Asian Journal of Biochemical and Pharmaceutical Research Issue 3 (Vol. 4) 2014
ISSN: 2231-2560
CODEN (USA): AJBPAD
Research Article
Asian Journal of Biochemical and Pharmaceutical Research
Spin –Orbit Coupling, Spin- Spin, and Electric Properties of Hydrogen Bromide
Molecule
Dhia Hamdi Al-Amiedy1, Zeyad Adnan Saleh2 and Rajaa Khedir Al-Yasari3
1. Physics Department, College of Science for Women, Univ. of Baghdad, Iraq;
2. Physics Department, College of Science, Al-Mustansriyah Univ, Iraq
3. Physics Department, College of Science, Univ. of Karbala, Iraq
Received: 22 August 2014; Revised: 04 September 2014; Accepted: 29 September 2014
Abstract: Research includes the study of the spin- orbit coupling, spin- spin, electronic structure and number
electric properties such as ionization potential(IP), electron affinity(EA), electronegativity (x), hardness( η ),
softness(S), and electrophilic(W)of hydrogen bromide molecule by using Gaussian program 09 and Gauss view
5.08 program using density function (DFT) method B3LYP/6-311G (d,p). It has been found that the values of
spin –orbit coupling are decreasing with increasing the bond length between hydrogen and bromide atoms.
Because the bromide has high electronegativity, therefore bromide attached the electrons towered themselves
this electrons lead to shielding the bromide for hydrogen atom, this indicated that the spin-orbit coupling and
spin-spin are depending on the bond length, also the diamagnetic shielding.
Key words: spin- orbit coupling, spin- spin, NMR, electronic structure, electric properties, hydrogen bromide
molecule, density function method.
INTRODUCTION:
Hydrogen bromide is the diatomic molecule, consisting of a hydrogen atom H and a bromide
atom Br. HBr molecule is a gas at standard conditions. Hydrobromic acid forms upon dissolving HBr
in water. Conversely, HBr can be liberated from hydrobromic acid solutions with the addition of a
dehydration agent. At room temperature, HBr is a nonflammable gas with an acrid odor, fuming in
moist air because of the formation of hydrobromic acid. HBr is very soluble in water [1].
There are many uses of HBr molecule in chemical synthesis open epoxides and lactones and in
the synthesis of bromoacetals. Beside catalyzes many organic reactions, and also in a utility-scale
flow-type battery [2].
Many studies investigated calculation of spin – orbit coupling, spin-spin, and electric
properties. Spin- spin values were calculated of (HF, BF, KNa, and HCl) molecules[3]. Spin –orbit
effects constitute a signification portion of relativistic effects for the studied molecules, and spin-spin
between nuclei is of fundamental importance in magnetic resonance spectroscopy [4].The geometric
derivatives of the static and dynamic electric dipole polarizability have been calculated at the
allelectron Dirac–Hartree–Focklevel for the hydrogen halides HF, HCl, HBr, and HI. A comparison
with the non-relativistic Hartree–Fock values shows that the relativistic corrections tend to be larger
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Asian Journal of Biochemical and Pharmaceutical Research
Issue 3 (Vol. 4) 2014
CODEN(USA) : AJBPAD
for the geometric derivatives of the polarizabilities than for the polarizabilities. [5]. The ionization
potential, electron affinity, electronegativity, hardness, and electron excitation energy for diatomic
molecules (Bc, Ne, Ar, HF) and organic molecules (NH3, CH4,C H2= CH2) [6]. Finally, the calculation
of spin- orbit coupling of the Nak 33 and 31 states, determination of the coupling constant and
observation of quantum interference effects[7].
CALCULATION
Calculation of spin- orbit coupling ( SOC) values using of the following equation[8,9].
SOC(J) = L+S
……………….(1)
Where L represent the orbital angular momentum of molecule
Where S represent spin angular momentum of molecule
Ionization potential (IP) and electron affinity (EA) have been calculated by using equations [10]:
IP= - EHOMO
……………….(2)
EA= - ELUMO
…………………(3)
Where EHOMO the energy of the highest occupied molecular orbital, while ELUMO the energy of
the lowest unoccupied molecular orbital.
The electronegativiy ( χ ) is defined as [11].
χ = - (IP+EA)/2
……………..(4)
The hardness ( η ) has been calculated by using equation [12].
η =(IP-EA)/2
………………….(5)
Expresses the softness (S) and electrophilic (W) by the following equation [12].
S= 1/2 η
W= χ 2/2η
………………(6)
……………………….(7)
RESULT AND CONCLUSION:
Table (1) and figure (1), shows the values of spin – orbit coupling for hydrogen bromide
molecule are calculation by using Gaussian program 09 and Gauss view 5.08 program using density
function (DFT) method. By using DFT, B3LYP/6-311G (d,p) [13] method, from this table and figure,
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Asian Journal of Biochemical and Pharmaceutical Research
Issue 3 (Vol. 4) 2014
CODEN(USA) : AJBPAD
it has been found that the values of spin –orbit coupling are decreasing with increasing the bond
length between hydrogen and bromide atoms.
Figure (2) and table (1) shows the values of spin–spin coupling of hydrogen bromide are
calculation by using Gaussian program 09 and Gauss view 5.08 program using density function (DFT)
method. By using DFT at biases set B3LYP /6-311G (d,p)[13] method, from this figure and table (1)
the values of spin- spin are decreasing with increasing the bond length, because the bromide has high
electronegativity ,therefore bromide attached the electrons towered themselves this electrons lead to
shielding the bromide for hydrogen atom, this indicated that the spin-orbit coupling and spin-spin are
depending on the bond length, also the diamagnetic shielding .
Table (2) shows the values of ( EHOMO, ELUMO,
IP, EA, χ η , , S, and W) (eV) calculated by
using DFT- B3LYP/ 6-311G (d,p) , it is clear from this table that the values of EHOMO and ELUMO are
slight difference with increasing of the bond length, also the values of all properties are slight
increasing with increasing of bond length, except the values of hardness are decreasing with
increasing the bond length between hydrogen and bromide atoms.
Table (1-1) : Bond length (R)measured in (Ao), spin- orbit coupling, and spin- spin measured
in(Hz) for hydrogen bromide molecule.
R(Ao)
1.46
1.48
1.5
1.52
1.54
1.56
Spin- orbit coupling (Hz)
0.00403945
0.00256576
0.0014168
0.000563289
-2.60468E-05
-0.000390246
Spin- spin (Hz)
-84.628
-107.31
-129.55
-151.397
-172.902
-194.127
Figure(1): spin – orbit coupling of hydrogen bromide molecule
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Asian Journal of Biochemical and Pharmaceutical Research
Issue 3 (Vol. 4) 2014
CODEN(USA) : AJBPAD
Figure (2): spin-spin of hydrogen bromide molecule
Table (2): boned length (Ao), EHOMO (eV), ELUMO(eV), IP(eV),EA(eV), χ (eV) , S(eV), η (eV) and W(eV) of hydrogen bromide
molecule.
R(Ao)
1.46
1.48
1.5
1.52
1.54
1.56
W (eV)
EHOMO (eV) ELUMO (eV)
IP(Ev)
EA(eV)
χ (eV)
η (eV)
S(eV)
8.4433012 0.621499
8.443301
0.621499
4.5324
3.910901
0.127848
2.626332
8.4433012 0.621771
8.443301
0.621771
4.532536
3.910765
0.127852
2.626581
8.4433012 0.622588
8.443301
0.622588
4.532944
3.910357
0.127866
2.627329
8.4433012 0.623404
8.443301
0.623404
4.533353
3.909949
0.127879
2.628076
8.4433012
-0.62422
8.443301
0.62422
4.533761
3.90954
0.127892
2.628824
8.4433012 0.624492
8.443301
0.624492
4.533897
3.909404
0.127897
2.629073
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Issue 3 (Vol. 4) 2014
CODEN(USA) : AJBPAD
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*Correspondence Author: Dhia Hamdi Al-Amiedy, Physics Department, College of Science for
Women, Univ. of Baghdad, Iraq.
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