Photo- and thermochromic spiranes 32*. Synthesis and photochromism of 3-methyl-4-oxospiro(2,3-dihydronaphtho-[2,1-e]-1,3-oxazine-2,2′-[2H]- chromenes)

Article abstract of DOI:10.1007/s10593-009-0253-3

Spiropyrans of the naphthoxazinone series have been obtained containing various substituents in the [2H]-chromene portion of the molecule. The spatial structure of a spiropyran containing ortho-positioned hydroxyl and formyl groups was established by X-ra

Full text of DOI:10.1007/s10593-009-0253-3

Chemistry of Heterocyclic Compounds, Vol. 45, No. 2, 2009
PHOTO- AND THERMOCHROMIC SPIRANES
32*. SYNTHESIS AND PHOTOCHROMISM OF
3-METHYL-4-OXOSPIRO(2,3-DIHYDRONAPHTHO-
[2,1-e]-1,3-OXAZINE-2,2'-[2H]-CHROMENES)
E. L. Mukhanov1, Yu. S. Alekseenko2, B. S. Lukyanov1**, V. I. Minkin1,2,
S. O. Bezuglyi2, A. N. Utenyshev3, V. V. Tkachev3, and S. M. Aldoshin3
Spiropyrans of the naphthoxazinone series have been obtained containing various substituents in the
[2H]-chromene portion of the molecule. The spatial structure of a spiropyran containing ortho-
positioned hydroxyl and formyl groups was established by X-ray structural analysis. The photochromic
properties of the obtained compounds have been studied.
Keywords: naphthoxazinone, spiropyran, photochromism.
The phenomenon of photochromism, the ability of a substance to undergo a reversible change of
absorption spectrum under the action of activating radiation of various spectral composition, is widely used in
contemporary molecular electronics for the design of optical switches and devices for three-dimensional
molecular memory. Of the organic photochromic materials the spiropyrans attract special attention, and undergo
photoinitiated valence isomerization under the action of UV radiation. This is accompanied by cleavage of the
Cspiro–O bond with the formation of colored quinonoid–betaine structures, the reversible rearrangement of which
into the initial spiro form occurs under the action of visible light or spontaneously [2-4].
One of the most widespread routes for the regulation of spectral and photochemical properties of
compounds of this class is the variation of the substituents in the [2H]-chromene portion [5]. Another direction
for the modification of properties of photochromic spiropyrans, to which the current investigation is devoted,
consists of varying the hetarene component and studying the effect of its structure on the photodynamic
characteristics of spiropyrans. The present work is a continuation of our investigations in [6].
_______
* For Communication 31 see [1].
** To whom correspondence should be addressed, e-mail: bluk@ipoc.rsu.ru.
1Institute of Physical and Organic Chemistry, Southern Federal University, Rostov-on-Don 344090, Russia.
2Southern Scientific Center, Russian Academy of Sciences, Rostov-on-Don 344090, Russia.
3Institute of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka 142432, Moscow
region, Russia.
__________________________________________________________________________________________
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 273-283, February, 2009. Original
article submitted November 20, 2008.
0009-3122/09/4502-0219©2009 Springer Science+Business Media, Inc.
219

3-Methyl-4-oxospiro(2,3-dihydronaphtho[2,1-e]-1,3-oxazine-2,2'-[2H]-chromenes) 4 were obtained by a
two-step synthesis. In the first step 2-[β-(2-hydroxyaryl)vinyl]-3-methyl-4-oxodihydronaphtho[2,1-e]-1,3-oxa-
zinium perchlorates 3 were obtained in 25-45% yield by boiling 2,3-dimethyl-4-oxodihydronaphtho-
[2,1-e]oxazinium perchlorate (1) and the appropriate o-hydroxyaromatic aldehyde in acidic medium. These
O
3
Me
O
O
O
4
1
N
OH
3'
Me
2
4'
Me
CHO
N
–
N
AcOH, ∆
Et3N
O
+
+
+
O
5'
6'
1'
–HClO4
O
Me
–
R
8'
ClO4
ClO4
1
R
2
7'
4a–g
HO
R
3
a R = 6'-Me, b R = 6'-Me, 8'-CHO; c R = 7'-OH, 8'-CHO; d R = 6'-NO2; e R = 8'-NO2; f R = 6'-OMe; g R = 6'-Cl
TABLE 1. 3-Methyl-4-oxospiro(2,3-dihydronaphtho[2,1-e]-1,3-oxazine-
2,2'-[2H]-chromenes) 4
Found, %
——————
Calculated, %
Com-
pound
Empirical
formula
mp, °C
Yield, %
С
H
N
4a
4b
4c
С22H17NO3
76.89
76.97
74.51
74.39
70.76
70.78
67.41
67.38
67.45
67.38
73.61
73.54
69.34
69.33
5.03
4.97
4.46
4.58
4.01
4.02
3.72
3.74
3.73
3.74
4.72
4.74
3.93
3.86
4.01
4.08
3.89
3.77
3.71
3.75
7.56
7.49
7.48
7.49
3.89
3.90
3.91
3.86
162
201
191
205
177
201
154
45
42
45
35
33
36
49
С23H17NO4
С22H15NO5
С21H14N2O5
С21H14N2O5
С22H17NO4
С21H14СlNO3
4d
4e
4f
4g*
_______
* Found, %: Cl 9.10. Calculated, %: Cl 9.21
TABLE 2. Spectral Characteristics of Spiropyrans 4
IR spectrum, ν, cm−1
1Н NMR spectrum, δ, ppm (J, Hz)
Com-
pound
H-4'
and arom.
protons
N–CH3
(3Н, s)
H-3'
(1Н, d)
Other
С=О
С=С
С
spiro–О
protons (s)
4a
4b
1662
1673
1634
972
986
3.20
3.22
6.12 (J = 9.7)
6.23 (J = 10.0)
6.64-8.06
7.07-8.02
2.30 (3Н, 6'-СН3)
1660,
1633
2.32 (3Н, 6'-СН3);
9.88 (1Н, 8'-СНО)
6.07 (J = 10.0)
6.32 (J = 9.9)
6.32 (J = 9.6)
4c
4d
4e
1673
1679
1673
1647
973
3.20
3.00
3.22
6.60-8.03
7.10-8.40
7.06-8.03
9.78 (1H, 8'-CHO);
11.64 (1H, 7'-OH)
1629
970,
940
1647,
1620
971
6.15 (J = 9.7)
6.19 (J = 9.7)
4f
1680
1660
1639
1640
927
972
3.20
3.18
6.60-8.05
6.67-8.03
3.80 (3Н, ОСН3)
4g
220

compounds are intensely colored orange-red crystalline substances which were later used without intermediate
purification. Perchlorates 3 suspended in absolute ether were treated with triethylamine, which led to removal of
HClO4 and cyclization with the formation of spiropyrans 4.
Characteristic bands were present in the IR spectra of the obtained spiropyrans (Table 2) for the
stretching vibrations in the 1660-1680 region (C=O oxazinone fragment), at 1620-1660 (C=C bond of the pyran
fragment), and also bands characteristic of the Cspiro–O bond in the 925-990 cm-1 range.
1
In the H NMR spectra of spiropyrans 4 (Table 2) signals were present in the 3.18-3.22 ppm region
for the N–CH3 group protons. In the spectrum there were also doublet signals for protons in position 3' of
the benzopyran fragment in the 6.12-6.32 ppm region (J = 9.6-10.0 Hz), which is characteristic of all
spiropyran structures.
The formation of spiropyran 4c may also theoretically proceed at each of the two formyl groups of the
initial 2,4-dihydroxyisophthalic aldehyde 5. The spiropyran structure of compound 4c was demonstrated with
1
1
the aid of data of H NMR spectroscopy. Characteristic of its H NMR spectrum is the presence of a doublet
signal for the H-3' proton (J = 10.0 Hz) at 6.07 ppm of the [2H]-chromene fragment and also singlet signals of
the protons of the formyl and hydroxyl groups at 9.78 and 11.64 ppm respectively. The significant displacement
of the signals of the OH group protons towards low field is explained by the presence of intramolecular
hydrogen bonds.
O
Me
N
CHO
CHO
+
OH
OH
O
Me
1
CHO
CHO
OH
OH
5
5
O
O
O
Me
N
O
Me
N
O
O
OH
OHC
CHO
OH
4c
4c'
The mutual disposition of OH and CHO groups in the [2H]-chromene portion of the spiropyran 4c
molecule was established by analogy with spiropyran 6 in [6].
O
Me
N
O
O
OHC
OH
6
221

Compound 4c crystallized as two independent molecules, the general shape of which is shown in Fig. 1
(notice that the numbering of atoms of the second molecule is increased by 20 relative to the numbering of the
first molecule). The two independent molecules differed insignificantly from one another in the character of
bond length distribution (Table 3) and size of valence angles (Table 4). In both independent molecules of the
investigated compound the benzopyran with an additional annelated benzene ring and the benzoxazinone
fragments, as in the previously investigated indoline and benzoxazinone derivatives of spiropyrans, are located
completely orthogonal to one another and are individually nonplanar.
4c-A
4c-B
Fig. 1. General form of the independent molecules 4c-A and 4c-B.
222

The nonplanarity of the additionally annelated benzoxazinone fragment in the independent molecule
4c-A is caused by a twist along the line N(3)···O(1) at an angle of 37.3°, and the nonplanarity of the benzopyran
fragment is caused by twists along the lines C(3')–O(1') and C(4')–O(1') at angles of 20.30° and 8.10°
respectively. The nonplanarity of the analogous fragments in the independent 4c-B molecule is caused by twists
along the lines N(23)···O(21) at an angle of 30.3° and C(23')–O(21') and C(24')–O(21') at angles of 15.9° and
5.4° respectively. The previously studied compound 6 without the additionally annelated benzene ring has a
similar structure [6]. The nonplanarity of the benzoxazinone fragment in this compound is caused by a twist
along the line of N(3)···O(1) of 33.9°, but the nonplanarity of the benzopyran fragment is caused by the twists
along the lines C(3')–O(1') and C(4')–O(1') at angles of 22.6° and 7.5° respectively. The atoms O(1), C(4), N(3),
O(4), and O(21), C(24), N(23), O(24) are disposed in the planes of the corresponding naphthalene fragments.
The geometric structure of the Cspiro–node and the benzopyran fragment in the independent molecules of
compound 4c are analogous to the structure of the previously investigated indoline and benzoxazine
spiropyrans. As in compound 6, the inclusion in the additionally annelated benzoxazinone fragment of
compound 4c of a carbonyl group C(4)=O(2) leads to a significant change in the electronic and geometric
picture of the structure of the N–node. The emergence of atoms N(3) and N(23) from the corresponding planes
of the coordinating C(2'A), C(4), and C(3) of compound 4c-A and C(2'B), C(24), C(23) of compound 4c-B was
0.171 and 0.162 Å respectively (0.152 Å in compound 6). The sum of the valence angles at the N(3) atom was
355.6° and at the N(23) atom was 356.1° (356.1° in compound 6). The length of the amide bond in the
independent molecules 4c-A and 4c-B was equal respectively, N(3)–C(4) = 1.375(4) and N(23)–C(24) 1.375(4)
Å (1.361(3) Å in compound 6), which indicates the appreciable conjugation of the unshared electron pair of the
N atom with the π-bond of the carbonyl group. The amide conjugation significantly weakens the interaction of
the unshared electron pair of the N atom with the σ*-orbital of the Cspiro–O(1') bond. In addition, the geometric
disposition of the Cspiro–O(1') bond relative to the coordinated plane of the nitrogen atom, CspiroC(4)C(3)
becomes less favorable for orbital n-σ* interactions. On the other hand, presence of a formyl group at the C(8')
atom increases the electron-withdrawing influence at the O(1') atom. This is indicated by some
TABLE 3. Bond Lengths (l) in the Two Independent Molecules of
Compound 4c
Bond
l, Å
Bond
l, Å
Bond
l, Å
O(1)–C(14)
O(1)–C(2'A)
O(4)–C(4)
1.370(3)
1.419(4)
1.219(3)
1.375(4)
1.425(4)
1.463(4)
1.460(4)
1.349(5)
1.431(4)
1.424(5)
1.376(6)
1.411(5)
1.381(6)
1.361(5)
1.410(5)
1.413(4)
1.426(4)
1.356(4)
1.357(3)
1.446(3)
1.339(4)
1.224(4)
C(2'A)–C(3')
C(3')–C(4')
1.491(4)
1.325(4)
1.440(5)
1.355(5)
1.398(5)
1.391(5)
1.405(4)
1.390(4)
1.423(4)
1.382(4)
1.372(3)
1.406(3)
1.223(3)
1.378(4)
1.433(4)
1.454(4)
1.459(4)
1.350(5)
1.423(4)
1.410(4)
1.360(5)
1.400(5)
C(28)–C(29)
C(29)–C(30)
C(30)–C(31)
C(31)–C(34)
C(31)–C(32)
C(33)–C(34)
C(2'B)–O(21')
C(2'B)–C(23')
O(21')–C(29')
O(27')–C(27')
О(31')–C(31')
C(23')–C(24')
C(24')–C(30')
C(25')–C(26')
C(25')–C(30')
C(26')–C(27')
C(27')–C(28')
C(28')–C(29')
C(28')–C(31')
C(29')–C(30')
1.405(5)
1.348(4)
1.417(4)
1.412(4)
1.418(4)
1.362(4)
1.447(3)
1.485(4)
1.366(3)
1.337(4)
1.211(4)
1.311(4)
1.444(4)
1.362(5)
1.391(4)
1.377(5)
1.409(4)
1.392(4)
1.437(4)
1.381(4)
C(4')–C(10')
C(5')–C(6')
N(3)–C(4)
N(3)–C(2'A)
N(3)–C(3)
C(5')–C(10')
C(6')–C(7')
C(4)–C(13)
C(5)–C(6)
C(7')–C(8')
C(8')–C(9')
C(5)–C(13)
C(6)–C(12)
C(7)–C(8)
C(8')–C(11')
C(9')–C(10')
O(21)–C(34)
O(21)–C(2'B)
O(24)–C(24)
N(23)–C(24)
N(23)–C(2'B)
N(23)–C(23)
C(24)–C(33)
C(25)–C(26)
C(25)–C(33)
C(26)–C(32)
C(27)–C(28)
C(27)–C(32)
C(7)–C(12)
C(8)–C(9)
C(9)–C(10)
C(10)–C(11)
C(11)–C(14)
C(11)–C(12)
C(13)–C(14)
O(1')–C(9')
O(1')–C(2'A)
O(7')–C(7')
O(11')–C(11')
223

shortening of the O(1')–C(9') bond in comparison with analogous compounds to 1.357(3) Å in the independent 4c-A
molecule and 1.366(3) in the independent 4c-B molecule. The increase in the electron-withdrawing effect of the 8'
substituent increases the polarity of the Cspiro–O(1') bond and additionally strengthens the n–σ* interaction in
TABLE 4. Values of Angles (ω) in the Two Independent Molecules of
Compound 4c according to X-ray Structural Analysis
Angle
ω, deg
Angle
ω, deg
C(14)–O(1)–C(2'A)
C(4)–N(3)–C(2'A)
C(4)–N(3)–C(3)
116.0(2)
119.3(2)
118.7(3)
117.6(2)
121.9(3)
123.3(3)
114.7(3)
120.5(3)
121.9(3)
121.2(4)
120.6(4)
120.5(4)
120.7(4)
123.6(3)
119.5(3)
116.9(3)
123.9(3)
117.5(3)
118.5(3)
117.7(3)
121.2(3)
121.0(3)
119.9(3)
124.3(3)
115.7(3)
119.8(2)
112.0(2)
106.3(2)
105.6(2)
105.3(2)
115.4(3)
111.9(3)
119.9(3)
122.1(3)
123.4(3)
119.0(3)
118.2(3)
121.8(3)
120.0(3)
118.8(3)
121.4(3)
119.8(3)
125.1(3)
121.0(3)
117.0(2)
122.0(3)
116.9(3)
117.4(3)
125.7(3)
C(34)–O(21)–C(2'B)
C(24)–N(23)–C(2'B)
C(24)–N(23)–C(23)
C(2'B)–N(23)–C(23)
O(24)–C(24)–N(23)
O(24)–C(24)–C(33)
N(23)–C(24)–C(33)
C(26)–C(25)–C(33)
C(25)–C(26)–C(32)
C(28)–C(27)–C(32)
C(27)–C(28)–C(29)
C(30)–C(29)–C(28)
C(29)–C(30)–C(31)
C(34)–C(31)–C(30)
C(34)–C(31)–C(32)
C(30)–C(31)–C(32)
C(27)–C(32)–C(26)
C(27)–C(32)–C(31)
C(26)–C(32)–C(31)
C(34)–C(33)–C(25)
C(34)–C(33)–C(24)
C(25)–C(33)–C(24)
C(33)–C(34)–O(21)
C(33)–C(34)–C(31)
O(21)–C(34)–C(31)
O(21)–C(2'B)–N(23)
O(21)–C(2'B)–O(21')
N(23)–C(2'B)–O(21')
O(21)–C(2'B)–C(23')
N(23)–C(2'B)–C(23')
O(21')–C(2'B)–C(23')
C(29')–O(21')–C(2'B)
C(24')–C(23')–C(2'B)
C(23')–C(24')–C(30')
C(26')–C(25')–C(30')
C(25')–C(26')–C(27')
O(27')–C(27')–C(26')
O(27')–C(27')–C(28')
C(26')–C(27')–C(28')
C(29')–C(28')–C(27')
C(29')–C(28')–C(31')
C(27')–C(28')–C(31')
О(31')–C(31')–C(28')
O(21')–C(29')–C(30')
O(21')–C(29')–C(28')
C(30')–C(29')–C(28')
C(29')–C(30')–C(25')
C(29')–C(30')–C(24')
C(25')–C(30')–C(24')
118.3(2)
121.5(2)
117.9(3)
116.7(3)
121.5(3)
123.5(3)
115.0(3)
120.7(3)
121.7(3)
121.5(3)
119.7(3)
121.0(3)
120.4(3)
123.2(3)
117.8(3)
119.0(3)
122.8(3)
118.5(3)
118.7(3)
118.1(3)
120.6(3)
121.3(3)
120.5(3)
123.0(3)
116.5(2)
112.5(2)
107.8(2)
105.1(2)
105.6(2)
113.2(3)
112.6(2)
121.4(2)
121.2(3)
122.1(3)
123.2(3)
119.2(3)
118.7(3)
121.5(3)
119.9(3)
119.0(3)
120.5(3)
120.4(3)
125.3(4)
121.0(3)
117.6(3)
121.4(3)
117.3(3)
117.7(3)
124.9(3)
C(2'A)–N(3)–C(3)
O(4)–C(4)–N(3)
O(4)–C(4)–C(13)
N(3)–C(4)–C(13)
C(6)–C(5)–C(13)
C(5)–C(6)–C(12)
C(8)–C(7)–C(12)
C(7)–C(8)–C(9)
C(10)–C(9)–C(8)
C(9)–C(10)–C(11)
C(10)–C(11)–C(14)
C(10)–C(11)–C(12)
C(14)–C(11)–C(12)
C(7)–C(12)–C(6)
C(7)–C(12)–C(11)
C(6)–C(12)–C(11)
C(14)–C(13)–C(5)
C(14)–C(13)–C(4)
C(5)–C(13)–C(4)
C(13)–C(14)–O(1)
C(13)–C(14)–C(11)
O(1)–C(14)–C(11)
C(9')-O(1')–C(2'A)
O(1)–C(2'A)–N(3)
O(1)–C(2'A)–O(1')
N(3)–C(2'A)–O(1')
O(1)–C(2'A)–C(3')
N(3)–C(2'A)–C(3')
O(1')–C(2'A)–C(3')
C(4')–C(3')–C(2'A)
C(3')–C(4')–C(10')
C(6')–C(5')–C(10')
C(5')–C(6')–C(7')
O(7')–C(7')–C(6')
O(7')–C(7')–C(8')
C(6')–C(7')–C(8')
C(9')–C(8')–C(7')
C(9')–C(8')–C(11')
C(7')–C(8')–C(11')
O(11')–C(11')–C(8')
O(1')–C(9')–C(10')
O(1')–C(9')–C(8')
C(10')–C(9')–C(8')
C(9')–C(10')–C(5')
C(9')–C(10')–C(4')
C(5')–C(10')–C(4')
224

comparison with previously studied spiropyrans. As a result of this the bond lengths of C(2'A)–O(1') = 1.446(3)
and C(2'A)–O(1) = 1.419(4) Å in the independent 4c-A molecule and C(2'B)–O(21') = 1.447(3) and C(2'B)–
O(21) = 1.406(3) Å in the independent 4c-B molecule, analogous to the values in compound 6 of C(2'2)–O(1') =
1.454(2) and C(2'2)–O(1) = 1.414(2) Å.
The molecular structure of both independent molecules 4c-A and 4c-B, like the molecular structure of
the previously studied compound 6, is characterized by the presence of strong intramolecular hydrogen bonds
between the hydroxyl hydrogen atom and the formyl oxygen atom. The parameters of the intramolecular
hydrogen bonds were O(11')···H(7') = 1.86(3), O(11')···O(7') = 2.598(4) Å, O(11')H(7')O(7') = 130.8° in the
4c-A molecule and O(31')···H(27') = 1,62(3). O(31')···O(27') = 2.629(4) Å, O(31')H(27')O(27') = 124.9° in the
4c-B molecule (O(3')···H(2') = 1.63(3), O(2')···O(3') = 2.586(3) Å, O(2')H(2')O(3') = 145.6° for compound 6).
Spiropyrans 4a,b did not display photochromic properties on irradiation of their alcoholic solutions in
the stationary mode at low (-70°C) temperatures regardless of the wavelength of the activating irradiation
(λmax 313, λmax 365 nm, or unfiltered light).
Me Me
N
O
NO2
Me
7
However on carrying out the experiment in toluene at room temperature solutions of spiropyrans 4
containing π-withdrawing groups at position 6' displayed photochromic properties (Fig. 2, Table 5). In general
an additionally annelated benzene ring led to a reduction in the lifespan of the photoinduced form, which is in
good agreement with the results of the investigation of 1,3,3-trimethyl-4,5-benzo-6-nitrospiro(indoline-
Fig. 2. UV absorption spectrum of spiropyran 4b in toluene before and after
irradiation in the stationary mode with light of λmax 365 nm at 20oC.
225

TABLE 5. Characteristics of the Absorption Spectra of Spiropyrans 4 in
Toluene at 20°C
Photoinduced form
ε (λAmax),
Com-
pound
R
λAmax, nm
M-1cm-1
(λBmax), nm
τ, sec
4а
6'-Me
300
6190
Not observed under the experimental
conditions
4b
6'-Me
8'-CHO
329
342
6710
7940
600
0.89
4c
4e
7'-OH
8'-CHO
343
6690
Not observed under the experimental
conditions
8'-NO2
298
327
8000
7740
576
3.1
sh 615
4f
6'-OMe
6'-Cl
327
300
6780
6540
Not observed under the experimental
conditions
4g
Not observed under the experimental
conditions
2,2'-[2H-I]-benzopyran (7), and shows that the strong reduction of the quantum yield of photoconversion on
annelation of an additional nucleus in the hetarene fragment of an indoline spiropyran may possibly be
explained by the unradiating deactivation of the activated state (for example, by the intramolecular transfer of
energy from the pyran ring to the indoline) [5].
EXPERIMENTAL
The IR spectra were recorded in nujol on a Specord IR-75 prism double-beam spectrometer (calibration
of sample with polystyrene). Electronic absorption spectra were obtained on a Agilent 8453 spectrophotometer.
The 1H NMR spectra were recorded on Bruker 250 (250 MHz) and Varian Unity 300 (300 MHz) instruments in
impulse Fourier mode in CDCl3. Standard was the residual proton signal in CDCl3.
3-Methylspiro(2,3-dihydronaphtho[2,1-e][1,3]-oxazin-4-oxo-2,2'-[2H]-chromenes) 4a-g. A mixture
of 2,3-dimethyl-4-oxodihydronaphtho[2,1-e][1,3]oxazinium perchlorate (1) [7] (3.25 g, 0.01 mol) and the
appropriate aldehyde (0.01 mol) in acetic acid (15 ml) was boiled for 3 min. The reaction mixture was cooled,
the precipitated salt 3 was filtered off, and washed with absolute ether. Triethylamine (1.5 ml, 0.01 mol) was
added to a solution of the residue in absolute ether (50 ml). After 6 h the ether was decanted and evaporated, The
residue of spiropyran was crystallized from alcohol (Tables 1 and 2).
The parameters of the unit cell of a crystal of spiropyran 4c and the three-dimensional set of intensities
were obtained on a KUMA 4 four-circle diffractometer with ω/2θ scanning (MoKα-radiation, graphite
monochromator) at 293(2) K. Absorption was not calculated, µMoKα = 0.102 mm-1. Light-yellow crystals of 4c
(alcohol) were triclinic: C22H15NO5, M = 373.35; a = 7.7400(15), b = 13.256(3), c = 17.370(4) Å, α = 97.03(3),
β = 93.84(3), γ = 97.15(3)o. V = 1748.9(6) Å3, Z = 4, ρcalc = 1.418 g/cm3, space group P-1. The intensities of 6830
reflections were measured at 2θ ≤ 50.1o from a monocrystal of size 0.4×0.4×0.35 mm. Averaging of measured
equivalent reflections F2(hkl) and σ(F2) resulted in 6051 independent reflections. Those 2779 reflections having
F2 > 4σ(F2) were used in subsequent calculations. The structure was solved by the direct method with the
SHELXS-97 [8] program and refined by the full matrix least squares method on F2 with the SHELXL-97 program
[8] in an anisotropic approximation for the non-hydrogen atoms. In the crystal structure of 4c all the H atoms
were located in an electron density Fourier difference synthesis. Subsequently the coordinates
226

and isotropic thermal parameters of all the H atoms were calculated in the least squares procedure according to
the "rider" model [8]. In the final cycle of the full matrix refinement the absolute displacements of all 100 varied
parameters of the structure were less than 0.001 σ. The closing interatomic distances and valence angles are
given in Tables 3 and 4. Final refinement parameters were R1 = 0.051, wR2 = 0.132 for reflections observed with
I ≥2σ(I); R2 = 0.069, wR2 = 0.155 for all measured reflections, quality of fit S was 0.862 and 0.862 respectively,
maximum and minimum electron density 0.222 and –0.358 eÅ-3.
The work was carried out with the financial support of the Russian Fund for Fundamental Investigations
(grant 07-03-00234, 08-03-90029-Bel), Ministry of Education and Science of the Russian Federation (project
RNP.2.2.2.3.16011), and Grant of the President of the Russian Federation NSh-363.2008.3.
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227