Crystal structure, vibrational, spectral investigation, quantum chemical DFT calculations and thermal behavior of Diethyl [hydroxy (phenyl) methyl] phosphonate

Article abstract of DOI:10.1016/j.molstruc.2017.05.029

Single Diethyl [hydroxy (phenyl) methyl] phosphonate (DHPMP) crystal with chemical formula C₁₁H₁₇O₄P, was synthesized via the base-catalyzed Pudovik reaction and Lewis acid as catalyst. The results of SXRD analyzes indicate that this compound crystallizes into a mono-clinic system with space group P2₁/n symmetry and Z = 4. The crystal structure parameters are a = 9.293 ?, b = 8.103 ?, c = 17.542 ?, β = 95.329° and V = 1315.2 ?³, the structure displays one inter-molecular O—H?O hydrogen bonding. The UV–Visible absorption spectrum shows that the crystal exhibits a good optical transmission in the visible domain, and strong absorption in middle ultraviolet one. The vibrational frequencies of various functional groups present in DHPMP crystal have been deduced from FT-IR and FT-Raman spectra and then compared with theoretical values performed with DFT (B3LYP) method using 6-31G (p, d) basis sets. Chemical and thermodynamic parameters such as: ionization potential (I), electron affinity (A), hardness (σ), softness (η), electronegativity (χ) and electrophilicity index (ω), are also calculated using the same theoretical method. The thermal decomposition behavior of DHPMP, studied by using thermogravimetric analysis (TDG), shows a thermal stability until to 125 °C.

Full text of DOI:10.1016/j.molstruc.2017.05.029

Accepted Manuscript
Crystal structure, vibrational, spectral investigation, quantum chemical DFT
calculations and thermal behavior of Diethyl [hydroxy (phenyl) methyl] phosphonate
Louiza Ouksel, Salah Chafaa, Riadh Bourzami, Noudjoud Hamdouni, Miloud Sebais,
Nadjib Chafai
PII:
S0022-2860(17)30612-9
10.1016/j.molstruc.2017.05.029
MOLSTR 23770
DOI:
Reference:
To appear in: Journal of Molecular Structure
Please cite this article as: Louiza Ouksel, Salah Chafaa, Riadh Bourzami, Noudjoud Hamdouni,
Miloud Sebais, Nadjib Chafai, Crystal structure, vibrational, spectral investigation, quantum chemical
DFT calculations and thermal behavior of Diethyl (hydroxy (phenyl) methyl) phosphonate, Journal of
Molecular Structure (2017), doi: 10.1016/j.molstruc.2017.05.029
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to
our customers we are providing this early version of the manuscript. The manuscript will undergo
copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please
note that during the production process errors may be discovered which could affect the content, and all
legal disclaimers that apply to the journal pertain.

ACCEPTED MANUSCRIPT
O
H
O
OC2H
OH
5
P
P(OCH )
CoCl .6H O C H O
2 2
2 5
2
5 3
+
RT

ACCEPTED MANUSCRIPT
High lights
•
DHPMP was synthesized following Pudovik rearrangement, and Lewis acid as
catalyst.
•
•
•
•
Single crystal was grown by slow evaporation of solvent.
SXRD result agrees with DFT calculation on the structure of DHPMP.
Spectral studies using FT-IR, Raman spectroscopy and DFT calculation was carry out.
TGA stable up to 125 °C, and the first TDA peak was observed at 159 °c.

ACCEPTED MANUSCRIPT
Crystal structure, vibrational, spectral investigation, quantum chemical
DFT calculations and thermal behavior of Diethyl [hydroxy (phenyl)
methyl] phosphonate
a
a
a
b
Louiza Ouksel , Salah Chafaa , Riadh Bourzami , Noudjoud Hamdouni ,
b
a
Miloud Sebais , Nadjib Chafai
a
Laboratoire d’Electrochimie des Matériaux Moléculaires et des Complexes (LEMMC), Département
de génie des procédés, Faculté de Technologie Université Ferhat Abbas, Sétif-1,19000, Algeria
b
Laboratoire de Crystallographie, Département de Physique, Faculté des Sciences Exactes, Université
des Frères Mentouri Constantine-1, 25000, Algeria
ABSTRACT
Single Diethyl [hydroxy (phenyl) methyl] phosphonate (DHPMP) crystal with
chemical formula C11
17 4
H O P, was synthesized via the base-catalyzed Pudovik reaction and
Lewis acid as catalyst. The results of SXRD analyzes indicate that this compound crystallizes
into a mono-clinic system with space group P2
1
/n symmetry and Z = 4. The crystal structure
3
parameters are a = 9.293 Å, b = 8.103 Å, c = 17.542 Å, β = 95.329° and V = 1315.2 Å , the
structure displays one inter-molecular O—H···O hydrogen bonding. The UV-Visible
absorption spectrum shows that the crystal exhibits a good optical transmission in the visible
domain, and strong absorption in middle ultraviolet one. The vibrational frequencies of
various functional groups present in DHPMP crystal have been deduced from FT-IR and FT-
Raman spectra and then compared with theoretical values performed with DFT (B3LYP)
method using 6-31G (p, d) basis sets. Chemical and thermodynamic parameters such as:
ionization potential (I), electron affinity (A), hardness (σ), softness (η), electronegativity (χ)
and electrophilicity index (ω), are also calculated using the same theoretical method. The
thermal decomposition behavior of DHPMP, studied by using thermo gravimetric analysis
(TDG), shows a thermal stability until to 125°C.
Key Words: Diethyl [hydroxy (phenyl) methyl] phosphonate, crystal structure, FT-IR, FT-
Raman, DFT calculation.

ACCEPTED MANUSCRIPT
1. Introduction
Organophosphorus compounds containing carbon-phosphorus (C-P) bonds have been
attracting significant attention, ever since the first discovery in natural products in 1959 [1, 2].
This compound family has found various applications in the pharmacology and agrochemical
fields, medicinal chemistry [3-7] and biological activities as enzyme inhibitors [8], owing to
their chemical stability and their noteworthy physicochemical properties [9-11]. At the
present time, organophosphorus compounds include many subclasses such as phosphonates,
α-aminophosphonates and α-hydroxyphosphonates. The last subclass compounds are used as
precursors for a significant variety of phosphonates derivatives [12, 13]. The α-
hydroxyphosphonates can be synthesized according to several approaches. The most used
approach is based on the reaction of aldehyde or ketone with dialkyl phosphite in the presence
of acidic or basic catalysts, via the base-catalyzed Pudovik reaction [14]. These compounds
are also synthesized via Michaelis-Arbuzov rearrangement reaction (transformation from
trivalent to pentavalent phosphorus), in the presence of different catalysts [8, 15-17]. Few
synthesis routes of α-hydroxyphosphonates have been developed using Lewis acids as catalyst
[
18]. In this work, synthesis of Diethyl hydroxy (phenyl) methyl phosphonate (DHPMP) was
reported using cobalt (II) chloride as Lewis acid catalyst. Cobalt (II) chloride is the adequate
catalyst due to its extensive use in numerous reactions [19-23], its large availability and low
price, it can also easily be removed from the reaction mixture [8].
Single crystal X-Ray Diffraction (SXRD) and quantum chemical calculation, were
used in order to confirm the structure of DHPMP. The spectral study using FT-IR, FT-Raman
and UV-visible analyses were also conducted in order to confirm whether a certain correlation
exists between molecular structure and vibrational frequencies of DHPMP.
Thermogravimetric analysis of DHPMP was also performed.
2. Experimental procedures
2.1. Synthesis
The Diethyl [hydroxy (phenyl) methyl] phosphonate (DHPMP) compound was
synthesized by chemical reaction at room temperature of benzaldehyde (1 mmol, purity 99 %,
Sigma Aldrich), triethyl phosphite (1 mmol, purity 99 %, Sigma Aldrich) and CoCl .6H
1mmol, purity 98 %, Sigma Aldrich) as a catalyst, under nitrogen reflux. A blue color
2
2
O
(
appeared after 1 h time. The progress of the reaction was followed by thin layer
chromatography TLC on silica gel (ethyl acetate/n-hexane 1:4); a single spot was observed
after 16 h. For purification, chloroform (10 ml) was added to the reaction mixture and then

ACCEPTED MANUSCRIPT
filtered to separate the catalyst, and then evaporated under vacuum to eliminate chloroform.
To be sure that all catalyst present was removed, the obtained product was separated in
funnel, adding distilled water (2x100 ml) and dichloromethane (2x50 ml).The organic phase
2 4
was dried with Na SO . The reaction scheme is shown in Fig.1.
1
Anal. H NMR for DHPMP Aromatic-H: 7.49-7.36 (m, 5H), OCH
CH : 1.27 (m, 6H), CH : 4.87 (s, 2H).
2
: 4.06 (m, 4H)
3
2
OC H
2
5
O
O
H
P
OH
C H O
2
5
CoCl .6H O
P(OC H )
2
2
2
5 3
+
RT
Fig.1. Reaction scheme for synthesis of DHPMP.
The synthesized compound was dissolved in n-hexane till the boiling point and then
allowed to crystallize by solvent evaporation for three weeks [24], the photograph of the
grown crystal is shown in Fig.2.
Fig.2. Photograph of DHPMP.
2.2. Single crystal X-ray Diffraction (SXRD)
Patterns SXRD were performed at room temperature, using Bruker X caliber
diffractometer, equipped with MoKα anticathod and a graphite monochromator (λ=0.7107 Å).
The refinement was performed by the full-matrix least square method using the Crystal
program [25]. Anisotropic thermal factors were determined for all non-hydrogen atoms. Unit

ACCEPTED MANUSCRIPT
cell refinement using all observed reflections and data reduction was performed using
CrysAlis Red program. The structure was visualized by the Mercury software.
2.3. UV-Visible spectroscopy
After solubilizing DHPMP in ethyl acetate, UV-Visible spectrum was recorded with
transmission mode at room temperature, in the range 200-800 nm, using a JASCO V680
spectrometer.
2
6
2
1
.4. FT-IR spectroscopy
Spectra were recorded using a FT-IR 4200 JASCO spectrometer, in the range 4000-
-1
00cm , at room temperature.
.5. Raman spectroscopy
Spectral measurements were made with a ꢀ-Raman Bruker Senterra, equipped with a
00 mW laser source operated at λ=785 nm, and aperture setting about 20x1000 ꢀm, the
-1
spectrum was situated in the range 3500 to 50 cm .
1
2
.6. Nuclear magnetic resonance H NMR
6
Spectra were recorded at room temperature, on solution (solvent: DMSO-d ), on a
Bruker AV III 300 MHz spectrometer.
2.7. Thermal behavior analysis ATG-ATD
The thermogravimetric and differential thermal analysis were carried out using a
Perkin Elmer TGA 4000 setup. The results were collected in the range of heating 5-600 °C,
with a 5 °C/min speed, under a nitrogen atmosphere.
2.8. Quantum chemical calculations
The full geometry optimization was performed by means of the Gaussian 09W
program, based on density functional theory (DFT) [26], using Beck’s three parameters
hybrid functional exchange [27], with 6-31G (d. p) basis sets, and Lee-yang-Parr correlation
functional (B3LYP) [28,29].
3. Results and discussion

ACCEPTED MANUSCRIPT
3
.1. SXRD analysis
Data collected by SXRD indicate that DHPMP crystal crystallizes in mono-clinic
system with space group P2 /n and Z = 4. The crystal structure parameters are a = 9.293(5) Ǻ,
1
b= 8.103(5) Ǻ, c= 17.542(5) Ǻ, β = 95.329(5) °.The detailed fractional atomic coordinates
and equivalent isotropic displacement parameters were deposited in CCDC with the reference
number 1488904.
The DHPMP crystalline structure has been given by Li-Tao An and al. [30]. The present
work extended furthermore the study by refining and detailing crystalline structure, where
results were completed with DFT quantum chemical calculation. The experimental crystal
data and structure refinement details are given in Table1.
Table 1
Crystallographic data and structure refinement parameters.
Empirical formula
Crystal system
Space group
a (Å)
b (Å)
c (Å)
11 17 4
C H 0 P
Monoclinic
P2 /n
1
9.293 (5)
8.103 (5)
17.542 (5)
95.329 (5)
293
β (°)
Temperature (K)
3
V (Å )
1315.2 (4)
4
Z
molecular weight (g/mol)
244.23
λMoKα (Å)
0.71073
1.23
0.21
3
Dcalc (mg /m )
-
1
µ (mm )
F(000)
520
3
Crystal size (mm )
Crystal colour/habit
θ Range (°)
6 x 2 x 1
White/Parallelepiped
3.342-32.352
hkl ranges
h
k
l
-13→7
-12→9
-25→26
Measured reflections
Independent reflections
Observed reflections
Rint
8818
4164
1634
0.035
0.753
88.6%
0.8961
0.079
1256
−
1
(sinθ/λ)max (Å )
Completeness to 2θ = 26.20
2
Goodness-of-fit on F
R[F >2σ(F )]
2
2
No. of reflections
No. of parameters
146
0.28, -0.28
-3
ꢁρ
max, ꢁρmin (e Å )

ACCEPTED MANUSCRIPT
The asymmetric unit of DHPMP contains one formal molecule with the chemical formula
11 17 4
C H O P (Fig.3).
Fig. 3. Asymmetric unit.
The presence of C(6)-P(1) and C(6)-OH bonds confirms the formation of a hydroxy-
phosphonate compound. The distances between the two carbons C(11)-C(16) and C(10)-
C(15) are 1.260(1) Å and 1.407(9) Å respectively. These differences between the two values
cause a deformation of the two ethyl groups of DHPMP. Benzene ring is distorted compared
to ideal hexagonal shape so that the internal angles are (120.2 (7) °, 120.2 (6) °, 121.1 (5) °,
1
19.8 (7) °, 119.7(5) °, 119.1 (4) °).This difference is attributed to the lone pair electron steric
effect, which is in good agreement with the theory of valence-shell electron pair repulsion
VSEPR) [31].
(
Fig.4. Packing of the molecules in elementary unit cell.
The unit cell structure of DHPMP is shown in Fig.4, where the mono-clinic unit cell is
centro-symmetric containing four molecules Z = 4. Table2 lists the experimental geometrical

ACCEPTED MANUSCRIPT
parameters (length bonds and angle measurements) in comparison with quantum calculated
values.
Table 2
Calculated and experimental geometrical parameters (Å, °) of DHPMP.
Bond
Exp.
Calc.
Bond
Exp.
Calc.
P(1)-O(5)
P(1)-O(2)
P(1)-O(3)
P(1)-C(6)
O(2)-C(10)
1.464(3) 1.487(2) C(16)-H(33) 0.960(4)
1.093(7)
1.415(7)
1.515(5)
1.102(4)
0.968(1)
1.093(4)
1.516(7)
1.401(6)
1.396(2)
1.083(5)
1.395(5)
1.086(4)
1.396(5)
1.086(2)
1.394(2)
1.086(1)
1.093(4)
1.094(7)
1.571(3) 1.618(4) C(6)-O(4)
1.577(4) 1.623(6) C(7)-C(6)
1.819(4) 1.855(2) C(6)-H(17)
1.398(6) 1.450(5) O(4)-H(24)
1.425(5)
1.520(6)
1.008(4)
0.822(3)
C(11)-C(16) 1.407(9) 1.515(2) C(16)-H(33) 0.960(4)
C(11)-H(23) 0.982(8) 1.098(6) C(10)-C(15) 1.370(7)
C(10)-H(22) 0.970(7) 1.094(8) C(7)-C(9)
C(15)-H(30) 0.970(6) 1.093(7) C(12)-C(8)
1.384(7)
1.400(1)
0.944(3)
O(3)-C(11)
1.440(9) 1.451(4) C(8)-H(18)
C(11)-C(16) 1.260(1) 1.515(8) C(12)-C(14) 1.370(1)
C(11)-H(22) 0.970(8) 1.095(5) C(12)-H(25) 0.935(6)
C(11)-H(23) 0.954(7) 1.094(8) C(14)-C(13) 1.360(1)
C(16)-H(31) 0.961(6) 1.094(5) C(14)-H(27) 0.949(6)
C(16)-H(32) 0.920(5) 1.093(4) C(9)-C(13)
C(9)-H(19) 0.940(7) 1.086(2) C(13)-H(26) 0.938(8)
C(10)-C(15) 1.407(9) 1.516(1) C(4)-H(41) 0.982(8)
C(15)-H(29) 0.953(6) 1.093(2) C(15)-H(28) 0.965(5)
1.381(9)
C(7)-C(8)
1.399(8)
Angles
Exp.
Calc.
Angles
Exp.
Calc.
O(5)- P(1)-O(2)
O(5)- P(1)- O(3)
O(5)- P(1)- C(6)
O(2)- P(1)-O(3)
O(2)-P(1)-C(6)
115.8(2) 115.1(6) P(1)-O(3)-C(11)
114.4(2) 11 3.9(7) O(3)-C(11)-C(16)
114.9(2) 114.9(6) O(3)-C(11)-H(22)
102.1(2) 102.6(1) O(3)-C(11)-H(23)
101.6(2) 103.8(7) C(16)-C(11)-H(23)
106.9(2) 106.7(8) C(16)-C(11)-H(22)
122.6(3) 121.3(3) H(23)-C(11)-H(22)
105.8(5) 108.6(2) C(11)-C(16)-H(31)
108.0(3) 109.7(1) C(11)-C(16)-H(32)
109.3(4) 108.8(6) C(11)-C(16)-H(33)
108.9(6) 109.1(9) H(31)-C(16)-H(32)
109.0(5) 109.4(6) H(31)-C(16)-H(33)
108.6(3) 109.8(6) H(32)-C(16)-H(33)
108.3(4) 109.6(3) P(1)-C(6)-O(4)
110.1(5) 109.3(5) P(1)-C(6)-C(7)
107.3(6) 109.7(1) P(1)-C(6)-H(17)
111.1(4) 109.4(1) O(4)-C(6)-C(7)
111.2(5) 109.5(2) O(1)-C(6)-H(17)
108.8(3) 109.4(1) C(7)-C(6)-H(17)
144.6(5) 109.4(6) C(12)-C(14)-H(27)
121.2(4) 120.4(4) C(13)-C(14)-H(27)
119.7(4) 119.3(2) C(14)-C(13)-C(9)
119.1(4) 120.2(1) C(14)-C(13)-H(26)
119.7(5) 119.8(2) C(9)-C(13)-H(26)
120.0(6) 120.0(4) C(7)-C(9)-C(13)
121.9(4)
115.0(8)
108.0(7)
108.5(6)
110.5(4)
107.1(5)
107.4(7)
109.7(6)
109.0(4)
109.2(3)
110.0(5)
109.0(6)
110.0(7)
104.7(3)
112.2(3)
106.8(4)
113.2(3)
110.2(6)
109.4(4)
119.8(6)
120.0(5)
119.8(7)
120.7(4)
119.5(3)
121.1(5)
122.5(2)
114.0(6)
109.1(3)
109.4(4)
109.7(3)
108.0(5)
108.3(8)
109.3(8)
109.6(2)
109.6(6)
109.4(1)
109.9(8)
109.3(4)
104.9(1)
112.1(5)
109.0(7)
110.3(7)
108.1(5)
106.9(6)
119.9(7)
120.0(1)
119.9(5)
120.0(6)
119.9(7)
120.1(6)
O(3)-P(1)-C(6)
P(1)-O(3)-C(4)
O(2) -C(10)-C(15)
O(2)-C(10)-H(21)
O(2)-C(10)-H(20)
C(15)-C(10)-H(20)
C(15)-C(10)-H(21)
H(20) -C(10)-H(21)
C(10)-C(15)-H(30)
C(10)-C(15)-H(28)
C(10)-C(15)-H(29)
H(30)-C(15)-H(28)
H(30)-C(15)-H(33)
H(28)-C(15)-H(29)
C(6)-O(4)-H(24)
C(6)-C(7)-C(8)
C(6)-C(7)-C(9)
C(8)-C(7)-C(9)
C(7)-C(8)-C(12)
C(7)-C(8)-H(18)

ACCEPTED MANUSCRIPT
C(12)-C(8)-H(18)
C(8)-C(12)-C(14)
C(8)-C(12)-H(25)
C(14)-C(12)-H(25)
C(12)-C(14)-C(13)
C(16)-C(11)-H(22)
O(4)-C(6)-H(17)
C(16)-C(11)-H(22)
120.3(4) 120.1(3) C(7)-C(9)-H(19)
118.2(6)
120.7(3)
119.8(6)
120.0(5)
119.8(7)
113.2(3)
110.5(4)
119.0(3)
120.7(1)
119.9(7)
120.0(1)
119.9(5)
112.7(8)
110.8(3)
120.2(6) 119.9(3) C(13)-C(9)-H(19)
119.3(5) 119.8(2) C(12)-C(14)-H(27)
120.5(4) 120.0(1) C(13)-C(14)-H(27)
120.2(7) 120.0(1) C(14)-C(13)-C(9)
107.1(5) 109.6(5) O(4)-C(6)-C(7)
110.2(6) 109.8(1) C(16)-C(11)-H(23)
107.1(5) 108.3(2)
The hydrogen atoms are all located in a difference map, but those attached to the carbon
atoms are repositioned geometrically. The hydrogen atoms were initially refined with soft
restraints on the bond lengths and angles to regularize their geometry (C-H in the range 0.93-
0.98 Å and O-H = 0.82 Å), after which the positions were refined with riding constraints [32].
The hydrogen bond O—H···O between the oxygen bonded with hydrogen as donor and the
oxygen in double-bond with the phosphorus as acceptor developing thereby, three-
dimensional chiral supra-molecular network [30].This hydrogen bond deforms the C(6)-O(4)-
H(24) angle, to form the crystalline structure (the experimental SXRD value is 144.6(5) ° and
the calculated one is 109.4(6) °). Table 3 shows the proposed hydrogen bond with the
corresponding acceptor-donor distances and its symmetry codes.
Table 3.
Hydrogen-bond geometry (Å, °)
D—H···A
O(4)—H(24)···O(5)
D—H
0.822
H···A D···A
2.701 2.701(9) 130.6(2)
D—H···A
i
i
Symmetry code: (i) −x+3/2, y−1/2, −z+1/2.
3. 2. UV-Vis analysis
The optical absorption spectrum of DHPMP (Fig. 5) exhibits a strong absorption band
-1
-1
around 258 nm (ε258= 17626 L.mol .cm ) assigned to the aromatic systems or electronic
excitation in this region [33, 34]. In general, the absorption band of benzene are mainly
located around 200 nm related to the energy required for π-π* transition [34]. The absorption
is negligible in visible range with a cut-off wavelength 292 nm, which is sufficient for laser
frequency doubling and other related opto-electronic applications in ultra violet domain [35]
.

ACCEPTED MANUSCRIPT
Fig.5.UV-Vis absorption spectrum.
3
. 3. FT-IR/Raman analysis
The FT-IR spectrum of DHPMP crystal is shown in Fig.6 (a).The characteristic
vibration frequencies of the functional groups present in the title crystal were assigned and
-1
collected in Table 4. The broad band around 3626 cm is due to symmetric stretching
vibrations of O–H, while C–H aromatic and aliphatic stretching vibrations are observed at
-1
-1
3
008 and 2925 cm respectively. Sharp band observed at 1646 cm is attributed to benzene
ring stretching vibrations, whereas C–H deformation asymmetric mode of CH and CH occur
3
2
-1
-1
-1
at 1493 cm and 1392 cm . The medium IR band at 1362 cm is assigned to O–H in plan
bending mode of vibration. The band corresponding to P=O stretching mode of vibrations
-1
-1
appears at 1231 cm .The medium strong band at 698 cm is due to symmetric ring mode
vibrations, characteristic of benzene monosubstituted.
Fig. 6 (b) shows FT-Raman spectrum of DHPMP with the vibrational band assignments given
-1
in Table 4. The most intense band at 1002 cm is due to symmetric vibrations of benzene
-1
ring. C−H stretching mode of vibration was observed at 3070 cm .The weak band which
-1
-1
2
appears at 1454 cm is due to CH bending mode. The band observed at 1216 cm is assigned
-1
-1
to P=O stretching vibration, and the medium bands at 1027 cm and 725 cm are attributed to
P-O and P−C vibration modes respectively. The last three frequency values confirm the
presence of phosphonate group i
n DHPMP structure. The symmetric stretching modes of C−O
-1
-1
-1
and C−C appear at 1172 cm and 859 cm respectively. The weak band at 775 cm is due to
-1
ring-sextant out of plane deformation. Ring bending vibration occurs at 627 cm in the case of
benzene. All the corresponding calculated vibration bonds are shown in Table 4.

ACCEPTED MANUSCRIPT
Fig.6. (a) FT-IR spectrum, (b) Raman spectrum.
Table 4
Experimental and theoretical vibration frequencies and assignments (the relative IR and
Raman intensities normalized by highest peak absorption to 100).
Experimental-
Calculated
frequencies (cm )
Calculated
Intensités
Assignments
1
-1
frequencies(cm )
IR
626
228
008
925
875
646
493
455
392
231
-
Raman Unscaled Scaled
IR
Raman
004.87
064.40
032.50
100.00
018.63
027.19
010.27
026.44
001.28
010.17
005.80
025.92
002.20
001.02
000.68
007.00
009.03
000.20
001.10
000.62
000.98
003.47
000.97
000.18
002.15
000.71
3
3
3
2
2
1
1
1
1
1
-
3709
3217
3119
3050
3034
1659
1504
1494
1419
1307
1294
1197
1179
1165
1156
1056
1012
886
3565.83
3092.82
2998.60
2932.27
2916.88
1594.96
1445.94
1436.33
1364.22
1256.54
1244.05
1150.79
1133.49
1120.03
1111.37
1015.23
0972.93
0851.80
0808.53
0747.96
0678.74
0609.52
0600.87
0383.59
0228.81
0095.17
000.00
004.26
000.17
000.03
000.01
002.62
002.56
003.76
001.85
005.61
015.67
100.00
054.59
060.75
055.02
047.27
001.56
016.32
016.49
008.49
000.58
002.66
053.53
000.37
000.51
001.15
O–H asymmetric stretch of alcohol
O–H symmetric stretch of alcohol
C–H aromatic stretch
C–H aliphatic asymmetric stretch
C–Haliphatic symmetric stretch
Benzene ring
-
3070
2935
2893
1605
-
Ring stretch
1454
-
CH
CH
2
bending modes
bending
3
1216
1172
1177
1110
1102
-
P=O stretching
C−OH in alcohol, C−O stretch
Rocking vibration for P−O−Et
Benzene C−H deformation
Benzene C−C deformation
C−C symmetric stretching
P–O symmetric stretching
Ring breath and Benzene C=C
C−C stretch
Ring-sextant out-plane deformation
P−C stretching
Benzene monosubstituted
Ring bend
-
-
-
1047
-
-
-
-
1027
1002
859
775
725
-
841
778
706
-
698
-
627
617
-
634
625
399
604
Benzene ring: quadrant out-of-Plane
O–H asymmetric stretch of alcohol
Lattice vibration
-
-
-
-
238
-
99
Lattice vibration

ACCEPTED MANUSCRIPT
3
3
.4. Quantum chemical calculations
.4.1. Molecular Electrostatic Potential (MEP)
In this work and for molecular electrostatic potential and frontier orbital molecular
calculations, a model of two molecules bonded by hydrogen bond was chosen, as shown in
fig.7. This model approaches the crystalline structure of DHPMP.
The molecular electrostatic potential surface was determined by DFT calculations. For
organophosphorus compounds, the total electron density surface mapped with electrostatic
potential indicates the presence of a high negative charge on phosphorus and oxygen atoms
[
36, 37].The total electron density mapped with electrostatic potential surface of DHPMP and
the electrostatic potential contour map for negative and positive potentials are shown in Fig.7.
The negative charge is indicated by red color, the blue region indicates the partially positive
charge, the light blue region shows electron deficiency, the yellow region reveals the slightly
rich electron and the green region shows neutral. The electrostatic potential of DHPMP is in
-2
-2
the range - 10.710 V to + 10.710 V.
(a)
(b)
Fig.7. (a) The contour map of electrostatic potential (b) The total electron density
mapped with electrostatic potential.
3
.5. Frontier Molecular Orbitals (FMO
The electron donor distribution in the highest occupied molecular orbital (HOMO) and
the electron acceptor distribution in the lowest unoccupied molecular orbital (LUMO) are
S
)

ACCEPTED MANUSCRIPT
calculate and the result is shown in Fig.8. The calculated energies values of HOMO and
LUMO were -6.785 eV and -0.175 eV respectively. The difference between them was the
energy gap is found to be 6.609 eV.
LUMO
6.609 eV
HOMO
Fig.8. Molecular orbitals.
Table 5 shows some calculated chemical properties of DHPMP such as: energies
values of HOMO, LUMO levels and the gap, ionization potential (I), electron affinity (A),
Global hardness (η), Global softness (σ), electronegativity (χ), Global electrophilicity (ω),
Chemical potentiel (ꢀ), and thermodynamic parameters. The results obtained for DHPMP are
comparable to those found in the literature for oganophosphorus compounds [36-38].
Table 5
Calculated quantum chemical and thermodynamic parameters.
Quantum chemical parameters
Etot (eV)
-29163.27
-6.785
-0.175
6.609
E
HOMO (eV)
ELUMO (eV)
Egap (∆)
Ionization potentiel (I)
Electron affinity (A)
Global hardness (η)
Global softness (σ)
6.785
0.175
3.304
0.302

ACCEPTED MANUSCRIPT
Electronegativity (χ)
Global electrophilicity (ω)
Chemical potentiel (ꢀ)
3.480
1.833
-0.072
Thermodynamic parameters
SCF energy (a. u.)
-2141.41
Total energy (thermal)
Total
Electronic
Translational
Rotational
328.802
0.0000
0.889
0.889
Vibrational
327.025
Heat capacity at const volume
Total
Electronic
Translational
Rotational
99.56
0.0000
2.981
2.981
Vibrational
Entropy (cal. mol .K )
93.598
-1
-1
Total
Electronic
Translational
Rotational
Vibrational
Zero-point vibrational energy
159.291
0.0000
44.444
36.658
78.189
313.99
Rotational constants (GHz)
X
Y
Z
0.18486
0.10176
0.07627
2
I=-EHOMO, A=-ELUMO, χ =-[1/2(ELUMO+ EHOMO)], η=1/2(ELUMO- EHOMO), ω=χ /2η. σ=1/ η, ꢀ= -1/[2(I+A)].
3
.6. Thermal analysis
The TGA and DTA curves of DHPMP are shown in Fig. 5. First the DHPMP crystals
exhibit a thermal stability until to 125 °C; no mass loss observed around 100 °C, which
indicates the absence of water molecule, which is due to water evaporation. Then, three stages
weight loss process is observed: the first stage takes place in the temperature range of 125-172
°
C, with DTA peak at 159 °C. These results are probably due to a break of the alkoxy group
O-C ) chemical bond [39]. The second stage is situated at the temperature range 172-210
C with the corresponding TDA peak at 194 °C, which is assigned to P-C-Carmotic
(
2 5
H
°
decomposition. The two stages are characterized by a significant weight loss about 80 %. The
third stage takes place in the temperature range of 210-600 °C with the corresponding DTA
peak at 361 °C this behavior could be assigned to phosphorus elimination [40].

ACCEPTED MANUSCRIPT
Fig. 9. TGA-DTA thermograms of DHPMP.
4
. Conclusion
Diethyl [hydroxy (phenyl) methyl] phosphonate (DHPMP) single crystal was
synthesized and grown by slow solvent evaporation technique, its molecular formula was
confirmed using single crystal X-ray diffraction to be C11 P, The mono-clinic unit cell is
centro-symmetric with space group P2 /n, containing four molecules Z = 4. The geometric
17 4
H O
1
parameters calculated by DFT confirmed the title crystalline structure. Theoretically predicted
IR and Raman frequencies compared with experimental values were well assigned for the
grown crystal, the obtained results are in good agreement with those found in the literature. It
is to be noted that DHPMP possesses hydrogen bonds, those hydrogen bonds, responsible of
the crystal chirality. These structural properties offer to the compound the possibility to
deviate the polarized light. The spectrum shows that the absorption is negligible within the
visible domain, with a 292 nm cut off wavelength. The latter value is sufficient for laser
frequency doubling and other related opto-electronic applications in ultra violet domain.
Another advantage for DHPMP crystal is its thermal stability, achieving experimentally up to
1
25°C.
References
[
[
[
[
[
[
1] H. Ait Youcef, S. Chafaa, R. Doufnoune, T. Douadi, J. Mol. Struct.1123 (2016) 138-143.
2] Z. Karimi-Jabiri, H. Zare, M. Amiri, N. Sadeghi, Chin. chem. Lett., 22 (2011) 559-562.
3] M. Juribasic, L. Tasek-Bosic, J. Mol. Struct., 924-926 (2009) 66-72.
4] K. A. Schug, W. Lindner, Chem. Rev., 105 (2005) 67-114
5] K. Moonen, I. Lauryn, C. V. Stevens., chem. rev, 104 (2005) 6177-6215.
6] R. L. Hildebrand, T. O. Henderson. In the Role of Phosphonate in living systems.Ed.CRC
press Boca Raton. 1983.

ACCEPTED MANUSCRIPT
[
7] S. R. Mandadapu, M. R. Gunnam, A. C. G. Kankanamalage, R. A. Z. Uy, K. R. Alliston, G.H.
Lushington, Y. Kim, K-Ok Chang, W. C. Groutas, Bioorg. Med. Chem. Lett., 23 (2013) 5941-
5
944.
8] G. S. Prasad, M. Manjunath, K. R. K. K. Reddy, O. V. S. Reddy, C.S. Reddy, Arkivoc, (2006)
28-135.
9] K. D. Karlin, Progress in inorganic chemistry. New York, 47 (1998) 371-510.
[
[
1
[
[
[
[
10] K. Maeda, Micro. Meso. Mater., 73 (2004) 47-55.
11] J. G. Mao, Coord. Chem. Rev., 251 (2007) 1493-1506.
12] Q. Li, C. J. Hou, Y. J. Liu, R. F. Yang, X. P. Hu, Tetrahedron :asymmetry, 26 (2015) 617-622.
13] N. Z. Kiss, A. Kaszás, L. Drahos, Z. Mucsi, G. Keglevich, Tetrahedron Lett., 53 (2012) 207-
209.
[
14] L. Nagarapu, R. Mallepalli, U. N. Kumar, P. Venkateswarlu, R. Bantu, L. Yeramanchi,
Tetrahedron Lett, 53 (2012) 1699-1700.
[
[
15] V. K. Yadav, Synth. Commun., 20 (1990) 239-246.
16] E. V. Mataveeva, I. L.Odinets, V. A. Kazlov, A. S. Shaplov, T. A. Mastryukova, Tetrahedron
Lett., 47 (2006) 7645-7648.
[
17] P. Y. Renard, P. Varon, E . Leclerc, A. Vallex, C. Mioskowski, Chem. Int. Ed., 42 (2003)
2389-2392.
[
[
[
[
[
[
18] Ye-Q. Wen, R.Hertzberg, C. Moberg, J. orga. chem., 79 (2014) 6172-6178.
19] S. K. De, Heteroatom Chem, 19 (2008) 592-595.
20] S. K. De, Tetrahedron Lett, 45 (2004) 1035-1036.
21] F. Fringuelli, F. Pizzo, L.Vaccaro., Synthesis, 5 (2000) 646-650.
22] R. R. Srivastava, G. W. Kabalka, Tetrahedron Lett.,33 (1992) 593-594.
23] A. A. Dabbawala, D. U. Parmar, H. C. Bajaj, R. V. Jasra., J. Mol. catal. A :chem., 282 (2008)
99-106.
[
[
24] B, Kaboudin., Tetrahydron Lett., 41 (2000) 3169-3171.
25] P. W. Betteridge, J. R. Carruthers, R. I. Cooper, K. Prout, D. J. Watkin, J. Appl. cryst., 36
(
2003) 1487-1487.
[
[
[
[
[
[
[
[
[
26] W. Kohn, L.J. Sham., Phys. Rev, 140 (1965) 1133-1138.
27] A. D. Becke, J. Chem. Phys, 98 (1993) 648-5652.
28] C. Lee, W. Yang, R.G. Parr., Phys. Rev, 37 (1998) 785-789.
29] B. Miehlich, A. Savin, A. Stoll, H. Preuss., Chem. Phys. Lett., 157 (1989) 200-206.
30] L. T. An, G. X. Gong, X. Liu, M. Xia, J. F. Zhou, Acta Crist. E, 64 (2008) 1320-1327.
31] R. P.Gillespie, J. Chem. Educ., 40 (1963) 295-301.
32] R. I .Cooper, A. L. Thompson, D. J. Watkin, J. Appl. Cryst., 43 (2010) 1100-1107.
33] K. Kirubavathi, K. Selvaraju, S. Kumararaman, Spectrochim. Acta A ,71 (2008) 1-4.
34] G. Madhurambal, B. Ravindran, M. Mariappan, S.C. Mojumdar, J. Therm. Anal. Calorim.,
100 (2010) 811–815.
[
[
[
35] Y. Le Fur, R. Masse, M. Z. Cherkaoui, J. F. Nicoud. , Z. Kristallogr, 210 (1995) 856–860.
36] A. Hellal, S. Chafaa, N. Chafai, J. Mol. Struct., 1103 (2017) 110-124.
37] N. Chafai, S. Chafaa, K. Benbouguerra, D. Daoud, A. Hellal, M. Mehri, J. Taiwan. Inst.
Chem. Eng.,70 (2016) 331-344.
[
[
[
38] V. Arjunan, M. Kalaivani, M. K. Marchewka, S. Mohan, J. Mol. Struct., 1045 (2013) 160-170.
39] M. A. De Souza RIOS, S. E. Mazzetto,Fuel. Process. Technol., 96 (2012) 1-8.
40] A. I. Balabanovich, V.P. Prokopovich,J.Anal.Appl.pyrolysis, 76 (2006) 169-177.