeol Mass spectrometer using
3
2
2
]
has been reported to show a remarkably high cytotoxicity, even
more pronounced than cisplatin in most of the tested cell lines.
The increased amount of possible binding modes of ruthenium
polypyridyl complexes to DNA as compared to those of the
first generations of platinum drugs, including intercalation of
the ligands between two parallel base pairs, could be crucial in
order to overcome resistance to cisplatin. In addition, a number
-1
NBA as matrix. FTIR spectrum in the range 4000-400 cm
were recorded in KBr pellets on Shimadzu-8400 PC. The
absorption spectra were recorded on Systronics 2201 UV-
visible double beam spectrophotometer equipped with P.C.
All chemicals were of A.R. grade and purified by standard
procedures.
of ruthenium complexes, such as NAMI-A, [H im][trans-
2

976 Choubey et al.
Asian J. Chem.
+
+
Synthesis of 1,6-bis(benzylidene)hexanediamine ligand
BDH): As shown in Fig. 1, the ligand BDH was synthesized
–CH=N); MS (m/z): [RuCl] = 136, [C
2
H
6
ClOSRu] = 214,
+
+
(
[C12
H
38
8
N
N
N
2
ClRu] = 316, [C14
H
14
N
2
OSClRu] = 394,
+
101 +
using hexanediamine (1 g; 1 mmol) in 20 mL ethanol. To this
solution benzaldehyde (1.749 mL; 2 mmol) was added and
the reaction mixture was kept on stirring for 4 h in an inert
atmosphere. Cream colour solid was recovered which was
filtered and dried under reduced pressure. The solid was recrys-
tallized in ethanol:methanol:acetone, 1:1:1 (v/v) mixture.
[C34
H
4
OSClRu] = 687, [C48
H
52
N
6
O
2
S
2
Cl
] = 1233; Anal. calcd. (%) for
: C, 48.05; H, 4.10; N, 6.10; S, 7.42; Ru,
3
Ru
2
] = 1231,
1
02 +
[C48
H
52
6
O
2
S
2
Cl
3
Ru
2
C
50
58 6 3
H N O S
3
Ru
2
Cl
4
16.01, Found (%): C, 48.78; H, 4.75; N, 6.83; S, 7.81; Ru,
16.42.
[{trans-RuCl
2
(DMSO)phen}
2
(µ-BDH)]·DMSO: Red
O)
1
Cream solid, Yield 85.31 % m.p.: 115 °C; H NMR (300
brown solid, Yield, 95.38 %; m.p.: 165 °C; UV-visible (H
(λmax, nm, ε, mol cm ): 625 (101), 540 (265), 490 (338), 467
(425), 449 (565), 432 (652), 425 (689); H NMR (300 MHz,
2
-1
-1
MHz; D
.8 (H , –CH=N), 3.6 (4H, s, H
4H, s, H
2
O, δ): 8.1 (4H, s, H
1
), 7.7 (4H, s, H
, -CH ), 3.2 (4H, s, H
); C NMR (300 MHz, δ D O) C -130.5, C -129.0,
-130.0, C -129.0, (Ar-C), C -161.0 (–CH=N), C -61, C -51,
-30 (CH ). Anal. calcd. (%) for C20 :C, 83.10; H, 6.25;
2
), 7.3, (2H, s, H
3
),
1
8
4
5
2
6
), 2.1
1
3
(
7
2
1
2
D
2
O, δ): 9.80 (–CH=N), 2.90 (12H, CH
3
), 2.31 (6H, CH
); C NMR (300 MHz, D O, δ): 152.0
(–CH=N), 44.0, 36.0 (S-C), 25.0, 26.0, 43.0. (CH ); IR (KBr,
3
),
13
C
C
3
8
4
5
6
1.4, 1.6, 2.4 (12H, t, CH
2
2
7
2
H
18
N
2
2
-1
+
N, 9.62, Found (%): C, 83.88; H, 6.33; N, 9.78.
Synthesis of complexes
cm ) 2900 (s, ν(CH
)
2 6
), 1619 (s, ν –CH=N); MS (m/z): [RuCl]
= 136, [C ClOSRu] = 214, [C12
OSClRu] = 394, [C34
] = 1231, [C48
1233; Anal. calcd. (%) for C50
+
+
2
H
6
H
N
8
N
2
ClRu] = 316,
OSClRu] = 687,
+
+
Synthesis of complex is performed in three steps: The
four starting complexes were prepared by the method reported
by Evans et al. [11] andAlessio et al. [12-14]. These complexes
[C14
[C48
H
14
N
2
H
38
4
1
01
+
102 +
H
52
N
6
O
2
S
2
Cl
3
Ru
2
H
52
N
Ru
6 2
O S
2
Cl
3
Ru
2
] =
H
58
N O S
6 3 3
2
Cl
4
: C, 48.05; H,
are [cis,fac-RuCl
2
(DMSO-S)
3
(DMSO-O), trans-RuCl
2
(DMSO)
4
,
4.10; N, 6.10; S, 7.42; Ru, 16.01, Found (%): C, 48.79; H,
4.76; N, 6.81; S. 7.82; Ru, 16.41.
cis-RuCl (TMSO)
2
4
, trans-RuCl
2
(TMSO)4. Recrystallized
starting complex was dissolved in small volume (about 5 mL)
of DMSO/TMSO. In this solution 1,10-phenanthroline/2,2'-
bipyridyl dissolved in about 10 mL acetone was added in 1:1
molar ratio. The above reaction mixture was refluxed for 1-2
h and the colour of the solution changed to red orange. This
solution on vacuum evaporation yielded red orange solid which
was recrystallized with 1:1 (v/v) mixture of diethyl ether:
[{cis-RuCl
2 2
(DMSO)bpy} (µ-BDH)]·DMSO: Brown
solid, Yield, 93.00 %; m.p.: 169 °C; UV-visible (H
2
O) (λmax,
-1
-1
nm, ε, mol cm ): 604 (145) 565 (208) 503 (290), 496 (348),
1
468 (496), 430 (674) 415 (698) H NMR (300 MHz, D
9.91 (-CH=N), 3.30 (12H, CH ) 2.41 (6H, CH ) 1.5, 2.3 2.9 (t,
); C NMR (300 MHz, δ D O): 152.3 (–CH=N),
47.1, 37.5 (S-C), 26.2, 28.0, 47.0 (CH ); IR (KBr, cm ): 2898
2
O, δ):
3
3
13
12H, CH
2
2
-1
2
+
acetone. Total eight precursors [cis-RuCl
2
(DMSO)
(DMSO)
(TMSO) (phen)];
(phen)]; [cis-RuCl (TMSO) (bpy)];
bpy] were synthesized.
Synthesis of dinuclear complexes: The recrystallized
2
(phen)];
(s, ν(CH
136, [C
2
)
6
), 1600 (s, ν –CH=N); MS (m/z): [RuCl] =
ClOSRu] = 214, [C10
+
+
[
[
[
[
trans-RuCl
trans-RuCl
2
(DMSO)
(DMSO)
2
(phen)]; [cis-RuCl
(bpy)]; [cis-RuCl
2
2
(bpy)];
2
H
6
H
8
N
4
2
ClRu] = 292,
+
+
2
2
2
2
[C12
[C44
H
14
N
2
OSClRu] = 370, [C32
H
38
N
OSClRu] = 663,
1
01
+
102 +
trans-RuCl
trans-RuCl
2
(TMSO)
(TMSO)
2
2
2
H
52
6 2
N O S
2
Cl
3
Ru
2
] = 1069, [C44
H
52
N
6
2
O S
2
Cl
3
Ru
2
] =
2
2
1071; Anal. calcd. (%) for C46
4.10; N, 7.24; S, 8.15; Ru, 17.05; Found (%): C, 46.70; H,
4.94; N, 7.10; S, 8.13; Ru, 17.09.
H N
58 6
3 3
O S Ru
2 4
Cl : C, 46.01; H,
precursor (1 mmol) was dissolved in minimum quantity of
DMSO/TMSO. The spacer 1,6-bis(benzylidene)hexanedi-
amine, (1 mmol) dissolved in 10 mL of acetone was mixed to
the above reaction mixture and kept under refluxed for 1-8 h
in an inert atmosphere. Colour of the reaction mixture changed.
The above solution was decanted and evaporated under vacuum
resulting into microcrystals, which were washed several times
with acetone and recrystallized from diethyl ether:acetone,
[{trans-RuCl
2
(DMSO)bpy}
2
(µ-BDH)]·DMSO: Dark
O)
brown solid, Yield, 87.87 %; m.p.: 170 °C; UV-visible (H
(λmax, nm, ε, mol cm ): 614 (135), 579 (178), 526 (295), 480
(345), 469 (423), 458 (468), 430 (674), 410 (746); H NMR
2
-1
-1
1
(300 MHz, D
(6H, CH ) 1.4, 2.1, 3.0 (t, 12H, CH
O, δ): 153.0 (–CH=N), 44.5, 38.2 (S-C), 24.5, 29.2, 43.0
2
O, δ): 9.89 (–CH=N), 2.90 (12H, CH
3
), 2.38
); C NMR (300 MHz,
13
3
2
D
2
-1
1
:1(v/v) mixture. In total, eight complexes were synthesized.
{cis-RuCl (DMSO)phen} (µ-BDH)]·DMSO: Dark red
solid, Yield, 87.10 %; m.p.: 160 °C; UV-visible (H
(CH
2
); IR (KBr, cm ): 2900(s, (CH ) )1610 (s, –CH=N); MS
(m/z): [RuCl] = 136, [C
2
6
+
+
+
[
2
2
2
H
6
+
ClOSRu] = 214, [C10
H
8
N ClRu]
2
+
2
O) (λmax
,
= 292, [C12
H
14
N
2
OSClRu] = 370, [C32
H
38
N OSClRu] = 663,
4
-1
-1
101
+
102 +
nm, ε, mol cm ): 604 (145), 523 (292), 490 (338), 454 (467),
[C44
H
52
6 2
N O S
2
Cl
3
Ru
2
] = 1069, [C44
52 6 2
H N O S
2
Cl
3
Ru
2
] =
1
4
30 (674), 410 (746), 392 (829), 385 (846). H NMR (300
MHz. D O, δ): 9.91 (HC=N), 3.41 (12H, CH ), 2.42 (6H, CH ),
.6, 2.5, 2.0 (12H, t, CH ); C NMR (300 MHz, D O, δ): 151.5
–CH=N) 46.0, 36.5 (-S-C), 28.0, 34.3, 47.5 (–CH ); IR (KBr,
1071; Anal. calcd. (%) for C46
4.10; N, 7.24; S, 8.15; Ru, 17.05; Found (%): C, 46.72; H,
4.91; N, 7.11; S, 8.11; Ru, 17.05.
H N
58 6
3 3
O S Ru
2 4
Cl : C, 46.01; H,
2
3
3
13
3
(
2
2
2
[{cis-RuCl
2
(TMSO)phen}
2
(µ-BDH)]·TMSO: Dark
O)
-1
cm ): 2895 (stretching for ν(CH
2
)
6
), 1620 (stretching for ν
orange solid,Yield, 93.75 %; m.p.: 172 °C; UV-visible (H
2
–
2
2H O
2
H N
NH2
C
H
O
O
C
H
C
H
N
N
C
H
Fig. 1. Reaction scheme for ligand preparation

Vol. 29, No. 5 (2017)
Synthesis of Ruthenium Polypyridyl Complexes Containing 1,6-bis(Benzylidene)hexanediamine as Ligand 977
-
1
-1
+
+
(
(
(
(
λ
max, nm, ε, mol cm ): 621 (105), 549 (260), 497 (392), 476
[C14
[C48
H
16
N
2
OSClRu] = 396, [C34
H
40
N OSClRu] = 689,
4
1
101
+
102 +
467), 458 (468), 448 (560), 412 (729), 385 (842); H NMR
300 MHz; D O δ): 9.91 (–CH=N), 4.20 (8H, S-CH ), 3.60
4H, S-CH ), 3.32 (12H, S-C-CH ), 2.1, 2.9, 3.8 (t, 12H,
); C NMR (300 MHz, D O, δ) 151.8 (–CH=N)) 47.8,
); IR (KBr,
H
56
N
6
2
O S
2
Cl
3
Ru
2
] = 1121, [C48
56 6 2
H N O S
2
Cl
3
Ru
2
] =
2
2
1123; Anal. calcd. (%) for C52
5.24; N, 6.25; S, 7.44; Ru, 16.30; Found (%): C 49.52 H 5.11
N 6.66 S 7.63 Ru 16.03.
(TMSO)bpy} (µ-BDH)]·TMSO: Red
2 2
orange solid,Yield %:0.050 g (93.46 %) M.p.:171; UV-visible
H
64
N
6
O
3
S Ru
3
2
Cl
4
: C, 49.05; H,
2
2
13
CH
4
2
2
0.5 (S-C), 25.2 (S-C-C) 30.2, 41.3, 48.0 (CH
2
[{trans-RuCl
-
1
+
cm ): 2904 (s (CH
36, [C ClOSRu] = 240, [C12
2
)
6) 1612 (s, –CH=N); MS (m/z): [RuCl] =
+
+
-1
-1
1
4
H
2
8
H
N
8
N
4
2
ClRu] = 316,
(H
478 (455), 448 (560) 429 (672) 402 (735), 398 (789); H NMR
(300 MHz, δ D O): δ (–CH=N) 9.83 δ (S-CH ) 3.95 (8H) 3.52
(4H) δ (S-C-CH ) 3.43 (12H) δ (CH ) 1.7, 2.7, 3.1 (t, 12H).
C NMR (300 MHz, δ D O) δ (–CH=N) 152.0, δ (S-C) 44.5,
40.2 δ (S-C-C) 24.1 δ (CH
ν(CH 2899(s) ν(–CH=N) 1611(s); MS (m/z): [RuCl] =
136, [C
2
O) (λmax/nm, ε in mol cm ): 648 (110) 549 (260), 497 (392)
+
+
1
[
[
C
16
H
56
16
N
6
OSClRu] = 420, [C36
H
40
OSClRu] = 713,
101
+
102 +
C
52
H
N
O
2
S
2
Cl
3
Ru
2
] = 1169, [C52
H
56
N
6
O
2
S
2
Cl
3
Ru
2
] =
2
2
1
4
4
171;. Anal. calcd. (%) for C56
.75; N, 6.10; S, 7.25; Ru, 15.35; Found (%): C, 51.37; H,
.93; N, 6.42; S, 7.35, Ru, 15.44.
H
64
6 3
N O S
3 2 4
Ru Cl :C, 51.10; H,
2
2
13
2
-1
2
) 30.5, 40.5, 47.5.; IR (KBr, cm )
+
[
{trans-RuCl
2
(TMSO)phen}
2
(µ-BDH)]·TMSO: Dark
O)
max, nm, ε, mol cm ): 610 (150), 575 (198), 510 (295), 492
378), 479 (450), 464 (508), 448 (560), 425 (689), 390 (830);
2 6
)
+
+
brown solid, Yield, 91.93 %; m.p.: 161 °C; UV-visible (H
2
4
H
8
ClOSRu]
=
240,[C10
H
8
N
2
ClRu]
=
292,
-1
-1
+
+
(
λ
[C14
[C48
H
56
16
N
2
OSClRu] = 396, [C34
H
40
N
4
OSClRu] = 689,
1
01
+
102 +
(
H
N
6
2
O S
2
Cl
3
Ru
2
] = 1121, [C48
H
56
N
6 2
O S
2
Cl
3
Ru
2
] =
1
H NMR (300 MHz; D
), 3.53 (4H, S-CH ), 3.45 (12H, S-C-CH
); C NMR (300 MHz, D O, δ): 152.2 (–CH=N),
3.0, 40.4 (S-C), 24.8 (S-C-C), 29.8, 40.3, 47.9 (CH ); IR (KBr,
2
O, δ): 9.82 (–CH=N), 3.90 (8H, S-
1123; Anal. calcd. (%) for C52
5.24; N, 6.25; S, 7.44; Ru, 16.30; Found:C 49.51 H 5.10 N
6.63 S 7.62 Ru 16.05.
Antibacterial activity: All the precursor complexes and
synthesized complexes were screened for antibacterial activity
against Gram-negative bacteria Escherichia coli MTCC, 1304
at different concentrations using, Well Diffusion method by
agar well diffusion method as described by Mehrotra et al.
H
64
N
6
O
3
S Ru
3
2
Cl
4
: C, 49.05; H,
CH
1
4
2
2
2
), 1.9, 2.5, 3.4 (t,
13
2H, CH
2
2
2
-1
+
cm ): 2892 (s, (CH
2
)
6
), 1610 (s, –CH=N); MS (m/z):[RuCl]
+
+
=
136, [C ClOSRu] = 240, [C12
4
H
8
H
8
N
2
ClRu] = 316,
+
+
[
[
C
16
H
16
N
2
OSClRu] = 420, [C36
H
40
N
4
OSClRu] = 713,
101
+
102 +
C
52
H
56
N
6
O
2
S
2
Cl
3
Ru
2
] = 1169, [C52
56
H N
6
O
2
S
2
Cl
: C, 51.10; H,
.75; N, 6.10; S, 7.25; Ru, 15.35; Found (%): C 51.37; H 4.91;
3
Ru
2
] =
5
1
4
171; Anal. calcd. (%) for C56
H
64
6 3 3
N O S Ru
2
Cl
4
[15]. In brief, overnight grown bacterial cells (about 10 colony
forming unit) were spread on Mueller Hinton (MH) agar plates
by using sterile cotton swab. Uniform wells were created in
agar slab by using cork borer. A 50 µL solution of test and
control was placed in respective wells. It was interestingly
observed that 0.01 % it showed less activity against Escherichia
coli but at 0.02 and 0.03 % active inhibition zone was observed
in comparison to chloramphenicol and they are active against
the same bacteria (Table-1).
N 6.41; S 7.36; Ru 15.45.
{cis-RuCl (TMSO) bpy}
solid,Yield: 93.97 %; m.p.: 167°; UV-visible (H
[
2
2
2
(µ-BDH)]·TMSO: Red brown
2
O) (λmax/nm,
-1
-1
ε in mol cm ): 625 (101) 568 (198), 505 (294) 490 (338) 468
1
(
(
(
420), 446 (578) 428 (675) 408 (743), 390 (830); H NMR
300 MHz, δ D O): δ (–CH=N) 9.82 δ (S-CH ) 4.18 (8H)3.61
4H) δ (S-C-CH ) 3.44 (12H) δ (CH ) 1.8, 2.4, 3.1 (t, 12H);
C NMR (300 MHz, δ D O) δ (–CH=N) 151.7 δ (S-C) 48.0,
0.5 δ (S-C-C) 25.4 δ (CH
ν(CH 2895(s) ν(–CH=N) 1614(s); MS (m/z): [RuCl] =
36, [C
2
2
2
2
13
2
-
1
RESULTS AND DISCUSSION
4
2
) 31.4, 41.2, 48.8; IR (KBr, cm )
+
2
)
6
The structure of the ligand given in Fig. 2 was illustrated
on the basis of various studies. FAB-Mass spectra of ligand
+
+
1
4
H
8
ClOSRu] = 240, [C10
H
8
N ClRu] = 292,
2
TABLE-1
ANTIBACTERIAL SCREENING AGAINST E. coli RESULTS SHOWING COMPARATIVE ACTIVITY OF
RUTHENIUM POLYPYRIDAL COMPLEXES AND LIGAND WITH CHLORAMPHENICOL
Activity against
E. coli
*Diameter of inhibition
zone (mm) ± SEM
S. No.
Complex/Precursor
2
A
µ-BDH (Ligand)
+
+
+
+
+
+
+
+
+
+
–
+
+
+
–
+
+
+
08 ± 0.75
19 ± 0.5
09 ± 0.8
15 ± 1.0
08 ± 0.9
17 ± 0.5
08 ± 0.8
19 ± 1.0
09 ± 0.9
16 ± 1.0
07 ± 0.5
21 ± 0.5
08 ± 0.8
19 ± 0.5
06 ± 0.5
21 ± 1.0
09 ± 0.8
40 ± 0.94
A1.
a.
A2.
a.
A3.
[{cis,fac-RuCl (DMSO)phen} (µBDH)].DMSO
2
2
1
[cis,fac-RuCl (DMSO) phen]
2
2
[{trans-RuCl (DMSO)phen} (µ-BDH)].DMSO
2
2
2
[trans-RuCl (DMSO) phen]
2
2
[{cis,fac-RuCl (DMSO)bpy} (µ-BDH)].DMSO
2
2
3
a
[cis,fac-RuCl (DMSO) bpy]
2
2
A4.
a.
A5.
a.
A6.
[{trans-RuCl (DMSO)bpy} (µ-BDH)].DMSO
2
2
4
[trans-RuCl (DMSO) bpy]
2
2
[{cis,fac-RuCl (TMSO)phen} (µ-BDH)]·TMSO
2
2
5
[cis,fac-RuCl (TMSO) phen]
2
2
[{trans-RuCl (TMSO)phen} (µ-BDH)]·TMSO
2
2
6
A7.
7
A8.
8
9
a
[trans-RuCl (TMSO) phen]
2
2
[{cis,fac-RuCl (TMSO)bpy} (µ-BDH)]·TMSO
2
2
a
[cis,fac-RuCl (TMSO) bpy]
2
2
[{trans-RuCl (TMSO)bpy} (µ-BDH)]·TMSO
2
2
a
.
[trans-RuCl (TMSO) bpy]
2
2
Chloramphenicol

978 Choubey et al.
Asian J. Chem.
H2
H1
H
H
H5
C5
H
H6
C6
H
H7
C7
H
H
C
H
H
C
H
H
C
H
C2
C
C
1
C
C
C
C
H3
C3
C8
C
N
N
C
H
C
C
H
4
C
H4
H
H
H
H
Fig. 2. Structure of ligand
shows pseudomolecular ion peak at m/z = 286 confirming the
Characterization of ruthenium complexes: Molecular
weight and empirical formula of all the complexes were
determined by FAB-Mass and elemental analyses. The low
mole-cular weight of the ligand. In FT-IR spectra of the ligand
-1
a broad absorption band was observed at 2939 cm assigned for
methylene chain. The presence of azomethine group (>CH=N)
-1
2
-1
molecular conductance value between 41-56 Ω cm mol for
all the complexes in a dilute solution (about 0.001 M) were
attributed to be non-electrolytic nature in the range suggested
for 1:1 electrolyte [20,21]. The results are slightly higher than
expected for non electrolyte, which is probably that in solution
state one chloro ligand is replaced by solvent molecule, which
leads to the formation of 1:1 electrolyte. Probably, second
chloro ligand does not undergo exchange by another solvent
molecule, thus it would not lead to formation of 2:1 electrolyte.
Electronic spectral study:All the complexes were diamag-
-1
was confirmed by a sharp peak at 1647 cm [16,17].
1
In the H NMR spectrum a signal for (>CH=N) group
was observed at δ 8.80 ppm. Multiplets observed in the range
δ 7.30-8.10 ppm were assigned for aromatic proton (Ar–H).
The presence of methylene protons attributed by the presence
13
of a triplet at δ 2.10, δ 3.20 and δ 3.60 ppm [18]. In C NMR
a signal at δ 161.0 ppm, was assigned for azomethine (>CH=N)
group. The signals in the range δ 129-130 ppm were attri-
buted for aromatic carbon. Singlets at δ 30, δ 51 and δ 60 ppm
were assigned for methylene carbon [18,19].
6
netic (low spin d , S = 0) as expected for low spin ruthenium(II)
2
In D NMR spectra of ligand (Fig. 3) the aromatic carbon
complexes and displayed seven to ten bands in electronic
spectra. Two/three less intense absorption bands observed in
visible region between 623-664 nm and 490-579 nm were due
C-1 at δ 130.50 ppm is found connected to H-1 at δ 8.10 ppm,
C-2 at δ 129.0 ppm is found connected to H-2 at δ 7.70 ppm.
The carbon atom C-3 at δ 130.0 ppm is found connected to H-
1
1
1
1
to d-d transition corresponding to A
1
g→ T
1
g and A
1
g→ T g,
2
3
at δ 7.30 ppm C-8 is found to appear at δ 129 ppm. The
respectively. Three to five bands with high extinction coeffi-
cient appeared between 410-478 nm were assigned to MLCT
transition. Two MLCT transitions appear due to the existence
of two different acceptor levels in 2,2'-bipyridyl/1,10-phenan-
throline. Two bands in the range 375-408 nm were designated to
intraligand transitions as π-π* and n-π* non-bonding electrons
present on the nitrogen of the azomethine group in the Schiff
base complexes respectively [21-24]. The enhancement (nearly
more than double) of the absorbance in dinuclear complexes
as compared to mononuclear precursor complexes could be
considered in favour of presence of two ruthenium(II) centers.
Infrared spectral study: In all the complexes a down-
azomethine carbon (>CH=N) C-4 appeared at δ 161 ppm is
found connected to H-4 at δ 8.80 ppm. The six equivalent
methylene carbons of hexane, C-5 at δ 61.0 ppm was found
connected to H-5 at δ 3.6 ppm, C-6 at δ 51.0 ppm was found
connected to H-6 at δ 3.20 ppm and the carbon C-7 at δ 30.0
ppm was connected to H-7 at δ 2.10 ppm.
ppm
-1
wards shift was observed by 25-30 cm and also the peak
intensity was decreased than the free ligand spectra indicating
that the two metal center were symmetrically coordinated to
40
-1
the nitrogen of ligand. In the ligand a peak at 2939 cm was
observed for methylene chain which was also observed in all the
60
-1
complexes in the range 2905-2895 cm . In all the complexes
-1
a peak observed in the range 1129-1085 cm was assigned for
80
ν(SO) [25-28].Another peak observed in the range 1060-1040
-1
cm was assigned for uncoordinated DMSO/TMSO [17,18].
-1
100
A weak band at about 450 cm was assigned for ν(Ru–S).
1
H NMR spectra: A broad signal observed at about δ
9.80 ppm for 2 protons was attributed to the azomethine group
120
(>CH=N). This signal was actually observed at higher δ value
than that of ligand, which confirms the involvement of azo-
methine-N in coordination to the ruthenium metal center. In
H NMR of all Ru(II) complexes signals in the range δ 7.80-
140
1
9
3
.80 ppm were assigned for pyridyl protons and in range δ
.64-3.35 ppm, δ 2.62-2.48 ppm and δ 2.12-2.00 ppm as a
1
60
8
7
6
5
4
3
2
1 ppm
triplet, were assigned for 4 methylene protons each associated
Fig. 3

Vol. 29, No. 5 (2017)
Synthesis of Ruthenium Polypyridyl Complexes Containing 1,6-bis(Benzylidene)hexanediamine as Ligand 979
with 5, 6, 7 carbon. In [cis/trans -RuCl
2
(SO)
2
(N-N)](L) one
δ 152 ppm confirming its involvement in co-ordination to the
metal center also signals observed in the range δ 133.5-142
ppm were assigned for pyridyl carbon [17,18].Similarly signals
in the range of δ 120.0-131.5 ppm were attributed for the
aromatic carbon [33,34].
signal at about δ 3.40 ppm for 12 protons was attributed to
methyl group of DMSO anti to Cl at both the ruthenium centers
and at about δ 2.90 ppm for 12 protons was attributed to methyl
group of DMSO trans to pyridyl-N of polypyridyl group. Three
signals were observed in the TMSO analogues at about δ 4.20
13
1
2
13
1
2
{ C- H} D NMR (HETCOR) spectrum: In { C- H} D
NMR spectrum of [{trans-RuCl (DMSO)phen} (µ-BDH)]·DMSO
ppm for 8 protons was attributed to S-CH
anti to Cl at both ruthenium centers. The multiplet centered at
about δ 3.60 ppm for 4 protons was assigned to S-CH of free
TMSO molecule. However, multiplet centered at about δ 3.40
ppm was assigned for all the 12 protons of S-C-CH of TMSO
29-32].
2
of TMSO situated
2
2
in Fig. 4(a) and 4(b) signal in the range δ 134.0-139.0 ppm
were assigned for pyridyl carbon which were connected to
the pyridyl protons in the range δ 8.0-9.2 ppm as multiplet.
The aromatic carbons were found in the range of δ 124-129
ppm, which were connected to the aromatic proton in the range
δ 7.5-7.7 ppm. The methylene carbon of n-hexane appeared
in the range δ 42-50 ppm, which were connected to the
methylene proton at δ 2.06-3.50 ppm. The azomethine carbon
2
2
[
13
13
C NMR spectra: In C NMR, the ligand signal for azo-
methine carbon appeared at about δ 161 ppm which was shifted
towards lower δ value in the complex and appeared at about
ppm
ppm
0
2
4
6
8
1
1
1
1
1
15
(a)
(b)
0
120
125
130
135
140
145
150
0
0
0
00
20
40
60
155
60
1
10
9
8
7
6
5
4
3
2
1 ppm
10.0
9.5
9.0
8.5
8.0
7.5
7.0 ppm
Fig. 4.
O
N
N
CH
3
Cl
N
S
N
O
S
CH
3
Ru
N
Ru
CH3
CH3
Cl
Cl
Cl
H
C
O
S
H
C
O
C
CH
3
C
H
N
CH
CH
3
N
N
S
O
S
CH
3
3
H
3
H C
Cl
Cl
Cl
N
3
H C
Ru
N
Ru
N
H
H
3
3
C
S
Cl
N
C
O
2
Complex A1
2
Complex A2

980 Choubey et al.
Asian J. Chem.
O
S
N
N
CH
3
N
N
Cl
CH
3
O
Ru
Ru
CH
3
Cl
Cl
Cl
S
CH3
H
C
O
S
H
C
O
C
H
N
CH
3
C
H
N
CH
CH
3
3
N
N
S
CH
3
O
S
H
3
C
Cl
Cl
Cl
Ru
N
H
3
C
Ru
N
H
H
3
3
C
S
N
N
Cl
C
O
2
Complex A3
2
Complex A4
N
N
Cl
N
S
N
Ru
Ru
O
S
O
O
Cl
Cl
Cl
H
C
H
C
O
S
S
C
H
N
C
H
N
N
N
O
Cl
Cl
Cl
S
O
Ru
N
Ru
N
S
N
N
Cl
2
Complex A5
2
Complex A6
N
N
Cl
N
S
N
Ru
Ru
O
O
S
O
Cl
Cl
Cl
H
C
H
C
S
O
O
S
S
C
H
N
C
H
N
N
N
Cl
Cl
Cl
O
Ru
N
Ru
N
S
N
N
Cl
2
Complex A7
2
Complex A8
2
2
2
2
2
2
2
2
Fig. 5. Proposed structure of complexes A
1
, A
2
, A
3
, A
4
, A
5
, A
6
, A
7
and A
8

Vol. 29, No. 5 (2017)
Synthesis of Ruthenium Polypyridyl Complexes Containing 1,6-bis(Benzylidene)hexanediamine as Ligand 981
(
b) M.K. Nazeeruddin, C. Klein, P. Liska and M. Grätzel, Coord. Chem.
(
>C=NH) was found to appear at δ 152 ppm connected to the
Rev., 249, 1460 (2005);
https://doi.org/10.1016/j.ccr.2005.03.025.
azomethine proton at δ 9.80 ppm [35]. The peak at δ 44 ppm
for the DMSO carbon was found connected to the DMSO
methyl proton at δ 2.9 ppm, also in the uncoordinated DMSO
molecule a peak of carbon at δ 36 ppm was found connected
to DMSO methyl proton at δ 2.3 ppm.
(c) F.T. Kong, S.Y. Dai and K.J. Wang, Chin. J. Chem., 25, 168 (2007);
https://doi.org/10.1002/cjoc.200790034.
6
.
(a) J.D. Badjic, C.M. Ronconi, J.F. Stoddart, V. Balzani, S. Silvi and
A. Credi, J. Am. Chem. Soc., 128, 1489 (2006);
https://doi.org/10.1021/ja0543954.
Conclusion
(b) A. Petitjean, F. Puntoriero, S. Campagna, A. Juris and J.M. Lehn,
Eur. J. Inorg. Chem., 3878 (2006);
https://doi.org/10.1002/ejic.200600466.
(c) V. Balzani, G. Bergamini, F. Marchioni and P. Ceroni, Coord. Chem.
Rev., 250, 1254 (2006);
https://doi.org/10.1016/j.ccr.2005.11.013.
Based on the charactization studies of the complexes, the
tantative structures are shown in Fig. 5. All complexes and
ligand were screened against bacteria but the ligand was found
less potent than the synthesized complexes. All the screened
(
4
d) S. Nitahara, N. Terasaki, T. Akiyama and S.Yamada, Thin Solid Films,
99, 354 (2006);
complexes,A1-
A ,inhibit the growth of bacteria and are found
8
more potent than their precursors. This was probably due to
the enhanced lipophilic nature of the complexes, which lead to
the breakdown of permeability barriers of the cell and thus retard
the normal cell process in bacteria.
https://doi.org/10.1016/j.tsf.2005.07.014.
(a) V. Balzani, A. Credi, S. Silvi and M. Venturi, Chem. Soc. Rev., 35,
7
.
1
135 (2006);
https://doi.org/10.1039/b517102b.
b) V. Balzani, M. Clemente-Leon, A. Credi, B. Ferrer, M. Venturi,
A.H. Flood and J.F. Stoddart, Proc. Natl. Acad. Sci. USA, 103, 1178
2006);
https://doi.org/10.1073/pnas.0509011103.
c) V. Balzani, M. Venturi and A. Credi, In Molecular Devices and
(
ACKNOWLEDGEMENTS
(
The authors are thankful to The Principal, Govt. Model
Science College, Jabalpur and Head, Department of Chemistry,
Govt. Model Science College, Jabalpur for providing laboratory
facilities. The authors are also indebted to Dr. K.K.Verma and
Dr. K.K. Mishra, Retired Professors, Department of Chemistry,
RDVV, Jabalpur, India for their help rendered in IR and UV
spectra. Thanks are also due to SAIF, CDRI Lucknow, India
(
Machines-A Journey in the Nano World, Wiley-VCH: Weinheim,
Germany (2003).
E. Corral, A.C.G. Hotze, D.M. Tooke, A.L. Spek and J. Reedijk, Inorg.
Chim. Acta, 359, 830 (2006);
8
.
https://doi.org/10.1016/j.ica.2005.05.017.
9. Z. Ganbaatar, S.A. Osadchii, É.É. Shul’ts, T.G. Tolstikova, M.P. Dolgikh
and G.A. Tolstikov, Pharm. Chem. J., 36, 478 (2002);
https://doi.org/10.1023/A:1021892621783.
13
1
2
for { C- H} D NMR (HETCOR) spectral analysis, FAB mass
and elemental analysis. The authors are also thankful to MPCOST,
Bhopal, (M.P.), India for providing financial Assistance.
1
0. D. Mlynarcik, F. Devinsky and I. Lacko, Folia Microbiol., 24, 188 (1979);
https://doi.org/10.1007/BF02927306.
11. I.P. Evans, A. Spencer and G. Wilkinson, J. Chem. Soc., Dalton Trans.,
04 (1973);
2
https://doi.org/10.1039/DT9730000204.
REFERENCES
1
2. E. Alessio, G. Mestroni, G. Nardin, W.M. Attia, M. Calligaris, G. Sava
and S. Zorzet, Inorg. Chem., 27, 4099 (1988);
https://doi.org/10.1021/ic00296a006.
1
2
3
.
.
.
F. Schramm, R. Chandrasekar, T.A. Zevaco, M. Rudolph, H. Görls, W.
Poppitz and M. Ruben, Eur. J. Inorg. Chem., 53 (2009);
https://doi.org/10.1002/ejic.200800628.
V. Balzani, A. Juris, M. Venturi, S. Campagna and S. Serroni, Chem.
Rev., 96, 759 (1996);
https://doi.org/10.1021/cr941154y.
(a) J.M. Berg, J.L. Tymoczko and L. Stryer, Biochemistry, W.H.
Freeman, New York, vol. 6 (2006).
13. E. Alessio, B. Milani, G. Mestroni, M. Calligaris, P. Faleschini and
W.M. Attia, Inorg. Chim. Acta, 177, 255 (1990);
https://doi.org/10.1016/S0020-1693(00)85984-8.
14. E. Alessio, G. Balducci, M. Calligaris, G. Costa, W.M. Attia and G.
Mestroni, Inorg. Chem., 30, 609 (1991);
https://doi.org/10.1021/ic00004a005.
(
b)A.F. Collings and C, Critchley,Artificial Photosynthesis: From Basic
Biology to IndustrialApplication,Wiley-VCH:Weinheim, Germany, (2005).
c) M. Chen, K.P. Ghiggino, S.H. Thang and G.J. Wilson, Angew. Chem.
15. R. Mehrotra, S.N. Shukla, P. Gaur and A. Dubey, Eur. J. Med. Chem.,
50, 149 (2012);
(
https://doi.org/10.1016/j.ejmech.2012.01.049.
Int. Ed., 44, 4368 (2005);
https://doi.org/10.1002/anie.200462796.
16. R.M. Silverstein, G.C. Bassler and T.C. Morrill, Spectrometric Identi-
fication of Organic Compouds, John Wiley & Sons, Inc, New York,
pp. 123-131, 219-262 (1991).
(
d) M.K. Nazeeruddin and M. Griaitzel, in eds.: J.A. McCleverty and
T.J. Meyer, Comprehensive Coordination Chemistry II, Elsevier
Amsterdam, vol. 9 (2003).
17. P.S. Kalsi, Spectroscopy of Organic Compounds, NewAge International
Ltd., pp. 206-210, 246-256, 342-350 (2005).
(
e) A. Hagfeldt and M. Gratzel, Acc. Chem. Res., 33, 269 (2000);
https://doi.org/10.1021/ar980112j.
f) C.A. Bignozzi, J.R. Schoonover, F.A. Scandola, in ed.: G.J. Meyer,
Progress in Inorganic Chemistry, Wiley: New York, vol. 44 (1999).
g) L. Hammarstrom, Curr. Opin. Chem. Biol., 7, 666 (2003);
18. J.M. Miller and K. Balasanmugam, Can. J. Chem., 67, 1496 (1989);
https://doi.org/10.1139/v89-228.
19. N.G. Tsierkezos, U. Ritter,A.I. Philippopoulos and D. Schroder, J. Coord.
Chem., 63, 3517 (2010);
(
(
https://doi.org/10.1080/00958972.2010.516362.
https://doi.org/10.1016/j.cbpa.2003.10.002.
20. K.D. Keerthi, B.K. Santra and G.K. Lahiri, Polyhedron, 17, 1387 (1998);
https://doi.org/10.1016/S0277-5387(97)00277-5.
21. S.N. Shukla, P. Gaur, R. Mehrotra, M. Prasad, H. Kaur, M. Prasad and
R.S. Srivastava, J. Coord. Chem., 62, 2556 (2009);
https://doi.org/10.1080/00958970902862628.
22. U.C. Sarma and R.K. Poddar, Polyhedron, 7, 1737 (1988);
https://doi.org/10.1016/S0277-5387(00)80405-2.
24. A.B.P. Lever, Inorganic Electronic Spectroscopy, Elsevier, Amsterdam,
The Netherlands (1984).
4
5
.
.
(a) F. Liu, J.J. Concepcion, J.W. Jurss, T. Cardolaccia, J.L. Templeton
and T.J. Meyer, Inorg. Chem., 47, 1727 (2008);
https://doi.org/10.1021/ic701249s.
(
b) T. Meyer, Nature, 451, 778 (2008);
https://doi.org/10.1038/451778a.
c) S. Rau, B. Schafer, D. Gleich, E. Anders, M. Rudolph, M. Friedrich,
(
H. Gorls, W. Henry and J.G.Vos, Angew. Chem. Int. Ed., 45, 6215 (2006);
https://doi.org/10.1002/anie.200600543.
(a) M.K. Nazeeruddin, S.M. Zakeeruddin, J.J. Lagref, P. Liska, P. Comte,
C. Barolo, G. Viscardi, K. Schenk and M. Graetzel, Coord. Chem. Rev.,
25. S. Dutta and P.K. Bhattacharya, Indian J. Chem., 42A, 262 (2003).
26. R.S. Srivastava, F.R. Fronczek and L.M. Romero, Inorg. Chim. Acta,
357, 2410 (2004);
2
48, 1317 (2004);
https://doi.org/10.1016/j.ccr.2004.03.012.
https://doi.org/10.1016/j.ica.2004.01.026.

982 Choubey et al.
Asian J. Chem.
2
2
7. T. Bora and M.M. Singh, J. Inorg. Nucl. Chem., 38, 1815 (1976);
https://doi.org/10.1016/0022-1902(76)80095-4.
8. W.L. Reynolds, in ed.: S.J. Lippard, Dimethyl Sulfoxide in Inorganic
Chemistry, In: Progress in Inorganic Chemistry, John Wiley & Sons,
Inc., Hoboken, NJ, USA, vol. 12 (1970):
32. F.D. Rochon, P.C. Kong and L. Girard, Can. J. Chem., 64, 1897 (1986);
https://doi.org/10.1139/v86-313.
33. P. Kumar,A. K. Singh, M.Yadav, P. Li, S. K. Singh, Q. Xu, D.S. Pandey,
Inorg. Chim. Acta, 368, 124 (2011);
https://doi.org/10.1016/j.ica.2010.12.057.
https://doi.org/10.1002/9780470166130.ch1.
34. J.D. Oliver and D.P. Riley, Inorg. Chem., 23, 156 (1984);
https://doi.org/10.1021/ic00170a009.
35. N.P.E. Barry, O. Zava, J. Furrer, P.J. Dyson and B. Therrien, Dalton
Trans., 39, 5272 (2010);
2
3
3
9. J.A. Davis, in eds.: H.J. Emeléus andA.G. Sharpe,Advances in Inorganic
Chemistry and Radiochemistry, Elsevier, vol. 24, p. 115 (1981).
0. E. Alessio, Chem. Rev., 104, 4203 (2004);
https://doi.org/10.1021/cr0307291.
1. P.K.L. Chan, B.R. James, D.C. Frost, P.K.H. Chan, H.L. Hu and K.A.
Skov, Can. J. Chem., 67, 508 (1989);
https://doi.org/10.1039/c001521k.
36. H.J. Guadalupe, J. Narayanan and T. Pandiyan, J. Mol. Struct., 989, 70
(2011);
https://doi.org/10.1139/v89-078b.
https://doi.org/10.1016/j.molstruc.2011.01.005.