Complexes of 15-crown-5 and cyclohexano-15-crown-5 with lithium, sodium, and potassium phenoxide having macrocycle: salt ratios of 1:1 and 1:2. The crystal structures of two polymorphs of 15-crown-5•2LiOPh

1988 ◽  
Vol 66 (10) ◽  
pp. 2515-2523 ◽  
Author(s):  
Michael P. Murchie ◽  
John W. Bovenkamp ◽  
André Rodrigue ◽  
Kimberley A. Watson ◽  
Suzanne Fortier

The syntheses, in ethereal solvents, of the complexes of 15-crown-5 and cyclohexano-15-crown-5 with lithium, sodium, and potassium phenoxide are described. The two macrocycles form complexes with lithium and sodium phenoxide with host:guest ratios of 1:2. Potassium phenoxide, however, was complexed by the two macrocycles to give products with macrocycle:salt ratios of 1:1. Crystals of 15-crown-5•2LiOPh were obtained for X-ray diffraction structure determinations. In fact, the crystal structures of two co-crystallizing polymorphs of this complex (1a and 1b) have been determined. Polymorph 1a crystallizes in space group [Formula: see text] with a = 11.386(4), b = 11.901(4), c = 10.654(4) Å, α = 106.53(3), β = 112.60(3), γ = 106.52(3)°, and Z = 2. Polymorph 1b crystallizes in space group P21/n with a = 15.355(4), b = 11.642(2), c = 13.595(6) Å, β = 104.56(3)°, and Z = 4. Both structures were solved by direct methods, and refined by full-matrix least-squares calculations to residuals, R, of 0.053 and 0.055 for polymorphs 1a and 1b, respectively. The structures of the two polymorphs differ only in the orientation of the phenoxides. The structures show a dimer, (15-crown-5•2LiOPh)2, which consists of an aggregate of four lithium phenoxide molecules complexed by two 15-crown-5 macrocycles. The two lithiums of each monomeric unit of this dimer have different crystallographic and chemical environments. One lithium is coordinated to all five oxygens of the macrocycle and to one of the phenoxide oxygens while the other lithium is coordinated to only one oxygen of the macrocycle and to three phenoxide oxygens.

1986 ◽  
Vol 64 (4) ◽  
pp. 816-823 ◽  
Author(s):  
Marie E. Fraser ◽  
Suzanne Fortier ◽  
André Rodrigue ◽  
John W. Bovenkamp

The crystal structures of the 1:2 host:guest complexes of dicyclohexano-18-crown-6 (isomer B) with potassium phenoxide and dicyclohexano-18-crown-6 (isomer A) with sodium phenoxide have been determined. The potassium phenoxide complex crystallizes in space group [Formula: see text] with a = 10.023(2), b = 11.238(2), c = 7.546(2) Å, α = 95.73(2), β = 103.04(2), γ = 92.03(2)°, and Z = 1. The sodium phenoxide complex crystallizes in space group P21/n with a = 19.185(12), b = 13.266(5), c = 13.038(5) Å, β = 96.55(4)°, and Z = 4. Both structures were solved by direct methods and refined by full matrix least-squares calculations to a residual, R, of 0.035. The host conformation as well as the metal cation coordination differ considerably in the two structures. In the potassium phenoxide complex, the two cations are related by symmetry and have, consequently, the same chemical environment. Each potassium is located approximately halfway between the plane formed by the crown ether oxygens and the phenoxide anions and is coordinated to four of the crown oxygens and to two phenoxide oxygens. The oxygens of the crown are found to outline an elliptical cavity and to lie approximately in a plane. In the sodium phenoxide complex, the two sodiums have different crystallographic and chemical environments. One sodium is coordinated to the six hexaether oxygens, with distances ranging from 2.36to2.84 Å, and to one of the phenoxide oxygens. The other sodium is coordinated to only one of the crown oxygens and to three of the phenoxide oxygens. The hexaether adopts a highly irregular conformation.


1977 ◽  
Vol 30 (10) ◽  
pp. 2195 ◽  
Author(s):  
RM Christie ◽  
RW Rickards ◽  
KJ Schmalzl ◽  
D Taylor

Alkaline chlorination of the 4-alkyl-2,6-dichlorophenols (2b) and (2c) proceeds through ring contraction and halolactonization to form the 4α- alkyl-2,2,5α-trichloro-1α,3α-dihydroxycyclopentane-1,4-carbolactones (4b) and (4c). Under similar conditions, 2,4,6-trichlorophenol affords the analogous 2,2,4α,5α-tetrachloro-1α,3α-dihydroxycyclopentane-1,4- carbolactone (4a) in low yield, in addition to the Hantzsch acid (3a) as the major product. The acid (3a) upon further treatment undergoes chloro-lactonization to give the lactone (4a). The structures of the lactones (4b) and (4c) follow from spectroscopic comparison with (4a), the structure of which has been established by X-ray diffraction (C6H4Cl4O4 orthorhombic a 13.485(1), b 12.348(1), c 11.371(1) Ǻ, space group Pccn, Z 8, solved by direct methods and refined by block-diagonal and full-matrix least squares to R 0.031, Rw 0.043 for 1313 unique counter data with I/σ(I) ≥ 3.0).


1999 ◽  
Vol 54 (2) ◽  
pp. 288-290 ◽  
Author(s):  
Wolfgang Czado ◽  
Susanne Rabe ◽  
Ulrich Müller

(PPh4)2[As2Cl8] · CH3CN was obtained from PPh4Cl and S2Cl2 with As or As4S4 or AsCl3 in acetonitrile. PPh4Cl, S2Cl2 and Sb2S3 yielded (PPh4)[Sb2Cl8] CH3CN. PPh4Br and AsBr3 gave (PPh4)2[Sb2Br8]-CH3CN. AsCl2OPh (from AsCl3 and NaOPh) reacted with Ph4Br in acetonitrile in the presence of Na2Se, selenium, and HCl, affording (PPh4)2[As2Br4,2Cl3,8] · CH3CN. According to their X-ray crystal structure determinations, all products are isotypic (space group C2/c, Z=4). The centrosymmetric anions consist of two ψ octahedra sharing an edge. In the [As2Br4,2Cl3,8]2- ion the bridging positions are taken solely by bromine atoms, whereas Br and Cl atoms occupy the other halogen positions randomly.


2007 ◽  
Vol 40 (4) ◽  
pp. 702-709 ◽  
Author(s):  
Michela Brunelli ◽  
Marcus A. Neumann ◽  
Andrew N. Fitch ◽  
Asiloé J. Mora

The crystal structures of bicyclo[3.3.1]nonane-2,6-dione and bicyclo[3.3.1]nonane-3,7-dione have been solved by direct methods and by direct-space simulated annealing, respectively, from powder synchrotron X-ray diffraction data. Both compounds have a transition to a face-centred-cubic orientationally disordered phase (phase I) near 363 K, as shown by differential scanning calorimetry and powder diffraction measurements. Phase II of bicyclo[3.3.1]nonane-2,6-dione, which occurs below 363 K, is monoclinic, space groupC2/c, witha= 7.38042 (4),b= 10.38220 (5),c= 9.75092 (5) Å and β = 95.359 (1)° at 80 K. Phase II of bicyclo[3.3.1]nonane-3,7-dione, which occurs below 365 K, is tetragonal, space groupP41212, witha= 6.8558 (1) andc= 16.9375 (1) Å at 100 K. This phase coexists in a biphasic mixture with a minor monoclinic phase II′ [a= 11.450 (6),b = 20.583 (1),c= 6.3779 (3) Å, β = 94.7555 (5)°, at 100 K] detected in the sample, which impeded indexing with standard programs. The crystal structures of phases II were solved by direct methods and by direct-space simulated annealing, employing powder synchrotron X-ray diffraction data of increased instrumental intensity and resolution from the ID31 beamline at the ESRF, and novel indexing algorithms.Ab initiomolecular orbital calculations on the two systems are reported. In the solid state, the molecules pack in chair–chair conformation; molecular structures and packing are discussed.


1975 ◽  
Vol 28 (1) ◽  
pp. 15 ◽  
Author(s):  
JC Dewan ◽  
K Henrick ◽  
AH White ◽  
SB Wild

The crystal structures of the title compounds have been established by X-ray diffraction at 295 K, being refined by full-matrix least-squares to residuals of 0.054 (0.051) respectively 2715 (469) reflections with I > σ(I)]. Crystals are monoclinic, space group C2/c, the compounds being isomorphous. Oxychloride: a = 14.534(4), b = 8.337(2), c = 7.653(1)Ǻ, β = 106.48(1)�. Oxybromide: a = 14.884(4), b = 8.360(2), c = 7.726(1)Ǻ, β = 105.30(1)�, Z = 4. With the exception-of the arsenic- halogen distance, the geometries of the two molecules are identical within the limits of error: for the oxychloride As-O-As, 121.8(3); Cl- As-O,98.03(6); Cl-As-C, 97.2(2); O-As-C, 92. 9(2)� ; As-O, 1.787(3); As-C, 1.941(5) Ǻ. As-Cl is 2.222(2) and As-Br 2.381(2) Ǻ.


1988 ◽  
Vol 66 (1) ◽  
pp. 123-131 ◽  
Author(s):  
William O. Nelson ◽  
Timothy B. Karpishin ◽  
Steven J. Rettig ◽  
Chris Orvig

A series of 3-hydroxy-2-methyl-4(1H)-pyridinones has been prepared with the substituents H, CH3, n-C6H11, and CH2CH2NH2 at the ring N. The dipyridinone 1,6-bis(3-hydroxy-2-methyl-4(1H)-pyridinon-1-yl)hexane has also been synthesized. The products with H and CH3 substituents have been studied by single crystal X-ray diffraction. Crystals of 3-hydroxy-2-methyl-4-pyridinone are monoclinic, a = 6.8351(4), b = 10.2249(4), c = 8.6525(4) Å, β = 105.215(4)°, Z = 4, space group P21/n and those of 3-hydroxy-1,2-dimethyl-4-pyridinone are orthorhombic, a = 7.3036(4), b = 13.0490(6), c = 13.7681(7) Å, Z = 8, space group Pbca. Both structures were solved by direct methods and were refined by full-matrix least-squares procedures to R = 0.037 and 0.044 for 914 and 857 reflections with I ≥ 3σ(I), respectively. Bond lengths and angles in the two compounds were normal. All the compounds have been studied by mass spectrometry, and by infrared and proton nmr spectroscopies. The importance of hydrogen bonding to both the solution and solid state properties of these compounds has been confirmed by these techniques.


1991 ◽  
Vol 69 (4) ◽  
pp. 687-695 ◽  
Author(s):  
Kimberly A. Watson ◽  
Suzanne Fortier ◽  
Michael P. Murchie ◽  
John W. Bovenkamp

The crystal structures of three crown ether complexes (cyclohexano-15•crown-5•2LiOPh (1): Li2O7C26H36, Mr = 474.45, λ(CuKα)filt. = 1.5418 Å; cyclohexano-15-crown-5•2NaOPh (2): Na2O7C26H36, Mr = 504.54, λ(CuKα)filt. = 1.5418 Å; and 15-crown-5•2NaOPh (3): Na2O7C22H30, Mr = 452.46, λ(CuKα)mono. = 1.5418 Å) have been determined by X-ray diffraction at room temperature (T = 298 K). Complex 1 crystallizes in space group P21/n with a = 15.032(5), b = 13.332(2), c = 13.533(3) Å, β = 106.28(2)°, V = 2603.2 Å3, and Z = 4. Complex 2 crystallizes in space group P21/n with a = 15.94(1), b = 12.194(7), c = 14.068(7) Å, β = 102.84(5)°, V = 2666.3 Å3, and Z = 4. Complex 3 crystallizes in space group P21/c with a = 12.451(3), b = 17.263(3), c = 12.659(6) Å, β = 115.74(3)°, V = 2450.8 Å3, and Z = 4. The three structures were solved by direct methods and refined by full-matrix least-squares calculations to residuals, R, of 0.080, 0.069, and 0.081 for complexes 1, 2, and 3, respectively. In each structure the macrocycle forms a 1:2 host–guest complex with the alkali metal. Each structure exhibits a dimer of the general form (MAC•2MOPh)2 where M = Li+ and Na+ for structures 1 and 2, respectively, and MAC = cyclohexano-15-crown-5, while M = Na+ and MAC = 15-crown-5 for structure 3. In each case the two metals of the monomeric unit have different crystallographic and chemical environments. In structures 1 and 3 one alkali metal is coordinated to all five oxygens of the macrocycle and to one of the phenoxide oxygens, while the other alkali metal is coordinated to only one oxygen of the macrocycle and to three phenoxide oxygens. In structure 2, one alkali metal is coordinated to only four of the five oxygens of the macrocycle and to two of the phenoxide oxygens, while the other alkali metal is coordinated to only one oxygen of the macrocycle and to three phenoxide oxygens (as in 1 and 3). Key words: crown ether, host–guest complexes, X-ray crystallography.


1999 ◽  
Vol 55 (1) ◽  
pp. 114-122 ◽  
Author(s):  
Arjen van Langevelde ◽  
Kees van Malssen ◽  
Frank Hollander ◽  
René Peschar ◽  
Henk Schenk

The crystal structure of the β polymorph of tripalmitin (1,2,3-trihexadecanoylglycerol, β-PPP) has been determined by single-crystal X-ray diffraction. The molecules crystallize in space group P1¯ in an asymmetric tuning-fork conformation. This structure and the already-known crystal structures of β-tricaprin (β-CCC) and β-trilaurin (β-LLL) could be matched in an overlap model. Apart from a difference in chain length, the three structures are almost identical. The overlap model can be used to predict the crystal structure of the other members of the C n C n C n -type (n = even) TAG series reasonably accurately. This is demonstrated by predicting the crystal structure for β-trimyristin (β-MMM) and successively comparing the experimental and calculated X-ray powder diagrams.


1992 ◽  
Vol 70 (3) ◽  
pp. 763-770 ◽  
Author(s):  
Zaihui Zhang ◽  
Steven J. Rettig ◽  
Chris Orvig

3-Hydroxy-1-carboxymethyl-2-methyl-4-pyridinone (Hcmp) and 3-hydroxy-1-(p-methoxyphenyl)-2-methyl-4-pyridine (Hpap) have been prepared and studied by single crystal X-ray diffraction. Crystals of Hemp are monoclinic, a = 6.340 (2), b = 7.705 (1), c = 16.226 (1) Å, β = 94.74 (1), Z = 4, space group P21/n and those for Hap are monoclinic, a = 10.8435 (9), b = 16.680 (2), c = 13.5665 (6) Å, β = 109.450 (4), Z = 8, space group C2/c. Both structures were solved by direct methods and were refined by full-matrix least-squares procedures to R = 0.030 and 0.041 (Rw = 0.039 and 0.058) for 1642 and 1819 reflections with I ≥ 3σ(I), respectively. Bond lengths and bond angles in the two compounds are normal; however, Hcmp forms as a zwitterion in the solid state. The two compounds were also studied by mass spectrometry, UV, infrared, proton NMR spectroscopies, and potentiometric equilibrium measurements. The protonation constants for Hcmp are log K1 = 9.76 (1), log K2 = 3.43 (1), and log K3 = 2.78 (3) and for Hpap are [Formula: see text] and [Formula: see text]. Keywords: 3-hydroxy-4-pyridinone, zwitterion, hydrogen bonding, protonation constant, crystallography, solid state.


1986 ◽  
Vol 39 (2) ◽  
pp. 339 ◽  
Author(s):  
JM Harrowfield ◽  
BW Skelton ◽  
AH White ◽  
FR Wilner

The crystal structures of the two title compounds, cis-[Co(en)2(NH3) Cl ] Cl2, (1), and cis-[Co(en)2( py ) Cl ]Cl2.H2O, (2), have been determined by single-crystal X-ray diffraction methods at 295 K, being refined by full-matrix least-squares techniques to residuals of 0.025 and 0.036 for 1744 and 3243 independent 'observed' reflections. Crystals of (1) and (2) are monoclinic, P21/c, Z = 4. For (1), a 7.499(1), b 11.986(2), c 14.325(3)Ǻ, β 111.45(1)°; for (2), a 7.617(2), b 12.866(3), c 16.561(5), β 97.33(2)°. Both complexes are racemates with cation conformations Δ( δ,λ ), (1), and Δ( λ,λ ), (2). The structure determinations suggest that variations in the rate of base hydrolysis of these complexes and their imidazole analogue may be correlated with the degree of steric crowding associated with the introduction of the monodentate nitrogen base into the coordination sphere.


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