Molecular structure, natural bond analysis, vibrational and electronic spectra, surface enhanced Raman scattering and Mulliken atomic charges of the normal modes of [Mn(DDTC)2] complex

Article abstract of DOI:10.1016/j.saa.2016.06.018

Theoretical and experimental bands have been assigned for the Fourier Transform Infrared and Raman spectra of the bis(diethyldithiocarbamate)Mn(II) complex, [Mn(DDTC)2]. The calculations have been based on the DFT/B3LYP method, second derivative spectra and band deconvolution analysis. The UV–vis experimental spectra were measured in acetonitrile solution, and the calculated electronic spectrum was obtained using the TD/B3LYP method with 6-311G(d, p) basis set for all atoms. Charge transfer bands and those d-d spin forbidden were assigned in the UV–vis spectrum. The natural bond orbital analysis was carried out using the DFT/B3LYP method and the Mn(II) hybridization leading to the planar geometry of the framework was discussed. Surface enhanced Raman scattering (SERS) was also performed. Mulliken charges of the normal modes were obtained and related to the SERS enhanced bands.

Full text of DOI:10.1016/j.saa.2016.06.018

Molecular structure, natural bond analysis, vibrational and electronic spectra,
surface enhanced Raman scattering and Mulliken atomic charges of the
normal modes of [Mn(DDTC)2] complex
Claudio A. T e´ llez S., Anilton C. Costa Jr., M.A. Mondrag o´ n, Glaucio
B. Ferreira, O. Versiane, J.L. Rangel, G. M u¨ ller Lima, A.A. Martin
PII:
DOI:
Reference:
S1386-1425(16)30332-8
doi: 10.1016/j.saa.2016.06.018
SAA 14495
To appear in:
Received date:
Revised date:
Accepted date:
30 October 2015
7 June 2016
8 June 2016
Please cite this article as: Claudio A. T ´e llez S., Anilton C. Costa Jr., M.A. Mondrag ´o n,
Glaucio B. Ferreira, O. Versiane, J.L. Rangel, G. M u¨ ller Lima, A.A. Martin, Molecular
structure, natural bond analysis, vibrational and electronic spectra, surface enhanced
Raman scattering and Mulliken atomic charges of the normal modes of [Mn(DDTC)2]
complex, (2016), doi: 10.1016/j.saa.2016.06.018
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Molecular structure, natural bond analysis, vibrational and electronic spectra,
ACCEPTED MANUSCRIPT
surface enhanced Raman scattering and Mulliken atomic charges of the normal
modes of [Mn(DDTC) ] complex.
2
1
2
3
4
Claudio A. Téllez S. , Anilton C. Costa Jr. , M. A. Mondragón , Glaucio B. Ferreira ,
2
1
1
1
O. Versiane , J. L. Rangel , G. Müller Lima , A. A. Martin .
1
Laboratory of Biomedical Vibrational Spectroscopy, IP&D, Research and
Development Institute - UNIVAP, Av. Shishima Hifumi, 2911, Urbanova, 12.224-000,
São José dos Campos, SP. Brazil.
2
Instituto Federal de Educação, Ciência e Tecnologia do Rio de Janeiro (IFRJ),
Unidade de Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
3
Centro de Física Aplicada y Tecnología Avanzada, Departamento de Nanotecnología,
Universidad Nacional Autónoma de México, Boulevard Juriquilla 3001, C.P. 76230,
Querétaro, Qro. México.
4
IQ. UFF. Departamento de Química Inorgânica, Morro do Valonguinho s/n-Centro,
2
4210-150 Niterói, RJ, Brazil.
ABSTRACT
Theoretical and experimental bands have been assigned for the Fourier Transform
Infrared and Raman spectra of the bis(diethyldithiocarbamate)Mn(II) complex,
[
Mn(DDTC) ]. The calculations have been based on the DFT/B3LYP method, second
2
derivative spectra and band deconvolution analysis. The UV-Vis experimental spectra
were measured in acetonitrile solution, and the calculated electronic spectrum was
obtained using the TD/B3LYP method with 6-311G(d, p) basis set for all atoms. Charge
transfer bands and those d-d spin forbidden were assigned in the UV-Vis spectrum. The
natural bond orbital analysis was carried out using the DFT/B3LYP method and the
Mn(II) hybridization leading to the planar geometry of the framework was discussed.
Surface enhanced Raman scattering (SERS) was also performed. Mulliken charges of
the normal mods were obtained and related to the SERS enhanced bands.
Key words: Bis(diethyldithiocarbamate)Mn(II) complex, FT-Infrared and Raman
spectra, DFT method, NBO analysis, UV-Vis spectrum, SERS effect.

Corresponding author. E-mail: cayotellez@gmail.com

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1. INTRODUCTION
The present study includes the bis(diethyldithiocarbamate)Mn(II) complex, herafter
abbreviated as [Mn(DDTC) ], among the [Cu(DDTC) [Zn(DDTC)] and [Co(DDTC)
previously studied and published [1-3]. Although the [Mn(DDTC) ] complex belongs to
2
2
]
,
2
]
2
a very important class of coordination compounds no conclusive structural, vibrational
nor electronic study has been carried out to the best of our knowledge. Due to this lack of
information, we propose for this complex an analysis of a synthesis route based on a
graphical method [4] and a complete spectroscopic study. The structural studies of the
solid marron powder were carried out by means of FT-IR and FT-Raman vibrational
spectra and quantum mechanical theoretical calculations. The Natural Bond Orbital
Analysis (NBO) [5, 6] was also used to study the charge transfer properties in the
complex, and as a way to study the Mn(II) hybridization leading to the planar geometry
of the framework. The UV-Vis spectra were measured in acetonitrile solution, looking
closely to very weak bands observed in the region between 400 to 600 nm; these bands
were assigned as spin forbidden transitions in a tetragonal square planar field. The
transition energies and oscillator strengths were calculated with Time Dependent (TD)
method to assign charge transfer (CT) bands. The theoretical-experimental study of the
vibrational and electronic properties confirmed the proposed structure for this complex.
The Mulliken atomic charges on the atoms in some of the vibrational modes of the
[
Mn(DDTC)
normal mode before the SERS effect. The analysis of the SERS effect [7, 8] of the
Mn(DDTC) ] complex identified which normal modes were intensified more
noticeably.
2
] complex were studied in order to obtain the perturbed geometry of the
[
2
2.
EXPERIMENTAL
2.1. Synthesis of bis-diethyldithiocarbamate Mn(II).
Previously we synthetized the ligand sodium diethylditiocarbamate as follows:
Monosodium DDTC salt was easily synthesized by a carbon disulfide treatment with
diethylamine in the presence of sodium hydroxide. The solid state complex is stable in
air, but its most important property is its protonation in acid solution and subsequent
decomposition into carbon disulfide and protonated amine. The composition is favored
2
+
when the pH of the reaction medium is lower than pKa of the R’RNH ion. The pKa of

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diethyldithiocarbamate acid derived from diethylamine is 3.95 at 19 °C [9]. Thus, the
synthesis must be performed in an optimum pH range, between 5.0 and 7.5, preventing
in this way the decomposition of DDTC and metal hydroxide formation. The definition
of these optimal conditions for the synthesis was evaluated for different pH conditions.
These data were obtained from the graphical method [4] presented in Figure 1S of the
supplementary material. The graph shows that the region of optimum pH to perform
the synthesis of the complex is around 6.5. This allowed us to obtain the complex with
adequate yield and satisfactory purity. The solid obtained after purification was
characterized through typical bands of the ligand in the infrared region observed
-1
between 3000-2900 cm and assigned to (C-H) stretching bands and to (C=N) for
-1
bands between 1500-1400 cm in the samespectrum.
To obtain the [Mn(DDTC)
2
] complex, a solution of diethyldithiocarbamate (5
+
mmol) in 50 mL of deionized water was stirred for 20 minutes reaching a pH3O = 10.
+
-1
The pH3O was adjusted to 8.0 with HNO
3
6 mol.L . Then manganese (II) nitrate
+
(
0.895 g, 5 mmol) was added to this solution and the pH3O was maintained around 8.0.
This control was done using a potentiometer and all the synthesis was carried out
stirring at room temperature. The agitation was maintained for ten minutes until an
ocher solid precipitate was formed, which was then filtered at a reduced pressure and
washed three times with deionized water. The [Mn(DDTC)
inside a desiccator with sulfuric acid.
2
] solid was kept in vacuum
2.2. Synthesis of silver nanoparticles.
The synthesis of the silver nanoparticles (AgNP) was based on the Lee and Meisel
methodology [10] with some modifications. All glassware was washed with deionized
and ultrapure MilliQ water in an ultrasonic bath and dried. In the first step, 200 mL of
ultrapure water were heated to the boiling point. Then 40 mg of AgNO were added
3
while maintaining the temperature. To the heated solution, 1 mL of trisodium citrate
was slowly dropped under vigorous magnetic stirring and the solution was held at
boiling point for 1 h. The resulting solution was cooled in an ice bath and then kept at 4
ºC away from light, by wrapping the flask in aluminum foil. All reagents were
purchased from Sigma Aldrich Company with the highest purity available and the
ultrapure water was obtained through Milli-Q Integral Water Purification System.

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2.3. Sample preparation for SERS.
The AgNPs were placed in 1.5 mL Eppendorf tubes and centrifuged for 3 minutes at
300 rpm to increase the interaction between nanoparticle/volume of sample. The
nanoparticles were washed three times, the liquid was then discarded and the
nanoparticles were removed, mixing them with the [Mn(DDTC) ] sample on a glass
slide. The mixture was lyophilized for 5 minutes to obtain a solid residue.
1
2
3
.
Instrumentation
.1. Infrared and UV-Vis spectra
The Fourier Transform Infrared (FT-IR) spectra of the [Mn(DDTC)
3
2
]
complex
dispersed in a KBr matrix were taken on a Perkin Elmer Spectrum 400 FT-IR
spectrometer equipped with a mercury cadmium telluride (MCT)(far infrared) and
Deuterated Tri Glycine Sulfate (DTGs) detector (mid-infrared). The FT-IR spectra were
-1
-1
collected at a 4 cm resolution in the range between 4000 and 370cm . Spectral
manipulations such as baseline adjustment, smoothing and normalization were
performed using Origin 7.5 software package. The far infrared spectrum was measured
-1
-1
at a 4 cm resolution in the 370 - 30 cm spectral range, with the substance dispersed in
a polyethylene matrix. The UV/Vis absorption spectra were obtained on a Cary 5000
spectrometer from Varian between 200 and 1000 nm in an acetonitrile solution.
3.2. FT-Raman spectra
The FT-Raman spectra of the [Mn(DDTC)
2
] solid sample were measured at room
temperature using a Bruker Spectrometer (model RFS 100/S). The excitation light
source was a 1064 nm Nd:YAG laser . The laser spot size was 200 m in diameter and
the power was kept at 30 mW to prevent any degradation. Instrument parameters: 200
-1
scans, signal gain of 1, a spectral resolution of 4 cm , and aperture setting of 70 nm.
3
.3 SERS spectra
The SERS spectra were acquired on an XploRA micro-Raman (Horiba Jobin Yvon)
system with 785 and 638 nm laser lines, 600 lines/mm grating, LWD x50 objective lens
and the laser spot diameter was around 1μm on the sample. The spectra were collected
-1
at room temperature, in the region between 50 and 800 cm at a spectral resolution of
-1
1
.2 cm , an integration time of 2 seconds and 10 accumulations.

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4. Calculations
The geometry for the neutral complex [Mn(DDTC)
units, was optimized using the Lee-Yang-Parr correlation functional (B3LYP) with the
-311G(d, p) basis set on all the atoms; this computational approach has yield reliable
2
], considered to have no interacting
6
molecular structures as shown in previous studies. Raman and IR wavenumbers, as
well as band intensities, were calculated at the same DFT level using GAUSSIAN 03W
program software suite [11]. The complex optimized geometry is shown in Figure 1. At
the optimized structure of the examined complex, no imaginary wavenumber modes
were obtained, thus proving that the true minimum on the potential surface was found.
Certainly this does not preclude the existence of other minima that could even give
lower energy values with the use of other appropriate basis set for Mn, but for our
purposes the 6-311G(d, p) basis set reproduced well the vibrational wavenumbers. The
assignment of the calculated wavenumbers (characteristic normal stretching and
bending modes of the CH
the CHEMCRAFT program, which gives a visual presentation of the vibrational modes
12], and through the potential energy distribution (PED) obtained using the VEDA 4
2
group) was performed with the aid of the animation option of
[
program [13]. The remaining modes were assigned using PED and in some case using
the percentage deviation of the geometrical parameters (PDPG) from its equilibrium
position [14-17].
Donor- acceptor interactions through the Second Order Perturbation Theory Analysis
of the Fox Matrix in NBO basis [5, 6] at the B3LYP/6-311G(d, p) level were carried out
to rationalize the factors that contribute to the total conformational energy. Mulliken
charge distributions for each normal modes were also calculated using the B3LYP/6-
3
11G(d, p) procedure.
Time dependent (TD-B3LYP) calculations were also carried out to assist in the
assignment of the UV-Vis for the [Mn(DDTC) ] complex in acetonitrile solution.
2
4.1. Optimization of the geometrical parameters
If a molecule has a center of inversion, none of its modes can be both IR and Raman active. In the
Mn(DDTC) complex we observe coincidences in the wavenumbers of active normal modes in
2
both infrared and Raman spectra. Is enough to see the IR and Raman spectra shown in Figure 2
for not consider symmetry with inversion center. Also, the wavenumbers of the different bands are
listed in Table 2. For this reason, we do not consider D symmetry in the whole complex. Other
4
h
reason is, first, to allow the most probable structure of the complex, the first step was to achieve an
approach of the geometry by means of the Molecular Mechanic procedure. In this procedure the

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random orientations of the four –CH -CH groups are orientated in a fixed position. To verify the
2
3
geometry obtained by Molecular Mechanic we calculate the structure by the RM1 semi-empirical
method. The orientations of the –CH groups are in C fashion. Next, using the set of Cartesian
3
2v
coordinates obtained by RM1, we calculated the geometry and structural parameters using the
B3LYP method. The Gaussian program is able to modify the position of the structure searching
the minimum of stabilization energy. At end of the calculation, the results indicate a C symmetry
2
v
for the Mn(DDTC) complex.
2
Results of the Ab initio optimization of the geometrical parameters followed by the
structural analysis of the [Mn(DDTC) ] complex were obtained using the DFT:
2
B3LYP/6-311G(d, p) procedure [11]. The calculated structure pointed a square planar
molecular geometry with symmetry pertaining to the point group C2v. The calculated
bond angles S9-Mn1-S10 and S8-Mn1-S11 were 179.9º. Theoretical values for the Mn-
S, C=N and C-S bond lengths were 2.31, 1.33 and 1.74 Å, respectively. According to
Pauling [18] the manganese-sulfur distance in hauerite with pyrite structure, MnS
2
, is
surprisingly large having a value of 2.70 Å. Our calculated values for the Mn-S
distances in the square planar [Mn(DDTC)
2
] complex resulted 14.4% shorter than the
the Mn-S distance in hauerite.
The five-coordinate, sixteen-electron manganese(I) complex [N(PPh
3
)
2
][Mn(CO)
3
(S,S–
2–
C
6
H
4
)] 1. The strong π-donating ability of the bidentate [S,S–C
6
H
4
] ligand stabilizes
I
the unsaturated complex 1 which has short Mn –S bond lengths of 2.230(1) Å
(average)
as a result [19]. In the compound Mn
2
(phen)Sb
2
S [20] the authors inform textually that
5
of the two unique manganese atoms, Mn(1) atom bonds to three sulfur atoms and two
nitrogen atoms from a phen ligand, forming a distorted square-pyramidal coordination
geometry. The Mn–S bond lengths are in the range of 2.550(1)–2.627(1) Å. Mn(2)
atom is octahedrally coordinated by six sulfur atoms with Mn–S bond lengths between
2
.540(1) and 2.708(1) Å. Calculated selected bond lengths and bond angles for the C2v
symmetry of the Mn(II) complex [Mn(DDTC) ] are given in Table 1.
2

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Figure 1. DFT:B3LYP/6-311G(d, p) calculated structure for the [Mn(DDTC) ]
2
complex. Mn(1), S(8, 9,10,11), C(2, 12), N(3, 13); C(4, 5, 6, 7: 14, 15, 16, 17)
4.2. Vibrational assignments
It was not necessary to use the diffuse functions to calculate the vibrational spectra, but
we have put the results in Table 2, to show that the obtained results are very close to the
result obtained with ordinary functions. The comparison was between the B3LYP/6-311G
and B3LYP/6-311++G(d, p) functions. Otherwise, we can also use a basis set with minor
interactions. For all the functions, there are scale factors to approach the calculated to the
observed values, so the use of the diffuse function appears to be here unnecessary.
Vibrational assignments were carried out with the support of Density Functional
Theory (DFT) calculations using the B3LYP method with a 6-311G(d, p) basis set
having the structural geometry obtained by the same method as starting point.
The calculated
values did not present imaginary frequencies and are listed in Table 2. The experimental
and simulated IR and Raman spectra are found in Figures 2 and 2S of the
Supplementary material, respectively. For the discussion of the vibrational assignments,
we took the DFT values corrected by the scale factor 0.9713 as a base of comparison
[
21] in all fundamental vibrational modes 3n-6 = 105. Some fundamentals were
associated with the second derivative spectrum, Fourier Self deconvolution and with the
deconvolution band analysis (DBA) of the infrared and Raman bands. Assignments
were based on the potential energy distribution (PED) obtained by the VEDA 4
conversion program [13]. As for the [Co(DDTC)
2
] complex [3] the obtained calculated
geometry for the [Mn(DDTC) ] complex is C2v with an irreducible representation equal
2

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to  vibrational = 28a
the infrared spectrum. Therefore all the fundamentals are expected in the Raman
spectrum, from which 80 are infrared active (a , b and b ). In Figure 3S the linear fit
1
+ 25a
2
+ 25b
1
+ 27b
2
, where a
2
vibrational modes are not active in
1
1
2
between calculated and experimental FT-Raman and FT-IR wavenumbers is displayed
with the equation y = 7.89263 + 0.99251x with R = 0.99975.
o
In this equation, the slope of 0.99251 corresponds to an inclination angle close to 45 .
Fig. 2. Experimental spectra of [Mn(DDTC)
bottom). In the middle FT-Raman x 10.
2
]; FT-IR (top) and FT-Raman
(
4.2.1. CH stretching
In the [Mn(DDTC)
2
] complex there are four –CH
3
groups and four –CH groups
2
totalizing 20 stretching (CH) vibrational modes. In the FT-Raman spectrum we
visualize only 8 bands with peaks at 2992, 2977, 2950, 2936. 2915, 2906, 2903 and at
-
1
2
2
895 cm . In the FT-IR spectrum we observed only bands at 2989, 2982, 2976, 2949,
-1
937, 2932, 2920, 2878, and at 2870 cm . Other (CH) stretching were found with the
support of the procedures described above, band deconvolution analysis and by means
of the Fourier self deconvolution. Calculated and experimental –CH stretchings are
given in Table 2. Figure 3 shows the band deconvolution analysis (Gaussian fit) in the
C-H stretching region of the FT-IR and F-Raman spectra.

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Fig. 3. Band deconvolution analysis for the FT-IR (top) and FT-Raman (bottom)
spectra in the (C-H) stretching mode region showing the second derivative
spectra.

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4.2.2. C=N stretching
The C=N stretching bands of weak intensity were found in the FT-Raman spectrum at
-1
-1
1
523 and 1510 cm , and at 1519 and 1511 cm with the assistance of the Fourier self
deconvolution shown in the FT-IR spectrum as shoulders of the band centered at 1497
-1
cm . The potential energy distribution (PED) showed that these vibrational modes were
a combination of the (C=N) and (HCH) stretching and bending internal coordinates.
4.2.3. HCH bending
HCH bendings are considered as characteristic wavenumbers. In the infrared and
Raman spectra, 13 Raman and 11 infrared bands were observed in the region between
-1
1
498 to 1352 cm , with the aid of deconvolution band analysis (DBA) and second
derivative spectra. These bands can be assigned as scissoring, wagging and twisting
vibrational modes. The rocking vibrations in both spectra were found in the region
-1
between 1096 to 1017 cm . The assignments are presented in Table 2. Calculated vs
Experimental FT-IR and FT-Raman spectra for the [Mn(DDTC)
bending vibrations are given in Figure 4S.
2
] complex for the
4.2.4. Skeletal framework vibrations
Due to the higher mixture of the different internal coordinates that take part in the
description of the normal modes, the identification of the metal-ligand vibrations is not
straightforward [22-24]. In spite of this difficulty the PED based assignments localized
-1
-1
one of these modes at 372 cm in the Raman spectrum and at 377 cm in the infrared.
-1
In the infrared spectrum, at 339 cm another (MnS) stretching was found with a
participation of 35%. Since the vibrational irreducible representation for the Mn-S
stretching internal coordinates is equal to vibr.= a
1
(IR, R) + a
2
(R) + b
1
(IR, R) + b (IR,
2
R) the assignment of the four Mn-N stretchings was tried, but the calculated PED [13]
did not give this information due to the considerable mixture of internal coordinates in
the vibrational modes of the low energy region. As an alternative route we look properly
at the L matrix providing the infinitesimal variations of the internal coordinates in the
-1
normal modes. As a result of these procedures the observed Raman band at 372 cm
-1
and the infrared one at 377 cm could be assigned as (MnS) 38% + (SMnS) 18% +
-1

(SCS) 15%. The Raman band observed at 351 cm was assigned as (MnS) 37% +
-1

(SCS) 31%. For the infrared observed band at 339 cm the assignment was (MnS)

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-1
4
9% + (SMnS) 17%. The Raman band of a symmetry observed at 315 cm was
2
ascribed as (MnS) 51% + SC=N) 26%. Earlier discussions of this methodology can
be found in the literature [25].
4.2.5. Torsional vibrations
The characterization of these torsional modes using the DFT results of the normal
modes is rather complicated. The PED results gave between 15 to 11 probable
assignments for these modes due to the different ways to label these coordinates. For
example in the VEDA 4 program [13] some coordinates are named as TORS CCNC,
TORS CSMnS, OUT NSSC. Perhaps same of the out of plane internal coordinates can
be labeled as torsion. In the DFT vibrational analysis eighteen torsion coordinates were
defined for the [Mn(DDTC) ] complex. The assignments are presented in Table 2.
2
5. NATURAL BOND ORBITAL ANALYSIS
NBO analysis [5, 6,] at the B3LYP/6-311G(d, p) level was carried out to rationalize the
factors contributing to the total energy of the Mn complex, Mn(DDTC)
Considering the interaction of alfa electrons, the Mn-S bonds (Mn1-S8 and Mn1-S9)
2
.
0
.04 1.12
were formed by the interaction between a sp
d
(46.36% s, 1.92 % p, 51.71% d)
1
2.03 0.02
orbital centered on the Mn atom, and a sp
d
(7.67% s, 92.20% p, 0.13% d) orbital
centered on the S atom. The electron occupancy in this bond was 0.971. The
polarization coefficient for the bond formation was 15.82% on the Mn atom, and
8
4.18% on the S atom showing a higher polarization through the sulfur atom, thus
indicating a strong ionic character for both Mn -S bonds. For beta electrons the Mn-S
bonds (Mn1-S8 and Mn1-S9) were formed by the interaction of the hybrid orbitals:
0
.04 1.13
sp
sp
d
(46.14% s, 1.93% p, 51.91% d) orbital centered on the Mn atom and a
(8.567% s, 91.32% p, 0.12% d) orbital centered on the S atom. The
1
0.67 0.01
d
polarization on the sulfur atom was around 86% thus showing a higher polarization.
The electron occupancy was 0.973 electrons and the total occupancy was 1.94 electrons.
For alfa electrons these bonds can be represented as:

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0
.04 1.12
12.03 0.02
Mn-S = 0.3978(sp
d
)Mn + 0.9175(sp
d
) .
S
For beta electrons the hybrid orbital representation is:
0
.04 1.13
10.67 0.01
Mn-S = 0.3711(sp
d
)Mn + 0.9286(sp
d
S
) .
The double bond C=N for alfa electrons can be represented as:
1
.83
1.65
C-N = 0.6050((sp
)
C
+ 0.7962(sp
)
N
9
9.99 4.21
99.99 0.39
C-N = 0.5163(sp
d
) + 0.8564(sp
d
N
) ,
and for beta electrons as:
1
.82
1.64
C-N = 0.6050((sp
)
C
+ 0.7962(sp
)
N
9
9.99 3.61
99.99 0.44
C-N = 0.5163(sp
d
) + 0.8564(sp
d
)
N
The total occupancy of the bond was 3.95 electrons thus characterizing the double bond,
where the polarization goes to the nitrogen atom with a mean value of 68.2%. This
unequal sharing of a pair of electrons in the molecular orbital is due, among other
factors, to the difference in electronegativity between the C and N atoms.
C2 – S8 and C2 – S9 bonds
These bonds are composed by the same hybrid orbitals, and their representations for alfa
electrons are:
2
.10 0.00
4.44 0.03

CS = 0.7514(sp
CS = 0.7520(sp
d
)
C
+ 0.6592(sp
d
)S, and for beta electrons:
2
.09 0.00
4.39 0.03

d
)
C
+ 0.6598(sp
d
)
S
The occupancy of the hybrid orbital is 1.983 electrons. The polarization goes to the
carbon atom with 56.55% thus meaning that the bond has a covalent character rather
than ionic.
S10 - C12 and – S11 – C12 bonds
In the same way as above, these bonds are composed by the following hybrid orbitals
represented for alpha electrons as:
4
.32 0.03
2.15 0.00

SC = 0.6592(sp
SC = 0.6600(sp
d
)
S
S
+ 0.7520(sp
+ 0.7513(sp
d
)
C, and for beta electrons:
4
.26 0.03
2.16 0.00

d
)
d
)
C
The occupancy for the S10-C12 bond is 1.983 electrons, and the polarization goes to the

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C atom with 56.54%
S8 - S9 and S10-S11 bridge bond
Centro symmetric polarization for the sulfur atoms, each one with 50%. The summed
occupancy of the alpha and beta electrons is 1.43 electrons showing clearly a very
weak bond. The representation for these hybrid molecular orbitals is:
1
.00 0.00
d
1.00 0.00
SS = 0.7071(sp
)S + 0.7071(sp
d
)S,
5.1. Donor-Acceptor Interactions: Second Order Perturbation Theory Analysis of
the Fox matrix in NBO basis.
-1
Tables 3 and 4 listed the donor and acceptor orbitals and the energy in Kcal.mol . The
most representative interactions are shown in the tables in the NBO/B3LYP
calculations for the Mn(DDTC) complex. The energy gap between the HOMO and
2
LUMO orbitals was -0,1328 a. u. for alpha orbitals and -0.1345 a.u. for beta orbitals
and are graphically represented in Fig.4.
Figure 4. Energy gap between the HOMO and LUMO orbitals for the [Mn(DDTC) ]
2

ACCEPTED MANUSCRIPT
complex.

ACCEPTED MANUSCRIPT
5.
. Molecular Orbitals for [Mn(DDTC)
2
]
The analysis of the molecular orbitals obtained with the CPCM methodology,
which incorporate the solvent effect in MeCN, presented the ground states of the
complex with many occupied molecular orbitals, distributed between –4 and –10 eV.
Table 2S presents the DFT orbitals, the Koopmans’ energy and the Mulliken analysis of
the occupied orbitals. Plots of the low energy occupied and virtual frontier orbitals in
the ground state of [Mn(DDTC)
The Koopmans’ energy difference between the highest occupied and the lowest
unoccupied orbitals, HOMO()–LUMO() gap, was 3.13 eV. HOMO() orbital (a
symmetry) was characterized by 3d metal (~84%). The LUMO() orbital (a symmetry)
2
] are presented in Figure 5.
1
1
characterized by *S-C=N with the participation of the carbon (48%), sulfur (28%) and
nitrogen (17%). The participation of the metal orbitals were consistent with the
5
evaluation of multiple adopts for d manganese (II). Also, the *S-Mn and 
S
orbitals are
identified in the same order in this figure.
Figure 5. Energy levels diagrams of [Mn(DDTC) ], with SCF molecular orbitals within
2
the B3LYP methods.

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6.
Electronic UV-Visible Spectra
Earlier discussions on the UV-Vis electronic spectra of Mn(II) complex can be
found in the literature [26-29]. The UV-Vis spectrum of [Mn(DDTC) ] was taken in
2
acetonitrile solution and was acquired between 200 and 800 nm, using a Cary 5000
spectrometer from Varian. The experimental UV-Vis spectrum between 250 and 330
nm is shown in Figure 6 also with its Gaussian deconvolution; in the same figure the
very low intensity absorption bands in the spectral region between 350 and 650 nm are
also depicted. Figure 5S illustrates the calculated TD/B3LYP spectra in the region
between 200 and 800 nm.
Calculations of the transition energies and oscillator strenghts in the UV-Visible
spectrum of the optimized structure with C2v symmetry were performed with the TD
method using orbitals calculated by the B3LYP procedure. 70 single states were
considered to carry out the calculations. Data from states greater than 0.01 a. u. are
shown in a reduced form in Table 1S(A), and all the information in Table 1S(B) as
supplementary material, respectively. Table 2S describes the different orbitals,
symmetry, energy in eV, and the Mulliken population giving the fundamental
information to understand the assignment nomenclature.
The obtained data in the Gaussian fitting of the experimental spectrum were
compared to theoretical data. Through this analysis presented in Tables 1S(A) and 5, the
following can be stated:
5
(
1) The electronic configuration of the Mn(II) complex is d .
(
2) All transitions from the ground state of Mn(II) involve a change in the spin
multiplicity.
6
(
3) In the weak field, the fundamental state is S.
(4) In the excited states the electronic configuration changes the spin number
4
giving the quartet states (G, F, D, P) in increasing energy order.
(5) d-d transitions must be spin forbidden with very weak intensity.
(
6) The DFT/TD method assigned transitions between 569 and 403 nm as charge
transfer transitions, but we must consider that the CT bands have higher
absorbance or higher oscillator strengths, so the observed transitions at 581

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-1
-1
-1
nm (17212 cm ), 541 nm (18484 cm ), 487 nm (20534 cm ), 446 nm (22422
-1
-1
cm ) and at 406 nm (24631 cm ) can be assigned also to d-d spin forbidden
transitions.
(
7) In a quadratic field of C2v symmetry the d orbitals split as: dyz (B
2
), dxz(B )
1
2
2 2
(lower energy); the following orbitals: d
z
(A
1
), dxy(A
2
) and d
x
- with
y
increasing energy. For each orbital there the spin number can change from
1/2 to -1/2 giving five possibilities of electronic configurations of excited
states with quarts multiplicities. Five very weak bands were observed.
+
(8) The Gaussian fitting of the large main band between 250 and 350 nm gave the
following bands: 243, 255, 258, 262, 271, 284, 300 and 303 nm, which were
assigned as charge transfer bands (CT) as follows: The 243 nm band was compared
with the theoretical one found at 244 nm and was assigned to the transition
*
*
*
S-
Mn (A)
(A) with 40% +  (A) 
(A) with 29% +  (B) 
3
d
S-C=N
S
S-C=N
S
C=N(B) with 21%. The experimental band at 255 nm had the same value as its
*
C-H
*
theoretical equivalent and was assigned to the transition Mn 
+ 
with
S-C
3
d
*
C-H
*
6
0% + Mn3d  
+ 
with 29% with the difference residing in the
S-C
percentage of orbital participation belonging to the C and S atoms for  electrons.
The experimental band at 258 nm had its theoretical counterpart at 257 nm and
*
could be assigned to the transition   Mn with 61% +   
with 24%
S-C=N
S
3d
S
for  electrons. The experimental 262 nm band correlated well with the calculated
*
transition at 259 nm and could be assigned to the transition  
with 41%
S-C=N
S
*
+
  Mn with 38% +   
with 13% for  electrons. The observed
S
3d
S
S-C=N
absorption at 271 nm matched the calculated value at 265 nm and was assigned as:
*
*
S  
with 67% for  electrons +   
with 21% for  electrons. The
S-C=N
S
S-C=N
next observed band at 284 nm matched the calculated value and was assigned as a
single transition between  *S-Mn with 93% for  electrons. However, a
S
theoretical band might be present at 280 nm and could be classified as the multi-
*
reference transition: H-1(A)  Lumo(A) or Mn3d  
(25%) + H-4(B)
S-C=N
*

Lumo (B) or    
(31%). On the other hand the observed band at 300
S-Mn
S+
N
nm agreed well with the calculated band at 299 nm and could be classified as the
*
multi-reference transition: H-1(B) Lumo(B) or   
(61%) +H-3(B)
S-C=N
S
*
*

Lumo (B) or   
(21%) + Homo (A) Lumo (A) or   
S
S-C=N
S
S-C=N
(15%). The experimental and calculated charge transfer bands coincided at 303 nm
*
*
and the assignment was:   
for  electrons with 75% +   
for
S-C=N
S
S-C=N
S

electrons with 18% participation.

ACCEPTED MANUSCRIPT
Figure 6. Experimental UV-Vis spectrum of the [Mn(DDTC) ] complex in
2
acetonitrile solution showing the Gaussian fitting for some observable charge
transfer bands in the region between 250 – 330 nm, and for the spin forbidden
transitions between 400 – 600 nm.
7.
Surface enhanced Raman scattering.
7.1.Intensity comparison between the Raman spectra of [Mn(DDTC)
2
] with and
without AgNP interactions.
In the above discussion, we have presented the vibrational spectra and changes on
the electronic structure through the natural bond orbital (NBO) analysis.
Concerning the SERS effect, we understand that some atoms in the complex
interact with the silver surface, and we do not lose the unity of the complex molecule. We
agree in the sense that there is a single Lewis acid-base interaction mechanism between
the empty d silver orbitals with the free electron pairs of the sulfur atoms. They form an
adduct with the silver surface, such as we have demonstrated in our publication [31]. It is
0
far away the substitution of the Mn(II) ion for metallic silver , Ag . Ligands neutralized
the positive charge of the Mn(II), because each of them is able to form a resonance
structure negatively charged. Far away, if such substitution occurs, metal-ligand vibrations
will be shifted to lower wavenumbers due to the different mass of the metallic central
atom, and such a situation was not observed in the Raman and infrared spectra.
In any way, our intention is to consider that the enhancement of bands is dependent on the
atomic charge distribution. The SERS effect has his own selection rules. The intention is
to infer how could be a probable orientation of the distorted geometry of any normal
mode, which has changed his polarizability related to the polarizability of the equilibrium

ACCEPTED MANUSCRIPT
structure (or not perturbate), with the plasmon interaction which are collective oscillations
of the free electron gas density. Otherwise, the long range manifestation of surface
enhanced Raman scattering can be occur, and it has been shown recently that SERS
enhancement can occur even when an excited molecule is relatively apart from the surface
which hosts metallic nanoparticles enabling surface plasmon phenomena [32], so it is not
meaningless to consider the atomic charge distribution of the complex without a strong
interaction with the metallic surface. Otherwise, such as in the complex formed by lipoic
acid + metallic silver (adduct), the atomic charge distribution of the organic part of the
complex remains almost the same as in the free lipoic acid, and, furthermore, the
wavenumbers of the (CS) normal modes in the free lipoic acid compared with the adduct
-1
formed with silver differ only in 7 and in 5 cm for the symmetrical C-S and
antisymmetric C-S stretching . In lipoic acid we have the following charge distribution
-1
among the sulfur and carbon atoms (bonds S-C) in the normal mode at 621 cm : S(1)
0.146318) C(4)(-0.323090) and S(26) (-0.155471) – C(2)(0.138261). It is
(
-
meaningful to think that in this normal mode under the plasmon interaction (long rang
manifestation) twist the positions of the sulfur and carbon atoms. For the correlate
vibration in the complex formed by the lipoic acid with metallic silver, the charge
distribution in this mode is: S(2) (-0.353198) – C(5) (-0.023088) and S(27) (-0.151903) –
C(3) (-0.145202), so, we can think that in this mode the sulfur and carbon atoms rise a
little bit from the plasmon surface. In any way we are not breaking the SERS selection
rules (absorbate-plasmon), we are only saying that a new orientation occurs in the
geometry of the distorted geometry of the normal mode, nothing else.
We will discuss now the SERS effect where the excited electronic plasmon of
the AgNP acts on the electronic distribution of the [Mn(DDTC)
spectra were acquired on a XploRA micro-Raman (Horiba Jobin Yvon) system with a
85 and 638 nm laser lines, 600 lines/mm grating, LWD x50 objective lens and laser
spot diameter was around 1μm on the sample. The spectra were collected at room
2
] complex. The Raman
7
-1
-1
temperature, in the region between 50 and 800 cm (1.2 cm spectral resolution), 2
seconds and 10 accumulations. Observed band positions in the SERS spectra obtained
with the 785nm excitation line and their assignments are given in Table 2. Raman bands
were enhanced
through the SERS effect observed with the 785 nm laser excitation on similar conditions
with the following results. The total area of the Raman spectra of the [Mn(DDTC) ]
2

ACCEPTED MANUSCRIPT
5
complex without AgNP was 1.19 x 10 [Raman Intensity (Arbitr. Units) x
-1
Wavenumbers (cm )]. The intensity enhancement for the SERS Raman spectra was
5
6
.80 x 10 . The Raman/SERS spectra are shown in Figure 7.
9
6
4
2
0
200
900
600
300
Mn_3_SERS
Mn_2_SERS
Mn_1_SERS
Mn_3)*5
Mn_2)*5
Mn_1)*5
(
(
(
4
00
600
800
1000
1200
1400
1600
1800
-1
Raman shift (cm
)
Figure 7. Comparison between the SERS enhanced Raman scattering spectra of
Mn(DDTC) ] complex on silver nano particles (AgNP) and the Raman spectra
[
2
without AgNP interactions. Both spectra were obtained with a 785 nm excitation
laser.

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7.2.Distribution of the Mulliken atomic charges (MAC) in the SERS enhanced
normal modes.
In the following discussion only the vibrational modes of SERS enhanced bands were
considered. In the normal mode assigned as (HCH)(CH ) with 48% of PED, and
3
-1
observed at 1496 cm the N3 electron donor atom lost 5.07% of its negative charge, and
on the other side of the complex structure the N13 atom won 4.20% of negative charge.
The sulfur atoms S8 and S9 lost 5.5% of negative charge, and the S10 and S11 atoms
had not significant variations in atomic charge. For this mode the SERS enhancement
factor was 54.
-1
For the Raman band observed at 1452 cm and assigned as (HCH)(CH
3
)(CH )
2
scissoring mode, all the –CH and –CH groups in the Mn(II) complex were considered,
3
2
but no VEDA 4 PED values could be obtained because each internal coordinate had
less than 10% contributions, nevertheless the assignment could be done observing the
displacement of all the bending (HCH) internal coordinates. For this particular
vibrational mode the SERS enhancement factor was 32. Symmetrical variations in
atomic charge were found for the following atoms: C(4) and C(15) with a 11%
decrease in their negative charge; C(6) and C(16) showed a 6% increase in their
negative charge. S(8) and S(10) increased their negative charge by 2%, whereas the S(9)
and S(11) atoms decreased their negative charge by 3%. Some H atoms also showed
variations in their atomic charge distribution, for example: H(33) and H(22) increased
their positive charge by 14%; H(32) and H(33) decreased their positive charge in 8%
and H(34) and H(24) increased theirs in 1%.
-
1
Similarly, the vibrational mode found at 1373 cm could be assigned
(HCH)(CH )wagg. + (HCH)(CH ) wagg. with mayor participation of the internal
bending coordinates of –CH groups. For this mode the SERS enhancement factor was
6. Significant charge variations were found for the carbon atoms as follows: C(4) and
as

2
3
2
1
C(14) increased their negative charge in 40% while for C(7) and C(16) the increment
was 15%. Carbon atoms 5 and 15 decreased their negative charges in 28%, whereas the
C(6) and C(17) in 9%.
-1
The wagging vibrational mode (HCH)(CH
3
)(CH ) at 1354 cm had a SERS
2
enhancement of 22 times its normal Raman band. Appreciable Mulliken atomic charge
variations were observed for the atoms: N(13) and N(3) increased their negative charge

ACCEPTED MANUSCRIPT
in 23%; C(6), C(7), C(16), C(17) decreased their negative charge in 13%; All S atoms
increased their negative charge in 8%, and the H(23), H(25), H(32), H(36) increased
their positive charge in 12%.
-1
The SERS enhanced Raman band at 1273 cm experienced an enhancement of 38% and
was assigned as (HCC) with 20% of PED. The contributions of other internal
coordinates to the vibrational mode description were less than 10%. The negative MAC
for the C(2) and C(12) atoms increased in 21% while for the N(3) and N(13) atoms the
increment was 10%. The carbon atoms labeled as 4, 5, 14 and 15 lost negative charge by
1
2%, but the carbon atoms 6, 7, 16 and 17 increased them in 7%. All the sulfur atoms
decreased their negative charge in 22%. Hydrogen atoms labeled 23, 25, 32 and 36 lost
positive MAC by 14%.
-1
The band found at 1149 cm had a SERS enhancement of 75%. No PED was obtained
for this mode because many internal coordinates participated with less than 10%
contributions; in spite of this difficulty the most probable assignment was (HCH)(CH
3
-
)
(CH )twist +  (C=N) + (CNC) + (SCS) in both sides of the complex. Appreciable
2
s
MAC variations were found among the different atoms. N(3) and N(13) decreased their
MAC in 15%; The sulfur atoms lost negative charge by 8%; The hydrogen atoms
labeled 22, 26, 33 and 35 won positive charge by 19% each one, and those labeled 18,
2
2
1, 28 and 31 increased their positive charge in 14%. The hydrogen atoms labeled 22,
6, 33 and 35 had a 19% increment in their positive charge.
-1
The Raman band at 1047 cm assigned as (CH
3
) + (HCH)(CH
2
)twist, with
participation of all the internal coordinates of the –CH
3
and –CH groups, present the
2
following MAC changes before the SERS effect: Carbon atoms, 5 and 4 with an 11%
decrement in their negative charge; 6 and 16 also decreased their negative charge by
1
2%; 7 and 17 increased it in 19%. Sulfur atoms: 8 and 10 decreased their negative
charge in 13% whereas the sulfur atoms 9 and 11 increased it by 9%. Hydrogen atoms:
2
3
2 and 33 decreased their positive charge in 17%; 24 and 34 increased it 16%; 26 and
5 increased 17% their positive charge; 23 and 27 decreased it 13%.
-1
The 886 cm very weak Raman band was SERS enhanced by 66% and assigned as
(CC) with 40% PED, with the following MAC variations: Carbon atoms 67 and 16
decreased in 11% their negative charge; 7 and 17 increased their negative charge in
2%. Sulfur atoms labeled as 8 and 10 decreased their negative charge in 27%, whereas

1

ACCEPTED MANUSCRIPT
the atoms 9 and 11 increased it by 23%. Hydrogen atoms: 21 and 28 increased their
positive charge by 7%, whereas atoms 24 and 34 decreased it by 22%. All these
observations can be obtained by inspection of the Mulliken atomic charges presented in
Table 6.
8
. CONCLUSIONS
Vibrational spectroscopic measurements and normal-mode analysis based on high-
accuracy ab-initio electronic structure calculations have been made for [Mn(DDTC) ].
2
The complete vibrational analysis and SERS of the title compound was performed on
the basis of DFT calculations at B3LYP/6-311G(d, p) basis set. The consistency
between the calculated and experimental FT-IR and Raman data indicated that the
B3LYP/3-21G method could generate reliable geometry and related properties of the
title complex, instead of the other basis set which can also give an accurate geometry.
The assignments for the skeletal vibrations were extremely useful and were based on the
interpretation of the distorted geometry of the normal modes, being centered on the
study of the percentage of energy distribution (PED) obtained by the VEDA 4 program.
In addition, the behavior of donor- acceptor interactions was also calculated in NBO
analysis and charge transfers within different orbitals were also discussed.
The multi-configurational nature of several excited states of the complex involving intra
ligand transitions was also observed. The calculated results were in agreement with the
experimental spectra, confirming the existence of MLCT, LLCT and LMCT transitions.
Analysis of the transition energies, using the TD-B3LYP method, was also in excellent
agreement with the experimental results. For the [Mn(DDTC) ] complex, where the
2
5
Mn(II) is a d system, internal d-d spin forbidden transition of low intensity were also
observed and assigned
Finally, it was possible to conclude that the electron mobility through charge transfer in
the different normal modes occurred independently of the SERS effect. The purpose of
the Mulliken atomic charge analysis in the different normal modes was to find out how
the atomic charge was distributed among the atoms that were more important in the
nucleus movement described by the normal modes. Surface enhanced Raman scattering
due to plasmonic excitation of the nano particles (AgNP in this case) was not observed
when the molecule was in its equilibrium position with a regular and well defined
electronic configuration. Nevertheless, the SERS effect was observed for the different

ACCEPTED MANUSCRIPT
normal modes in which the atomic charges on the atoms had different values from those
at the equilibrium configuration, as was interpreted here.
The Mulliken charge distribution of the vibrational modes gave the instantaneous
charge distribution of the molecule when the SERS effect occurred, so we could infer
different orientations of the molecule interacting with the Plasmon formed by the silver
nano particles.
Acknowledgments
We are grateful to CNPq (project number 47.3901/2008-0), and to the Brazilian agency
CAPES (PNPD. Project number 02526/09-3) for financial support.
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1. Leanne J. Lucas, Claudio Téllez, Maiara L. Castilho, Christopher L. D. Lee,
2
2
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2
3
2
3
Michael A. Hupman, Lais S. Vieira, Isabelle Ferreira, Leandro Raniero and Kevin C.
Hewit, Journal of Raman Spectroscopy, 46(5) (2015) 434-446.
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2. Kukushkin, V. I., Vanikov, A. B., Kukushkin, I. V., JETP Letters, 98(2) (2013) 64-
9.

ACCEPTED MANUSCRIPT
Caption for the figures.
Figure 1. DFT:B3LYP/6-311G(d, p) calculated structure for the [Mn(DDTC)
complex. Mn(1), S(8, 9,10,11), C(2, 12), N(3, 13); C(4, 5, 6, 7: 14, 15, 16, 17).
2
]
Figure 2. Experimental spectra of [Mn(DDTC)
bottom).
2
]; FT-IR (top) and FT-Raman
(
Fig. 3 Band deconvolution analysis for the FT-IR (top) and FT-Raman (bottom)
spectra in the (C-H) stretching mode region.
Figure 4. Energy gap between the HOMO and LUMO orbitals for the
Mn(DDTC) complex.
2
Figure 5. Energy levels diagrams of [Mn(DDTC)
2
], with SCF molecular orbitals
within the B3LYP methods.
Figure 6. Experimental UV-vis spectrum in acetonitrile solution showing the
Gaussian fitting for some charge transfer observable bands in the region between
2
50 – 330 nm, and for the spin forbidden transitions between 400 – 600 nm.
Figure 7. Self enhanced Raman scattering spectra of [Mn(DDTC) ] complex on
2
silver nano particles (AgNP) with the 785 nm excitation laser, compared the
sample without AgNP.
Tables out the main text due his extension:
Table 2 Experimental spectra
Table 6 Mulliken charges

ACCEPTED MANUSCRIPT
TABLE 1. Calculated parameters with B3LYTP using 6-311G(d, p) basis set for
[
Mn(DDTC ) complex of framework group C .
2
2v
Atoms I, j
Bond
lengths (Å)
2.31
Atoms I, j, Bond angles Atoms I, j, Bond angles
k
(º)
k
(º)
R(1-8)
R(1-9)
R(1-10)
R(1-11)
R(2-3)
R(2-8)
R(2-9)
A(8-1-9)
77.5
A(9-1-10)
A(8-1-11)
A(3-2-9)
A(2-3-5)
A(4-3-5)
A(3-5-7)
A(10-12-
179.9
179.9
123.7
120.8
118.3
114.0
112.7
2.31
A(10-1-11) 77.5
2.31
A(8-1-10)
A(8-1-11)
A(1-8-2)
A(2-3-4)
A(8-2-9)
102.5
179.9
84.9
2.31
1.33
1.74
120.8
112.7
1.74
1
1)
A(10-12-
3)
R(3-4)
R(3-5)
1.48
1.48
A(3-4-6)
A(11-12-
114.0
123.7
123.7
1
1
3)
R(4-6)
1.53
1.53
1.74
1.74
1.33
A(3-2-8)
A(1-9-2)
123.7
84.9
R(5-7)
R(10-12)
R(11-12)
R(12-13)
A(1-10-12) 84.9
A(1-11-12) 84.9
A(9-1-11)
102.5

ACCEPTED MANUSCRIPT
Table 2. Experimental FT-IR and FT-Raman and DFT/B3LYP:6-311G(d, p) calculated spectra for the [Mn(DDTC) ] complex
2
-1
(
Wavenumbers in cm ). In the second column Raman intensities and infrared intensities separated by semicolon
B3LYP/6-
B3LYP/6-
B3LYP/6-
Exp. FT-
Raman (1069
nm)
Raman.
FT-
IR.2d.der/BD Assignment. PED values in % obtained
by the VEDA4 program. [13].|x| = x, if x
3
11++G(d, 311++G(d,
311G(d, p)
2der/BDA) IR/(Abs)
A
≥
0; -x, if x < 0 for % values of PED.
p) x
p).Int.Raman (calc. wn) x
2
0
.9713
x 10 ; Int
Infrared
0.9713
/(I :Arbitr.
R
Units)
3
3
3
3
3
3
3
036 (a1)
0.64; 0.07
3026
3026
3021
3021
3006
3006
3004
2992(0.16)
2991/2986
(CH)(CH ) 48%
3
036 (b )
0.43; 85.33
0.00; 0
2989 (0.25) 2991/…
(CH)(CH ) 48%
2
0
3
031 (a2)
031 (b1)
016 (a1)
016 (b2)
014 (a2)
(CH)(CH ) 56%
3
0.14; 7.99
5.16; 18.08
0.70; 9.82
6.36;0
2982 (0.36) …/2983
(CH)(CH ) 56%
3
2977 (0.59)
2976/2976
2976 (0.45) 2975/2975
(CH)(CH ) 40%
3
(CH)(CH ) 40%
3
(CH)(CH ) + (CH)(CH ).
3
2
(participates 20 internal coordinates)
3
3
014 (b1)
009 (a1)
0.46; 44.90
1.30; 11.70
3004
2999
.../ 2961 (CH)(CH ) + (CH)(CH ).
3
2
(participates 20 internal coordinates)
2950 (0.43)
2952/2951
2949 (0.16) 2948/2949
(CH)(CH ) + (CH)(CH ).
3
2
(participates 20 internal coordinates)