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Crystal and molecular structure of 2,3-dimethylnaph-thazarin: A charge-transfer complex
112 (1984) 101-109 Elsevier Science Publishers B.V., Amsterdam - Printed in The Netherlands
Journnl of MolecuiarStnxture,
CRYSTAL AND MOLECULAR STRUCTURE OF 2,3-DIMETHYLNAPHTHAZARIN: A CHARGE-TRANSFER COMPLEX
3_ G. RODRiGUEZ
Departamento de Quimica Madrid-34 (Spain) P. SMITH-VERDIER,
Departamento
Orgbnica
de la Uniuersidad
F. FLORENCIO
de Rayos-X,
Instituto
Autbnoma
de Madrid,
Canto Blancc
and S. GARCiA-BLANC0
Rocasolano,
C.S.I.C, de Madrid, Madrid
(Spain)
(Received 2 March 1983)
ABSTRACT X-ray analysis of 2,3dimethylnaphthazarin (C,,H,,O,) has been carried out from three dimensional diffractometer data and refined to an R-factor of 0.053 with w = 1.0 for 1278 observed reflections. The compound crystallizes in the P2,1r space group, with a monoclinic cell of dimensions a = 16.429 (d), b = 6.524 (l), c = 9.136 (4) X, B = 90.19 (2)” and four molecular formulae in the unit cell. The crystal is built from molecule stacked up the c axis and the dimethylnaphthazarin molecules overlap to form a chargetransfer complar. Moreover, naphthazarin and methylnaphthazarin derivatives are examined es charge-transfer complexes. BW’RODUCTION
The naphthazarin nucleus 5&dihydroxy-1,Cnaphthoquinone exists in Nature in the spinochromes of the echinoderms [l] . Naphthazarin derivatives can be used as the starting products in the synthesis of tetracyclic antibiotics [2]. Various investigations in the solid state of each of the three naphthazarin crystalhne forms designated as A, B and C 133 have led to the conchxsion that the mokcule is centrosymmetric and can be represented as a resonance hybrid of the structures 2a, 2b, with 1 and 3 contributing to a minor extent (Scheme 1). NMR studies on solutions [4] indicated that a fast tautomeric ,~u.ihbrium between1 +2a=+2b* 3 is present at temperatures down to -75°C. Moreover IR studies carried out by Schmand and Boldt [5] showed that it exists as 5,7-dihydroxy-l&naphthoquinone. Shiau et al. [S] found evidence for a dynamic disordered structure of naphthazarin (B form) in the solid state at -160°C by 13C-NMR using “magic angle” spinning techniques.
0022-2860/84/$03.00
o 1984 Elsevier Science Publishers B.V.
102 OH
OH
0
OH
0
0
I
Scheme
1
2b
SYNTHESIS
The synthesis of 2,3dimethylnaphthazarin is shown in Scheme 2. The cycloaddition between the 2,3dimethyl-1,3-butadiene and p -benzoquinone, aceelation, chromic acid oxidation of the adduct and finally the hydrolysis
of the diacetate, gives 2,3dimethylnaphthazarin, which can also be obtained by starting with a similar cycloaddition reaction between 1,3-butadiene and 2,3-dimethylquinone. RESULTS
AND
DISCUSSION
‘ET-and l 3C-NMR
Spectru
In chloroform solution the ‘I+NMR spectrum (Varian XL-loo) of 2,3dimethylnaphthazarin shows two protins at 7.18 and two methyl groups at 2.18 ppm both as singlet signals and
103
12.60 ppm. The 13C-NMR spectrum (Varian XL-loo) shows two different signals at 186.4 and 158.8 ppm for two different oxygenated carbon atoms (C,, C4 and CS, Cs, respectively), at 144.4 and 129.4 ppm for the two quinonoid and the two benzenoid carbon atoms respectively, at 111.7 ppm for the two common carbon atoms of the annular system, and at 12.5 ppm for the two methyl groups. From those NMR data, it was deduced that in chloroform solution, the molecule exists as the tautomeric form 1, 2,3-dimethyl-5,8-dihSTdrcxy-l,4naphthoquinone. X-my
structure
determination
Crystal data: C12H1004, M = 218.21, monoclinic, o = 16.429(4), b = 6.524(l), c = 9.136(4) A, p = 90.19(2)“, V = 979-l(3) A’, 2 = 4, F
measurements
and structure
analysis
A red single crystal of approximate dimensions 0.2 X 0.3 X 04 mm was used to obtain the data. The space group was determined from Weissenberg photographs. The cell parameters and the intensity data were collected on a 1100 Philips four circle diffractometer by the use of graphite monochromated MO I&Y radiation. Measurements were carried out in the o /20 scan mode. Of the 3317 reflections measured, 1278 were considered as observed, I> 30 (I). The phase problem was solved by a IMULTAN-80 program using 300 normalized structure factors with E > 2.00. The refinement of the structie was carried out by the full-matrix least-squares method* with anisotropic temperature factors for all non-hydrogen atoms. The hydrogen atoms were ob+tained from a difference Fourier map. Fkll-matrix least-squares cycles were then made, with anisotropic temperature factors for the heavy atoms and isotropic temperature factors for the hydrogen atoms. The hydrogen atom parameters were held fixed. The R terminal values were Rti = [Ew(IFol -lFcl)2/~~lIFol*]“2 = 0.059 with w = 1.0 and R = 0.053. The scattering factors were from International Tables for X-ray Crystallography (1974). The final positional and thermal parameters are listed in Tables 1 and 2. Crystal structure
of 2,3-dimefhylnaphthazarin
The crystaRographic numbering scheme adopted, bond distances and angles are given in Fig. 1. The molecule of 2,3dimethylnaphthazarin is planar but not centrosymmetric. *The structure factors and bond lengths are deposited with the British Division as Supplementary Publication number SUP 26245 (26 pages).
Library
Lending
104 TABLE1 Posiit;!nal parameters for heavy atoms and isotropictemperatw therefiiedankkropicvalnea Atom
x/a
CO)
0.3248(2) 0.3921(Z) 0.4585(2) O-5296(2) 0.5988(2) O-5965(2) 0.5249(3) O-4560(2) O-3879(2) 0.3230(2) O-6693(2) 0.6639(2) O-3822(2) 0.3809(2) 0.5318(2) 0.524212)
(x2) c(3) C(4) C(5) C(6) C(7) c(8) C(9) C(l6) W2) W3) o(l) O(2) O(3) O(4)
y/b
-0.2168(7) -O-2652(7) -0.1306(6) --O-1736(7) -O-0283(7) 0.1460(7) 0.1960(6) 0.0532(7) 0.0964(7) -O.O424(7) -0.0894(7) 0.3032(7) -0.4406(5) 0.2667(5) -0.3304(5) 0.3565(5)
factorsequivalentto
Z/C
%
O-1665(5) O-2545(4) O-2579(4) 0.3491(4) O-3534(4) 0.2750(4) O-1813(5) O-1747(4) 0.0882(5) 0.0849(5) 0.4499(5) O-2758(5) O-3336(3) 0.0039(4) O-4263(4) 0.1086(3)
0.044(l) 0.039(l) 0.033(l) 0.037(l) 0.037(l) 0.037(l) 0.038(l) 0.034(l) 0.040(l) 0.044(l) O-049(2) 0.054(2) 0.052(l) 0.055(l) 0.057(l) 0.055(l)
TABLE2 Positional and isotropicthermsl parametersforhydrogenatoms da
H(l) HW) H(121) H(122) H(123) H(131) H(132) H(133) H(O2) H(O1)
O-286(3) O-277(3) O-691(4) O&49(4) O-717(4) 0.715(4) O-671(4) 0.663(4) 0.415(3) 0.43563)
-O-312(7) -0.016(7) -0.225(8) -0.105(S) 0.008(8) 0.230(8) O-347(8) 0.434(8) O-339(5) -O-448(5)
Z/C
B
O-168(5) 0.025(5) O-415(6) 0.553(S) O-454(6) 0.245(6) 0.381(6) 0.219(6) 0.016(4) 0.389(4)
1.9 1.4 6.1 6.1 6.1 6.8 6.8 6.8 7.4 5.2
The bond lengths C+& = l-355(5) and C,--O, = 1.357(5) A are shown ti be single bonds with some double bond character and C4--03 = 1.243(5) and C,--O, = 1.240(S) A are double bonds with some single bond character; both intermediate bond lengths are due to an important chellation of the oxygen atoms to hydrogen HoI and Hoz atoms. The annular system has two different rings, with benzenoid and quinonoid characters. The benzenoid ring has a short bond length, C1-CIO = 1.360(7), with considerable double bond character. The quinonoid ring has bond = l-467(6) A shorter than G-C, = and C,-Cs disk&s CI)-Ca = l-460(5)
105
Fig. 1. Bond distances and an@
of dimethylnaphthazarin.
l-481(6) and C6-C, = l-488(6) A; this could be due to the inductive effect of the two methyl groups that are affected by the shortening of their bond = 1.510(6) A, since chelation of and C6--& distances C5-CI 2 = l-507(6) oxygen atoms 01, O2 and OS, O4 to hydsogens HoI and Hoz is an intermolecular effect arising from molecular packing (Fig. 2).
Fig. 2. MoIecuIar packing of dimethylnaphthazarin and intermolecular hydrogen bonds.
showing tbe molecular overlapping
106 By comparing the bond distance CS-CB = l-344(6) A with the same bond distance in the diacetate of naphthazarin (1.314(7) A) 173, and in the diacetate of tetramethglnaphthazarin (1.35W) A) C31, we can conclude that the methyl groups in the present compound are affected by some steric interaction (see also bond angle values in Fig. 1). It is remarkable that 2,3_dimethylnaphthazarin forms a charge-transfer complex with itself in the solid state and it is possible that distortion of some bond distances is caused by overlap of the molecules. The crystal is built from molecules stacked up the c-axis (Fig. 2). Each stack contains a symmetry center which acts in such a way that the quinonoid part of a molecule overlaps the benzenoid part of its symmetryrelated neighbours. The intermolecular distance between the overlapping planes is 3.42 A. Methyl
substituted
naph thazarins:
visible
spectra
The visible spectra of the methyl substituted naphthazarins in chloroform show three main peaks and a shoulder except for the naphthazarin molecule which shows four main peaks which could he due to the presence of the B and C modifications in solution (Table 3). Molecular
structure
of the naph thazmins
a. Naph thazarin Naphthazarin has been studied in each of its crystalline modifications in the solid state [3] _ These crystahize in the P2,?, space group; the molecules have a symmetry centre, which indicates that in the solid state the forms 2a and 2b shown in Scheme 1 predominate.
TABLE3
R, =R_
OH
0
OH
0
=R,
=R,
R, =CH, R,=R,=R,=H q=R,=H Ro=R,=CHI, R, 'R, =R,=CH, R,=H R,=R,=R,=R4=Me
=H
563(3750) 544(3670)
522(6075)
489(5465)
458(3700)
552(2830)
514(4610)
484(4150)
459(2700)
511(7500)
483(6850)
459(4800)
511(5900)
482(5100)
459(3400)
514(5100)
483(4000)
459(2350)
547(4500) 549(3800) 554(3700)
107
The moIecular overlapping is shown in Fig. 3. The in&planar distances between two overlapping molecules are 3.34, 3.42 and 3.40 A respectively for A, B and C crystalline modifications. b. Methylnaphthazarin Methylnaphthazarin has been also studied in the solid state [9]. The methyl substituent in position 2 and the molecule has no symmetry centre, which indicates that in the molecular structure form 1 (Scheme 1) has a remarkable predominance. The molecular overlapping is shown in Fig. 4. The interplanar distance between two overlapping molecules is 3.38 A. c.
t
e I
Fig.
3.
thazarin
Molecular
ProJ. (0 10
overlapping
of
the
A,
B and
3.
Fig. 4. Molecular
overlapping
of methylnaphthazarin.
1
C crystalline
modifications
of
naph-
108
Fig. 5. Molecular overlapping of btramethglnaphthazarin. Fig. 6. Mdecukr
overlapping of juglone.
TABLE 4
Naphtbzarin
Mod. Ab Mod. Bb Mod. C+= Tebamethyl~
Bond disstances a
b
C
d
e
1.43 1.40 1.44 1.44 1.46
1.43 1.46 1.43 1.41 1.41
1.43 1.47 1.43 1.43 1.46
1.44 1.46 1.43 1.43 1.47
1.34 1.37 1.34 1.36 1.37
=From Cradwick et al. [3]. dFrom ref. IO.
%?rom
Pascard-Billy
131.
‘?IVO
independent
molecules.
109
Moreover it is noticeable that the bond distances in the molecules are distorted by effect of the charge-transfer complexation as shown in Table 4. Thus, the molecular overlap could be regarded as the intermolecular interaction between acceptor molecular zones, C1, C2 and C3 and CS, Cs and C, and donor molecular zones, Cq, CIO, C9 and C8.
Juglone is a 5-hydroxy-1,4naphthaquinone and it has been studied in the solidstate [ll] . It crystallizes in the P2 1jn space group. The molecular overlapping is shown in Fig. 6. The interplanar distance between two overlapping molecules is 3.41 A. REFERENCES 1 J. S. Grossed, Chem. Sot. Rev., 1 (1972) 1. 2 T. Kametani and K Fukumoto, Med. Res. Rev., 1 (1981) 23. 3 C. Pascard-Billy, Bull. Sot. Chim. Fr., (1962) 2282-2293; C. Pascard-Billy, Acta Crystaiiogr., 15 (1962) 519; P. D. Cradwick and D. Hall, Acta Crystailogr. Sect. B, 27 (1971b) 1990-7. 4 H. Brockmann and A. Zeek, Chem. Ber., lOl(l968) 4221. 5 H. L. K. Schmand and P. Boldt, J. Am. Chem. Sot., 97 (1975) 447. 6 W. Shiau, E. N. DuesIer, I. C. Paul, D. Y. Curtin, W. G. Blann and C. A. Fyfe, J. _4m. Chem. Sot., (1980) 4546. 7 J. G. Rodriguez, F. H. Cano and S. Garcfa-Blanco, Acta Crystallogr. Sect. B. 23 (1977) 491. 8 J. G. Rodriguez, F. H. Cane and S. Garcia-BIanco, Cry& Struct. Commun., 8 (1979) 93. 9 P. D. Cradwick, D. HaB and M. K. Wood, Acta Crystaliogr. Sect. B. 33 (1977) 2380-4. 10 J. G. Rodriguez et aL, unpublished results. 11 P. D. Cradwick and D. Hall, Acta Crystailogr. Sect. B, 27 (1971) 1468-1470.
Journnl of MolecuiarStnxture,
CRYSTAL AND MOLECULAR STRUCTURE OF 2,3-DIMETHYLNAPHTHAZARIN: A CHARGE-TRANSFER COMPLEX
3_ G. RODRiGUEZ
Departamento de Quimica Madrid-34 (Spain) P. SMITH-VERDIER,
Departamento
Orgbnica
de la Uniuersidad
F. FLORENCIO
de Rayos-X,
Instituto
Autbnoma
de Madrid,
Canto Blancc
and S. GARCiA-BLANC0
Rocasolano,
C.S.I.C, de Madrid, Madrid
(Spain)
(Received 2 March 1983)
ABSTRACT X-ray analysis of 2,3dimethylnaphthazarin (C,,H,,O,) has been carried out from three dimensional diffractometer data and refined to an R-factor of 0.053 with w = 1.0 for 1278 observed reflections. The compound crystallizes in the P2,1r space group, with a monoclinic cell of dimensions a = 16.429 (d), b = 6.524 (l), c = 9.136 (4) X, B = 90.19 (2)” and four molecular formulae in the unit cell. The crystal is built from molecule stacked up the c axis and the dimethylnaphthazarin molecules overlap to form a chargetransfer complar. Moreover, naphthazarin and methylnaphthazarin derivatives are examined es charge-transfer complexes. BW’RODUCTION
The naphthazarin nucleus 5&dihydroxy-1,Cnaphthoquinone exists in Nature in the spinochromes of the echinoderms [l] . Naphthazarin derivatives can be used as the starting products in the synthesis of tetracyclic antibiotics [2]. Various investigations in the solid state of each of the three naphthazarin crystalhne forms designated as A, B and C 133 have led to the conchxsion that the mokcule is centrosymmetric and can be represented as a resonance hybrid of the structures 2a, 2b, with 1 and 3 contributing to a minor extent (Scheme 1). NMR studies on solutions [4] indicated that a fast tautomeric ,~u.ihbrium between1 +2a=+2b* 3 is present at temperatures down to -75°C. Moreover IR studies carried out by Schmand and Boldt [5] showed that it exists as 5,7-dihydroxy-l&naphthoquinone. Shiau et al. [S] found evidence for a dynamic disordered structure of naphthazarin (B form) in the solid state at -160°C by 13C-NMR using “magic angle” spinning techniques.
0022-2860/84/$03.00
o 1984 Elsevier Science Publishers B.V.
102 OH
OH
0
OH
0
0
I
Scheme
1
2b
SYNTHESIS
The synthesis of 2,3dimethylnaphthazarin is shown in Scheme 2. The cycloaddition between the 2,3dimethyl-1,3-butadiene and p -benzoquinone, aceelation, chromic acid oxidation of the adduct and finally the hydrolysis
of the diacetate, gives 2,3dimethylnaphthazarin, which can also be obtained by starting with a similar cycloaddition reaction between 1,3-butadiene and 2,3-dimethylquinone. RESULTS
AND
DISCUSSION
‘ET-and l 3C-NMR
Spectru
In chloroform solution the ‘I+NMR spectrum (Varian XL-loo) of 2,3dimethylnaphthazarin shows two protins at 7.18 and two methyl groups at 2.18 ppm both as singlet signals and
103
12.60 ppm. The 13C-NMR spectrum (Varian XL-loo) shows two different signals at 186.4 and 158.8 ppm for two different oxygenated carbon atoms (C,, C4 and CS, Cs, respectively), at 144.4 and 129.4 ppm for the two quinonoid and the two benzenoid carbon atoms respectively, at 111.7 ppm for the two common carbon atoms of the annular system, and at 12.5 ppm for the two methyl groups. From those NMR data, it was deduced that in chloroform solution, the molecule exists as the tautomeric form 1, 2,3-dimethyl-5,8-dihSTdrcxy-l,4naphthoquinone. X-my
structure
determination
Crystal data: C12H1004, M = 218.21, monoclinic, o = 16.429(4), b = 6.524(l), c = 9.136(4) A, p = 90.19(2)“, V = 979-l(3) A’, 2 = 4, F
measurements
and structure
analysis
A red single crystal of approximate dimensions 0.2 X 0.3 X 04 mm was used to obtain the data. The space group was determined from Weissenberg photographs. The cell parameters and the intensity data were collected on a 1100 Philips four circle diffractometer by the use of graphite monochromated MO I&Y radiation. Measurements were carried out in the o /20 scan mode. Of the 3317 reflections measured, 1278 were considered as observed, I> 30 (I). The phase problem was solved by a IMULTAN-80 program using 300 normalized structure factors with E > 2.00. The refinement of the structie was carried out by the full-matrix least-squares method* with anisotropic temperature factors for all non-hydrogen atoms. The hydrogen atoms were ob+tained from a difference Fourier map. Fkll-matrix least-squares cycles were then made, with anisotropic temperature factors for the heavy atoms and isotropic temperature factors for the hydrogen atoms. The hydrogen atom parameters were held fixed. The R terminal values were Rti = [Ew(IFol -lFcl)2/~~lIFol*]“2 = 0.059 with w = 1.0 and R = 0.053. The scattering factors were from International Tables for X-ray Crystallography (1974). The final positional and thermal parameters are listed in Tables 1 and 2. Crystal structure
of 2,3-dimefhylnaphthazarin
The crystaRographic numbering scheme adopted, bond distances and angles are given in Fig. 1. The molecule of 2,3dimethylnaphthazarin is planar but not centrosymmetric. *The structure factors and bond lengths are deposited with the British Division as Supplementary Publication number SUP 26245 (26 pages).
Library
Lending
104 TABLE1 Posiit;!nal parameters for heavy atoms and isotropictemperatw therefiiedankkropicvalnea Atom
x/a
CO)
0.3248(2) 0.3921(Z) 0.4585(2) O-5296(2) 0.5988(2) O-5965(2) 0.5249(3) O-4560(2) O-3879(2) 0.3230(2) O-6693(2) 0.6639(2) O-3822(2) 0.3809(2) 0.5318(2) 0.524212)
(x2) c(3) C(4) C(5) C(6) C(7) c(8) C(9) C(l6) W2) W3) o(l) O(2) O(3) O(4)
y/b
-0.2168(7) -O-2652(7) -0.1306(6) --O-1736(7) -O-0283(7) 0.1460(7) 0.1960(6) 0.0532(7) 0.0964(7) -O.O424(7) -0.0894(7) 0.3032(7) -0.4406(5) 0.2667(5) -0.3304(5) 0.3565(5)
factorsequivalentto
Z/C
%
O-1665(5) O-2545(4) O-2579(4) 0.3491(4) O-3534(4) 0.2750(4) O-1813(5) O-1747(4) 0.0882(5) 0.0849(5) 0.4499(5) O-2758(5) O-3336(3) 0.0039(4) O-4263(4) 0.1086(3)
0.044(l) 0.039(l) 0.033(l) 0.037(l) 0.037(l) 0.037(l) 0.038(l) 0.034(l) 0.040(l) 0.044(l) O-049(2) 0.054(2) 0.052(l) 0.055(l) 0.057(l) 0.055(l)
TABLE2 Positional and isotropicthermsl parametersforhydrogenatoms da
H(l) HW) H(121) H(122) H(123) H(131) H(132) H(133) H(O2) H(O1)
O-286(3) O-277(3) O-691(4) O&49(4) O-717(4) 0.715(4) O-671(4) 0.663(4) 0.415(3) 0.43563)
-O-312(7) -0.016(7) -0.225(8) -0.105(S) 0.008(8) 0.230(8) O-347(8) 0.434(8) O-339(5) -O-448(5)
Z/C
B
O-168(5) 0.025(5) O-415(6) 0.553(S) O-454(6) 0.245(6) 0.381(6) 0.219(6) 0.016(4) 0.389(4)
1.9 1.4 6.1 6.1 6.1 6.8 6.8 6.8 7.4 5.2
The bond lengths C+& = l-355(5) and C,--O, = 1.357(5) A are shown ti be single bonds with some double bond character and C4--03 = 1.243(5) and C,--O, = 1.240(S) A are double bonds with some single bond character; both intermediate bond lengths are due to an important chellation of the oxygen atoms to hydrogen HoI and Hoz atoms. The annular system has two different rings, with benzenoid and quinonoid characters. The benzenoid ring has a short bond length, C1-CIO = 1.360(7), with considerable double bond character. The quinonoid ring has bond = l-467(6) A shorter than G-C, = and C,-Cs disk&s CI)-Ca = l-460(5)
105
Fig. 1. Bond distances and an@
of dimethylnaphthazarin.
l-481(6) and C6-C, = l-488(6) A; this could be due to the inductive effect of the two methyl groups that are affected by the shortening of their bond = 1.510(6) A, since chelation of and C6--& distances C5-CI 2 = l-507(6) oxygen atoms 01, O2 and OS, O4 to hydsogens HoI and Hoz is an intermolecular effect arising from molecular packing (Fig. 2).
Fig. 2. MoIecuIar packing of dimethylnaphthazarin and intermolecular hydrogen bonds.
showing tbe molecular overlapping
106 By comparing the bond distance CS-CB = l-344(6) A with the same bond distance in the diacetate of naphthazarin (1.314(7) A) 173, and in the diacetate of tetramethglnaphthazarin (1.35W) A) C31, we can conclude that the methyl groups in the present compound are affected by some steric interaction (see also bond angle values in Fig. 1). It is remarkable that 2,3_dimethylnaphthazarin forms a charge-transfer complex with itself in the solid state and it is possible that distortion of some bond distances is caused by overlap of the molecules. The crystal is built from molecules stacked up the c-axis (Fig. 2). Each stack contains a symmetry center which acts in such a way that the quinonoid part of a molecule overlaps the benzenoid part of its symmetryrelated neighbours. The intermolecular distance between the overlapping planes is 3.42 A. Methyl
substituted
naph thazarins:
visible
spectra
The visible spectra of the methyl substituted naphthazarins in chloroform show three main peaks and a shoulder except for the naphthazarin molecule which shows four main peaks which could he due to the presence of the B and C modifications in solution (Table 3). Molecular
structure
of the naph thazmins
a. Naph thazarin Naphthazarin has been studied in each of its crystalline modifications in the solid state [3] _ These crystahize in the P2,?, space group; the molecules have a symmetry centre, which indicates that in the solid state the forms 2a and 2b shown in Scheme 1 predominate.
TABLE3
R, =R_
OH
0
OH
0
=R,
=R,
R, =CH, R,=R,=R,=H q=R,=H Ro=R,=CHI, R, 'R, =R,=CH, R,=H R,=R,=R,=R4=Me
=H
563(3750) 544(3670)
522(6075)
489(5465)
458(3700)
552(2830)
514(4610)
484(4150)
459(2700)
511(7500)
483(6850)
459(4800)
511(5900)
482(5100)
459(3400)
514(5100)
483(4000)
459(2350)
547(4500) 549(3800) 554(3700)
107
The moIecular overlapping is shown in Fig. 3. The in&planar distances between two overlapping molecules are 3.34, 3.42 and 3.40 A respectively for A, B and C crystalline modifications. b. Methylnaphthazarin Methylnaphthazarin has been also studied in the solid state [9]. The methyl substituent in position 2 and the molecule has no symmetry centre, which indicates that in the molecular structure form 1 (Scheme 1) has a remarkable predominance. The molecular overlapping is shown in Fig. 4. The interplanar distance between two overlapping molecules is 3.38 A. c.
t
e I
Fig.
3.
thazarin
Molecular
ProJ. (0 10
overlapping
of
the
A,
B and
3.
Fig. 4. Molecular
overlapping
of methylnaphthazarin.
1
C crystalline
modifications
of
naph-
108
Fig. 5. Molecular overlapping of btramethglnaphthazarin. Fig. 6. Mdecukr
overlapping of juglone.
TABLE 4
Naphtbzarin
Mod. Ab Mod. Bb Mod. C+= Tebamethyl~
Bond disstances a
b
C
d
e
1.43 1.40 1.44 1.44 1.46
1.43 1.46 1.43 1.41 1.41
1.43 1.47 1.43 1.43 1.46
1.44 1.46 1.43 1.43 1.47
1.34 1.37 1.34 1.36 1.37
=From Cradwick et al. [3]. dFrom ref. IO.
%?rom
Pascard-Billy
131.
‘?IVO
independent
molecules.
109
Moreover it is noticeable that the bond distances in the molecules are distorted by effect of the charge-transfer complexation as shown in Table 4. Thus, the molecular overlap could be regarded as the intermolecular interaction between acceptor molecular zones, C1, C2 and C3 and CS, Cs and C, and donor molecular zones, Cq, CIO, C9 and C8.
Juglone is a 5-hydroxy-1,4naphthaquinone and it has been studied in the solidstate [ll] . It crystallizes in the P2 1jn space group. The molecular overlapping is shown in Fig. 6. The interplanar distance between two overlapping molecules is 3.41 A. REFERENCES 1 J. S. Grossed, Chem. Sot. Rev., 1 (1972) 1. 2 T. Kametani and K Fukumoto, Med. Res. Rev., 1 (1981) 23. 3 C. Pascard-Billy, Bull. Sot. Chim. Fr., (1962) 2282-2293; C. Pascard-Billy, Acta Crystaiiogr., 15 (1962) 519; P. D. Cradwick and D. Hall, Acta Crystailogr. Sect. B, 27 (1971b) 1990-7. 4 H. Brockmann and A. Zeek, Chem. Ber., lOl(l968) 4221. 5 H. L. K. Schmand and P. Boldt, J. Am. Chem. Sot., 97 (1975) 447. 6 W. Shiau, E. N. DuesIer, I. C. Paul, D. Y. Curtin, W. G. Blann and C. A. Fyfe, J. _4m. Chem. Sot., (1980) 4546. 7 J. G. Rodriguez, F. H. Cano and S. Garcfa-Blanco, Acta Crystallogr. Sect. B. 23 (1977) 491. 8 J. G. Rodriguez, F. H. Cane and S. Garcia-BIanco, Cry& Struct. Commun., 8 (1979) 93. 9 P. D. Cradwick, D. HaB and M. K. Wood, Acta Crystaliogr. Sect. B. 33 (1977) 2380-4. 10 J. G. Rodriguez et aL, unpublished results. 11 P. D. Cradwick and D. Hall, Acta Crystailogr. Sect. B, 27 (1971) 1468-1470.