Reactivity and Catalytic Activity of Homobimetallic Vanadium(V) Complex Derived from Bis(5-chlorosalicylaldehyde)oxaloyldihydrazone Ligand

Article abstract of DOI:10.1002/aoc.4984

Homobimetallic vanadium(V) complex of the composition [(CH₃)₂NH₂⁺]₂[(VO₂)₂(sloxCl)].4H₂O was synthesized from the reaction of V₂O₅ with bis(5-chlorosalicylaldehyde)oxaloyldihydrazone ligand in a 1:1 molar ratio in methanol. The structure of the complex was established by X-ray crystallography. Reactivity of the complex with H₂O₂ leads to bis (monooxidoperoxidovanadate(V)) [{VO(O₂)}₂(sloxCl)]^2? formation and with HCl, oxidohydroxido complex of composition [(VO (OH)(sloxCl)]^2? was formed. Binding interaction of the complex was also investigated toward protein (BSA) and it was found to be 2.21 x 10⁸?M^?1. The catalytic activity of the complex in the oxidation of alcohols and oxidative bromination of some organic substrates was also studied, and it showed a great potent as a catalyst.

Full text of DOI:10.1002/aoc.4984

Received: 15 January 2019
DOI: 10.1002/aoc.4984
Revised: 26 March 2019
Accepted: 13 April 2019
F U L L P A P E R
Reactivity and Catalytic Activity of Homobimetallic
Vanadium(V) Complex Derived from
Bis(5‐chlorosalicylaldehyde)oxaloyldihydrazone Ligand
1
2
1
Ibanphylla Syiemlieh
| Mrityunjaya Asthana | Ram A. Lal
1
Department of Chemistry, Centre for
Advanced Studies, North‐Eastern Hill
University, Shillong 793022, India
Homobimetallic
vanadium(V)
complex
of
the
composition
+
[
(CH ) NH ] [(VO ) (sloxCl)].4H O was synthesized from the reaction of
3
2
2
2
2 2
2
2
TCG Life Sciences Private Limited, Salt
V O with bis(5‐chlorosalicylaldehyde)oxaloyldihydrazone ligand in a 1:1
2
5
Lake, Kolkata 700091, India
molar ratio in methanol. The structure of the complex was established by X‐
Correspondence
ray crystallography. Reactivity of the complex with H O2 leads to bis
2
Ram A. Lal, Department of Chemistry,
Centre for Advanced Studies, North‐
Eastern Hill University, Shillong, 793022,
India.
2−
(
monooxidoperoxidovanadate(V)) [{VO(O )} (sloxCl)] formation and with
2 2
2
−
HCl, oxidohydroxido complex of composition [(VO (OH)(sloxCl)]
was
formed. Binding interaction of the complex was also investigated toward
Email: ralal@rediffmail.com
8
−1
protein (BSA) and it was found to be 2.21 x 10 M . The catalytic activity
of the complex in the oxidation of alcohols and oxidative bromination of
some organic substrates was also studied, and it showed a great potent as a
catalyst.
KEYWORDS
aldehydes, homobimetallic vanadium(V), ketones, oxidative bromination, protein interaction
1
| INTRODUCTION
attractive model for elucidation of various biochemical
processes such as antifungal, antitumoral and antiviral
[
8]
The discovery of vanadate(V)‐dependent haloperoxidases
activities.
Oxaloyldihydrazide is condensed with 5‐
aroused a great interest in the catalytic activity of vana-
chlorosalicylaldehyde to form dihydrazone moiety, which
consists of O‐N‐O hexadentate donor ligand.
[1–4]
dium complexes
the presence of hydrogen peroxide and a halide anion
in which the vanadium(V) ions in
[
5]
Oxidation of alcohols to aldehydes and ketones is a
[9]
act as the active center for the halogenation of organic
substrates and are also involved in the biosynthesis of
fundamental reaction in synthetic organic chemistry
specially aldehydes derived from primary alcohols consti-
tute important ingredient of natural products and fine
[
6]
several compounds with potential medicinal uses. This
enzyme was also used for the catalytic oxidation of bro-
mides which is the key intermediate for synthesis of
organobromo compounds. It has been found that the
organobromo compounds possess some great potential
applications for medicinal purposes, as they have been
found to possess both antimicrobial and anticancer
[10–12]
chemicals like fragrances and food additives.
Although, molecular oxygen and air are the ideal oxidant,
yet, molecular oxygen cannot be used on the large scale
since its use is constrained by safety concerns as the com-
[
13,14]
bination of O , organic solvents and reagents
make
are
2
[15]
explosive mixture. Further, halogenated solvents
undesirable from the environmental point of view.
[7]
properties.
Schiff base hydrazone compounds have widely been
used as versatile ligands in coordination chemistry and
vanadium complexes with Schiff base hydrazones are
Hydrogen peroxide is another eco‐friendly oxidant
which can be used safely in the oxidation reactions, and
which can reduce the safety hazards. Although some
Appl Organometal Chem. 2019;e4984.
wileyonlinelibrary.com/journal/aoc
© 2019 John Wiley & Sons, Ltd.
1 of 13
https://doi.org/10.1002/aoc.4984

2
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SYIEMLIEH ET AL.
work has been done on the oxidation of alcohols using
homogeneous catalyst with aqueous H O as a terminal
a monochromated Mo K radiation ((k = 0.71073 Å)
source. Data collection and reduction was used on
CrysAlis PRO; Agilent, 2013 software packages. For struc-
2
2
[16]
oxidant,
yet heterogeneous systems as a catalyst with
H O on the oxidation of alcohols remains a major
challenge.
ture solutions and refinements, SHELXT‐2014 and
2
2
[17]
[21]
SHELX‐2014 was used.
The structure was solved by
2
In view of the above importance of vanadium and its
complexes in biological system as well as in oxidation
and oxidative bromination catalysis, and great tendency
direct methods and refined on F by a full matrix least
[
22]
squares.
All non‐hydrogen atoms were refined aniso-
tropically, whereas the hydrogen atom positions were
isotropically refined freely in the final refinement.
[18,19]
of dihydrazones to form metal complexes
the pres-
ent paper aims to synthesize some vanadium complexes
bis(5‐chlorosalicylaldehyde)oxaloyldihydrazone
2
.2.1 | Preparation of Bis(5‐
chlorosalicylaldehyde)oxaloyldihydrazone
H sloxCl)
(
H sloxCl) and characterize them by various conven-
4
tional methods and establish their structure by X‐ray
crystallographic techniques. Further, it aims at exploring
some of its catalytic properties.
(
4
Oxaloyldihydrazine was prepared by reacting diethyl oxa-
late (10 ml) and hydrazine hydrate (7 ml) in 1:2 M ratios
under stirring for 30 min. The product thus isolated was
2
2
| EXPERIMENTAL
recrystallized from H O.
2
.1 | Physical measurements
Bis(5‐chlorosalicylaldehyde)oxaloyldihydrazone
(
H sloxCl) was prepared by reacting oxaloyldihydrazine
4
Diethyl
oxalate,
hydrazine
hydrate,
5‐
(3.0 g, 25.42 mmol) in H O (100 mL) with 5‐
2
chlorosalicylaldehyde, V O , 30% H O , HCl, BSA, KBr,
chlorosalicylaldehyde (7.96 g, 50.84 mmol) in ethanol
(20 ml) over hot plate at 70 °C with constant stirring
for 1 hr. The yellow precipitate thus obtained was
2
5
2 2
7
0% HClO , alcohols, salicylaldehyde, aniline, aromatic
4
aldehyde and ketones were Himedia, E‐Merck, or equiva-
lent grade and solvents were reagent grade and used as
received. Vanadium was determined by standard litera-
filtered, washed with hot H O‐ethanol and dried over
2
anhydrous CaCl2.
[20]
ture method.
C, H, N was used by Perkin‐Elmer 2400
CHNS/O Analyzer 11. Molar conductance of the
−
3
2.2.2 | Synthesis of
complexes in DMF solution at 10
M dilution was
+
[
(CH ) NH ] [(VO ) (sloxCl)].4H O (1)
3
2
2
2
2 2
2
measured at room temperature on a Direct Reading
Conductivitymeter‐303 with a dip type conductivity cell.
Bis(5‐chlorosalicylaldehyde)oxaloyldihydrazone
H sloxCl) (0.43 g, 1.1 mmol) was suspended in methanol
−
1
In the region 4000–200 cm
infrared spectra were
(
4
recorded by using a BX‐III/FTIR Perkin Elmer Spectro-
photometer in KBr discs. Bruker Avance II‐400 MHz
solution (20 ml) by stirring, to it vanadium pentoxide
V O ) (0.20 g, 1.1 mmol) in methanol solution (10 ml)
(
2 5
1
13
and 100 MHz was used to record H NMR and
C
was added dropwise and gently stirred for 30 mins. The
reaction mixture was then refluxed for 1 hr, cooled to room
NMR spectra in DMSO‐d or CDCl solution using TMS
6
3
as internal standard. Electronic spectra were recorded
on a Perkin‐Elmer Lambda‐25 spectrophotometer. Cyclic
voltammogram was recorded on a CH Electrochemical
Analyzer using a standard three‐electrode assembly
temperature, filtered and dried over CaCl . Single crystal
2
of the complex was obtained within a week by slow evapo-
ration of complex solution in DMF/water systems (1:1.5) at
room temperature. Yield: 84%. Color: Yellow. Anal. (%),
Calc. for C H Cl N O V (MW: 721.286 g/mol); C,
(glassy‐carbon working, Pt wire auxiliary, SCE reference)
20
32
2 6 12 2
and 0.1 M Tetra‐n‐butyl ammonium perchlorate (TBAP)
as supporting electrolyte. Gas Chromatography (GC)
analysis was performed on a Bruker 430‐GC Gas Chro-
matograph equipped with a 30 m x 0.32 mm x 0.5 μm
HP‐Innowax capillary column and a flame ionization
detector (FID).
3
1
3.30; H, 4.47; N, 11.65. Found: C, 33.39; H, 4.46 N,
−
1
2
−1
1.71. Molar conductance Λ (ohm cm mol ) 68.97.
m
−
1
IR data (cm , KBr): 3434 (s br) ν (OH + NH); 1609 (s)
ν(‐C=N); 940 (s), 914 (s) ν(V=O); 574 (w) ν(V‐O). H
1
NMR (400 MHz, DMSO‐d , Me Si): δ (ppm): 6.82–8.37
6
4
13
(
m, 6H, Ar‐H), 8.90 (s, 2H, C(H)‐N). C NMR (100 MHz,
DMSO‐d , Me Si): 166.48, 164.04, 156.99, 133.46, 131.65,
6
4
2.2 | X‐ray crystallography diffraction
122.01, 121.09, 120.31, 79.71–79.04, 40.46–39.21 ppm. Elec-
tronic spectrum in DMF solution, λmax (nm): 305 nm,
Crystallographic data for the complex (1) were recorded
using Xcalibur, Eos, Gemini diffractometer equipped with
355 nm, 425 nm. CV: E (V): +1.32, +0.20, −0.48, −1.09;
Epa(V): +1.56, +0.87, −0.42.
pc

SYIEMLIEH ET AL.
3 of 13
2
.2.3 | General experiment for catalytic
enolization of the ligand in complex. The two bands at
−
1
oxidation of benzyl alcohol
940 and 914 cm arise due to (V=O) stretching vibrations
−
1
−1
and the bands at 574 cm and 478 cm indicate bonding
of phenolate oxygen atoms and enolate oxygen atoms to
the metal centres and are attributed to V‐O stretching
In 50 ml round bottom flask, benzyl alcohol (0.30 ml,
2
.90 mmol), 15% H O (1.31 ml, 5.80 mmol) and complex
2 2
[
25]
1
(1) (0.03 g, 0.05 mmol) in acetonitrile (10 ml) were taken.
vibrations. The H NMR spectra of the ligand shows sig-
nals at δ 12.69, δ 10.99, δ 8.77 and δ 6.90–8.27 ppm, respec-
tively (Figure S1). The peak at δ 12.69 ppm was assigned to
the ‐OH protons attached to the phenyl ring, the peak at δ
10.99 ppm was due to the secondary ‐NH protons, the peak
at δ 8.77 ppm due to ‐CH=N protons and the peak in the
region δ 6.90–8.27 ppm was due to the aromatic protons.
The peaks due to –OH and –NH protons disappeared on
complexation. The ‐CH=N peak at δ 8.90 ppm shifted
downfield and the aromatic protons appeared in the region
The reaction mixture was stirred at ambient temperature
for 20 min and raised to 70 °C for 6 hr. The crude product
was extracted and dried over anhydrous sodium sulfate.
To afford purified product column chromatography was
done. The NMR spectra of oxidation products are given
in supporting information (Figures S12‐S23).
2.2.4 | General experiment for oxidative
bromination
6.82–8.37 ppm in the complex, respectively (Figure S1).
This revealed the coordination of azomethine nitrogen
Salicyaldehyde (0.24 g, 2 mmol) was taken in a 50 ml
round bottom flask maintained at 0 °C, KBr (0.47 g,
13
atom to the vanadium ion. The C spectra of the complex
1) was almost similar to the spectra of the uncoordinated
(
4
mmol) in 5 ml water was added followed by the addi-
dihydrazone ligand (Figures S2, S3). The ligand showed
tion of 30% H O (1.70 g, 15 mmol). To the reaction mix-
2
2
signal at δ 148.99 ppm, which was assigned to the
ture, complex (1) (0.03 g, 0.05 mmol) and 70% HClO4
0.14 g, 1 mmol) were added and stirred at 0 °C. In three
13
azomethine carbons, in complex the C NMR spectra
(
shows downfield shift of this signal to δ 156.99 ppm with
Δδ = 8.00 ppm. This confirmed coordination of
azomethine nitrogen atom to vanadium metal center.
The ligand resonance appeared at δ 156.21 and δ
equal portions an additional 1 mmol of 70% HClO was
4
further added after every 10 mins with continuous stir-
ring. A light brown solid product was obtained which
was separated using a separating funnel. The crude prod-
uct thus obtained was purified by column chromatogra-
phy. The NMR spectra of brominated products are given
in supporting information (Figures S24‐S31).
155.82 ppm, which were assigned to the –C‐OH and car-
bonyl carbon, whereas upon complexation these signals
shifted downfield to δ 166.48 ppm and δ 164.04 ppm. The
downfield shift of these signals confirmed the coordination
of the ligand to the metal center. The carbon signal of the
aromatic ring appeared at the expected position. The
electronic spectrum of the complex shows three
3
3
| RESULTS AND DISCUSSION
.1 | Synthesis and characterization
3
−1
−1
3
peaks at 305 nm (8600 dm mol cm ), 355 (7800 dm
−
1
−1
3
−1
−1
mol cm ) and 425 nm (4800 dm mol cm ), respec-
tively (Figure S4). The bands at 305 nm and 355 nm are
assigned to the ligand centered charge transfer while the
band at 425 nm is assigned to the ligand to metal charge
transfer (LMCT), due to the p‐orbital lone pair of the
phenolate oxygen donated in an empty d‐orbital of
Reaction
of
bis(5‐chlorosalicylaldehyde)
oxaloyldihydrazone with vanadium pentoxide in 1:1
molar ratio in methanol under reflux for 1 hour leads
to a good yield formation of complex (1). The
complex was found to have the composition
+
2
[26]
[
(CH ) NH ] [(VO ) (sloxCl)].4H O (1). Recrystalliza-
vanadium(V) center.
3
2
2
2 2
2
tion of the complex (1) from DMF/water system in 1:1.5
ratio by volume leads to the formation of yellow coloured
crystals which was isolated by filtration, dried between
folds of filter paper and kept under vacuum.
3.2 | Crystal structure
The IR spectra of the complex shows a broad band in
Single crystal X‐ray crystallography was used to deter-
mine the crystal structure of the complex (1) and a repre-
sentative ORTEP view of complex was shown in Figure 1.
−
1
the region 3600–3000 cm . This band was assigned to
the ν (OH) vibration of water molecules present in the lat-
−
1
tice structure of the complex. The other band at 1609 cm
The complex crystallized in monoclinic P2 /n space
1
[23]
was assigned to ν(C=N) vibration.
New band at 1479,
40, 914 and 574 cm was also observed in the IR spectra
of the complex. The band at 1479 cm was characteristic
group. The molecule contains two parts, one cationic
and the other anionic part (Figure 1). The cationic
coordination sphere consists of two dimethylammonium
ions while the anionic coordination sphere contains
−
1
9
−
1
[24]
of newly created νNCO‐ group
arising as a result of

4
of 13
SYIEMLIEH ET AL.
FIGURE 1 ORTEP plot of the complex (1) with 50% probability
2−
[
(VO ) (sloxCl)] unit. The relevant metrical parameters
structure, the vanadium ion is in an O N‐donor atom
2
2
4
are summarized in Table 1. Selected bond lengths and
bond angles of the complex are listed in Table S1. In the
environment, arranged in a square pyramidal geometry
[
27]
(addison parameter
τ = 0.16; τ = 0.00 for a square
pyramidal and 1.00 for a trigonal bipyramidal). The equa-
torial plane is made up of O1, O3, O2 and N1 atoms
around V1 atom of one half molecule. Similarly, the cor-
responding donor atoms surround the V1a atom in the
equatorial plane of other half of the molecule. The
dihydrazone coordinated in a bis (dibasic tridentate) fash-
ion through ‐(O‐N‐O)‐ donor atoms to each of the metal
center and thus acting as a tetrabasic hexadentate ligand.
The metrical parameters are similar to those reported in
the literature for tetraanionic divanadium(V) complexes
TABLE 1 Crystal data and structure refinement of the
complex (1)
Complex (1)
CCDC
1873558
3 6
16ClN O V
Empirical formula
C
10
H
Formula weight
360.65
Temperature/K
298.56(10)
Crystal system
monoclinic
P21/n
in an O N donor environment, which indicates two oxido
4
[
18]
groups.
The metal ligand distances fall in the order
Space group
V=O (O and O) < V‐O (O3 and O4) < V‐N. The V=O
and V‐N bond distances in the present complex compare
well with those of the chloroperoxidase enzyme from C
inaequals, where the corresponding bond distances are
a/Å
8.3077(11)
19.475(2)
9.4246(13)
90
b/Å
c/Å
[
28,29]
α/°
1.65 and 2.25 Å, respectively.
β/°
99.578(14)
90
γ/°
3
.3 | Reaction with hydrogen peroxide
Volume/Å3
1503.6(3)
4
Z
In the present study, we set our aim to study the oxida-
tion of alcohols and oxidative bromination of some
organic substrates by H O as terminal oxidant using
vanadium complex as a catalyst. Hence, it was incumbent
upon us to study the reactivity of the complex towards
H O to determine the nature of the active complex cata-
Radiation
MoKα (λ = 0.71073)
3054/0/198
Data/restraints/parameters
Goodness‐of‐fit on F2
Final R indexes [I > =2σ (I)]
Final R indexes [all data]
2 2
1.031
R1 = 0.0663, wR2 = 0.1583
R1 = 0.0830, wR2 = 0.1741
2
2
lyst intermediate formed in the reaction. Accordingly, we

SYIEMLIEH ET AL.
5 of 13
carried out extensive investigation of reaction of the
complex with H O .
to 336 nm, respectively. The continuous addition of HCl
solution to the complex solution shows the presence of
three isosbestic points at 382 nm, 472 nm and 502 nm
for complex (1), respectively. Complex (1) (20 ml of
2
2
The reaction of the complex (1) with an aqueous meth-
anolic solution of 30% H O was monitored with UV–
2
2
−
4
visible spectroscopy (Figure S5). When 30% of H O in
10 M) was also titrated with saturated methanolic solu-
2
2
aqueous methanolic solution is added to the solution of
bis (dioxidovanadate(V)) complex, the formation of bis
tion of HClO (Figure S7). The bands at 305 nm and
4
328 nm showed an increase in intensity and merged
together giving one band at 331 nm while the band at
418 nm showed a decrease in intensity with a red shift
to 425 nm, respectively. Two isosbestic points were
observed at 382 nm and 455 nm, respectively. These
results have been interpreted in terms of the formation
of oxidohydroxido complexes of the composition [{VO
(monooxidomonoperoxidovanadate(V)) complex occurs.
Tentatively, the complex when reacted with H O has
2
2
been assumed to give a new oxidoperoxido complex of
2
−
the composition [{VO(O )} (sloxCl)] in solution. The
2
2
poor stability of the peroxo complexes at room tempera-
ture in the solid state did not allow their isolation and
characterization in detail. However, the formation of
2−
2−
(OH)} (sloxCl)] via [{(VO )} (sloxCl)]
2
2 2
peroxo complexes from the corresponding bis (dioxido)
Here one of each of = N‐N = nitrogen is protonated
upon acidification. The protonation of hydrazone nitrogen
atom has been shown to occur in the structurally charac-
[30]
species was established in a methanolic solution.
when 20 mL of 5 x 10 M solution of the complex (1)
was treated with 30% aqueous H O (total of 2.440 g,
Thus,
−
5
terized complex [(VO)(Hsal‐bhz)] (H sal‐bhz derived from
2
2
2
1
8.00 mmol) by adding H O solution two drop portion
salicylaldehyde and benzoylhydrazide), which is formed
2
2
(
10 μL) after each 10 mins, the spectra was recorded.
when the corresponding anionic dioxido vanadate
[
34]
The absorption band of the complex at 423 nm shows a
decrease in the intensity, but other ligand bands suffer
blue or red shift on titration with H O
complex reacts with HCl.
When K[VO (sal‐inh)H O]
2
2
(H sal‐inh = hydrazone derived from salicylaldehyde and
2
[31,32]
When fur-
isonicotinic acid hydrazide) and [K(H O) ][VO (Clsal‐
2
2.
2
2
2
ther amount of H O is added to the complex solution
sbdt)] (H Clsal‐sbdt
=
ligand derived from 5‐
2
2
2
in methanol, an increase in the intensity of the band at
chlorosalicylaldehyde and s‐benzyldithiocarbazate) were
acidified, oxido‐hydroxido vanadium complexes gener-
3
3
05 nm with a blue shift to 303 nm, and the band at
35 nm with a red shift to 341 nm, respectively. The con-
[
35]
+
ated.
(where
hydroxyethyl)ethylenediamine) in solution was also
reported to be formed from dinuclear
dioxidovanadium(V) precursor in a similar manner,
An oxido‐hydroxido complex [VO (OH)(LH)]
tinuous addition of 30% H O also show the presence of
LH=N‐{(O‐hydroxyphenyl)methyl}‐N′‐bis(2‐
2
2
one isosbestic point at 372 nm in the complex. The
amount of peroxo species formation depends upon the
amount of H O added. This result indicates the forma-
a
[36]
2
2
V
[37]
[38]
tion of V O‐(O ) species in solution. Sufficient literature
evidence is available for this contention
Giacomelli et al.
and Moro‐oka et al.
reported the
2
[30–33]
V
IV
and that
complexes [V O (OH)(8‐oxyquinolinate)] and [V O
both metal‐centers are peroxygenated.
(OH)Tp(H O)] [Tp = tris(3, 5‐diisopropyl‐1‐pyrazolyl)
borate(1‐)] and characterized them in the solid state.
2
+
These result suggest the formation of oxidohydroxido
2
−
3
.4 | Reaction with HCl and KOH
complex of composition [{(VO (OH)}
(sloxCl)] . The
2
spectral patterns regained their original feature on the
−
4
The reactivity of complex (1) with HCl was studied by
electronic absorption spectroscopy. Spectral changes were
observed with the addition of 1‐drop portions of metha-
nol saturated with HCl gas to a methanolic solution of
complex (1) (20 mL of 5.02 x 10 M) (Figure S6). The
addition of 1‐drop portion of HCl methanolic solution to
the solution of the complex led to a progressive decrease
in the intensity of 429 nm with a red shift (bathochromic
shift) to 432 nm and the band at 329 nm showed an
increase in intensity with a red shift (bathochromic shift)
addition of methanolic solution of KOH (10
M),
therefore, the reaction is reversible. This reversibility is
an important observation for the catalytic activity of
vanadate‐dependent haloperoxidases and the active site
−
5
[39]
structure.
In this connection, it is imperative to men-
tion that for vanadate dependent haloperoxidases, from
X‐ray diffraction studies, it has been established that
hydroxido is bonded to vanadium atom in the apical posi-
[
40]
tion.
This has also been suggested on the basis of the
[
41]
kinetic investigation.

6
of 13
SYIEMLIEH ET AL.
3
.5 | Protein binding studies
a biphasic medium oxidation, and it was found that
aqueous acetonitrile (1:1, v/v) as a medium gave a best
yield of the product (Figure S10). Different amount of
the complex catalyst was examined and it was found that
0.05 mmol of the catalyst led to the highest yield (Figure
S11). Using the standard amount of catalyst (0.05 mmol),
temperature (70 °C) and acetonitrile (10 ml) as a solvent,
the effect of additives was also studied. The oxidation of
benzyl alcohol was also performed using different
sources of vanadium such as vanadyl acetylacetonate,
VOSO , V O and NaVO , but it was found that the com-
Fluorescence spectroscopy was used to study the binding
mode of complex (1) with protein (BSA) on the excitation
at wavelength 285 nm. The emission intensity of BSA was
found to be quenched gradually on increasing the con-
centration of the complex. The fluorescence quenching
of BSA by the complex (1) (2 x 10 to 2 x 10 M) and
the Stern–Volmer plot are given in Figure S8. In folded
proteins, the tryptophan (in BSA) emission is suppressed
by the presence of charged residues which results in
−
6
−5
4
2
5
3
[
42]
decrease in intensity of emission spectra of BSA.
quantify the binding affinity of complex (1) with protein
BSA), the Stern‐Volmer equation was used to analyze
fluorescence quenching studies
To
plex gave best yield. From the Table S2, we could see
that the yield of benzaldehyde with 0.05 mmol of catalyst
was almost same (83.8%) (Table S2, entry 22) as that in
the case of TEMPO (85.0%) (Table S2, bottom). Hence,
the addition of TEMPO in the reaction medium as an
additive appears to be superfluons. Consequently, we
have neither used TEMPO nor any other additive in
the further reaction. Present vanadium complex is
formed from a multidentate ligand in which some bond-
ing sites remain uncoordinated. These uncoordinated
bonding sites offer more stability to the complex which
enable the complex to afford the best yield of the benzyl
alcohol oxidation than vanadyl acetylacetonate, V O ,
(
I =I ¼ 1 þ K ½Qꢀ
(1)
(2)
0
Sv
log ½ðI − IÞ=Iꢀ ¼ log K þ nlog½Qꢀ
0
Stern–Volmer quenching constants (K ) of complex
Sv
(1) was obtained from the slope of the linear plot I /I vs
0
[
Q], while the binding constant (KBSA) of complex and
2
5
the number of binding sites (n) were obtained from the
plot of log [(I ‐ I)\I] vs. log[Q]. The Stern–Volmer
quenching constants (K ) for the complex is 3.23 x
VOSO , and NaVO . The reaction was also tested in the
4
3
0
absence of the catalyst at 70 °C in acetonitrile, but it
was found that no conversion of benzyl alcohol into
benzaldehyde occurred, hence, the catalyst is the active
species in the reaction. Following the above standardized
protocol, catalytic oxidation of several alcohols has been
carried out (Table 2).
Sv
6
−1
8
−1
1
0 M , binding constant (K ) is 2.21 x 10 M and
BSA
the number of binding site (n) is 1.38. Hence, from the
KBSA value, it is assumed that dioxidovanadium(V) com-
plex binds strongly to serum proteins.
[43,44]
Primary benzyllic alcohols bearing both electron
donating and electron withdrawing substituents (Table 2
3.6 | Catalytic oxidation of alcohols
,
entries 1–10) were oxidized in good yield to their corre-
The catalytic activity of the complex was initially tested
sponding aldehyde, respectively. Hence, from Table 2, we
conclude that primary benzyllic alcohols bearing electron
donating groups on the aromatic ring can be oxidized to
higher yield compared to those benzyllic alcohols con-
taining electron withdrawing groups. Selectively
cinnamyl alcohol (Table 2, entry 11) was oxidized to
81% without effecting the double bond. Benzoin was also
oxidized to benzil (Table 2, entry 12) with 90% yield. Sec-
ondary alcohols such as phenyl ethanol, cyclohexanol
and cycloheptanol (Table 2, entries 13–15) were also oxi-
dized but negligible yield with only <2% conversion
occurred. Hence, this system has a drawback that it can-
not oxidize secondary benzyl alcohols and secondary
alcohols. Hetero‐aryl alcohols such as 2‐furan methanol
and 2‐pyridine methanol (Table 2, entries 16, 17) were
also oxidized in good yield. Propargylic alcohols such as
2‐hexyne‐1‐ol when stirred for 50 hr, was oxidized to 2‐
hexyne‐1‐al with 19% yield without oxidizing the triple
bond (Table 2, entry 18).
using benzyl alcohol as a standard substrate, 15% H O2
2
and catalyst (0.005 mmol) in which benzaldehyde was
the sole product. Optimization of the reaction conditions
was carried out such as temperature, solvent, concentra-
tion of catalysts and effect of additives (Table S2). Firstly,
the reaction was carried out at different temperatures
and the best conversion was at 70 °C (Figure S9). Solvent
effect was also studied using both polar and non‐polar
solvents. In non‐polar solvents such as hexane, CH Cl ,
2
2
toluene, xylene and benzene lower yield of benzaldehyde
(in the range 3.4–14.0) was obtained while in the polar
solvents, the yield of benzaldehyde increased and
became more falling in the range (19.2–33.2). This may
be due to higher dielectric constant of the polar solvent.
In fact, the oxidation of benzaldehyde was carried out
in CH CN solvent and as 15% H O was added into the
3
2 2
reaction medium, the medium, automatically, became
aqueous‐acetonitrile. Actually, this oxidation process is

SYIEMLIEH ET AL.
7 of 13
a
TABLE 2 Catalytic oxidation of different alcohols using complex (1)
Yield (%)
Entry
Substrate
Product
Time (h)
Complex (1)
b
1
6
81(83.8)
b
2
7.2
94(95.9)
b
3
4
7.2
7.2
88(90.5)
b
84(86)
b
5
6
7
8
9
7.2
7.2
7.2
7.2
7.2
77(79.2)
b
75(77.6)
b
69(71.3)
b
85(87.9)
b
70(72.3)
b
1
0
6.5
96(98.2)
b
1
1
1
2
12
81(83)
b
7.1
90(92.7)
b
1
3
9
(1.3)
b
1
1
4
5
6.5
6.5
(1.7)
b
(0.8)
b
1
1
6
7
6.2
7
82(85.3)
b
81(83.7)
b
1
8
50
19(21.3)
a
2 2 3
Reaction conditions: Catalyst (0.05 mmol), 15% H O (5.80 mmol), CH CN, Temperature (70 °C).
b
GC Yield.

8
of 13
SYIEMLIEH ET AL.
+
3.7 | Plausible mechanism for oxidation
H
{
O
2
2
, forms monoperoxo {VO(O
2
) } or bis (peroxo)
−
VO(O ) } species. These peroxo species ultimately cause
2
2
Regarding the mechanism, a catalytic cycle is proposed
for the oxidation of alcohols to aldehydes and ketones
in Scheme 1. First, a vanadium(V) complex (A) reacts
with hydrogen peroxide forming oxidoperoxido‐
vanadium(V) species (B). The species (B) then reacts with
benzyl alcohol to afford a vanadium alcoholate (C). In
this species, hydrogen abstraction occurs on the α‐
hydroxyl group. Next the product accompanied by
subsequent dehydration benzaldehyde was formed via β‐
oxidation of bromide, most probably, via hydroperoxide
intermediate. The subsequent bromination of the sub-
4, 29, 30c, 46, 47
strate
takes place by oxidized bromine spe-
−
cies (Br , Br3 and/or HOBr). When the catalyst was not
2
added to the reaction mixture, no brominated product
was obtained. This demonstrated the active role of
dioxidovanadium complex in catalysis for catalytic bromi-
nation, the acid HClO was found to be essential. During
4
the course of the reaction, the complexes decompose
[45]
hydrogen elimination from species (C).
slowly, when larger amount of HClO (6 mmol or more)
4
were used. The decomposition of the complex catalyst
can be reduced when HClO is added to the reaction mix-
ture successively in about 4–5 equal portions.
4
3.8 | Oxidative bromination
Complex (1) was used, as the pre‐catalysts, the reac-
tions were studied by varying parameters such as amount
of catalyst/substrate ratios, effect of bromide sources,
effect of H O2 and volume of HClO . The reaction
The oxidative bromination was first checked using
salicylaldehyde as a substrate model (Table S3). It is
known that vanadate‐dependent bromoperoxidases, in
the presence of H O and bromide, catalyze the bromina-
2
4
2
2
was first examined with different amounts of
catalyst/substrate and it was found that the reaction
proceeded well with 1:40 molar ratios. Firstly, the reac-
tion was carried out at low temperature (0 °C) and then
raised to room temperature. The effect of bromide sources
were also tested by using complex/substrate 1:40 molar
ratios and it was found that complex/substrate/KBr in
tion of organic substrates. Further it has been
demonstrated that vanadium compounds have the ability
to mimic this reaction. The bromination of
+
[41]
trimethoxybenzene by the VO2 ion
and also that of
+
[41]
phenol red by [VO(O )(H O)] and the related species
2
2
are the typical examples. Here we shall show that the
present complex catalyzes the oxidative bromination of
salicylaldehyde and other organic compounds using
aqueous H O /KBr in the presence of HClO .
1
:40:80 molar ratios gave the good yield. The effect of
hydrogen peroxide were also tested and found that
:40:80:300 molar ratios of complex/substrate/KBr/hydro-
2
2
4
1
gen peroxide gave the best conversion. The effects of acid
were also studied and found that 4 mmol of HClO gave
4
good yield (Table S4). Solvent effect was also tested by
using different varieties of solvents and found that water
gave a maximum yield. The oxidative bromination
reactions were also performed using different sources
It has been shown that during oxidative bromination
with H O /KBr catalyzed by V O and oxovanadium(V)
complexes, vanadium, with one or two equivalents of
2
2
2 5
19b
of vanadium such NaVO4, V O
VOSO4 and
2
5,
SCHEME 1 Plausible mechanism for
the catalytic oxidation of alcohols (only
one unit of the complex is shown)

SYIEMLIEH ET AL.
9 of 13
vanadylacetylacetonate, but it was found that the com-
plex gave best catalytic performance. This is due to
greater stability of the complex as some bonding sites
coordinated multidentate dihydrazone remains uncoordi-
nated in the complex which offer more stability to the
complex. In this connection, it is imperative to mention
that Rehder and Pessoa have carried out original works
on oxidative bromination of some organic substrates by
α‐bromo‐2‐hydroxy acetophenone as the product
(Table 3, entry 4). Substituted ketones such as 4‐methyl‐
2‐hydroxy‐acetophenone
and
5‐methyl‐2‐hydroxy‐
acetophenone were monobrominated to α‐bromoketone
i.e., 2‐bromo‐1‐(2‐hydroxy‐4‐methylphenyl)ethanone and
2‐bromo‐1‐(2‐hydroxy‐5‐methylphenyl)ethanone (Table 3
, entries 5, 6). Ethyl salicylate was also brominated to 5‐
bromoethyl salicylate with 85% yield as the product
(Table 3, entry 7).
[18,19]
vanadium complexes derived from dihydrazones.
To explore the catalytic behaviour of the complex in
oxidative bromination other organic substrates were also
investigated (Table 3). Following the above optimized
conditions for the oxidative bromination reaction, the
3.9 | Plausible mechanism of oxidative
bromination
reaction was carried out using 4 mmol of HClO , 2 mmol
4
of substrate, 15 mmol of H O , 0.05 mmol of catalyst and
The plausible mechanism of oxidative bromination is
shown in Scheme 2 in which electrophilic mechanism is
predicted preferably, bromination at either para or ortho
positions.
2
2
4
mmol of KBr, respectively.
The bromination reaction of salicylaldehyde gave good
yield of 5‐bromo salicylaldehyde in 35 min (Table 3, entry
). Aniline was also brominated giving p‐bromoaniline as
1
When HClO4 is added into the reaction, the complex
species [VOL/2] is most likely to transform into [VO
the product within 30 min (Table 3, entry 2). Bromination
of acetophenone gave α‐bromoacetophenone as the only
product (Table 3, entry 3). Substituted α‐bromoketone,
such as 2‐hydroxy acetophenone within 30 min gave
+
(OH)(HL/2)] and when H O is added, the correspond-
2
2
−
ing oxidoperoxido species [VO(O2)L/2] /[VO (HO )L/2]
2
may, most likely, be formed in acidic methanol. Thus
TABLE 3 Oxidative bromination reaction of some organic substrate catalyzed by complex (1)
Yield (%) (isolated)
Melting point (°C)
Nnn
Substrate
Product
Time (min)
Complex (1)
1
35
89
104
2
3
30
33
83
85
62
51
4
5
30
45
81
90
46
67
6
7
45
30
87
85
65
52
a
Reaction conditions: salicylaldehyde (0.24 g, 2 mmol), H
water (5 ml).
2 2 4
O (1.70 g, 15 mmol), catalyst (0.02 g, 0.05 mmol), KBr (0.47 g, 4 mmol), HClO (0.57 g, 4 mmol) and

10 of 13
SYIEMLIEH ET AL.
2 2 4
SCHEME 2 Plausible mechanism of bromide oxidation by complex (1) in presence of H O , KBr and HClO
the active species essential for the catalytic reaction is
obtained. The coordination of peroxide to vanadium acti-
vates peroxide. This allows nucleophilic attack of the bro-
oxidation of various alcohols and also oxidative bromina-
tion of some organic substrates. The catalytic process is
considerably advantageous because of availability and
cheapness of the vanadium(V) source. Binding efficiency
of the complex with BSA was also investigated and it
was found that the binding constant (KBSA) is 2.21 x
10 M and the number of binding site (n) is 1.38. There-
fore, the KBSA value shows that bis (dioxidovanadium(V))
complex binds strongly to the protein serum.
[48]
mide
and then, subsequently, release hypobromous
acid, which causes bromination of organic substrates.
Electron spray ionization mass spectra on model systems
has shown that a hypobromite intermediate may also
8
−1
[49]
involve in the reaction.
4
| CONCLUSION
ACKNOWLEDGMENTS
In conclusion, in this paper, we have synthesized bis
Authors are thankful to the Head, SAIF, NEHU, for pro-
viding NMR spectra. We would also like to acknowledge
the Head, Department of Chemistry, NEHU, for X‐ray
crystallographic studies. I. Syiemlieh would like to thank
UGC, New Delhi for the award of NFHE Fellowship. We
thank Dr. S. D. Kurbah for helping us in solving crystal
structure of vanadium complex. We are highly thankful
to the learned reviewer for drawing our attention on
some important papers on dihydrazone complexes and
vanadium complexes.
+
(dioxidovanadium(V))
complex
[(CH ) NH ]
3 2 2 2
[
(VO ) (sloxCl)].4H O which has been characterized by
2
2
2
various physico‐chemical studies. On the basis of spectro-
scopic studies, we have inferred that amide group in
dihydrazone ligand undergoes enolization to the extent
of two secondary NH protons involving carbonyl groups.
The dihydrazone coordinates to the metal centers as a
tetrabasic hexadentate ligand, through enolate oxygen
atom via deprotonation and phenolate oxygen atom via
deprotonation and azomethine nitrogen atom. Each half
of dihydrazone binds to metal center through one pheno-
late oxygen atom, one enolate oxygen atom and one
azomethine nitrogen atom. The structure of the complex
has been established by X‐ray crystallography. Using the
complex as a catalyst, we have carried out catalytic
ORCID
Ibanphylla Syiemlieh
https://orcid.org/0000-0003-2800-
9018
Ram A. Lal https://orcid.org/0000-0002-4957-0958

SYIEMLIEH ET AL.
11 of 13
REFERENCES
L. Kuznetsov, J. C. Pessoa, A. Kumar, Y. P. Patil, A. Crochet,
R. Dinda, Inorg. Chem. 2016, 55, 8407. (e)S. P. Dash, A. K.
Panda, S. Pasayat, R. Dinda, A. Biswas, E. R. T. Tiekink, Y. P.
Patil, M. Nethaji, W. Kaminsky, S. Mukhopadhyay, S. K.
Bhutia, Dalton Trans. 2014, 43, 10139. (f)S. P. Dash, A. K.
Panda, S. Pasayat, R. Dinda, A. Biswas, E. R. T. Tiekink, S.
Mukhopadhyay, S. K. Bhutia, W. Kaminsky, E. Sinn, RSC
Adv. 2015, 5, 51852. (g)A. Buchholz, S. Nica, R. Debel, A. Fenn,
H. Breitzke, G. Buntkowsky, W. Plass, Inorg. Chim. Acta 2014,
[
1] (a)C. Leblanc, H. Vilter, J. B. Fournier, L. Delage, P. Potin, E.
Rebuffet, G. Michel, P. L. Solari, M. C. Feiters, M. Czjzek,
Coord. Chem. Rev. 2015, 301, 134. (b)W. Plass, Coord. Chem.
Rev. 2011, 255, 2378. (c)S. Nica, M. Rudolph, I. Lippold, A.
Buchholz, H. Görls, W. Plass, J. Inorg. Biochem. 2015, 147,
1
93. (d)A. Butler, in Bioinorganic Catalysis, (Ed: J. Reedijk),
Marcel Dekker, New York 1993 424. (e)J. Costa Pessoa, E.
Garribba, M. F. A. Santos, T. Santos‐Silva, Coord. Chem. Rev.
420, 166. (h)S. Banerjee, A. Hussain, P. Prasad, I. Khan, B.
2
015, 301, 49.
Banik, P. Kondaiah, A. R. Chakravarty, Eur. J. Inorg. Chem.
2012, 2012, 3899. (i)C. Redshaw, L. Clowes, D. L. Hughes, M.
R. J. Elsegood, M. R. J. Elsegood, T. Yamato, Organometallics
2011, 30, 5620. (j)J. ‐B. Wang, L. ‐P. Lu, J.‐Y. Liu, Y.‐S. Li, Dal-
ton Trans. 2014, 43, 12926. (k)Q. Yan, Z. Sun, W. Zhang, K.
Nomura, W. ‐H. Sun, Macromol. Chem. Phys. 2014, 215, 1744.
(l)V. A. Tuskaev, N. A. Kolosov, D. A. Kurmaev, S. C. Gagieva,
V. N. Khrustalev, N. S. Ikonnikov, N. N. Efimov, E. A.
Ugolkova, V. V. Minin, B. M. Bulychev, J. Organomet. Chem.
2015, 798, 393. (m)J. ‐B. Wang, L. ‐P. Lu, J. ‐Y. Liu, H. ‐L.
Mu, Y. ‐S. Li, J. Mol. Catal. A: Chem. 2015, 398, 289. (n)J. A.
Littlechild, E. Garcia‐Rodriguez, Coord. Chem. Rev. 2003, 237,
65. (o)C. Dıaz‐Urrutia, W. ‐C. Chen, C. ‐O. Crites, J. Daccache,
I. Korobkov, R. T. Baker, RSC Adv. 2015, 5, 70502.
[
2] (a)V. Conte, A. Coletti, B. Floris, G. Licini, C. Zonta, Coord.
Chem. Rev. 2011, 255, 2165. (b)M. Sutradhar, L. M. D. R. S.
Martins, M. F. C. Guedes da Silva, A. J. L. Pombeiro, Coord.
Chem. Rev. 2015, 301, 200. (c)S. P. Dash, A. K. Panda, S. Dhaka,
S. Pasayat, A. Biswas, M. R. Maurya, P. K. Majhi, A. Crochet, R.
Dinda, Dalton Trans. 2016, 45, 18292. (d)K. Kanmani Raja, L.
Lekha, R. Hariharan, D. Easwaramoorthy, G. Rajagopal,
J. Mol. Struct. 2014, 1075, 227. (e)I. Gryca, K. Czerwinska, B.
Machura, A. Chrobok, L. S. Shul'pina, M. L. Kuznetsov, D. S.
Nesterov, Y. N. Kozlov, A. J. L. Pombeiro, I. A. Varyan, G. B.
Shul'pin, Inorg. Chem. 2018, 57, 1824. (f)A. Chieregato, J. M.
López Nieto, F. Cavani, Coord. Chem. Rev. 2015, 30, 3. (g)A.
Pokutsa, Y. Kubaj, A. Zaborovskyi, D. Maksym, T. Paczesniak,
B. Mysliwiec, E. Bidzinska, J. Muzart, A. Sobkowiak, Mol.
Catal. 2017, 434, 194. (h)S. Barroso, P. Adão, F. Madeira, M.
T. Duarte, J. Pessoa, A. M. Martins, Inorg. Chem. 2010, 49,
[
[
5] aD. Wischang, O. Brücher, J. Hartung, Coord. Chem. Rev. 2011,
255, 2204. bP. Schwendt, J. Tatiersky, L. Krivosudský, M.
Šimuneková, Coord. Chem. Rev. 2016, 318, 135. cE.
Palmajumder, S. Patra, M. G. B. Drew, K. K. Mukherjea, New
J. Chem. 2016, 40, 8696.
7
452. (i)B. N. Wigington, M. L. Drummond, T. R. Cundari, D.
L. Thorn, S. K. Hanson, S. L. Scott, Chem. – Eur. J. 2012, 18,
4981. (j)M. R. Maurya, N. Chaudhary, A. Kumar, F. Avecilla,
1
6] (a)K. D. Mjos, C. Orvig, Chem. Rev. 2014, 114, 4540. (b)D.
Rehder, Future Med. Chem. 2012, 4, 1823. (c)D. Rehder, Inorg.
Chim. Acta 2017, 455, 378. (d)T. Scior, J. Guevara‐Garcia, Q. ‐
T. Do, P. Bernard, S. Laufer, Curr. Med. Chem. 2016, 23, 2874.
J. Costa Pessoa, Inorg. Chim. Acta 2014, 420, 24. (k)M.
Sutradhar, L. M. D. R. S. Martins, M. F. C. Guedes da Silva,
A. J. L. Pombeiro, Appl. Catal. A 2015, 493, 50. (l)M. R.
Maurya, N. Chaudhary, F. Avecilla, P. Adão, J. Costa Pessoa,
Dalton Trans. 2015, 44, 1211. (m)A. I. Elkurtehi, A. G. Walsh,
L. N. Dawe, F. M. Kerton, Eur. J. Inorg. Chem. 2016, 2016,
(
e)S. P. Dash, S. Pasayat, S. Bhakat, S. Roy, R. Dinda, E. R. T.
Tiekink, S. Mukhopadhyay, S. K. Bhutia, M. R. Hardikar, B.
N. Joshi, Y. P. Patil, M. Nethaji, Inorg. Chem. 2013, 52, 14096.
3
5
123. (n)E. Kober, Z. Janas, J. Jezierska, Inorg. Chem. 2016,
5, 10888. (o)D. Dragancea, N. Talmaci, S. Shova, G. Novitchi,
(
1
f)J. L. Domingo, M. Gómez, Food Chem. Toxicol. 2016, 95,
37. (g)D. Rehder, Metallomics 2015, 7, 730. (h)Y. Yoshikawa,
H. Sakurai, D. C. Crans, G. Micera, E. Garribba, Dalton Trans.
014, 43, 6965. (i)A. Levina, A. I. McLeod, S. J. Gasparini, A.
D. Darvasiová, P. Rapta, M. Breza, M. Galanski, J. Kozǐséǩ, N.
M. R. Martins, L. M. D. R. S. Martins, A. J. L. Pombeiro, V. B.
Arion, Inorg. Chem. 2016, 55, 9187. (p)A. ‐C. Schmidt, M.
Hermsen, F. Rominger, R. Dehn, H. Teles, A. Schäfer, O.
Trapp, T. Schaub, Inorg. Chem. 2017, 56, 1319.
2
Nguyen, W. G. M. De Silva, J. B. Aitken, H. H. Harris, C.
Glover, B. Johannessen, P. A. Lay, Inorg. Chem. 2015, 54,
7753. (j)J. Costa Pessoa, J. Inorg. Biochem. 2015, 147, 4. (k)I.
[
3] (a)M. M. Hanninen, A. Peuronen, P. Damlin, V. Tyystjarvi, H.
Kivela, A. Lehtonen, Dalton Trans. 2014, 43, 14022. (b)K.
Nomura, S. Zhang, Chem. Rev. 2011, 111, 2342. (c)J. ‐Q. Wu,
Y. ‐S. Li, Coord. Chem. Rev. 2011, 255, 2303. (d)H. Makio, H.
Terao, A. Iwashita, T. Fujita, Chem. Rev. 2011, 111, 2363. (e)
A. Butler, in Comprehensive Biological Catalysis, (Ed: M.
Sinnott), British Academic Press, Oxford, U. K. 1997 427. (f)
H. Vilter, Met. Ions Biol. Syst. 1995, 31, 325. (g)H. Pellissier,
Coord. Chem. Rev. 2015, 284, 93.
Z. Gundhla, R. S. Walmsley, V. Ugirinema, N. O. Mnonopi,
E. Hosten, R. Betz, C. L. Frost, Z. R. Tshentu, J. Inorg. Biochem.
2015, 145, 11. (l)B. Fernandez, A. Gomez‐Vılchez, C. Sanchez‐
Gonzalez, J. Bayon, E. San Sebastian, S. Gomez‐Ruiz, C.
Lopez‐Chaves, P. Aranda, J. Llopis, A. Rodrıguez‐Dieguez,
New J. Chem. 2016, 40, 5387.
[
7] (a)E. Kioseoglou, S. Petanidis, C. Gabriel, A. Salifoglou, Coord.
Chem. Rev. 2015, 301, 87. (b)D. Gambino, Coord. Chem. Rev.
2011, 255, 2193. (c)P. P. Hazari, A. K. Pandey, S. Chaturvedi,
[
4] (a)P. K. Sasmal, S. Saha, R. Majumdar, R. R. Dighe, A. R.
Chakravarty, Inorg. Chem. 2010, 49, 849. (b)A. Bianchi, E.
Delgado‐Pinar, E. García‐Espana, C. Giorgi, F. Pina, Coord.
Chem. Rev. 2014, 260, 156. (c)S. Pasayat, M. Bohme, S. Dhaka,
S. P. Dash, S. Majumder, M. R. Maurya, W. Plass, W.
Kaminsky, R. Dinda, Eur. J. Inorg. Chem. 2016, 2016, 1604.
A. K. Tiwari, S. Chandna, B. S. Dwarakanath, A. K. Mishra,
Chem. Biol. Drug des. 2012, 79, 223. (d)S. Kowalski, S. Hac, D.
Wyrzykowski, A. Zauszkiewicz‐Pawlak, I. Inkielewicz‐
Stepniak, Oncotarget 2017, 8, 60324. (e)L. Naso, E. G. Ferrer,
L. Lezama, T. Rojo, S. B. Etcheverry, P. Williams, J. Biol. Inorg.
Chem. 2010, 15, 889. (f)L. G. Naso, M. Valcarcel, M. Roura‐
Ferrer, D. Kortazar, C. Salado, L. Lezama, T. Rojo, A. C.
(d)S. P. Dash, S. Roy, M. Mohanty, M. F. N. N. Carvalho, M.

12 of 13
SYIEMLIEH ET AL.
Gonzalez‐Baro, P. A. Williams, E. G. Ferrer, J. Inorg. Biochem.
014, 135, 86. (g)L. Naso, M. Valcarcel, P. Villace, M. Roura‐
Ferrer, C. Salado, E. G. Ferrer, P. A. M. Williams, New J. Chem.
014, 38, 2414. (h)X. Liao, J. Lu, P. Ying, P. Zhao, Y. Bai, W. Li,
2008, 123, 41. (d)P. Sarmah, R. Chakrabarty, P. Phukan, B. K.
Das, J. Mol. Catal. A: Chem. 2007, 268, 36.
2
[
18] (a)M. R. Maurya, C. Haldar, A. A. Khan, A. Azam, A.
2
Salahuddin, A. Kumar, J. C. Pessoa, Eur. J. Inorg. Chem. 2012,
M. Liu, J. Biol. Inorg. Chem. 2013, 18, 975. (i)B. Balaji, B.
Balakrishnan, S. Perumalla, A. A. Karande, A. R. Chakravarty,
Eur. J. Med. Chem. 2014, 85, 458. (j)N. A. Lewis, F. Liu, L. Sey-
mour, A. Magnusen, T. R. Erves, J. F. Arca, F. A. Beckford, R.
Venkatraman, A. Gonzalez‐Sarrias, F. R. Fronczek, D. G.
VanDerveer, N. P. Seeram, A. Liu, W. L. Jarrett, A. A. Holder,
Eur. J. Inorg. Chem. 2012, 2012, 664. (k)I. Correia, P. Adão, S.
Roy, M. Wahba, C. Matos, M. R. Maurya, F. Marques, F. R.
Pavan, C. Q. F. Leite, F. Avecilla, J. Costa Pessoa, J. Inorg.
Biochem. 2014, 141, 83. (l)S. D. Kurbah, M. Asthana, I.
Syiemlieh, R. A. Lal, Appl. Organomet. Chem. 2018, 32, e4299.
2
012, 2560. (b)M. R. Maurya, A. A. Khan, A. Azam, S. Ranjan,
N. Mondal, A. Kumar, J. C. Pessoa, Eur. J. Inorg. 2009, 5377. (c)
M. R. Maurya, A. A. Khan, A. Azam, S. Ranjan, N. Mondal, A.
Kumar, F. Avecilla, J. C. Pessoa, Dalton Trans. 2010, 39, 1345.
(
d)M. R. Maurya, S. Agarwal, C. Bader, D. Rehder, Eur. J. Inorg.
Chem. 2005, 1, 147. (e)S. Gupta, M. V. Kirillova, M. F. C. G. da
Silva, A. J. L. Pombeiro, A. M. Kirillov, Inorg. Chem. 2013, 52,
8601. (f)H. H. Monfared, N. A. Lalami, A. Pazio, K. Wozniak,
C. Janiak, Inorg. Chim. Acta 2013, 406, 241. (g)N. A. Lalami,
H. H. Monfared, H. Noei, P. Mayer, Trans. Met. Chem. 2011,
3
6, 669. (h)T. Sedaghat, M. Aminian, G. Bruno, H. A. Rudbari,
[
8] (a)D. X. West, A. E. Liberta, S. B. Padhye, R. C. Chikate, P. B.
Sonawane, A. S. Kumbhar, R. G. Yerande, Coord. Chem. Rev.
J. Organomet. Chem. 2013, 737, 26. (i)H. H. Hosseini, R. Bikas,
P. M. Anarjan, A. J. Blake, V. Lippolis, N. B. Arslan, C. Kazak,
Polyhedron 2014, 69, 90. (j)S. D. Kurbah, A. Kumar, I.
Syiemlieh, R. A. Lal, Polyhedron 2018, 139, 80. (k)R. Bikas, H.
H. Monfared, G. Zoppellaro, R. Herchel, J. Tucek, A. M.
Owczarzak, M. Kubicki, R. Zboril, Dalton Trans. 2013, 42,
1
993, 123, 49. (b)D. Kovala‐Demertzi, A. Domopoulou, M.
Demertzis, C. P. Raptopoulou, A. Terzis, Polyhedron 1994, 13,
917.
1
[
9] (a)A. Pohlmann, S. Nica, T. K. K. Luong, W. Plass, Inorg. Chem.
Commun. 2005, 8, 289. (b)W. Plass, Coord. Chem. Rev. 2003,
2803. (l)H. H. Monfared, H. Falakian, R. Bikas, P. Mayer, Inorg.
Chim. Acta 2013, 394, 526. (m)X. –. M. Zhang, X. –. Z. You, X.
Wang, Polyhedron 1996, 15, 1793.
2
37, 205. (c)S. Nica, A. Pohlmann, W. Plass, Eur. J. Inorg.
Chem. 2005, 2005, 2032. (d)T. Ghosh, Trans. Met. Chem. 2006,
1, 560. (e)J. C. Pessoa, S. Etcheverry, D. Gambino, Coord.
Chem. Rev. 2015, 301, 24.
3
[19] (a)S. D. Kurbah, A. Kumar, I. Syiemlieh, M. Asthana, R. A. Lal,
Inorg. Chem. Commun. 2017, 86, 39. (b)S. D. Kurbah, A.
Kumar, S. Shangpung, I. Syiemlieh, I. Khongjoh, R. A. Lal, Z.
Anorg. Allg. Chem. 2017, 643, 794. (c)A. Kumar, R. A. Lal,
J. Mol. Struct. 2015, 1092, 122. (d)R. Borthakur, A. Kumar, R.
A. Lal, Spectrochim. Acta A Mol. Biomol. Spectrosc. 2014, 118,
[
[
10] (a)G. Zhang, B. L. Scott, R. Wu, L. A. Silks, S. K. Hanson, Inorg.
Chem. 2012, 51, 7354. (b)C. H. Bai, A. Q. Li, X. F. Yao, H. L.
Liu, Y. W. Li, Green Chem. 2016, 18, 1061.
11] (a)N. Gunasekaran, Adv. Synth. Catal. 2015, 357, 1990. (b)C.
Parmeggiani, F. Cardona, Green Chem. 2012, 14, 547. (c)R.
Munirathinam, J. Huskens, W. Verboom, Adv. Synth. Catal.
94. (e)R. Borthakur, U. Thapa, M. Asthana, S. Mitra, K. Ismail,
R. A. Lal, J. Photochem. Photobiol. A Chem. 2015, 301, 6. (f)A.
Ahmed, R. A. Lal, J. Mol. Struct. 2013, 1048, 321. (g)A. Kumar,
R. Borthakur, A. Koch, O. B. Chanu, S. Choudhury, A. Lemtur,
R. A. Lal, J. Mol. Struct. 2011, 999, 89. hR. A. Lal, O. B. Chanu,
R. Borthakur, M. Asthana, A. Kumar, A. K. De, J. Coord. Chem.
2
015, 357, 1093. (d)B. Gutmann, D. Cantillo, C. O. Kappe,
Angew. Chem. Int. Ed. 2015, 54, 6688.
[
12] (a)G. Tojo, M. Fernandez, Oxidation of Alcohols to Aldehydes
and Ketones, Springer, New York 2010. (b)G. Tojo, M.
Fernandez, Oxidation of Primary Alcohols to Carboxylic Acids,
Springer, New York 2010.
2011, 64, 8601. iR. Borthakur, A. Kumar, R. A. Lal, J. Ind.
Chem. Soc. 2014, 91, 407.
[
[
20] A. I. Vogel, A Textbook of Quantitative Inorganic Analysis
Including Elementary Instrumentation Analysis, 4th ed., ELBS
and Longmans, London 1978.
[
13] D. J. C. Constable, P. J. Dunn, J. D. Hayler, G. R. Humphrey, J.
L. Leazer Jr., R. J. Lindermann, K. Lorenz, J. Manley, B. A.
Pearlman, A. Wells, A. Zaks, T. Y. Zhang, Green Chem. 2007,
21] (a)G. M. Sheldrick, Acta Crystallogr. 2015, C71, 3. (b)G. M.
Sheldrick, SHELXL‐14: Program for Crystal Structure Refine-
ments, University of Gottingen, Gottingen, Germany 1996.
9, 411.
[
[
14] S. Caron, R. W. Dugger, S. G. Ruggeri, J. A. Ragan, D. H. B.
Ripin, Chem. Rev. 2006, 106, 2943.
[
[
22] G. M. Sheldrick, Acta Crystallogr. 2015, A71, 3.
15] (a)S. D. Kurbah, A. Kumar, M. Asthana, S. Shangpung, A.
Koch, R. A. Lal, Curr. Organocatal. 2016, 3, 45. (b)R. Noyori,
M. Aoki, K. Sato, Chem. Commun. 2003, 16, 1977. (c)Y. M. A.
Yamada, C. K. Jin, Y. Uozumi, Org. Lett. 2010, 12, 4540. (d)S.
Rani, B. R. Bhat, Tetrahedron Lett. 2010, 51, 6403.
23] (a)H. Yamada, Bull. Soc. Jpn. 1959, 32, 1051. (b)H. Hosseini‐
Monfared, R. Bikas, P. Mahboubi‐Anarjan, A. J. Blake, V.
Lippolis, N. B. Arslan, C. Kazak, Polyhedron 2014, 69, 90.
[
24] (a)M. K. Singh, N. K. Kar, R. A. Lal, J. Coord. Chem. 2008, 61,
3158. (b)Z. Y. Yang, R. D. Yang, K. B. Yu, Polyhedron 1996,
[
16] (a)T. Hida, H. Nogusa, Tetrahedron 2009, 65, 270. (b)T. M. A.
Shaikh, A. Sudalai, Eur. J. Org. Chem. 2008, 2008, 4877. (c)J.
Wang, L. Yan, G. Qian, S. Li, K. Yang, H. Liu, X. Wang,
Tetrahedron 2007, 63, 1826.
15, 3749.
[
[
25] S. Orecchio, V. Romano, R. Zingales, J. Chem. Res. 1989, 14,
14.
2
26] S. Samanta, D. Ghosh, S. Mukhopadhyay, A. Endo, T. J. R.
[
17] (a)M. Lamblin, L. Nassar‐Hardy, J. –. C. Hierso, E. Fouquet, F.
Weakley, M. Chaudhury, Inorg. Chem. 2003, 42, 1508.
–
. X. Felpin, Adv. Synth. Catal. 2010, 352, 33. (b)T. Mitsudome,
A. Noujima, T. Mizugaki, K. Jitsukawa, K. Kaneda, Adv. Synth.
Catal. 2009, 351, 1890. (c)G. Maayan, R. Neumann, Catal. Lett.
[27] A. W. Addison, T. N. Rao, J. Reedijk, J. V. Rijn, G. C.
Verschoor, J. Chem. Soc. Dalton Trans. 1984, 7, 1349.

SYIEMLIEH ET AL.
13 of 13
[
[
[
28] (a)A. Messerschmidt, R. Wever, Proc. Natl. Acad. Sci. U. S. A.
[41] (a)G. J. Colpas, B. J. Hamstra, J. W. Kampf, V. L. Pecoraro,
J. Am. Chem. Soc. 1996, 118, 3469. (b)B. J. Hamstra, G. C.
Colpas, V. L. Pecoraro, Inorg. Chem. 1998, 37, 949.
1
996, 93, 392.
29] C. Das, P. Adak, S. Mondal, R. Sekiya, R. Kuroda, S. I.
Gorelsky, S. K. Chattopadhyay, Inorg. Chem. 2014, 53, 11426.
[42] R. Itri, W. Caetano, L. R. S. Barbosa, M. S. Baptista, Braz. J.
Phys. 2004, 34, 58.
30] (a)P. Comba, S. Kuwata, G. Linti, M. Tarnai, H. Wadepohl, Eur.
J. Inorg. Chem. 2007, 2007, 657. (b)M. R. Maurya, C. Haldar, A.
Kumar, M. L. Kuznetsov, F. Avecilla, J. Costa Pessoa, Dalton
Trans. 2013, 42, 11941. (c)M. R. Maurya, S. Agarwal, C. Bader,
M. Ebel, D. Rehder, Dalton Trans. 2005, 537. (d)M. R. Maurya,
S. Agarwal, C. Bader, D. Rehder, Eur. J. Inorg. Chem. 2005,
[43] M. Sedighipoor, A. H. Kianfar, W. A. K. Mahmood, M. H.
Azarian, Polyhedron 2017, 129, 1.
[44] P. Sathyadevi, P. Krishnamoorthy, R. R. Butorac, A. H. Cowley,
N. S. P. Bhuvanesh, N. Dharmaraj, Dalton Trans. 2011, 40,
9690.
2
005, 147.
[
45] (a)R. A. Sheldon, J. K. Kochi, Metal‐Catalyzed Oxidations of
Organic Compounds, New York, Academic Press 1981. (b)T.
Itoh, K. Jitsukawa, K. Kaneda, S. Teratani, J. Am. Chem. Soc.
1979, 101, 159.
[
31] (a)M. R. Maurya, B. Sarkar, F. Avecilla, S. Tariq, A. Azam, I.
Correia, Eur. J. Inorg. Chem. 2016, 2016, 1430. (b)M. R. Maurya,
A. Kumar, A. R. Bhat, A. Azam, C. Bader, D. Rehder, Inorg.
Chem. 2006, 45, 1260.
[46] D. Wischang, M. Radlow, J. Hartung, Dalton Trans. 2013, 42,
1926.
1
[
32] S. P. Dash, S. Majumder, A. Banerjee, M. Fernanda, N. N.
Carvalho, P. Adao, J. C. Pessoa, K. Brzezinski, E. Garribba,
H. Reuter, R. Dinda, Inorg. Chem. 2016, 55, 1165.
[47] P. Adak, B. Ghosh, B. Pakhira, R. Sekiya, R. Kuroda, S. K.
Chattopadhyay, Polyhedron 2017, 127, 135.
[
48] A. Butler, Coord. Chem. Rev. 1999, 187, 17.
[49] O. Bortolini, M. Carraro, V. Conte, S. Moro, Eur. J. Inorg. Chem.
003, 2003, 42.
[
[
[
33] P. Paciorek, J. Szklarzewicz, A. Jasinska, B. Trzewik, W. Nitek,
M. Hodorowicz, Polyhedron 2015, 87, 226.
2
34] W. Plass, A. Pohlmann, H. –. P. Yozgatli, J. Inorg. Biochem.
2
000, 80, 181.
35] (a)M. R. Maurya, S. Khurana, W. Zhang, D. Rehder, J. Chem.
Soc. Dalton Trans. 2002, 3015. (b)M. R. Maurya, S. Khurana,
W. Zhang, D. Rehder, Eur. J. Inorg. Chem. 2002, 2002, 1749.
SUPPORTING INFORMATION
Additional supporting information may be found online
in the Supporting Information section at the end of the
article.
[
[
[
[
36] G. J. Colpas, B. J. Hamstra, J. W. Kampf, V. L. Pecoraro, Inorg.
Chem. 1994, 33, 4669.
37] A. Giacomelli, O. Floriani, A. O. De Souza Duarte, A. Chiesi‐
Villa, C. Guastini, Inorg. Chem. 1982, 21, 3310.
How to cite this article: Syiemlieh I, Asthana M,
Lal RA. Reactivity and Catalytic Activity of
Homobimetallic Vanadium(V) Complex Derived
from Bis(5‐chlorosalicylaldehyde)
38] M. Kosugi, S. Hikichi, M. Akita, Y. Moro‐oka, Inorg. Chem.
1
999, 38, 2567.
39] (a)D. Rehder, J. Inorg. Biochem. 2000, 80, 133. (b)S. Macedo‐
Ribeiro, W. Hemrika, R. Renirie, R. Wever, A. Messerschmidt,
J. Biol. Inorg. Chem. 1999, 4, 209.
oxaloyldihydrazone Ligand. Appl Organometal
Chem. 2019;e4984. https://doi.org/10.1002/aoc.4984
[
40] A. Messerschimdt, L. Prade, R. Wever, Biol. Chem. 1997, 378,
3
09.