New organic extractant based on pyridazinone scaffold compounds: Liquid-liquid extraction study and DFT calculations

Article abstract of DOI:10.1016/j.molstruc.2019.04.033

In this work, the synthesis of new organic compounds is reported based on pyridazin-3-(2H)-one compounds. The extraction efficiency of metal ions (e.g. Lead Pb(II), Cadmium Cd(II), Copper Cu(II) and Zinc Zn(II)) from aqueous solutions to organic solutions

Full text of DOI:10.1016/j.molstruc.2019.04.033

Accepted Manuscript
New organic extractant based on pyridazinone scaffold compounds: liquid-Liquid
extraction study and DFT calculations.
Fouad El Kalai, Tarik Chelfi, Noureddine Benchat, Brahim Hacht, Mohamed
Bouklah, Abdelmalek Elaatiaoui, Said Daoui, Mustapha Allali, Taibi Ben Hadda, Faisal Almalki
PII:
S0022-2860(19)30428-4
10.1016/j.molstruc.2019.04.033
MOLSTR 26405
DOI:
Reference:
To appear in:
Journal of Molecular Structure
Received Date:
Accepted Date:
04 September 2018
06 April 2019
Please cite this article as: Fouad El Kalai, Tarik Chelfi, Noureddine Benchat, Brahim Hacht,
Mohamed Bouklah, Abdelmalek Elaatiaoui, Said Daoui, Mustapha Allali, Taibi Ben Hadda, Faisal
Almalki, New organic extractant based on pyridazinone scaffold compounds: liquid-Liquid
extraction study and DFT calculations., Journal of Molecular Structure (2019), doi: 10.1016/j.
molstruc.2019.04.033
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ACCEPTED MANUSCRIPT
New organic extractant based on pyridazinone scaffold compounds: liquid-
Liquid extraction study and DFT calculations.
Fouad El Kalai1, Tarik Chelfi1,*, Noureddine Benchat1, Brahim Hacht4, Mohamed Bouklah3,
Abdelmalek Elaatiaoui1, Said Daoui1, Mustapha Allali2, Taibi Ben Hadda1, 5, and Faisal
Almalki5
1
Laboratory of Applied Chemistry & Environment, Faculty of Sciences, University
Mohammed the first, MB 524, 60000, Oujda, Morocco.
Institute of Nursing Professions and Health Techniques Fez, EL Ghassani Hospital, Fez
2
30000, Morocco.
3 Laboratory of Applied Analytical Chemistry, Materials & Environment, Faculty of Sciences,
University Mohammed the first, MB 524, 60000, Oujda, Morocco
4 Department of Chemistry, Faculty of Sciences, University Mohammed the first, MB 524,
60000, Oujda, Morocco
5 Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Umm AlQura University,
Makkah, 21955, Saudi Arabia.
*Corresponding author- E-mail: tarikchelfi@gmail.com.
Abstract
In this work, the synthesis of new organic compounds is reported based on pyridazin-3-(2H)-one
compounds. The extraction efficiency of metal ions (e.g. Lead Pb(II), Cadmium Cd(II), Copper Cu(II)
and Zinc Zn(II)) from aqueous solutions to organic solutions of those compounds was studied.
Accordingly, the studied ligands show a remarkable affinity for the transition metals, especially Zn(II)
with (Ligand L5), Cu(II) and Cd(II) with (Ligand L3) in the presence of withdrawing and donor
electron group. Theoretical calculations DFT were made in order to get better insight into the
geometry of the studied ligands.
Keywords: Pyridazin-3-(2H)-one, Liquid-Liquid extraction, Heavy metal ions, DFT calculations.
Introduction
Pyridazin-3-(2h)-ones form a class of nitrogen heterocyclic compounds which have drawn
substantial attention. This significance was due to their interesting pharmacological and
medicinal properties such as anti-inflammatory [1], anticancer [2], antiviral [3], antimicrobial
[4], cardiovascular [5], anti-tubercular [6], anti-obesity [7] and anti-diabetic activity [8]. The
synthesis of novel pyridazinone derivatives and the evaluation of their chemical and
biological behaviour have gained much importance in recent decades for biological, medicinal
and agricultural reasons [9]. Besides, pyridazinones are known for their interesting physio-
chemical proprieties. In fact, many researchers’ works have proved that those compounds are
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good corrosion inhibitors [10,11] and that they can be used as organic extractant of some ion
metals from the aqueous phase [12].
One of the most used methods for complementary experimental studies is the exploration of
the relationships between the quantum proprieties of the organic molecules and their various
biological and physicochemical activities [13].
The Density Functional Theory (DFT) and the Time-Dependent DFT (TDDFT) are among the
most used methods in the study of structural properties, spectral properties and various
structures based on the molecular properties of organic molecules. For organic molecules, the
hybrid function B3LYP [14,15] remains the more frequently used method because it offers a
low cost of computation in comparison with the other Post Hartree-Fock methods and it
generally gives comparable results.
In this research, we have synthesised new pyridazinone ligands for which we have evaluated
their ability to act as coordinating sites for some bivalent metal cations through the liquid-
liquid extraction process.
Results and discussions
1- Chemistry:
The synthesis of the studied pyridazinones started by the condensation of the corresponding
aldehyde 1a-c with Levulinic acid. This step leads to the formation of the corresponding
Oxopentanoic acid, which forms pyridazin-3-(2H)-ones L1-3 by the action of Hydrazine
hydrate. Pyridazinones L4-L6 are formed by an N-condensation of pyridazinones L1-L3 in the
presence of 2-Bromoacetophenone (Scheme 1).
Scheme 1: synthetic scheme and chemical structures of studied ligands L1-L6
The resulting spectroscopic data of the three new ligands L1-L6 confirms the proposed
structure of those ligands. Thus, the IR spectra show characteristic absorption bands at 1680-
1
1700 cm-1 assigned for the aromatic ketone carbonyl Ph-C=O. Also, the H NMR spectral
results show characteristic singlets at H 5,48-5,57 ppm assigned to the CH2 of the
acetophenone group in the absence of the singlet at H 11,8-12 ppm assigned to the NH of the
pyridazinic ring. This confirms the condensation process between pyridazinone L1-3 and 2-
Bromoacetophenone.
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2- Individual extraction of metal ions with the ligands L1-L6:
To evaluate the extraction efficiency of these ligands against some metal, we proceeded by
liquid-liquid extraction of those metal ions from aqueous media using L1-L6 as organic
extracting agents. The obtained results are shown in Table 1.
Table 1: Extraction efficiencies of metal cations using L1-L6 ligands.
The structural differences between L1-L6 mainly affect the para position of the phenyl group
and the N2 position of the pyridazinic ring in the case of L4-L6. Thus, we will discuss the
obtained results according to the position where the modification took place in order to study
the relationship between the extraction efficiency of metals and structural modification.
Para phenyl Modification:
As illustrated in figure 1, it is very clear that the extraction efficiency of the transition metals
increases as a function of the substituent the two series of ligands (L1-L3) and (L4-L6) in the
para position. In fact, the percentage of the extraction increases considerably for Cd(II),
Cu(II) and Zn(II) by passing from methyl to chlorine and to fluorine. In addition, the highest
percentage of extraction is recorded for ligands L3 and L6 for all the metals except for Zn (II)
which was the most extracted by L5.
Figure 1: variation of the Extraction efficiency of metals by Ligands L1-L6.
To explain these results, we must take into account the nature of the paragroup of phenyl and
the factors influencing the formation and stability of the metal complex. Indeed, L3 and L6
have in their structures a fluorine atom in the para position of phenyl, which is very
electronegative against other methylated and chlorinated ligands. This will, thus, have a direct
impact on the chelating power of the ligands L3 and L6 by the participation of the fluorine
atom in the chelation cycle with the oxygen of the pyridazinic ring.
As for lead, the structural modification does not improve its extraction efficiency while it is
comparable between all ligands.
N2 Pyridazinic Ring Modification:
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Figure 2: comparison of the extraction efficiency of metals between Ligands (L1-L3) and (L4-
L6).
Products L4-L6 were obtained by grafting an acetophenone group at the N2 of the pyridazinic
ring of the L1-L3 compounds. Thus, the comparison of the extraction efficiency of metals by
ligands L1-L6 (Fig.2) reveals the following:
 In the case of Zn(II) and Cd(II), grafting the acetophenone group increases the
extractability of Zn(II) (from 31.2% (L2) to 67.5% (L5)) and of Cd (II) (from 6.6%
(L2) to 51.6% (L5)) (Fig. 2b).
 In the case of Pb(II) and Cu(II), grafting the acetophenone group decreases the
extractability of Pb(II) and Cu(II) (from 34% (L1) to 6.6% (L4)) (Fig. 2a).
 The acetophenone group decreases the extraction efficiency of metals by ligand L1
with the exception of Zn (II) which increases from 5.2% to 20.9% (Fig. 2a).
 As for ligand L2, grafting the acetophenone group improves the ability of this
molecule to extract metals especially for Cd(II) and Zn(II). The extractability of these
two methods increases successively from 6.6% to 51.6% and from 31.2% to 67.5%
(Fig. 2b).
 The appearance of the graph relating to ligand L3 seems to be the same as that of
ligand L6. So, this structural modification does not bring any improvement in the
extracting power of this ligand (Fig. 2c).
According to the results obtained by these ligands, it is very clear that some compounds tend
to coordinate with transition metal especially Zn(II) except for Pb(II) which shows low
affinity with those compounds. This is mainly due to the structural differences between these
ligands particularly in the para position of the phenyl and in the N2 position of the pyridazinic
group. Each substituent group has a specific effect on the coordination site in a way that may
increase or decrease the coordination capacity of the ligands.
3- DFT calculations:
To investigate the structure geometries, we performed full geometry optimization for the
studied compounds L1-L6 in the gas phase using DFT/B3LYP level calculations. The
optimized structures are shown in Fig.3.
Figure 3: Optimized structures of ligands L1-L6 obtained by DFT/ B3LYP/6-31G(d,p).
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As illustrated in Fig. 3, the optimized structures of L1-L3 are non-planar. The angle which was
formed between the two rings (whose vertex is the carbon C6) is 116° and the planes of both
rings are perpendicular with an angle of 90°.
As for ligands L4-L6, we note the following:
 The angle C9-C4-C6 is 116° and N40-C23-C26 (N44-C27-C30 in the case of L4) is 112°.
 The angle between the plane formed by atoms C11-C9-C6 and the plane formed by
atoms C6-C4-C1 is 90°.
 The angle between the plane formed by atoms C2-C40-C23 and the plane formed by
atoms C40-C23-C26 is 90°. (C2-C44-C27 and C44-C27-C30 in the case of L4) is 87°.
In addition, to the geometry optimization, the analysis of the frontier molecular orbitals is a
crucial way to obtain information on the reactivity of molecules and to study electron
excitation from the highest occupied molecular orbital (HOMO) to the lowest unoccupied
molecular orbital (LUMO).
The ability of the molecule to capture an electron can be evaluated by the LUMO, while the
HOMO represents the ability to donate an electron. The difference between the energy values
of the HOMO (EH) and the LUMO (EL) orbitals is termed the HOMO–LUMO energy gap
(ΔE) which explains the eventual charge transfer interaction taking place within the molecule.
Having access to the energy gap (ΔE) will help us to define the kinetic as well as the chemical
reactivity of our molecules. In fact, molecules with small energy gap are generally associated
with a high chemical reactivity and low kinetic stability and they are considered as soft
molecules. Whereas those molecules with large energy gap have higher stability and are
termed as hard molecules. This is because they oppose charge transfer and the changes in
their electron density and distribution [16,17].
In addition, some other proprieties can be used to describe more of our molecules and they are
directly related to the HOMO and LUMO energies such as the ionization potential IP (IP = -
EH) and the electron affinity EA (EA = -EL) [18]. Using these proprieties, we can calculate the
following: [19–23]
 Global hardness (η) (and it’s inverse  global softness [24]), is a qualitative
indication of how polarisable is a molecule and it is given by the formula:
IP ― EA
η =
2
 Electronegativity (χ), is the tendency of a molecule to attract electrons and it is given
by the formula:
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IP + EA
χ =
2
 Chemical potential (µ) denotes the affinity of an electron to flee and it is defined as
the first derivative of the total energy with respect to the number of electrons in a
molecule [25]. The chemical potential is simply the negative of electronegativity
value:
µ = -χ
 Electrophilicity index (ω) is the capability of a substance to accept electrons and it
was proposed as a measure for the electrophilic power of a molecule. It is given by the
formula:
μ2
ω =
2η
The calculated proprieties are listed in Table 2. Those results show a marked difference in
EH, EL, and ΔE. The presence of chloride group in the phenyl ring (L2 and L5) reduces the
value of EH, conversely, to L1 and L4 which they contain a methyl group, L3, and L6 with a
fluoride group.
Table 2: Quantum chemical parameters for L1-L6 obtained by using B3LYP/6-31G(d,p).
In addition, grafting the acetophenone group in the N2 position seems to have a
remarkable effect on the reactivity and stability of the studied ligands. In fact, the comparison
of energy gap between L1 and L4, L2, and L5, and between L3 and L6 show that the
acetophenone group increases the chemical reactivity and decreases the stability of those
ligands as long as the energy gap of L1, L2 and L3 decreases when grafting the acetophenone
group (L4, L5 and L6).
In Figure 4, we presented the MOs frontiers shapes of the studied ligands. In all
molecules, the occupied and unoccupied molecular orbitals are localized on the pyridazinic
ring with the exception of L4 and L5 which are respectively located on the acetophenone
group (in the case of LUMO L4) and on the phenyl ring (in the case of HOMO L5). These
results suggest that the transition involves charge transfer from the pyridazinic ring to the
acetophenone group in the case of L4 and from the phenyl group to the pyridazinic ring in the
case of L5.
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Figure 4: Shapes of MOs frontiers of L1-L6 obtained by DFT (B3LYP/6-31G(d,p)) method.
4- POM Analyses of Physico-Chemical Properties of L1-L6
For series of compounds L4-L6, depending on the pH and position of the dissociate
methylene hydrogen atom, various possible conformations and tautomers can be described for
the neutral, deprotonated, and protonated forms. These relevant structures are sketched in
Figures 5 & 6.
Figure 5. Tautomerism/isomerism of compounds L4-L6.
In the past, attention was mainly devoted to the Tautomer-A. However, from a chemical
point of view, all other structures are possible.
For the development of binding approaches for L4-L6 in the metal extraction, the
identification of the active bidentate site of coordination of dicationic atom present is
important. Neither experimental nor theoretical data is available for the identification of
water-solved L4-L6 species. Theoretically, NMR spectroscopy could be useful for identifying
chemical structures. Theoretical speciation studies of compound L4-L6 as an example could
supplement these measurements (Fig. 6).
Figure 6. Impact of pH on microspecies distribution of compounds L4-L6.
In brief, the objective of this study is to investigate the potential coordination sites of L4-
L6 species using experimental adsorption method with taking into consideration dependence
on pH and comparison with the calculated molecular properties. To verify these structures,
further, Petra/Osiris/Molinspiration (POM) analyses were carried out for example calculation
of net atomic charges, bond polarity, atomic valence, electron delocalization, and
lipophilicity.
Finally, to investigate the coordinative site of the L4-L6 species, the tautomeric structure was
performed. L4-L6 were found to be charged negatively at pH values between 7.2 and 12
(specience 3) as indicated in Figure 6.
So we can provide a hypothetic structure of the resulting complexes. Compounds L4-
L6 were able to play a crucial role in the coordination of transition metals because they present
a bidentate stable site (O, N), more than (O, O) site, (Fig.7).
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Figure 7. Hypothetic structure of the resulting complexes.
Experimental section
1- Materials
Unless otherwise stated, all reagents were purchased from commercial suppliers and were
used as received without further purification. Solvents were used with a technical purity for
reactions, or, when mentioned purified by standard literature methods prior to use.
2- Physical measurements
Melting points were measured using a Buchi-Tottoli apparatus and are uncorrected. Atomic
absorption measurements were performed using a double beam Varian AA 20
Spectrophotometer. 1H NMR and 13C NMR spectra were recorded in CDCl3 or DMSO using a
Bruker AC 300 MHz (1H) or 75 MHz (13C) spectrometer. Chemical shifts are reported as
parts per million (ppm) using Tetramethylsilane (TMS) as an internal standard. Infrared (IR)
spectra were recorded on a Perkin-Elmer Fourier Transformer FT Pargamon 1000 PC
Spectrophotometer using potassium bromide disks (KBr).
3- Theoretical calculations
The theoretical part of this work is based on the DFT method. For that, we used the
GAUSSIAN 09 software package with the aid of the Gauss View visualization program
[26,27].
The geometrical structure of the pyridazinone compounds L1-L6 has been optimized at the
electronic ground state (S0) using the hybrid functional Becke three parameters B3 with the
nonlocal correlation of Lee-Yang-Parr LYP (called B3LYP method) combined with the 6-
31G (d,p) basis set [15,28]. No symmetry constraints were imposed during the optimization
process. It is noted that the use of this method as well as this basis set appears to be an
adequate approach for the study of physicochemical properties of these compounds and most
organic compounds [29–32].
Then, the excited state properties of the optimized ground state geometries were
calculated in both the gas phase and with dichloromethane solvent (DCM) by using the time-
dependent density functional formalism (TD-DFT) and the pople 6-31G (d,p) basis set.
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Solvent effects were included by employing the Polarizable Continuum Model (PCM) as
implemented in Gaussian09 [33].
4- Liquid-Liquid Extraction
Preparation of the organic solution 7.10-5 M
The organic solution was prepared by dissolving an amount mi of the pyridazinic compounds
(L1-L6) in 200 mL of dichloromethane. Table1 shows the used amounts for the preparation of
the organic solution 7.10-5M.
Table 3: Required masses for the preparation of organic solutions 7.10-5
Liquid-liquid extraction procedure
The organic solution is brought into contact with aqueous solution containing the heavy metal
ions at a concentration of 7.10-5M. Magnetic stirring for 2 hours ensures the contact between
the two immiscible phases. This time is considered largely sufficient to reach the equilibrium
during which the pH of the mixture is maintained neutral and the temperature at room
temperature 25 °C [34–36]. Once the equilibrium is achieved, the two phases are separated by
decantation and the aqueous phase is collected and analysed using atomic absorption
spectrophotometer Varian A20. The percentage of extraction is calculated by the sentence:
[C(M)f ― C(M)i]
%E =
C(M)i
With:
 C(M)i: the initial concertation of the metallic solution
 C(M)f :the concentration of the metallic solution after extraction
5- Synthesis
Compounds 2a-2c and (L1-L3) were synthesised following the reported procedure [37–39].
The analytical data of the obtained product matches that reported in the literature
General procedure for the synthesis of ligands L4-L6:
A suspension of pyridazin-3-(2H)-one (L1-L3) (9 mmol), potassium carbonate (18 mmol) in
20 ml of tetrahydrofuran (THF) was refluxed for 1 hour in the presence of 10% of tert-
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butylammonium bromide (TBAB). After cooling the reaction mixture, a slight excess of
bromoacetophenone is added and the reaction mixture is refluxed for six hours and is
monitored by TLC until the pyridazine-3-(2H)-one (L1-L3) disappears. After filtration and
evaporation of the solvent under reduced pressure, the residue is purified by chromatography
on a silica column, (Eluent: acetate / hexane: 3/7) the products (L4-L6) are obtained.
6-Methyl-5-(4-methylbenzyl)-2-(2-oxo-2-phenylethyl)pyridazin-3(2H)-one (L4)
Yield: 65%. MP: 146–148°C. IR (KBr, cm−1): 1650 (N-C=O), 1680 (Ph-C=O). 1H NMR (300
MHz, CDCl3 ; TMS) δ (ppm) : 2.28 (s, 3H, CH3); 2.37 (s, 3H, CH3); 3.79 (s, 2H, CH2), 5.57
13
(s, 2H, CH2); 6.58 (s, 1H, CH); 7.10-8.10 (m, 9H, Ar-H). C NMR (CDCl3) δ (ppm): 19.29
(CH3); 21.20 (CH3); 38.34 (CH2); 57.62 (CH2-C=O); 77.71; 128.61; 128.92; 129.02; 129.61;
129.86; 129.92; 130.50; 133.37; 134.67; 135.74; 137.75; 146.29; 147.52; 161.68 (Ph-C=O),
193.22 (N-C=O). MS: [M + H]+: 333.9 m/z.
6-Chloro-5-(4-methylbenzyl)-2-(2-oxo-2-phenylethyl)pyridazin-3(2H)-one (L5)
Yield: 62%. MP: 140–142°C. IR (KBr, cm−1): 1610 (N-C=O), 1700 (Ph-C=O). 1H NMR (300
MHz, CDCl3 ; TMS) δ (ppm) : 2.17 (s, 3H, CH3); 3.71 (s, 2H, CH2); 5.48 (s, 2H, CH2); 6.46
(s, 1H, CH); 7.04-7.91 (m, 9H, Ar-H). 13C NMR (CDCl3) δ (ppm): 19.29 (CH3); 38.06 (CH2);
57.66 (CH2-C=O); 77.51 (CDCl3); 128.60; 128.92; 129.18; 129.35; 129.53; 129.64; 130.03;
131.31; 134.08; 134.73; 134.99; 135.68; 145.94; 146.66; 161.49 (Ph-C=O); 193.12 (N-C=O).
MS: [M + H]+: 354 m/z.
6-Fluoro-5-(4-methylbenzyl)-2-(2-oxo-2-phenylethyl)pyridazin-3(2H)-one (L6)
Yield: 71%. MP: 152–154°C. IR (KBr, cm−1): 1610 (N-C=O), 1700 (Ph-C=O). 1H NMR (300
MHz, CDCl3; TMS) δ (ppm): 2.18 (s, 3H, CH3); 3.71 (s, 2H, CH2); 5.48 (s, 2H, CH2), 6.46 (s,
13
2H, CH2); 6.96-7.94 (m, 9H, Ar-H). C NMR (CDCl3) δ (ppm) : 19.28 (CH3); 37.91 (CH2);
57.65 (CH2-C=O); 77.50 (CDCl3); 128.63; 128.92; 129.63; 131.50; 132.17; 134.72; 135.69;
145.99; 147.03; 161.55; 161.78; 164.25 (Ph-C=O), 193.15 (N-C=O). MS: [M + H]+: 337.8
m/z.
Conclusion
Pyridazin-3(2H)-ones derivatives possess many interesting physiochemical and biological
activities. However, a few studies have described their ability to extract metals from aqueous
solutions. The present study revealed that the studied ligands exhibit promising coordinating
properties and that they were found to be effective for the liquid-liquid extraction of metal
such as Zn (II), Cd(II) and Cu(II). These results have conclusively shown that the nature of
the substituents on the para-position of the phenyl influences the formation of coordination
complexes with those metal cations. The present work has also investigated the ground and
excited state geometries using DFT from which we conclude that grafting the acetophenone
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group in the N2 position increases the chemical reactivity and decreases the stability of those
ligands.
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a
b
Figure 1: variation of the Extraction efficiency of metals by Ligands L1-L6.

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a
b
c
Figure 2: comparison of the extraction efficiency of metals between Ligands (L1-L3) and (L4-
L6).

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Figure 3: Optimized structures of ligands L1-L6 obtained by DFT/ B3LYP/6-31G(d,p).

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Ligand
L1
HOMO
LUMO
L2
L3
L4
L5
L6
Figure 4: Shapes of MOs frontiers of L1-L6 obtained by DFT (B3LYP/6-31G(d,p)) method.

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Figure 5. Tautomerism/isomerism of compounds L4-L6.

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Figure 6. Impact of pH on microspecies distribution of compounds L4-L6.

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Figure 7. Hypothetic structure of the resulting complexes.

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Scheme 1: synthetic scheme and chemical structures of studied ligands L1-L6

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Highlights
 Synthesis of new organic ligand based on pyridazin-3-(2H)-one compounds.
 Liquid-liquid extraction of metal ions from aqueous solution using new organic ligands.
 Selectivity for transition metal ions specially Cu(II), Cd(II) and Zn(II).
 Theoretical study of pyridazinones using DFT.

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Table 1: Extraction efficiencies of metal cations using L1-L6 ligands.
Extractability (%E)
Ligands
L1
Cd(II)
01.0
06.6
60.3
02.1
51.6
57.6
Cu(II)
34.0
27.7
61.5
06.6
31.2
44.0
Pb(II)
12.6
16.6
3.1
02.5
12.6
13.0
Zn(II)
05.2
31.2
57.3
20.9
67.5
56.8
L2
L3
L4
L5
L6

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Table 2: Quantum chemical parameters for L1-L6 obtained by using B3LYP/6-31G(d,p).
Frontier MO Energies (eV)
Global reactivity descriptors (eV)
EA
Ligand
EH
EL
ΔE
IP
η
σ
χ
μ

L1
L2
L3
L4
L5
L6
-6,038
-6,528
-5,973
-5,560
-6,758
-6,454
-1,019
-1,645
-1,075
-2,583
-2,024
-1,645
5,019
4,883
4,899
2,977
4,734
4,809
6,038 1,019 2,509 0,398 3,528 -3,528 2,480
6,528 1,645 2,441 0,410 4,087 -4,087 3,420
5,973 1,075 2,449 0,408 3,524 -3,524 2,535
5,560 2,583 1,488 0,672 4,071 -4,071 5,568
6,758 2,024 2,367 0,423 4,391 -4,391 4,073
6,454 1,645 2,405 0,416 4,049 -4,049 3,410

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Table 3: Required masses for the preparation of organic solutions 7.10-5
Compound m(mg) M(g.mol-1) VCH2Cl2(mL)
L1
L2
L3
L4
L5
L6
3,00
3,29
3,06
4,65
4,94
4,71
214,26
234,68
218,23
332,4
200
200
200
200
200
200
352,81
336,36