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Органическая химия
THE STRUCTURE OF TETRAPHENYLANTIMONY DIBENZOYLMETHANATE.
THE FACTORS AFFECTING THE STRENGTH OF LIGAND BINDING IN ANTIMONY(V) p-DIKETONATE COMPLEXES
V.V. Sharutin, South Ural State University, Chelyabinsk, Russian Federation, [email protected] O.K. Sharutina, South Ural State University, Chelyabinsk, Russian Federation, [email protected]
Tetraphenylantimony dibenzoylmethanate (1) was obtained by substitution reaction from pentaphenylantimony and dibenzoylmethane (2) in toluene. The ligand is bidentate in molecule 1, antimony atom has octahedral coordination (trans-angles CSbO and CSbC 165.7(1)°, 168.7(1)° and 159.4(2)°, distances Sb-O 2.256(3), 2.235(3) A, Sb-C 2.157(4)-2.170(4) A). Compound 2 is in the enol form in the crystal, the length of C=O and O-C bonds are equal to 1.283 (2) and 1.303(2) A.
Keywords: tetraphenylantimony dibenzoylmethanate, dibenzoylmethane, molecular structures, X-ray analysis.
Introduction
The P-diketones are bidentate chelating ligands, which form many complexes with transition metals. These complexes are well-studied and are of practical use. Chelate complexes with P-diketones are known for some non-transition metals. Thus, the existence of uncompleted d-orbitals with the lowest energy of the antimony atom determines its acceptor properties for electron pairs, provided by various donor molecules or intramolecular donor centers. This type of metal - ligand binding appears in orga-noantimony(V) P-diketonates where antimony atom is hexacoordinated. The synthesis of a sufficiently large number of antimony P-diketonate complexes are described in the literature, for example [1-7], but only a few of these complexes with acetylacetonate ligands are characterized structurally: Ph2SbCl2[OC(Me)CHC(Me)O] [8, 9], MeCl3Sb[OC(Me)CHC(Me)O] [8], Me2Br2Sb[OC(Me)CHC(Me)O] [8], Ph4Sb[OC(Me)CXC(Me)O], where X = H [10], Cl [11], Et, All [12], Ph [13, 14], SBu [14].
Analysis of the geometric characteristics of the established structures has allowed us to identify some dependences of the ligand binding strength, electron density distribution in the chelate cycle and distortion of octahedral polyhedron of the central atom from the nature of the substituents at the antimony atom and y-substituents of acetylacetone [15].
In continuation of the study of the ligand chemical nature influence on the structure of tetraphenylantimony P-diketonates we have determined the structure of tetraphenylantimony dibenzoylmethanate (1) and the original dibenzoylmethane (2).
Experimental
Synthesis of tetraphenylantimony dibenzoylmethanate (1) was realized by the method known from [7]. Yield 82 %, mp: 223-225 °C.
IR spectrum (v, cm -1): 3067, 3047, 1591, 1518, 1477, 1450, 1429, 1363, 1329, 1303, 1225, 1180 (cp.), 1085, 1021, 998, 935, 842, 771, 730, 718, 694, 656, 619, 520, 458, 450.
IR spectra were recorded on the Bruker Tensor 27 FT-IR spectrometer using KBr pellet, spectra were measured in the range 4000-400 cm-1.
The X-ray diffraction analyses of crystals 1 and 2 were carried out on the D8 Quest Bruker dif-fractometer (Mo Ka-radiation, X = 0.71073 A, graphite monochromator). Data were collected and edited, unit cell parameters were refined, and an absorption correction was applied using the SMART and SAINT-Plus programs [16]. All calculations on structure determination and refinement were performed
using the SHELXL/PC programs [17]. The structures 1 and 2 were determined by a direct method and refined by the least-squares method in the anisotropic approximation for non-hydrogen atoms. The main crystallographic data and refinement results for structures 1 and 2 are listed in Table 1. Selected bond lengths and bond angles are given in Table 2.
Table 1
Crystallographic data and the experimental and structure refinement parameters for compounds 1-2
Parameter Value
1 2
Empirical formula CssH^Sb C15O2H12
Formula weight 653,40 224,25
T, K 296(2) 296(2)
Crystal system Monoclinic Orthorhombic
Space group P2j/n Pbca
a, A 11.3741(3) 8.7609(3)
b, A 14.9349(4) 10.8556(3)
c, A 18.9137(6) 24.4698(8)
a, deg 90.00 90.00
P, deg 101.7630(10) 90.00
Y, deg 90.00 90.00
V, A3 3145.42(15) 2327.20(13)
Z 4 8
p(calcd.), g/cm3 1.380 1.280
|i, mm1 0.910 0.084
F(000) 1328.0 944.0
Crystal size, mm) 0.33 x 0.14 x 0.11 1.37 x 0.6 x 0.39
8 Range of data collection, deg 2.9 - 26.41° 3.1 - 26.41°
Range of refraction indices -14 < h < 14, -18 < k < 18, -23 < l < 23 -10 < h < 10, -13 < k < 13, -30 < l < 30
Measured reflections 42462 55097
Independent reflections 6450 2387
Rint Rint = 0.0677 Rlnt = 0.0393
Refinement variables 379 155
GOOF 1.042 1.468
R factors for F2 > 2ct(f2) Rj = 0.0438, wR2 = 0.0995 Rj = 0.0553, wR2 = 0.1672
R factors for all reflections Rj = 0.0834, wR2 = 0.1190 Rj = 0.0663, wR2 = 0.1825
Residual electron density (min/max), e/A3 2.17/Â-0.58 0.26/-0.32
Table 2
Selected bond lengthes and bond angles in the structures of compounds 1-2
Bond d, Â Angle ю, deg Bond d, Â Angle ю, deg
1 2
Sb(1)-C(1) 2.157(4) C(1)Sb(1)C(21) 159.37(17) C(1)-C(7) 1.481(2) С(1)С(7)С(8) 122.57(13)
Sb(1)-C(11) 2.157(5) C(11)Sb(1)0(1) 165.68(14) C(7)-C(8) 1.409(2) С(7)С(8)С(9) 120.93(13)
Sb(1)-C(21) 2.160(4) C(31)Sb(1)0(2) 168.70(15) С(8)-С(9) 1.389(2) С(8)С(9)С(10) 124.07 (13)
Sb(1)-C(31) 2.170(4) O(1)Sb(1)O(2) 79.10(11) С(9)-С(10) 1.480(2) С(1)С(7)О(1) 117.53(12)
Sb(1)-0(1) 2.256(3) C(1)Sb(1)C(31) 96.00(16) О(1)-С(7) 1.283(2) С(8)С(7)О(1) 119.89(13)
Sb(1)-O(2) 2.235(3) C(1)Sb(1)C(11) 97.14(17) О(2)-С(9) 1.303(2) С(8)С(9)О(2) 120.52(13)
О(1)-С(49) 1.277(5) C(11)Sb(1)C(31) 104.49(18) С(1)-С(2) 1.384(2) С(10)С(9)0(2) 115.41(13)
O(2)-C(47) 1.287(5) C(11)Sb(1)C(21) 95.46(19) С(1)-С(6) 1.396(2)
C(48)-C(49) 1.392(6) C(21)Sb(1)C(31) 96.57(17) С(2)-С(3) 1.380(2)
C(48)-C(47) 1.395(6) C(1)Sb(1)0(1) 82.28(14) С(10)-С(11) 1.397(2)
С(49)-С(51) 1.491(6) C(1)Sb(1)0(2) 80.58(14) С(10)-С(15' 1.383(2)
С(47)-С(41) 2.490(6) С(47)С(48)С(49) 126.9(4) С(12)-C(13) 1.372(3)
The full tables of atomic coordinates, bond lengths, and bond angles were deposited with the Cambridge Crystallographic Data Centre (CCDC 998579, and 998580 for compounds 1 and 2, respectively; [email protected]; http ://www.ccdc. cam.ac.uk).
Results and Discussion
According to the X-ray diffraction data, in the complex 1 the antimony atom has a distorted octahedral coordination with the chelate ring in the equatorial position (Fig. 1). The axial angle C(1)SbC(21) is equal to 159.37(17)°, the diagonal angles at the equatorial plane C(11)SbO(1) and C(31)SbO(2) are equal to 165.68(14)° and 168.70(15)°, respectively. Deviations of the atoms O(1), O(2), C(11), C(31) and Sb from the equatorial plane are +0,036, -0,035, +0,030, -0,029 and +0,005 A, respectively. The sum of angles in the equatorial plane is equal to 360°. Six-membered metallocycle [SbO2C3] is distorted so that the planes of the two half-cycles [O2Sb] and [O2C3] form an angle of 156.4°, i.e. there is an inflection on the O-O diagonal. The planes of the phenyl rings C(41)-C(46) and C(51)-C(56) form angles of 27.8° and 7.8° with the plane [O2C3], respectively.
The Sb-C bond lengths in the equatorial (2.157(4), 2.170(4) A) and axial (2.157(4), 2.160(4) A) positions are not very different from each other. The ligand demonstrates anizobidentate character of coordination: the Sb-O(1) and Sb-O(2) distances are 2.256(3) and 2.235(3) A. The O(1)-C(49) and O(2)-C(47) bonds in the cycle do not differ much (1.277 (5) and 1.287 (5) A), the same is true about the C(48)-C(49) and C(48)-C(47) (1.392(6) and 1.395(6) A).
The valence angles at the antimony atom in the molecule of tetraphenylantimony y-phenylacetylacetonate are close to those observed in the compound 1, however, the binding of ligand to the central atom (the Sb-O distances are 2.215(1) and 2.228(1) A [14]) is stronger. Since the strength of the donor-acceptor interaction is due to both the acceptor ability of the metal and donor properties of the ligand, it can be assumed that the methyl groups with the positive inductive effect play the decisive role in strengthening these properties of 7-penylacetylacetonate ligand. The effect of the group nature at the antimony atom and the chelate cycle on the ligand binding strength to the central atom can be seen in the inorganic complexes CUSb[OC(Ph)CHC(Ph)O] [18] and CUSb[OC(Me)CHC(Me)O] [18, 19]. In tetrahloroantimony dibenzoylmethanate with symmetrical ligand coordination the Sb-O bond length (2.011(4) A) is close to the sum of the covalent radii of antimony and oxygen atoms (2.07 A [20]) that can be explained by an increase in acceptor properties of the antimony atom having four electron-withdrawing substituents (Cl atoms). Replacement of the phenyl groups, showing a weak negative inductive effect, by methyl groups in the chelate cycle of tetrachloroantimony acetylacetonate leads to greater consolidation of ligand binding (the Sb-O bonds are 1.928(11) and 1.991(14) A). Strengthening
Fig. 1. The structure of the compound 1
of the Sb-O bonds in inorganic complexes is accompanied by some lengthening of the C-O bonds in the chelate cycle (1.298(5) and 1.318(19), 1.320(19) A, respectively).
The above analysis of the structural data demonstrates that the strength of the chelate cycle in tetra-phenylantimony ytf-diketonate is significantly affected by the nature of the substituent not only in the y-position, as stated previously [15].
P-Diketone 2 is in the enol form in the crystal (Fig. 2). The planes of the phenyl ring C(1)-C(6) and fragment O(1)C(7)C(8)C(9)O(2) are coplanar, the C(10)-C(15) plane amounts to angle 14.4° with this plane. The C(7)-O(1) bond length (1.283(2) A) is shorter than the C(9)-O(2) bond (1.303(2) A), while the C(7)-C(8) bond length (1.409(2) A) is greater than the C(9)-C(8) bond (1.389(2) A). The distances C(1)-C(7) and C(9)-C(10) (1.481(2), 1.480(2) A) are less than the corresponding distances of 1 (1.490(6), 1.491(6) A).The angle C(7)C(8)C(9) is equal to 120.93(13)° and corresponds to the valence angle at the carbon atom in the sp2-state. In compound 1 the angle at the atom C(48) in the chelate ring is 126.9(4)°.
Fig. 2. The structure of the compound 2
Intramolecular hydrogen bond has parameters: O (2)-H 0.82 Â, O(1)-H 1.72 Â, angle O(2)HO(1) 149°.
Conclusions
Thus, the nature of the substituent groups in the cycle determines the chelate ligand binding strength in the antimony(V) P-diketonate, but has virtually no effect on both the distortion of the coordination polyhedron antimony atom and the complex structure as a whole.
At binding of dibenzoylmethane in the complex there is redistribution of the electron density, which causes the alignment of C-O and C-C bonds in the cycle. In addition, the formation of the chelate ring is accompanied by distortion of the CCC bond angle compared with the theoretical value.
References
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2. Matsumura Y., Okawara R. Hexacoordinated Tetraphenylantimony Complexes. Inorg. Nucl. Chem. Lett., 1968, vol. 4, no. 9, pp. 521-524.
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Received 18 December 2014
Bulletin of the South Ural State University
Series "Chemistry" _2015, vol. 7, no. 1, pp. 5-11
УДК 546.865+547.53.024+547.442.3+548.312.5
СТРОЕНИЕ ДИБЕНЗОИЛМЕТАНАТА ТЕТРАФЕНИЛСУРЬМЫ. ФАКТОРЫ, ВЛИЯЮЩИЕ НА ПРОЧНОСТЬ СВЯЗЫВАНИЯ ЛИГАНДА В ß-ДИКЕТОНАТНЫХ КОМПЛЕКСАХ СУРЬМЫ (V)
В.В. Шарутин, О.К. Шарутина
Дибензоилметанат тетрафенилсурьмы (1) синтезирован по реакции замещения из пентафенилсурьмы и дибензоилметана (2) в толуоле. В молекуле 1 лиганд бидентатен, координация атома сурьмы октаэдрическая (транс-углы CSbO и CSbC 165,7(1)°, 168,7(1)° и 159,4(2)°, расстояния Sb-O 2,256(3), 2,235(3) Ä, Sb-C 2,157(4)-2,170(4) Ä). В кристалле соединение 2 находится в енольной форме, длины связей C=O и C-O равны 1,283(2) и 1,303(2) Ä.
Ключевые слова: дибензоилметанат тетрафенилсурьмы, дибензоилметан, молекулярные структуры, рентгеноструктурный анализ.
Литература
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2. Matsumura, Y. Hexacoordinated Tetraphenylantimony complexes / Y. Matsumura, R. Okawara // Inorg. Nucl. Chem. Lett. - 1968. - V. 4. - N. 9. - P. 521-524.
3. Singhal, K. Studieson ß-Diketonate and ß-Diketones ter Derivatives of Tri- and Tetraorganoan-timony(V) / K. Singhal, A.K. Aggarwal, P. Ray // Indian J. Chem. - 1992. - V. 31A. - N. 10. - P. 797799.
4. Jain, V.K. Synthesis and Spectral Studies of (1,3-Diketonato)triphenylantimony (V) Complexes / V.K. Jain, B. Bohra, R.C. Mehrotra // J. Organomet. Chem. - 1980. - V. 184. - N. 1. - P. 57- 62.
5. Otero, A. Pentafluorophenylantimony Compounds / A. Otero, P. Royo // J. Organomet. Chem. -1978. - V. 154. - N. 1. - P. 13-19.
6. Pentahalophenyl Derivatives of Antimony (V) with Bidentate Ligands / A. Espinosa, A.J. Barbero, J.M.G. Sanchez et al. // An. Quim. - 1983. - V. 79B. - N. 2. - P. 217-220.
7. ^нтез ß-дикетонатов тетраарилсурьмы из пентаарилсурьмы и ß-дикетонов /
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8. The Crystal and Molecular Structures of three Acetylacetonato-Organoantimony (V) Compounds [(acac)RnSbX4_n] / N. Kanehisa, K. Onuma, S. Uda et al. // Bull. Chem. Soc. Japan. - 1978. - V. 51. -N. 8. - P. 2222-2233.
9. Kroon, J. The Molecular Structure of (Acetylacetnato)dichlorodiphenylantimony in the Crystalline State / J. Kroon, J.B. Hulscher, A.F. Peerdeman // J. Organomet. Chem. - 1972. - V. 37. - N. 2. -P. 297-301.
10. Шарутин, В.В. Кристаллическая и молекулярная структура ацетилацетоната тетрафенилсурьмы / В.В. Шарутин, О.К. Шарутина // Бутлеровские сообщения. - 2014. - Т. 38. - № 5. -
C.118-121.
11. Синтез и строение хлорацетилацетоната тетрафенилсурьмы / В.В. Шарутин, О.К. Шарутина, О.П. Задачина и др. // Журн. общ. химии. - 2000. - Т. 70. - № 10. - С. 1672-1674.
12. Синтез и строение у-алкилацетилацетонатов тетрафенилсурьмы / В.В. Шарутин, О.К. Шарутина, О.П. Задачина и др. // Коорд. химия. - 2003. - Т. 29. - № 1. - С. 8-12.
13. Синтез и строение у-фенилацетилацетоната тетрафенилсурьмы / В.В. Шарутин,
A.П. Пакусина, О.К. Шарутина и др. // Химия и компьютерное моделирование. Бутлеровские сообщения. - 2003. - Т. 4. - № 1. - С. 34-35.
14. Синтез и строение у-фенил- и у-тиобутилацетилацетонатов тетрафенилсурьмы /
B.В. Шарутин, А.П. Пакусина, И.В. Егорова и др. // Коорд. химия. - 2008. - Т. 34. - № 4. -
C.267-271.
15. Шарутина, О.К. Молекулярные структуры органических соединений сурьмы (V) / О.К. Шарутина, В.В. Шарутин. - Челябинск: Издательский центр ЮУрГУ. - 2012. - 395 с.
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19. Structures of two Acetylacetonate Complex: Sb(Acac)Cl4 and (NHEt3)[Sn(Acac)Cl4] / L. Korte, D. Mootz, M. Scherf, M. Wiebcke // Acta Crystallogr. - 1988. - V. C44. - P. 1128-1130.
20. Бацанов, С.С. Атомные радиусы элементов / С.С. Бацанов // Журн. неорган. химии. -1991. - Т. 36. - Вып. 12. - С. 3015-3037.
Шарутин Владимир Викторович - доктор химических наук, профессор, кафедра органической химии, Южно-Уральский государственный университет. 454080, г. Челябинск, пр. им. В.И. Ленина, 76. E-mail: [email protected]
Шарутина Ольга Константиновна - доктор химических наук, профессор, кафедра органической химии, Южно-Уральский государственный университет. 454080, г. Челябинск, пр. им. В.И. Ленина, 76. E-mail: [email protected]
Поступила в редакцию 18 декабря 2014 г.
