Vol.1, No.2, 119-133 (2010)
doi:10.4236/jbpc.2010.12015
Copyright © 2010 SciRes. Openly accessible at http://www.scirp.org/journal/JBPC/
Journal of Biophysical Chemistry
Overtone spectra of porphyrins and its substituted
forms: an algebraic approach
Srinivasa Rao Karumuri1*, Ambati Siva Rama Prasad2, Nirmal Kumar Sarkar3, Joydeep
Choudhury4, Ramendu Bhattacharjee4
1Faculty of Sciences & Humanities, Sri Viveka Institute of Technology (SVIT), Vijayawada, India; *Corresponding Author:
drsrkarumuri@rediffmail.com
2Faculty, Department of Mathematics, P.B. Siddhartha College of Arts & Sciences, Vijayawada, India
3Faculty, Department of Physics, Karimganj College, Karimganj, India
4Faculty, Department of Physics, Assam (A Central) University, Silchar, India
Received 8 June 2010; revised 13 July 2010; accepted 18 July 2010.
ABSTRACT
We introduce an algebraic model to vibrations
of polyatomic Bio-molecules and present, as an
example, the vibrational analysis of Cm-H, Cm-C,
Cm-D, Cb-Cb, pyrrol breathing and Cb-C, stretch-
ing modes of Metalloporphyrins and its substi-
tuted forms. The excited energy levels of Cb-C,
pyrrol breathing stretching modes of Ni(OEP)
and Ni(OEP)-d4 are calculated by using U(2) al-
gebraic mode Hamiltonian. The higher excited
energy levels of Cm-H, Cm-C, Cm-D and Cb-Cb
vibrational modes of Porphyrin and its substi-
tuted forms are predicted upto second overtone.
It shows that the energy levels are clustering at
the higher overtones. The results obtained by
this method are accuracy with experimental
data.
Keywords: Algebraic Model; Vibrational Spectra;
Energy Levels; Metalloporphyrins
1. INTRODUCTION
Recently measurement of highly-excited overtone-com-
bination spectra of molecules have renewed in a theo-
retical description and understanding of the observed
spectral properties. Two approaches have been mostly
used so far in an analysis of experimental data: 1) the
familiar Dunham like expansion of energy levels in
terms of rotations-vibrations quantum numbers and 2)
the solution of Schrodinger equation with potentials ob-
tained either by appropriately modifying ab-initio calcu-
lations or by more phenomenological methods. In this
article, we begin a systematic analysis of overtone-
combination spectra of molecules in terms of novel ap-
proach: 3) Vibron model [1-4]. This model is a formula-
tion of the molecular spectral problem in terms of ele-
ments of Lie algebra and it contains the same physical
information of the Dunham and potential approach.
However, by making use of the powerful methods of
group theory, one is able to obtain the desired results in a
much faster and straightforward way.
In recent years, these polyatomic bio-molecules (i.e
Metalloporphyrins) have numerous importances in the
field of Chemical Physics. In case of polyatomic bio-
molecules the parameters play major role in the Vibron
model. Of course, we have explicitly described with few
parameters, the vibrational bands of the triatomic linear
molecules HCN, OCS, HCP [5-7] and tetratomic mole-
cules HCCF, HCCD by using an algebraic approach [8].
We have also reported the vibrational bands of tetrahe-
dral molecules CCl4, SnBr4 and Propadiene [9-11] and
polyatomic bio-molecules like Nickel Octaethyl porphy-
rin, Nickel porphyrin molecules using U (2) Vibron
model respectively [12-18]. The advantage of the alge-
braic approach, as compared to that of Dunham or pho-
nological potential models, is that typically it requires
few parameters to obtain the same level of accuracy. It
also provides a simultaneous description of bending and
stretching modes [19-25].
In Section 2, review the theory of algebraic model to
polyatomic molecules is described. In Section 3, the
calculation procedure of Vibron number and the fitting
algebraic parameters corresponding to various Porphy-
rins and its substitute form molecule results are dis-
cussed. Finally, the conclusions are presented in Section 4.
2. THEORY: AN ALGEBRAIC
APPROACH
A complete description of the theoretical foundations
S. R. Karumuri et al. / Journal of Biophysical Chemistry 1 (2010) 119-133
Copyright © 2010 SciRes. http://www.scirp.org/ journal/JBPC/
120
Openly accessible at
needed to formulate the algebraic model for a vibrating
molecule. We apply the one-dimensional algebraic model,
consisting of a formal replacement of the interatomic,
bond coordinates with unitary algebras. To say it in dif-
ferent words, the second-quantization picture suited to
describe anharmonic vibrational modes, is specialized
through an extended use of Lie group theory and dy-
namical symmetries. By means of this formalism, one
can attain algebraic expressions for eigenvalues and ei-
genvectors of even complex Hamiltonian operators, in-
cluding intermode coupling terms as well expectation
values of any operator of interest (such as electric dipole
and quadrupole interactions). Algebraic model are not
ab-initio methods, as the Hamiltonian operator depends
on a certain number of a priori undetermined parameters.
As a consequence, algebraic techniques can be more
convincingly compared with semi-empirical approaches
making use of expansions over power and products of
vibrational quantum numbers, such as a Dunham-like
series. However, two noticeable advantages of algebraic
expansions over conventional ones are that 1) algebraic
modes lead to a (local) Hamiltonian formulation of the
physical problem at issue(thus permitting a direct calcu-
lation of eigenvectors in this same local basis) and 2)
algebraic expansions are intrinsically anharmonic at their
zero-order approximation. This fact allows one to reduce
drastically the number of arbitrary parameters in com-
parison to harmonic series, especially when facing me-
dium-or large- size molecules. However, it should also
be noticed that, as a possible drawback of purely local
Hamiltonian formulations (either algebraic or not) com-
pared with traditional perturbative approaches, the actual
eigenvectors of the physical system. Yet, for very local
situations, the aforementioned disadvantage is not a se-
rious one. A further point of import here is found in the
ease of accounting for proper symmetry adaptation of
vibrational wave functions. This can be a great help in
the systematic study of highly excited overtones of
not-so-small molecules, such as the present one. Last but
not least, the local mode picture of a molecule is en-
hanced from the very beginning within the algebraic
framework. This is an aspect perfectly lined up with the
current tendencies of privileging local over normal mode
pictures in the description of most topical situations.
2.1. Hamiltonian Operators
We address here the explicit problem of the construction
of the vibrational Hamiltonian operator for the Metal-
loporphyrin molecules. According to the general alge-
braic description for one-dimensional degrees of free-
dom, a dynamically-symmetric Hamiltonian operator for
n-interacting (not necessarily equivalent) oscillators can
be written as
H = E0 +
1
n
i
AiCi +
n
ij
Aij Cij +
ij Mij (1)
n
ij
In this expresssion, one finds three different classes of
effective contributions. The first one, AiCi
is devo-
ted to the description of n independent, anharmonic
sequences of vibrational levels (associted wih n inde-
pendent, local oscillator) in terms of the operators Ci.
The second one,
1
n
i
n
ij
Aij C
ij leads to cross-anhar-
monicities between pairs of distinct local oscillators in
terms of the operators Cij. The third one,
n
ij
ij M
ij,
describes anharmonic, non-diagonal interactions involving
pairs of local oscillators in terms of the operators Mij.
The Ci, Cij operators are invariant (Casimir) operators of
certain Lie algebras, whilst the Mij are invariant (Ma-
jorana) operators associated with coupling schemes
involving algebras naturally arising from a systematic
study of the algebraic formulation of the one-dimen-
sional model for n interacting oscillators. We work in the
local (uncoupled oscillaators) vibrational basis written as
123
....... n
 
In which the aforementioned operators have the
following matrix elements
4( )
iii
CN
i


4( )()
iji iij ij
CNN
 
 
!!
!(2)
iij j
ijiijji j
MNN

 

!!
!1
11
[(1)()(1)]
iij j
ijiii jjj
MNN
/2
 
 

 
!!
!1
11
[(1)() (1)]
iij j
ijjjj iii
MNN
/2
 
 


We note, in particular, th the expressions above de-
pe
ral Hamiltonian operator (1) can be adapted
to
at
nd on the numbers Ni (Vibron numbers). Such num-
bers have to be seen as predetermined parameters of
well-defined physical meaning, as they relate to the in-
trinsic anharmonicity of a single, uncoupled oscillator
through the simple relation. We report in Table 4 & Ta-
ble 5 the values of the Vibron numbers used in the pre-
sent study.
The gene
describe the internal, vibrational degrees of freedom
of any polyatomic molecule in two distinct steps. First,
we associate three mutually perpendicular one-dimen-
sional anharmonic oscillators to each atom. This proce-
dure eventually leads to a redundant picture of the whole
molecule, as it will include spurious (i.e transla-
tional/rotational) degrees of freedom. However, it is
possible to remove easily such spurious modes through
S. R. Karumuri et al. / Journal of Biophysical Chemistry 1 (2010) 119-133
Copyright © 2010 SciRes. http://www.scirp.org/ journal/JBPC/
121
m-H/Cm-D/Cm-N
st
Openly accessible at
different techniques. One is thus left with a Hamiltonian
operator dealing only with true vibrations. Such modes
are given in terms of coupled oscillators in the local ba-
sis (3). The coupling is induced by the Majorana opera-
tors. A sensible use of these operators is such that the
correct symmetries of vibrational wave functions are
properly taken into account. As a second step, the alge-
braic parameters Ai, Aij, λij of Eq.1 need to be calibrated
to reproduce the observed spectrum. Let us clarify the
actual meaning of these two steps by considering explic-
itly the Cm-H/Cm-D/Cm-N stretches manifold of the
Nickel Metalloporphyrin molecule.
We limit ourselves to in-plane C
retching motions i.e ., without including possible cou-
pling terms with ring deformation. So, we can write for
these remaining four degrees of freedom the Hamilto-
nian operator,
44 4
!
1
CHi iijijijij
iijij
H
ACA CM
 
 
 
The algebraic theory of polyatomic molecules consists
in
For the stretching vibrations of polyatomic olecules
co
p(–βs)] (2)
For
re
the separate quantization of rotations and vibrations in
terms of vector coordinates r1, r2, r3,……. quantized
through the algebra
1
( 2)GU23
(2)(2) ..........U U
m
rrespond to the quantization of anharmonic Morse
oscillators, with classical Hamiltonian
H(ps, s) = ps
2/2μ + D[1 – ex2
each oscillator i, states are characterized by rep-
sentations of
(2) (2)
ii
ii
UO
Nm

(3)
With m = N, N – 2,…..,1 or 0 (N - odd or even). The
M
H = ε0i + A C, (4)
where C is the invar
ε =ε0i+Ai (m2 – N2).
Introducing th number ν =
(N
A (N ν ν2 ). (5)
For non-interac
iiii
orse Hamiltonian (2) can be written, in the algebraic
approach, simply as
ii i
iant operator of Oi(2), with eigen
i
values
ii i
e vibrational quantumi
i-mi)/2, [26] one has
εi =ε0i – 4iiii
ting oscillators the total Hamiltonian is
H = i
i
,
With eigenvalues
E = i
i
= E0
i
4A (N νν2). (6)
2.2. Hamiltonian for Stretching Vibrations
αj sj)], (7)
which
kij si sj .
Interaction of thetaken into account
in
ii ii
The interaction potential can be written as
V(si, sj)=kij´[1 – exp(–αi si)][1 – exp(
reduces to the usual harmonic force field when
the displacements are small
V(si, sj)
type Eq.7 can be
the algebraic approach by introducing two terms [26].
One of these terms is the Casimir operator, Cij, of the
combined (2) (2)
ij
OO
algebra. The matrix elements
of this operator ins Eq. 3 are given by
Ni, νi; Nj, νjCij Ni, νi; Nj, νj = 4[(νi + ν
the basi
j)2
(8)
The operator C
tu
ν)2
(9)
The
op
νi; Nj, νjMijNi, νi; Nj,. νj = (Niνj + Njνi – 2νiνj)
= –10)
Th
of
total Hamiltonian for n stretching vibrations is
H = E0 +
(νi + νj)(Ni + Nj)]
ij is diagonal and the vibrational quan-
m numbers νi have been used instead of mi. In practical
calculations, it is sometime convenient to substract from
Cij a contribution that can be absorbed in the Casimir
operators of the individual modes i and j, thus consider-
ing an operator Cij´ whose matrix elements are
Ni, νi; Nj, νjCij Ni, νi; Nj, νj = 4[(νi + j
(νi + νj)(Ni + Nj)] + [(Ni + Nj)/Ni]4 (Niνi νi
2)
+ [(Ni + Nj)/Nj]4(Njνjνj
2).
second term is the Majorana operator, Mij. This
erator has both diagonal and off-diagonal matrix ele-
ments
Ni,
Ni, νi +1 ; Nj, νj – 1MijNi, νi; Nj,. νj
= – [νj(νi + 1)(Ni νi)(Nj νj + 1)]1/2
Ni, νi – 1; Nj, νj + 1MijNi, νi; Nj,.νj
[νi(νj + 1)(Njνj)(Ni νi + 1)]1/2 (
e Majorana operators Mij annihilâtes one quantum
vibration in bond i and create one in bond j, or vice
versa.
The
1i
n
n
ij
A C +
i iAij Cij +
ij Mij (11)
If λij =0 the vibrations have local behavior. As the λij s
in
ymmetry- Adapted Operators
int group
n
ij
crease, one goes more and more into normal vibra-
tions.
2.3. S
In polyatomic molecules, the geometric po
symmetry of the molecule plays an important role. States
must transform according to representations of the point
symmetry group. In the absence of the Majorana opera-
tors Mij, states are degenerate. The introduction of the
Majorana operators has two effects: 1) it splits the de-
generacies of figure and 2) in addition it generates states
with the appropriate transformation properties under the
point group. In order to achieve this result the λij must be
chosen in an appropriate way that reflects the geometric
symmetry of the molecule. The total Majorana operator
S. R. Karumuri et al. / Journal of Biophysical Chemistry 1 (2010) 119-133
Copyright © 2010 SciRes. http://www.scirp.org/ journal/JBPC/
122
Openly accessible at
S =
n
ij
ij
M
(12)
is divided into subsets reflecting the symmetry of the
S = S + S + -------------. (13)
The operators
op
e
(14)
Where we
(15)
This Hamiltonian
rat
E =
molecule
S, S, ------ are the symmetry-adapted
erators. The construction of the symmetry-adapted
operators of any molecule become clear in the following
sections where the cases of Porphyrins (D4h) discussed.
2.4. Hamiltonian for Bending Vibrations
We emphasize once more that the quantization schem
of bending vibrations in U(2) is rather different from
U(4) and implies a complete separation between rota-
tions and vibrations. If this separation applies, one can
quantize each bending oscillator i by means of an alge-
bra Ui(2) as in Eq.2. The Poschl-Teller Hamiltonian
H(ps, s) = ps
2/2µ - D/cosh2(αs)
have absorbed the λ(λ – 1) part into D, can be
written, in the algebraic approach, as
Hi = ε0i + Ai Ci,
is identical to that of stretching vib-
ion (Eq.3). The only difference is that the coeffici-
ents Ai in front of Ci are related to the parameters of the
potential, D and α, in a way that is different for Morse
and Poschl-Teller potentials. The energy eigenvalues of
uncoupled Poschl-Teller oscillators are, however, still
given by
i
i
n pro
= E0 – 4Ai (Ni νiνi
2). (16)
One ca
pr
e Metalloporphyrin Molecule
rators and
types
of
ent interactions)
s)
th
ij ijij Mij.
c12 = c23 = c34 = c45= - - - - - = 1, c13 = c24 = c35 = c46
i
coupn theceed to le the oscillators as done
eviously and repeat the same treatment of Eqs.2, 3,
and 4.
2.5. Th
The construction of the symmetry-adapted ope
of the Hamiltonian operator of polyatomic molecule illu-
strated using the example of Metalloporphyrin. In order
to do the construction, draw a figure corresponding to
the geometric structure of the molecule (Figure 1).
Number of degree of freedom we wish to describe.
By inspection of the figure, one can see that two
interactions in Metalloporphyrin:
1) First-neighbor couplings (Adjac
2) Second–neighbor couplings (Opposite interaction
With D4h symmetry here, the operators (on the basis of
e considerations mentioned above) are
n
S=
n M, S=
n
ij
ij
SM
,
ij
c
ij
c
C
b
C
b
C
a
Y
Y
C
a
C
m
C
m
N
Ca C
b
C
b
C
a
N
C
m
C
a
C
b
C
b
M
C
a
C
b
C
b
C
a
N
C
m
Y
Y
Y
Y
Y
Y
Ca
XX
X
X
N
12
3
4
Figure 1. The structure of Metalloporphyrin.
yl
- - - - - =0,
34 = c45 = - - - - - = 0, c13 = c24 = c35
7)
Diagona
se
. RESULTS AND DISCUSSIONS
e have used U (2) algebraic model to study vibrational
Ni (OEP) X = H, Y = Ethyl,
Ni (OEP)-d4 X = D, Y = Ethyl.
Ni (TPP) X = Phen, Y = H,
Cu (TMP) X = Mesityl, Y = H.
Ni Por X = H, Y = H.
=
c12 = c23 = c
= c46 = - - - - - = 1, (1
lization of S produces states that carry repre-
ntations transform according to the representations A1g,
B1g, A2g, B2g, and E1u of D4h. The S operator is thus the
“symmetry adapter” operator. This result, which, at first
sight, appears to be surprising, can be easily verified by
computing the characters of the representations carried
by the eigenstates of S in the usual way. Here, in this
case the value of n is either 4 (j = 4, i = 3) or 8 (j = 8, i =
7).
3
W
spectra of the Porphyrin and its substituted form mole-
cules. The fitting algebraic parameters are A, A΄, λ, λ΄
and N (Vibron number). The values of Vibron number (N)
can be determined by the relation
1
e
i
ee
Nx
, (i = 1, 2,……) (18)
where
e and
exe are the spectroscopic constants of
diatomic molecules [27]. This numerical value must be
seen as initial guess; depending on the specific molecu-
lar structure, one can expect changes in such an estimate,
which, however, should not be larger than ± 20% of the
original value (Eq.18). The Vibron number N between
S. R. Karumuri et al. / Journal of Biophysical Chemistry 1 (2010) 119-133
Copyright © 2010 SciRes. http://www.scirp.org/ journal/JBPC/
123
rting guess for the
pa
(N – 1). (19)
In the pre
co
the diatomic molecule C-C, C-H and C-D are 140, 44
and 59 respectively. From the figure 1, it is noticed that
some of the bonds are equivalent. It may be noted that
during the calculation of the vibrational frequencies of
Porphyrins and substituted forms, the value of N is kept
fixed and not used as free parameter.
The second step is to obtain a sta
rameter A. As such, the expression for the single-
oscillator fundamental mode as
E (ν = 1) = –4 A
sent case we have three different energies,
rresponding to symmetric and antisymmetric combi-
nations of the different local modes. A possible strategy
is to use the center of gravity of these modes, so the
guess for
Openly accessible at
4(1 )
E
AN
(20)
The third step is to obtain an initial guess for λ. Its
role is to split the initially degenerate local modes,
placed here at the common value E used in Eq.19. Such
an estimate is obtained by considering the simple matrix
structure, we can find
1
2
EuA g
EE
N
(21)
& 21
!
4
Bg Ag
EE
N
(22)
Finally a numerical fitting procedure is to be carried
to
are calcu-
la
study the
hi
4. CONCLUSIONS
nted a systematic analysis of
st
f the method is that it allows one to
do
MENTS
e to thank Prof. Thom-
adjust (in a least- square sense, for example) the para-
meters A and λ starting from values Eq.20 and Eq.21,
and A΄ (whose initial guess can be zero).
Using the Eqs.20, 21 and 22, A,
and
ted [4,5-7,27] using the available data points. We have
taken
 = 0 (In this case, the next nearest neighbor
couplings are omitted). As one can see from Table 1 &
Table 2, the agreement with experiment is good and thus
we think that the parameter set of Table 4 & Table 5 can
be used reliably to compute energies of highly excited
overtones. We note that in Table 2 & Table 3, there are
many predicted overtones that have not been studied
experimentally. We have explicit calculations up to the
second overtone (energy up to 10000 cm-1).
We have used the algebraic Hamiltonian to
ghly excited vibrational levels of the molecule Ni
(TPP), Cu (OEP), Mg (OEP), Cu (TPP), Cu (TMP), Ni
Porphyrin, Ni (OEP) and its substitution form Ni
(OEP)-d4. Eight bands are studied, which can be labeled
the Cm-H, Cb-Cb and only for Ni (OEP)-d4 the bands
labeled are Cm-D, Cb-Cb respectively. The highly excited
vibrational levels, calculated by using the algebraic
Hamiltonian Eq .11, are shown in Figures 2, 3, 4, and 5
(The detail calculated vibrational energy levels are listed
in Tables 3). Figures 2 and 3 gives the levels corre-
sponding to the Cm-H, Cb-Cb of Ni (TPP). Figures 4 and
5 gives the levels corresponding to the Cm-H, Cb-Cb of
Cu (TPP). Figures 6 and 7 gives the levels correspond-
ing to the Cm-H, Cb-Cb of Cu (TMP). Figures 8 and 9
gives the levels corresponding to the Cm-D, Cb-Cb of Ni
(OEP)-d4. When the quantum number ν increases in a
fixed band, the numbers of energy levels increase rapidly.
Usually, the degeneracy or quanti-degeneracy of energy
levels is called clustering. It may be seen from Figures 2,
3, 4, 5, 6, 7, 8 and 9 that the vibrational energy levels of
Porphyrin and its substituted form make up clusters.
In this paper, we have prese
vibrational spectra of Porphyrin and its substituted
forms in the algebraic framework making use of the
one-dimensional Vibron model i.e. U (2) Vibron model.
Using the U (2) algebraic model Hamiltonian, the
retching frequencies of Cb-C and Pyrrol breathing up to
Second overtone (
= 2), the combinational bands of
Nickel Octaethyl Porphyrin [Ni(OEP)] and its substitu-
ted form Ni(OEP)-d4 molecules are given in Table 2.
However, due to lack of sufficient data base, we could
not compare the calculated vibrational frequencies with
that of observed data of Nickel Metalloporphyrin and its
substituted forms at higher overtones. This study is use-
ful to the experimentalist to analyze the predicted vibra-
tional frequencies with the observed data. The model pre
sented here describes the splitting of local stretch-
ing/bending modes due to residual interbond interactions.
The splitting pattern determines the nature of interaction
(Parameter
׳). Once we get the parameter, we predict
the splitting pattern of overtones. It is worth to point out
that most applications of previous algebraic models
available in literature [28-33] are restricted to vibrations
of Bio-molecules.
The importance o
a global analysis of all molecular species in terms of
few algebraic parameters. In turn provides a way to
make assignments of unknown levels or to check as-
signments of known levels. The study of vibrational ex-
citations of these bio-molecules (proteins) has numerous
importance not only in human life but also in scientific
research.
5. ACKNOWKEDGE
The author Dr. Srinivasa Rao Karumuri would lik
son G Spiro for providing the necessary literature for this study. The
authors Dr.Srinivasa Rao Karumuri and Prof. Ramendu Bhattacharjee
are grateful to the DST, New Delhi for supporting this work. The au-
thor is very much grateful to the anonymous referee of this paper for
his valuable suggestions and comments, which greatly helped to im-
prove the quality of the paper.
S. R. Karumuri et al. / Journal of Biophysical Chemistry 1 (2010) 119-133
Copyright © 2010 SciRes. http://www.scirp.org/ journal/JBPC/Openly accessible at
124
etween the Observed and Calculated frequencies of the fundamental vibrations of Porphyrin and its
Obs(cm-1) ECalc(cm-1) Δ (Obs-Calc) (cm-1) EObs(cm-1) ECalc(cm-1) Δ (Obs-Calc)(cm-1)
Table 1. Comparison b
substitution forms.
Sym E
Ni (OEP) Molecule Ni Porphyrin Molecule
Cm-H vibrationamode l
A1g(1) 3041 3041.9321 3042 3042.0322 -0.0322 -0.9321
B2g(27) 3041 3040.8903 +0.1103 3041 3041.0420 -0.0420
E1u(36) 3040 3040.0189 -0.0189 3041 3041.4001 -0.4001
Cb-Cb vibrate ional mod
B1g(2) 1602 1602.0445 1579 1579.0590 -0.0590 -0.0445
A1g(11) 1577 1577.9601 -0.9601 1509 1509.0589 -0.0589
E1u(38) 1604 1604.2822 -0.2822 1547 1548.9754 -1.9754
Cu (OEP) M Mg (Oolecolecule EP) Mule
Cm-H vibrational mode
A1g(1) 3041 3042.3001 3041 3039.3000 +1.7000 -1.3001
B2g(27) ........ 3052.3226 ......... ........ 3052.3207 .........
E1u(36) ........ 3062.2923 ......... ........ 3062.2910 .........
Cb-Cb vibrational mode
B1g(2) 1592 1594.6856 ....... 1596.8243 ........ -2.6856
A1g(11) 1568 1575.6450 -7.6450 1578 1578.0634 -
PP) Mole Cu Molecu
0.0634
E1u(38) ....... 1613.7239 ........ ....... 1615.58 ........
Ni (Tcule (TPP)le
Cm-C vibrational mode
A1g(1) 1235 1234.4200 1234 1235.6438 -1.6438 +0.5800
B2g(27) 1269 1270.6832 -1.6832 ......... 1245.0709 .........
E1u(36) ........ 1306.9467 ........ ......... 1271.1534 .........
Cb-Cb vibrational mode
B1g(2) 1572 1571.9300 1530 1532.5800 -2.5200 +0.0700
A1g(11) 1504 1504.6540 -0.6540 ......... 1524.7402 .........
E1u(38) ....... 1639.2243 ......... .
(OEP)-d4
........
1626.8234 .........
Ni Cu (TMP)
Cm-D vibrational mode Cm-C vibrational mode
A1g(1) 3041 1236.8843 -1.8843 3038.6800 +2.3200 1235
B2g(27) 3041 3040.4000 +0.6000 ........ 1246.3940 .......
E1u(36) 3041 3042.1219 -1.1219 1256 1256.7238 -
Cb-Cb vibrate
0.7238
ional mod
B1g(2) 1602 1602.0484 1567 1567.5587 -0.5587 -0.0484
A1g(11) 1576 1577.9629 -1.9629 1495 1495.2902 -0.2902
E1u(38) 1604 1604.2889 -0.2889 ------- 1639.7793 ........
S. R. Karumuri et al. / Journal of Biophysical Chemistry 1 (2010) 119-133
Copyright © 2010 SciRes. http://www.scirp.org/ journal/JBPC/Openly accessible at
125
Table arison betwe Observculated freqb-C stretching vibrickel Oyl Por-
phyrin [Ni(OEP)] and its substited form i.e 4.
2. Compeen th
tu
ed and Cal
Ni(OEP)-d
uencies of Cations of Nctaeth
n species EObs(cm-1) ECalc(cm-1)
Δ
(Obs-C -1 -1 -1 -1
alc) (cm) EObs(cm) ECalc(cm) Δ(Obs-Calc)(cm )
Ni(OPculei(Eolecu E) Mole NOP)-d4 Mle
C-C vibrational
bmode
A1g (5) 1025 1729 1.8271 1043.3471 -18.3471 1026 1024.
B1g (14) 1151 1134.4480 1187 1168.2545 18.7455
tone
16.5520
A2g (23) 1022 1045.5548 -23.5548 1029 1026.7901 2.2099
B2g (31) 1019 1010.5280 8.4720 999 1006.2923 -7.2923
Eu (43) …… 1159.4680 ………. 1165.7804
Eu (45) ……. 994.4080 ………. 978.6798
First Over
A 1831 1828 4.3351
1g(5+6)1837.3438 -6.3438 1823.6649
Eu 1981.8380 1924.4935
A1g(23) 2135 -10.06 2216 -30.47
A1g(31) 2494 3.8610 2460 7.3031
Second Overtone
B1g 2039.4881 1948.6704
A2g 2040.7594 2019.2772
Eu 2089.0281 2088.5504
Eu 2126.0643 2189.3792
22+2145.5906 592246.3847 38
Eu 2190.3683 2289.3098
Eu 2261.3456 2293.3070
B1g 2289.6720 2309.3572
Eu 2324.6758 2365.8686
Eu 2356.7683 2371.8268
Eu 2454.6856 2398.7437
Eu 2488.9103 2404.7578
28+2490.1380 2452.6969
B1g 2497.4836 2479.8699
A1g 2502.3920 2529.2334
Eu 2519.2033 2530.8538
A2g 23) 2541 3.72539 -2.9693
A2g(29) 2568 -1.3040 2607 -2.5773
B1g(14) 2670 -19.94 2710 6.6453
E
Pyr breathing vibrational mode
(3+2537.2890 110 2541.9693
14+2569.3040 2609.5773
Eu 2582.2093 2601.3572
A1g(19+23) 2614 2606.4803 7.5197 2604 2599.9575 4.0425
3+2689.3094 302703.3547
Eu 2730.3802 2734.8643
A1g 2772.9689 2767.8346
u 2826.3283 2798.3468
A1
g
(
6
)
806 1.82418020.3622804.1759 801.6378
B1
g
(15) 761 751.2534 758759.7356 -1.73569.7466
E
u
(47) …… 765.7932 783.3495
First Overtone
A1
g
1496.0304 1398.7654
E
u
1524.7395 1404.8475
E
u
1548.6704 1439.8364
B1
g
(16) 1557 -2.277214814.1636
6+1559.2772 1476.8364
Eu 1668.5904 1558.8239
S. R. Karumuri et al. / Journal of Biophysical Chemistry 1 (2010) 119-133
Copyright © 2010 SciRes. http://www.scirp.org/ journal/JBPC/Openly accessible at
126
Eu 1782.3804 1702.7529
A1g 6) 1831 -33.26 1828 2.5296
Second Overtone
(5+1864.0326 031825.4704
Eu 1893.4056 1870.7354
Eu 1899.0328 1892.7253
A2g(21) 2109 -22.44 214 10.6 6+2131.9844 9812103.7364 263
B1g(6+20) 2144 2148.4379 2148 2152.7856 -4.7856
0
24
1g
A2g(19) 2626 9.1962 2628 -1.7439
E
-4.4379
A1g(4+6) 2184 2231.9844 -47.9844 2189 2190.4356 -1.4356
Eu 2260.5412 2237.2455
Eu 2339.6766 2290.5472
A1g 2310.9441 2367.3864
Eu 2363.584 2443.9763
Eu 2417.2044 2489.8322
Eu 81.1734 2547.3453
B2542.5424 2601.3643
5+2616.8038 2629.7439
u 2683.3023 2668.5233
Os takeneferenc
Tcies of Cm-H stretching vibrations of Porphyrins & its substituted forms (Cm-1).
bserved value from the re [34-36]
able 3. Calculated excited vibrational frequen
Sym EObs E
Calc E
Obs E
Calc E
Obs E
CalC E
Obs E
Calc
Ni (OEP) Ni Porphyrin Cu (OEP) Mg (OEP)
12.30 A
1g(1) 3041 304.93 3042 3042.03 3041 3042.30 3041 304
n = 1 3052.32
1g 942.44 951.37 946.23 923.63
= 2
1u 708.52 731.73 709.53 676.95
= 3
lculated eited vibrationcies of C
B2g(27) 3041 3040.89 3041 3041.04 ........ 3052.32 ........
E
1u(36) 3040 3040.01 3041 3041.40 ........ 3062.29 ........ 3062.29
E
1u 5941.47 5951.92 5945.15 5922.78
B 5 5 5 5
A
2g 5944.38 5951.73 5947.14 5924.36
n E1u 5945.16 5952.00 5948.14 5924.89
E
1u 5946.84 5953.35 5986.70 5924.65
E
1u 5947.29 5953.72 5994.28 5925.15
E
1u 5948.07 5954.35 6007.48 5925.94
A
1g 8707.29 8730.98 8708.54 8676.16
E 8 8 8 8
E
1u 8708.97 8731.97 8709.90 8677.24
E
1u 8709.75 8732.33 8712.60 8679.38
B
1g 8712.30 8731.90 8713.53 8680.12
n E1u 8713.45 8732.96 8812.42 8681.44
E
1u 8715.91 8735.95 8853.97 8683.71
A
1g 8716.09 8735.02 8858.35 8683.79
E
1u 8703.35 8737.94 8874.75 8684.60
E
1u 8717.14 8737.94 8899.68 8685.87
B
1g 8712.13 8738.08 8904.67 8691.29
E
1u 8719.56 8738.93 8921.42 8695.86
Ca xcnal freque
b
- C
b
stretratioof Porphyrinbstitd forms ching vibns s & its suute
Sym E E
Calc Obs E
Calc E
Obs E
Ca E
Obs ECalc
Obs E lC
S. R. Karumuri et al. / Journal of Biophysical Chemistry 1 (2010) 119-133
Copyright © 2010 SciRes. http://www.scirp.org/ journal/JBPC/Openly accessible at
127
P) Ni (OEP) Ni Por Cu (OEP) Mg (OE
1596.82 B
1g(2) 1602 1602.04 1579 1579.05 1592 1594.68
n = 1 578.06
1u 159.17 033.88 157.61 142.67
= 2
1u 720.62 559.73 707.83 695.26
= 3
Calculated excited vibrational s of -C & Cm-D vibrons of Porphs substituted forms
A1g(11) 1577 1577.96 1509 1509.05 1568 1575.64 1578 1
E
1u(38) 1604 1604.28 1547 1548.97 1613.72 1615.58
A
2g 3143.88 3021.25 3138.57 3137.07
E 3 3 3 3
B
2g 3170.90 3061.13 3164.55 3144.71
n E1u 3183.36 3161.24 3176.65 3148.27
E
1u 3192.04 3081.13 3190.09 3174.59
E
1u 3200.82 3231.24 3195.69 3181.43
E
1u 3216.12 3068.45 3215.85 3193.35
A
1g 4696.54 4539.77 4688.79 4689.66
E 4 4 4 4
E
1u 4729.40 4567.02 4714.77 4697.30
E
1u 4744.70 4579.69 4766.28 4712.45
B
1g 4794.54 4621.02 4783.99 4717.66
n E1u 4816.94 4639.59 4869.11 4820.98
E
1u 4865.10 4679.51 4878.12 4827.54
A
1g 4868.71 4682.52 4894.87 4839.74
E
1u 4817.61 5183.77 4925.89 4862.25
E
1u 4889.18 4699.48 4927.63 4867.88
B
1g 4762.34 4889.77 4933.51 4872.57
E
1u 4895.60 4939.95 4874.32
frequencie Cmstretching atiyrins & it
Sym EOb E
Calc E
Ob Calc E s E
CalC E s E
Calc
s s E Ob Ob
) Ni (TPP) Cu (TPP) Cu (TMP Ni (OEP)-d
4 (Cm - D
3038.68 A
1g(1) 1235 1234.42 1234 1235.64 1235 1236.88 3041
n = 1 2710.40
1g 495.39 427.57 474.51 953.77
= 2
1u 713.46 554.51 692.22 776.62
= 3
B2g(27) 1269 10.68 245.07 1246.39 3041 304
E
1u(36) 1306.94 1271.15 1256 1256.72 3041 3042.12
E
1u 2459.13 2417.34 2464.18 5952.05
B 2 2 2 5
A
2g 2508.62 2436.20 2475.39 5953.91
n E1u 2531.65 2452.85 2484.84 5955.49
E
1u 2777.49 2459.33 2524.26 6007.76
E
1u 2835.59 2470.61 2535.23 6017.93
E
1u 2936.67 2445.64 2554.31 6035.62
A
1g 3674.12 3545.08 3681.89 8774.90
E 3 3 3 8
E
1u 3710.38 3557.95 3695.99 8777.25
E
1u 3821.69 3583.47 3702.55 8778.34
B
1g 4321.98 3633.87 3723.94 8781.91
n E1u 3855.42 3669.38 3804.16 8888.28
E
1u 4470.02 3675.60 3832.11 8914.19
A
1g 4788.38 3687.14 3892.19 8969.91
S. R. Karumuri et al. / Journal of Biophysical Chemistry 1 (2010) 119-133
Copyright © 2010 SciRes. http://www.scirp.org/ journal/JBPC/Openly accessible at
128
E
1u 4812.25 3704.90 3902.71 8979.66
E
1u 4947.56 3708.45 3922.24 8997.77
B
1g 5138.57 3617.35 3952.28 9025.63
E
1u 5187.30 3718.93 3958.29 9031.21
Calculated eited vibrationcies of Cb-Cb stretationof Porphyrinstitud forms xc nal freque ching vibrs s & its subte
Sym EObs Calc E
Obs E
Calc E s E
CalC E
Obs E
Calc E Ob
Ni (TPP) Cu (TPP) Cu (TMP) Ni (OEP)-d
4
(1602.04 A
1g 1) 1572 1571.93 1530 1532.58 1567 1567.55 1602
n = 1 B2g(27 11577.96
1g 062.66 027.25 229.30 159.17
1u 571.45 478.84 810.31 720.62
= 3
) 1504 504.65 1524.74 1495 1495.29 1576
E
1u(36) 1639.22 1626.82 1639.77 1604 1604.28
E
1u 3035.20 3018.75 3201.84 3143.88
B 3 3 3 3
A
2g 3065.00 3034.43 3231.64 3170.90
E
1u 3090.13 3042.27 3256.77 3183.36
E
1u 3169.76 3120.83 3346.37 3192.04
E
1u 3194.32 3139.46 3372.75 3200.82
E
1u 3237.05 3171.88 3418.64 3216.12
A
1g 4543.99 4471.00 4782.85 4696.54
E 4 4 4 4
E
1u 4581.48 4481.70 4820.34 4729.40
E
1u 4598.92 4502.90 4837.78 4744.70
B
1g 4655.78 4678.74 4894.64 4794.54
E
1u 4817.83 4726.22 5076.98 4816.94
n E1u 4880.41 4828.30 5144.19 4865.10
A
1g 5014.97 4846.17 5288.72 4868.71
E
1u 5038.52 4879.35 5314.01 4817.61
E
1u 5082.26 4930.39 5360.99 4889.18
B
1g 5149.54 4940.60 5433.26 4762.34
E
1u 5163.00 4945.56 5447.71 4895.60
TVa lueof Algebraic Parame in the calculatio, CStretchin of rphyrins ansti-
tuted forms.
(C
m -D)
able 4. s (a ) ters Usedn of Cm-H m-D g ModesPod its sub
Ni(OEP) Cu(OEP) Mg(OEP) Ni(TPP) Cu(TPP) Cu(TMP) Ni Por Ni(OEP)-d
4
N 44 44 44 44 44 44 44 59
A -12 -10 -14 -2 -70 -23 - -13
0
7.680 7.6827.61.213.174.21717.653.04
A΄ -0.24 -0.25 -0.28 -0.9985 -0.4302 -1.0182 -1.3108 -0.2782
λ 0.014 .011360.009 0.1295 0.1072 0.0369 0.0113 0.0146
λ΄ 0.011 0.012 0.012
0.5685 0.2018 0.1073 0.0021 0.2361
(a) All values in cm-1 except N, which is dimensionless.
S. R. Karumuri et al. / Journal of Biophysical Chemistry 1 (2010) 119-133
Copyright © 2010 SciRes. http://www.scirp.org/ journal/JBPC/
129
Table Va lu e s (a) ofbbtretching Modes of Porphyriforms.
Ni(OEP) Cu(OEP) Mg(OEP) Ni(TPP) Cu(TPP) Cu(TMP) Ni Por Ni(OEP)-d
4
5. Algebraic Parameters Used in the calculation of C-C Sns and its substituted
N 140 140 140 140 140 140 140 140
A -2.83 -2.825 -2.835 -2.7205 -2.7502 -2.8825 -2.691 -2.83
A΄ -1.223 -1.286 -0.452 -1.986 1.0921 -1.223 -3.216 -1.223
λ 0.086 0.068 0.067 0.2403 0.028 0.2581 0.0713 0.086
λ΄ 0.047 0.092 0.020 0.0981 0.1823 0.0981 0.25 0.047
(a) All values in cm-1 except N, which nsionles
is dimes.
Figure 2. Cm-H band vibrational energy level of Ni(TPP).
Figure 3. Cb-Cb band vibrational energy level of Ni(TPP).
Openly accessible at
S. R. Karumuri et al. / Journal of Biophysical Chemistry 1 (2010) 119-133
Copyright © 2010 SciRes. http://www.scirp.org/ journal/JBPC/
130
Figure 4. Cm-H band vibrational energy level of Cu(TPP).
Figure 5. Cb-Cb band vibrational energy level of Cu(TPP).
Figure 6. Cm-H band vibrational energy level of Cu(TMP).
Openly accessible at
S. R. Karumuri et al. / Journal of Biophysical Chemistry 1 (2010) 119-133
Copyright © 2010 SciRes. http://www.scirp.org/ journal/JBPC/
131
Figure 7. Cb-Cb band vibrational energy level of Cu(TMP).
F
igure 8. Cm-H band vibrational energy level of Ni(OEP)-d4.
Figure 9. Cb-Cb band vibrational energy level of Ni(OEP)-d4.
Openly accessible at
S. R. Karumuri et al. / Journal of Biophysical Chemistry 1 (2010) 119-133
Copyright © 2010 SciRes. http://www.scirp.org/ journal/JBPC/
132
REFERENCES
[1] Iachello, F. (1981) Algebraic methods for molecular rota-
tion-vibration spectra. Chemical Physics Letters, 78(3),
581-585.
[2] Iachello, F. and Levine, R.D. (1982) Algebraic approach
to molecular rotation-vibration spectra. I. Diatomic mole-
cules. Journal of Chemical Physics, 77(6), 3046-3055.
[3] Van Roosmalen, O.S., Dieperink, A.E.L. and Iachello, F.
(1982) A dynamic algebra for rotation-vibration spectra
of complex molecules. Chemical Physics Letters, 85(1),
32-36.
[4] Van Roosmalen, O.S., Iachello, F., Levine R.D. and Die-
perink, A.E.L. (1983) Algebraic approach to molecular
rotation–vibration spectra. II. Triatomic molecules. Jour-
nal of Chemical Physics, 79(6), 2515-2536.
[5] Sarkar, N.K., Choudhury, J. and Bhattacharjee, R. (2006)
An algebraic approach to the study of the vibrational
spectra of HCN.
[6] Sarkar, N.K., Chou
Algebraic approach: Study of vibrational spectra of some
olecules. Indian Journal of Physics
tra of OCS and HCP using the Lie algebraic
-
ury, J., Karumuri, S.R., Sarkar, N.K. and Bhat-
. (2008)
(2), 020308.
evelopment,
aic approach.
ing and bending modes of Nickel Tetra Phenyl Porphyrin:
An algebraic approach. Chinese Physics Letters, 26(9),
093301.
[16] Karumuri, S.R., Sarkar, N.K., Choudhury, J. and Bhat-
tacharjee, R. (2009) U(2) algebraic model applied to
stretching vibrational spectra of Metalloporphyrins. Jour-
nal of Molecular Spectroscopy, 255(2), 183-188.
[17] Karumuri, S.R. and Prasad, A.S.R. (2009) Analysis of
vibrational spectra of Copper Octaethyl Porphyrin [Cu
(OEP)] using U(2) algebraic technique. International
Journal of Computational Mathematical Ideas, 1(3), 68.
[18] Karumuri, S.R., Choudhury, J., Sarkar, N.K. and Bhat-
tacharjee, R. (2010) Vibrational spectroscopy of Cm-C/
Cb-Cb stretching vibrations of Copper Tetramesityl Por-
phyrin Cu (TMP): An algebraic approach. Pramana -
Journal of Physics, 74(1), 57-66.
[19] Iachello, F. and Oss, S. (1990) Overtone frequencies and
intensities of bent XY2 molecules in the vibron model.
Journal of Molecular Spectroscopy, 142(1), 85-107.
[20] Iachello, F., Oss, S. and Lemus, R. (1991) Vibrational
ear triatomic molecules in the vibron model.
olecular Spectroscopy, 146(1), 56-78.
nal
Openly accessible at
Molecular Physics, 104(19), 3051-3055.
dhury, J. and Bhattacharjee, R. (2008) spectra of lin
linear triatomic m
82(6), 767-772.
, [2
[7] Sarkar, N.K., Choudhury, J., Karumuri, S.R. and Bhat-
tacharjee, R. (2009) A comparative study of the vibra-
tional spec
method. European Physical Journal D, 53(2), 163-171.
[8] Sarkar, N.K., Choudhury, J., Karumuri, S.R. and Bhat-
tacharjee, R. (2008) An algebraic approach to the com
parative study of the vibrational spectra of monofluo-
roacetylene (HCCF) and deuterated acetylene (HCCD).
Molecular Physics, 106(5), 693-702.
[9] Choudh
tacharjee, R. (2008) Vibrational spectroscopy of SnBr4
and CCl4 using Lie algebraic approach. Pramana -
Journal of Physics, 71(3), 439-445.
[10] Choudhury, J., Sarkar, N.K. and Bhattacharjee, R
Algebraic approach to analyze the vibrational spectra of
tetrahedral molecules. Indian Journal of Physics, 82(5),
561-565.
[11] Choudhury, J., Karumuri, S.R., Sarkar, N.K. and Bhat-
tacharjee, R. (2009) Vibrational spectroscopy of CH/CD
stretches in propadiene: An algebraic approach. Chinese
Physics Letters, 26
[12] Karumuri, S.R., Sarkar, N.K., Choudhury, J. and Bhat-
tacharjee, R. (2008) Vibrational spectroscopy of Cm-H,
Cb-Cb stretching vibrations of Nickel Metalloporphyrins:
An algebraic approach. Molecular Physics, 106( 14), 1733- [28
1738.
[13] [Karumuri, S.R., Choudhury, J., Sarkar, N.K. and Bhat-
tacharjee, R. (2008) Analysis of resonance raman spectra
of Nickel Octaethyl Porphyrin using Lie algebra. Journal
of Environmental Research and D3(1),
benzene in the algebraic model. Chemical Physics Let-
ters, 187(5), 500-505.
[30] Alhassid, Y., Gursey, F. and Iachello, F. (1983) Group
theory approach to scattering. Annual Physics (New
York), 148(2), 346-380.
250-256.
[14] Karumuri, S.R., Sarkar, N.K., Choudhury, J. and Bhat-
tacharjee, R. (2009) Study of vibrational spectra of
Nickel Metalloporphyrins: An algebrPra-
mana - Journal of Physics, 72(3), 517-525.
[15] Karumuri, S.R., Sarkar, N.K., Choudhury, J. and Bhat-
tacharjee, R. (2009) Vibrational spectroscopy of stretch-
Journal of M
1] Iachello, F., Oss, S. and Lemus, R. (1991) Linear
four-atomic molecules in the vibron model. Journal of
Molecular Spectroscopy, 149(1), 132-151.
[22] Wang, M.S., Ding, S.L., Feng, D.T. and Liu, H.Y. (2002)
Lie-algebraic approach to vibrational spectra of a linear
symmetrical tetratomic molecule: C2H2. Physical Review
A, 66, (022506)1-10.
[23] Van Roosmalen, O.S., Levine, R.D. and Dieperink, A.E.L.
(1983) The geometrical-classical limit of algebraic Ham-
iltonians for molecular vibrotational spectra. Chemical
Physics Letters, 101(6), 512-517.
[24] Benjamin, I., Van Roosmalen, O.S. and Levine, R.D.
(1984) A model algebraic Hamiltonian for interacting
nonequivalent local modes with application to HCCD
and H12C13CD. Journal of Chemical Physics, 81(7),
3352-3353.
[25] Van Roosmalen, O.S., Benjamin, I. and Levine, R.D.
(1984) A unified algebraic model description for inter-
acting vibrational modes in ABA molecules. Journal of
Chemical Physics, 81(12), 5986-5997.
[26] Halonen, L. and Child, M.S. (1983) Model stretching
overtone eigenvalues for SF6, WF6, and UF6. Journal of
Chemical Physics, 79(2), 559-570.
[27] Bowman, J.M., Wierzbicki, A. and Zuniga, J. (1988) Exact
vibrational energies of non-rotating H2O and D2O using
an accurate ab initio potential. Chemical Physics Letters,
150(3-4), 269-274.
] Iachello. F and Oss, S. (1991) Model of n coupled an-
harmonic oscillators and applications to octahedral
molecules. Physical Review Letters, 66(23), 2976-2979.
[29] Iachello. F and Oss, S. (1991) Stretching vibrations of
[31] Alhassid, Y., Gursey, F. and Iachello, F. (1983) Group
theory of the Morse oscillator. Chemical Physics Letters,
99(1), 27-30.
[32] Levine, R.D. (1983) Representation of one-dimensio
S. R. Karumuri et al. / Journal of Biophysical Chemistry 1 (2010) 119-133
Copyright © 2010 SciRes. http://www.scirp.org/ journal/JBPC/Openly accessible at
133
quen-
J.R., Stein, P.
d infrared isotope shift. Journal o
of nonfundamental Raman lines.
) Resonance Raman spectros-
loroiron(III) octaethyl- and tetraphenyl-
motion in a morse potential by a quadratic Hamiltonian.
Chemical Physics Letters, 95(2), 87-90.
[33] Child, M.S. and Halonen, L.O. (1984) Overtone fre
cies and intensities in the local mode picture. Advances
in Chemical Physics, 57, 1-58.
[34] Li, X.-Y., Czernuszewicz, R.S., Kincaid,
and Spiro, T.G., (1990) Consistent porphyrin force field.
2. Nickel octaethylporphyrin skeletal and substituent
mode assignments from nitrogen-15, meso-d4, and me-
thylene-d16 Raman anf por
Physical Chemistry, 94(1), 47-61.
[35] Kitagawa, T., Abe, M. and Ogoshi, H. (1978) Resonance
Raman spectra of octaethylporphyrinato-Ni(II) and meso-
deuterated and 15N substituted derivatives. I. Observa-
tion and assignments
Journal of Chemical Physics, 69(10), 4516-4525.
[36] Czernuszewicz, R.S., Macor, K.A., Li, X.-Y., Kincaid,
J.R. and Spiro, T.G. (1989
copy reveals a1u vs. a2u character and pseudo-Jahn-
Teller distortion in radical cations of nickel(II), cop-
per(II), and ch
phyrins. Journal of the American Chemical Society,
111(11), 3860-3869.