Dezortsev, S.

Dolomatov, M.Yu

Shutova, S.

SocioEconomic Challenges Journal (Sumy State University)

30                   Nanomaterials: Applications and Properties (NAP-2011). Vol. 2, Part I            
 
ASPHALTENS OF OIL AND OF HIDROCARBONS DIS-
TILLATES AS NANOSCALE SEMICONDUCTORS 
Michail Yu. Dolomatov* , Sergei V. Dezortsev , Svetlana  Shutkova 
 
Department of physics, Ufa State Academy of economic and service,  
145 Chernyshevsky Str., 450014, Ufa, Russia 
 
ABSTRACT 
The  asphaltenes  are  composed  mainly  of  polyaromatic  carbon   with  NSO-
compounds  combined with traces vanadium and nickel, which are in porphyrin 
structures. The asphaltenes include   paramagnetic centers. The concentration of free 
radical is 1019-1020 spin /g (EPR). The experiment and calculation results indicate that 
the molecular complexes of the asphalt pitch substances on  the nanomolecular level 
associates in the structural units’ formation with the charge transfer properties involved. 
The spectra and quantum calculations indicate that the most probable centers for the 
electron transfer are the structures containing the aromatic rings, heteroaromatic rings 
and the corresponding free radicals. [1] The calculations showed that the asphaltenes 
structural units, containing from 6 to 13 aromatic rings have the  forbidden gap size 
from 4.92-6.49 eV - for the molecular fragments and from 2.84 to 3.20 eV - for the free 
radical form. This indicates possible belonging of the asphaltenes to the amorphous 
compensatory organic broadband  semiconductors. The experiments  for estimation 
band gap of the molecules asphaltenes confirmed by of computing  ab-initio methods. 
The  Asphaltenes have nanomolecular structures, that can be   used as  a semiconductors  
for nanoelectronics.  
INTRODUCTION 
The asphaltenes are complex substances that are found in grude oil, 
bitumen and high-boiling hydrocarbons distillates. The asphaltenes are 
composed mainly of polyaromatic carbon  with heterocyclic compounds  
combined with traces vanadium and nickel, which are in porphyrin structures. 
The asphaltenes include   paramagnetic centers. The concentration of free 
radical is 1019-1020 spin /g (EPR). Average molecular mass ascertain in diapa-
son 500- 2500 u (mass spectrum) .  The molecules of asphaltenes  may contain 
5- 10-member bensene and naphteno  rings in their structure. The oil dispersion 
systems which include oils itself and high-boiling oil fractions are the asphalt 
pitch substances (APS) colloidal solutions, represented by the resins and as-
phaltenes. According to F.G. Unger [1] ideas, the oil resins and asphaltenes 
represent paramagnetic metastable substances, where the paramagnetic asphal-
tene fragments are the micelles formation centers in dispersed hydrocarbon 
environments. Around the micelles core the solvate layers are grouped in the 
                                               
* e-mail: dolomatov@gmail.com 
Nanomaterials: Applications and Properties (NAP-2011). Vol. 2, Part I                   31 
 
order of the dispersed system intermolecular interaction potentials decrease. 
The electron structure of asphaltenes have not been researched enough.  
The aim of this work is to study the electronic structure of the heteroatom-
ic nanoparticles of the asphaltenes molecules using the electron spectroscopy 
and computational chemistry. The aim of this work is to study the electronic 
structure of the heteroatomic  fragments of the nanoparticles of asphaltene 
moleculas using the electron phenomenological spectroscopy and computation-
al chemistry methods 
METHODS OF RESEARCH AND ANALYSIS 
Unlike conventional  method, the phenomenological spectroscopy(EPS) 
studies a substances as a single whole without  separating the spectrum of the 
substance into characteristic frequencies and wavelengths of individual func-
tional groups or  components  of  the  systems.[2,3] The electronic phenomeno-
logical spectroscopy is based on the regularities of the relations bet ween  ab-
sorptivity  coefficients and physicochemical properties of the substance the 
values of physicochemical properties of  a substance  are  proportional  to its 
ultraviolet and/or visible absorption [2].      
Let us consider the method, which was proved in our previous works [1]. 
The ionization potential (PI) and electron affinity (EA) are estimated according 
to empirical dependences which links these characteristics with integral index 
of absorption?  (1).  
 
Figure 1. Absorption spectrum of asphaltene toluene solutions in UV and VIS area: 1 – 
asphaltenes of Surgut oilfield, 2 - asphaltenes of Ust-Balyksk oilfield, 3 - asphaltenes of 
Petelinsk oilfield, 4 - asphaltenes of Arlan oilfield, 5 - asphaltenes of Radaevsk oilfield 
0
5
10
15
20
25
30
200 300 400 500 600 700 800
C
oe
ff
ic
ie
nt
 o
f a
bs
or
pt
io
n,
 *
10
5 
m
ol
*m
-3
m
-1
Wavelenght, nm
1
2
3
4
5
32                   Nanomaterials: Applications and Properties (NAP-2011). Vol. 2, Part I            
 
The test subjects are asphaltenes, separated from crude oils, oil fractions 
and solid deposits, including paraffins. The solid deposits were processed by 
benzene, filtered out from the impurities and paraffins. Then the asphaltenes 
were isolated from the samples properly by sedimentation with the n-heptane 
excess by Marcusson method.  
The electronic absorbance spectrums were registrated on the double-beam 
spectrometer in the range of 280 ... 760 nm in the dilute toluene solutions at the 
asphaltenes concentrations of 1.10 gram-mol / m3.    The spectra in the visible 
and ultraviolet range have no clear absorption fields (Figure 2).   
Ab initio RHF/3-21G** method (Restricted Hartree-Fock method) with 
the minimal basis of Gaussian functions and full geometry optimization [4] was 
used to calculate the molecules..  
RESULTS AND DISCUSSION 
Further calculation of IP and EA average values were based on the corre-
lations [2,3] between the electronic states energies and oscillators integral 
strengths (OIS):  
??? 21 ???  
(1)       
??
?
?
??????
2
1
2
1
?
?
 
where: ?— effective IP or EA, eV; ?1, ?2 — empirical coefficients, de-
pending on the orbital type, permanent in this series, respectively eV, eV·gram-
mol·m-3 (for IP— ?1 = 9.495, ?2 = - 2.38, for EA — ?1 = 0.11, ?2 = 0.98); ? — 
OIS logarithmic function, m3·10-10·gram-mol-1. 
OIS logarithmic function was calculated on the area under the absorption 
curve by the trapezoid method:  
 
?
n
kkkkk
n
dk nnnn
n
lglglglg
2
lglglg 112100
0
??????
?
?
?
????
?
??
? ???????? ?? ?          (2) 
where:  ?? — molar absorption coefficient at specific wavelengths in the 
near ultraviolet and visible spectrum area, m3·gram-mol-1·m-1;  n — number of 
the spectrum sampling points in the radiation absorption area.; ?0 , ?k — the 
spectrum boundaries, nm; M - molecular weight, gram/mol. 
It was revealed, during the study of different asphaltenes and hydrocarbon 
systems origin data, that asphaltene fraction is a strong electron donor and ac-
ceptor at the same time (IP=4.37-5.8  eV, EA=1.65-2.66 eV). This means, that 
the processes in asphaltenes solutions and concentrates, including those related 
to ARPD (asphalt, resin and paraffin deposits), may be described by the for-
mation of molecular charge-transfer complexes. 
Nanomaterials: Applications and Properties (NAP-2011). Vol. 2, Part I                   33 
 
??ble  1 – Donor-acceptor properties of asphaltenes and resins by the elec-
tronic  spectroscopy data 
Asphaltenes PI, eV 
EA, 
eV 
Forbidden 
gap,eV 
Imref, 
eV 
Asphaltenes and resins of 
Radaevsk oilfield 5.70 1.85 3.85 1.93 
Asphaltenes of Surgut 
oilfield 5.20-5.70 2.10-2.50 3.10-3.20 1.55-1.60 
Asphaltenes of strait-run 
stoks 4.37-5.27 2.44-2.50 1.93-2.77 0.96-1.38 
Asphaltenes of tar 4.70-4.90 2.10-2.15 2.60-2.75 1.30-1.38 
Asphaltenes of Kushkul 
oilfield 5.20 1.90 3.30 1.65 
 
?able 2 – IP and EA values, computed on the base of the model fragments of 
resins and asphaltenes molecular and stable free-radical forms  
Model 
structure 
Molecular form (?) Free-radical form (R) without hydrogen (?) 
IP, 
eV 
EA, 
eV 
Forbidden 
gap,eV 
IP, 
eV 
EA, 
eV 
Forbidden 
gap, eV 
1 2 3 4 5 6 7 
N
 
7.05 1.47 5.58 5.43 1.89 3,54 
 
6.67 1.22 5.46 5.15 2.04 3.10 
 
6.44 1.36 5.08 4.99 1.96 3.02 
 
7.11 0.92 6.20 5.47 2.23 3.24 
?H3
 
6.39 1.44 4.95 4.95 1.91 3.04 
N
 
6.55 1.52 5.03 5.06 1.86 3.20 
 
 
34                   Nanomaterials: Applications and Properties (NAP-2011). Vol. 2, Part I            
 
1 2 3 4 5 6 7 
 
6.57 1.32 5.25 5.08 1.98 3.10 
 
6.65 1.30 5.35 5.14 1.99 3.14 
 
6.80 0.62 5.16 5.24 2.41 2.84 
 
Our studies assume that the asphaltenes in the liquid phase decompose 
into free radicals, according to the equations [1]: 
?
?
?
?? 1nn RRM       ,                                    (3) 
where  nM  - the asphaltenes molecular form, 
?
nR  and 
?
?1nR  - the as-
phaltenes free radical forms. The oil resins and asphaltenes model fragments 
were selected to feature the elementary structural units in the associates decay 
scheme (3). In order to simulate the resins the polycyclic aromatic structures 
with the molecular masses of 276-379 amu (compounds 1-4 ) were used. Struc-
tures with molecular masses of 398-512 amu and the number of aromatic rings 
from 6 to 13 reflect the asphaltenes (compounds 5-9).  
The empirical dependence, which connects the calculated values of the 
highest occupied molecular orbital energy (EHOMO) and the experimental values 
of the ionization potentials (IPmol) is:  
IP mol= A1*EHOMOl+ ?2,                                  (4) 
wher?  ?1 = 0.83;  ?2 = 1.51 eV. 
 
For the calculated values of the lowest unoccupied molecular orbital en-
ergy (ELUMO) and the experimental values of the affinity to the electron (EAmol) 
the following empirical dependence is applied:  
          EAmol= A3*ELUMO + ?4,                                 (5) 
 wher???3 = - 0.46;  ?4 = 1.45 eV. 
 
The correlation coefficients equal 0.93 and 0.97 respectively. The de-
pendences (4) and (5) were obtained for the polycyclic aromatic hydrocarbons.  
It is necessary to calculate the free-radical fragments, taking into account 
the high concentration of the asphaltenes paramagnetic centers and the modern 
views onto their free-radical structure. Unfortunately, the quantum chemistry 
methods do not make correct IP and EA assessments for the free radicals that is 
Nanomaterials: Applications and Properties (NAP-2011). Vol. 2, Part I                   35 
 
why we used the semi empirical correlation for calculating the ionization po-
tentials (IPrad) and free radicals affinities (EArad) to the electron.  
IPrad = A5* EHOMO + A6,                                        (6) 
wher???5 = 0.72;  A6 = 0.36 eV. 
 
EArad = A7*ELUMO  + A8,                                        (7) 
wher???7 = - 0.60; A8 = 2.78 eV. 
 
The correlation coefficients equal 0.90 and 0.83 respectively.  
The results, calibrated for the experiment, are shown in Table 2. 
It is necessary to calculate the free-radical fragments, taking into account 
the high concentration of the asphaltenes paramagnetic centers and the modern 
views onto their free-radical structure. Unfortunately, the quantum chemistry 
methods do not make correct IP and EA assessments for the free radicals that is 
why we used the semi empirical correlation for calculating the ionization po-
tentials (IErad) and free radical electron affinities (EArad):  
IErad = A5* EHOMO + A6,                                    (8) 
 wher?  ?5 = 0.72;  A6 = 0.36 eV. 
 
EArad = A7*ELUMO  + A8,                                   (9) 
wher?  ?7 = - 0.60; A8 = 2.78 eV. 
 
The correlation coefficients equal 0.90 and 0.83 respectively 
 
??ble 3 – Computed and experimental ranges of IP and EA 
Data IP, eV EA, eV
By UV and VIS spectrums [5] 4.37-5.70 1.85-2.50 
Computed molecular fragments (RHF/3-21G** 
method) 6.36-7.56 0.54-1.65 
IP and EA estimation of free-radical fragments by 
equations (4)-(6) 4.92-5.79 1.78-2.45 
 
The exciton formation energy can be estimated by the half of the forbid-
den gap value (quasi-Fermi level). The quasi-Fermi level for the resins molecu-
lar fragments values from 2.54 to 3.10 eV, for the asphaltenes molecular frag-
ments  -  from 2.46  to  3.25  eV;  for  the  free  radical  fragments  of  resins  -  from 
1.51  to  1.77  eV,  for  the  free  radical  fragments  of  asphaltenes  -  from  1.42  to  
1.60 eV. 
According to the calculations for the molecular fragments of the resins the 
IP range is about 6.44-7.25 eV, the EA range is about 0.81-1.65 eV. For the 
free radical fragments the IP changes from 4.99 to 5.57 eV, the EA changes 
from 1.78 to 2.29 eV. For the asphaltene molecular fragments the IP changes 
from 6.36 to 7.03 eV, the EA changes from 0.54 to 1.52 eV. For the free radi-
36                   Nanomaterials: Applications and Properties (NAP-2011). Vol. 2, Part I            
 
cal fragments the IP changes from 4.92 to 5.41 eV, the EA changes from 1.86 
to 2.45 eV.  
The calculations results are confirmed by the APS spectroscopic data 
???ble 3). According to the experimental estimates, IP values are in the range 
from 4.37 to 5.70 eV, EA - in the range from 1.85 to 2.50 eV. Thus, the best 
agreement with the experiment is observed in the free radical fragments 
CONCLUSIONS 
The experiment and calculation results indicate that the molecular com-
plexes of the asphalt pitch substances on  the nanomolecular level associates in 
the structural units’ formation with the charge transfer properties involved.The 
spectra and quantum calculations indicate that the most probable centers for the 
electron transfer are the structures containing the aromatic rings, heteroaro-
matic rings and the corresponding free radicals.   The calculations showed that 
the asphaltenes structural units, containing from 6 to 13 aromatic rings have the 
forbidden gap size from 4.92-6.49 eV - for the molecular fragments and from 
2.84 to 3.20 eV - for the free radical form. This indicates possible belonging of 
the asphaltenes to the amorphous compensatory organic broadband  semicon-
ductors [4]. 
The experiments  for estimation band gap of the molecules asphaltenes 
confirmed by of computing  ab-initio methods. The  Asphaltenes have nanomo-
lecular structures, that can be   used as  a semiconductors  for nanoelectronics.  
REFERENCES:  
[1] Unger F.G., Andreeva L.N. 1995. Fundamental aspects of oil chemistry. Nature of 
the resins and asphaltenes. Novosibirsk:   Science, 192 
[2] Dolomatov M.Yu. 1989. Electronic spectroscopy applications to the physical chem-
istry of multi-component accidental and complicated molecular systems. Ufa. - 47 
p. 
[3] Dolomatov M.Yu. 2000. Chemical physics of multi-component organic systems. 
Ufa, 99 P.4.  
[4] Jensen F. 2007. Introduction to Computational Chemistry. John Wiley&Sons, 119-
124. 
[5] Dolomatov M.Yu.,  Shutkova S. A., Dezortsev S. V.Asphaltenes of oil and of hy-
drocarbons distillates as compensated organic semiconductors. Abstracts of 5th in-
ternational Meeting on Molecular Electronics. MINATEC, Grenoble, France. De-
cember 6-10, 2010, p. 258 
 


English

Asphaltens of oil and of hidrocarbons distillates as nanoscale semiconductors

Electronic Sumy State University Institutional Repository

30                   Nanomaterials: Applications and Properties (NAP-2011). Vol. 2, Part I             ASPHALTENS OF OIL AND OF HIDROCARBONS DIS-TILLATES AS NANOSCALE SEMICONDUCTORS Michail Yu. Dolomatov* , Sergei V. Dezortsev , Svetlana  Shutkova  Department of physics, Ufa State Academy of economic and service,  145 Chernyshevsky Str., 450014, Ufa, Russia  ABSTRACT The  asphaltenes  are  composed  mainly  of  polyaromatic  carbon   with  NSO-compounds  combined with traces vanadium and nickel, which are in porphyrin structures. The asphaltenes include   paramagnetic centers. The concentration of free radical is 1019-1020 spin /g (EPR). The experiment and calculation results indicate that the molecular complexes of the asphalt pitch substances on  the nanomolecular level associates in the structural units’ formation with the charge transfer properties involved. The spectra and quantum calculations indicate that the most probable centers for the electron transfer are the structures containing the aromatic rings, heteroaromatic rings and the corresponding free radicals. [1] The calculations showed that the asphaltenes structural units, containing from 6 to 13 aromatic rings have the  forbidden gap size from 4.92-6.49 eV - for the molecular fragments and from 2.84 to 3.20 eV - for the free radical form. This indicates possible belonging of the asphaltenes to the amorphous compensatory organic broadband  semiconductors. The experiments  for estimation band gap of the molecules asphaltenes confirmed by of computing  ab-initio methods. The  Asphaltenes have nanomolecular structures, that can be   used as  a semiconductors  for nanoelectronics.  INTRODUCTION The asphaltenes are complex substances that are found in grude oil, bitumen and high-boiling hydrocarbons distillates. The asphaltenes are composed mainly of polyaromatic carbon  with heterocyclic compounds  combined with traces vanadium and nickel, which are in porphyrin structures. The asphaltenes include   paramagnetic centers. The concentration of free radical is 1019-1020 spin /g (EPR). Average molecular mass ascertain in diapa-son 500- 2500 u (mass spectrum) .  The molecules of asphaltenes  may contain 5- 10-member bensene and naphteno  rings in their structure. The oil dispersion systems which include oils itself and high-boiling oil fractions are the asphalt pitch substances (APS) colloidal solutions, represented by the resins and as-phaltenes. According to F.G. Unger [1] ideas, the oil resins and asphaltenes represent paramagnetic metastable substances, where the paramagnetic asphal-tene fragments are the micelles formation centers in dispersed hydrocarbon environments. Around the micelles core the solvate layers are grouped in the                                                * e-mail: dolomatov@gmail.com Nanomaterials: Applications and Properties (NAP-2011). Vol. 2, Part I                   31  order of the dispersed system intermolecular interaction potentials decrease. The electron structure of asphaltenes have not been researched enough.  The aim of this work is to study the electronic structure of the heteroatom-ic nanoparticles of the asphaltenes molecules using the electron spectroscopy and computational chemistry. The aim of this work is to study the electronic structure of the heteroatomic  fragments of the nanoparticles of asphaltene moleculas using the electron phenomenological spectroscopy and computation-al chemistry methods METHODS OF RESEARCH AND ANALYSIS Unlike conventional  method, the phenomenological spectroscopy(EPS) studies a substances as a single whole without  separating the spectrum of the substance into characteristic frequencies and wavelengths of individual func-tional groups or  components  of  the  systems.[2,3] The electronic phenomeno-logical spectroscopy is based on the regularities of the relations bet ween  ab-sorptivity  coefficients and physicochemical properties of the substance the values of physicochemical properties of  a substance  are  proportional  to its ultraviolet and/or visible absorption [2].      Let us consider the method, which was proved in our previous works [1]. The ionization potential (PI) and electron affinity (EA) are estimated according to empirical dependences which links these characteristics with integral index of absorptionș  (1).   Figure 1. Absorption spectrum of asphaltene toluene solutions in UV and VIS area: 1 – asphaltenes of Surgut oilfield, 2 - asphaltenes of Ust-Balyksk oilfield, 3 - asphaltenes of Petelinsk oilfield, 4 - asphaltenes of Arlan oilfield, 5 - asphaltenes of Radaevsk oilfield 051015202530200 300 400 500 600 700 800Coefficient of absorption, *105 mol*m-3m-1Wavelenght, nm1234532                   Nanomaterials: Applications and Properties (NAP-2011). Vol. 2, Part I             The test subjects are asphaltenes, separated from crude oils, oil fractions and solid deposits, including paraffins. The solid deposits were processed by benzene, filtered out from the impurities and paraffins. Then the asphaltenes were isolated from the samples properly by sedimentation with the n-heptane excess by Marcusson method.  The electronic absorbance spectrums were registrated on the double-beam spectrometer in the range of 280 ... 760 nm in the dilute toluene solutions at the asphaltenes concentrations of 1.10 gram-mol / m3.    The spectra in the visible and ultraviolet range have no clear absorption fields (Figure 2).   Ab initio RHF/3-21G** method (Restricted Hartree-Fock method) with the minimal basis of Gaussian functions and full geometry optimization [4] was used to calculate the molecules..  RESULTS AND DISCUSSION Further calculation of IP and EA average values were based on the corre-lations [2,3] between the electronic states energies and oscillators integral strengths (OIS):  TDD 21  ȿ  (1)       GȜȜȜȜİ³³ 42121HH where: ȿ— effective IP or EA, eV; D1, D2 — empirical coefficients, de-pending on the orbital type, permanent in this series, respectively eV, eV·gram-mol·m-3 (for IP— D1 = 9.495, D2 = - 2.38, for EA — D1 = 0.11, D2 = 0.98); ș — OIS logarithmic function, m3·10-10·gram-mol-1. OIS logarithmic function was calculated on the area under the absorption curve by the trapezoid method:   Ɇnkkkkkndk nnnnnlglglglg2lglglg 1121000OOOOOTOOO»¼º«¬ª | ³ !          (2) where:  İȜ — molar absorption coefficient at specific wavelengths in the near ultraviolet and visible spectrum area, m3·gram-mol-1·m-1;  n — number of the spectrum sampling points in the radiation absorption area.; Ȝ0 , Ȝk — the spectrum boundaries, nm; M - molecular weight, gram/mol. It was revealed, during the study of different asphaltenes and hydrocarbon systems origin data, that asphaltene fraction is a strong electron donor and ac-ceptor at the same time (IP=4.37-5.8  eV, EA=1.65-2.66 eV). This means, that the processes in asphaltenes solutions and concentrates, including those related to ARPD (asphalt, resin and paraffin deposits), may be described by the for-mation of molecular charge-transfer complexes. Nanomaterials: Applications and Properties (NAP-2011). Vol. 2, Part I                   33  Ɍɚble  1 – Donor-acceptor properties of asphaltenes and resins by the elec-tronic  spectroscopy data Asphaltenes PI, eV EA, eV Forbidden gap,eV Imref, eV Asphaltenes and resins of Radaevsk oilfield 5.70 1.85 3.85 1.93 Asphaltenes of Surgut oilfield 5.20-5.70 2.10-2.50 3.10-3.20 1.55-1.60 Asphaltenes of strait-run stoks 4.37-5.27 2.44-2.50 1.93-2.77 0.96-1.38 Asphaltenes of tar 4.70-4.90 2.10-2.15 2.60-2.75 1.30-1.38 Asphaltenes of Kushkul oilfield 5.20 1.90 3.30 1.65  Ɍable 2 – IP and EA values, computed on the base of the model fragments of resins and asphaltenes molecular and stable free-radical forms  Model structure Molecular form (Ɇ) Free-radical form (R) without hydrogen (ɇ) IP, eV EA, eV Forbidden gap,eV IP, eV EA, eV Forbidden gap, eV 1 2 3 4 5 6 7 N 7.05 1.47 5.58 5.43 1.89 3,54  6.67 1.22 5.46 5.15 2.04 3.10  6.44 1.36 5.08 4.99 1.96 3.02  7.11 0.92 6.20 5.47 2.23 3.24 ɋH3 6.39 1.44 4.95 4.95 1.91 3.04 N 6.55 1.52 5.03 5.06 1.86 3.20   34                   Nanomaterials: Applications and Properties (NAP-2011). Vol. 2, Part I             1 2 3 4 5 6 7  6.57 1.32 5.25 5.08 1.98 3.10  6.65 1.30 5.35 5.14 1.99 3.14  6.80 0.62 5.16 5.24 2.41 2.84  Our studies assume that the asphaltenes in the liquid phase decompose into free radicals, according to the equations [1]: xx 1nn RRM       ,                                    (3) where  nM  - the asphaltenes molecular form, xnR  and x1nR  - the as-phaltenes free radical forms. The oil resins and asphaltenes model fragments were selected to feature the elementary structural units in the associates decay scheme (3). In order to simulate the resins the polycyclic aromatic structures with the molecular masses of 276-379 amu (compounds 1-4 ) were used. Struc-tures with molecular masses of 398-512 amu and the number of aromatic rings from 6 to 13 reflect the asphaltenes (compounds 5-9).  The empirical dependence, which connects the calculated values of the highest occupied molecular orbital energy (EHOMO) and the experimental values of the ionization potentials (IPmol) is:  IP mol= A1*EHOMOl+ Ⱥ2,                                  (4) wherɟ  Ⱥ1 = 0.83;  Ⱥ2 = 1.51 eV.  For the calculated values of the lowest unoccupied molecular orbital en-ergy (ELUMO) and the experimental values of the affinity to the electron (EAmol) the following empirical dependence is applied:            EAmol= A3*ELUMO + Ⱥ4,                                 (5)  wherɟȺ3 = - 0.46;  Ⱥ4 = 1.45 eV.  The correlation coefficients equal 0.93 and 0.97 respectively. The de-pendences (4) and (5) were obtained for the polycyclic aromatic hydrocarbons.  It is necessary to calculate the free-radical fragments, taking into account the high concentration of the asphaltenes paramagnetic centers and the modern views onto their free-radical structure. Unfortunately, the quantum chemistry methods do not make correct IP and EA assessments for the free radicals that is Nanomaterials: Applications and Properties (NAP-2011). Vol. 2, Part I                   35  why we used the semi empirical correlation for calculating the ionization po-tentials (IPrad) and free radicals affinities (EArad) to the electron.  IPrad = A5* EHOMO + A6,                                        (6) wherɟȺ5 = 0.72;  A6 = 0.36 eV.  EArad = A7*ELUMO  + A8,                                        (7) wherɟȺ7 = - 0.60; A8 = 2.78 eV.  The correlation coefficients equal 0.90 and 0.83 respectively.  The results, calibrated for the experiment, are shown in Table 2. It is necessary to calculate the free-radical fragments, taking into account the high concentration of the asphaltenes paramagnetic centers and the modern views onto their free-radical structure. Unfortunately, the quantum chemistry methods do not make correct IP and EA assessments for the free radicals that is why we used the semi empirical correlation for calculating the ionization po-tentials (IErad) and free radical electron affinities (EArad):  IErad = A5* EHOMO + A6,                                    (8)  wherɟ  Ⱥ5 = 0.72;  A6 = 0.36 eV.  EArad = A7*ELUMO  + A8,                                   (9) wherɟ  Ⱥ7 = - 0.60; A8 = 2.78 eV.  The correlation coefficients equal 0.90 and 0.83 respectively  Ɍɚble 3 – Computed and experimental ranges of IP and EA Data IP, eV EA, eVBy UV and VIS spectrums [5] 4.37-5.70 1.85-2.50 Computed molecular fragments (RHF/3-21G** method) 6.36-7.56 0.54-1.65 IP and EA estimation of free-radical fragments by equations (4)-(6) 4.92-5.79 1.78-2.45  The exciton formation energy can be estimated by the half of the forbid-den gap value (quasi-Fermi level). The quasi-Fermi level for the resins molecu-lar fragments values from 2.54 to 3.10 eV, for the asphaltenes molecular frag-ments  -  from 2.46  to  3.25  eV;  for  the  free  radical  fragments  of  resins  -  from 1.51  to  1.77  eV,  for  the  free  radical  fragments  of  asphaltenes  -  from  1.42  to  1.60 eV. According to the calculations for the molecular fragments of the resins the IP range is about 6.44-7.25 eV, the EA range is about 0.81-1.65 eV. For the free radical fragments the IP changes from 4.99 to 5.57 eV, the EA changes from 1.78 to 2.29 eV. For the asphaltene molecular fragments the IP changes from 6.36 to 7.03 eV, the EA changes from 0.54 to 1.52 eV. For the free radi-36                   Nanomaterials: Applications and Properties (NAP-2011). Vol. 2, Part I             cal fragments the IP changes from 4.92 to 5.41 eV, the EA changes from 1.86 to 2.45 eV.  The calculations results are confirmed by the APS spectroscopic data Ɍɚble 3). According to the experimental estimates, IP values are in the range from 4.37 to 5.70 eV, EA - in the range from 1.85 to 2.50 eV. Thus, the best agreement with the experiment is observed in the free radical fragments CONCLUSIONS The experiment and calculation results indicate that the molecular com-plexes of the asphalt pitch substances on  the nanomolecular level associates in the structural units’ formation with the charge transfer properties involved.The spectra and quantum calculations indicate that the most probable centers for the electron transfer are the structures containing the aromatic rings, heteroaro-matic rings and the corresponding free radicals.   The calculations showed that the asphaltenes structural units, containing from 6 to 13 aromatic rings have the forbidden gap size from 4.92-6.49 eV - for the molecular fragments and from 2.84 to 3.20 eV - for the free radical form. This indicates possible belonging of the asphaltenes to the amorphous compensatory organic broadband  semicon-ductors [4]. The experiments  for estimation band gap of the molecules asphaltenes confirmed by of computing  ab-initio methods. The  Asphaltenes have nanomo-lecular structures, that can be   used as  a semiconductors  for nanoelectronics.  REFERENCES:  [1] Unger F.G., Andreeva L.N. 1995. Fundamental aspects of oil chemistry. Nature of the resins and asphaltenes. Novosibirsk:   Science, 192 [2] Dolomatov M.Yu. 1989. Electronic spectroscopy applications to the physical chem-istry of multi-component accidental and complicated molecular systems. Ufa. - 47 p. [3] Dolomatov M.Yu. 2000. Chemical physics of multi-component organic systems. Ufa, 99 P.4.  [4] Jensen F. 2007. Introduction to Computational Chemistry. John Wiley&Sons, 119-124. [5] Dolomatov M.Yu.,  Shutkova S. A., Dezortsev S. V.Asphaltenes of oil and of hy-drocarbons distillates as compensated organic semiconductors. Abstracts of 5th in-ternational Meeting on Molecular Electronics. MINATEC, Grenoble, France. De-cember 6-10, 2010, p. 258  

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Asphaltens of oil and of hidrocarbons distillates as nanoscale semiconductors

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