Polycarboxylate crown ethers from meso-tartaric acid

1991 ◽  
Vol 69 (1) ◽  
pp. 12-19 ◽  
Author(s):  
Frank R. Fronczek ◽  
Richard D. Gandour ◽  
Thomas M. Fyles ◽  
Philippa J. Hocking ◽  
Susan J. McDermid ◽  
...  

The synthesis of crown ethers derived from meso-tartaric acid was investigated. The sodium salt of the bis(dimethylamide) of meso-tartaric acid reacted with diethylene glycol ditosylate to give a mixture of 18-crown-6 tetraamide and 27-crown-9 hexaamide crown ethers. The 2R,3S,11S,12R 18-crown-6 isomer crystallized in triclinic space group [Formula: see text] (a = 7.557(2), b = 8.866(2), c = 10.4133(13) Å, α = 94.13(2), β = 95.86(2), γ = 99.26(2)°, R = 0.040 for 2090 observed of 3129 unique reflections). The structures of the remaining products were then assigned from the NMR spectra. The solution conformations of the amide crown ethers were examined by NMR, and provide a rationale for the product distribution obtained. One of the 18-crown-6 isomers and a mixture of the two 27-crown-9 isomers were hydrolyzed to the respective crown ether carboxylic acids, and the stability constants for complexation of cations were determined by potentiometric titration. The meso tetra- and hexacarboxylates are remarkably nonselective and inefficient cation complexing agents, compared to related crown ethers from R,R-(+)-tartaric acid, due to the unfavorable conformational control exerted by the tartaro units. Key words: crown ether synthesis, complexation, crown ether conformation, meso-tartaric acid, crystal structure.

2003 ◽  
Vol 58 (8) ◽  
pp. 745-750 ◽  
Author(s):  
Stefan Rannabauer ◽  
Tassilo Habereder ◽  
Heinrich Nöth ◽  
Wolfgang Schnick

The oxonium acid [H(OEt2)2]+[Ti2Cl9]− (1) was obtained by the reaction of TiCl4 with Et2O in n-pentane and subsequent partial hydrolysis. Suitable single crystals of 1 were obtained by sublimation at 5° C ([H(OEt2)2]+[Ti2Cl9]−, P212121 (no. 19), Z = 4, a = 1101.08(8), b = 1328.4(2), c = 1525.0(2) pm, T = 193(2) K, 4489 independent reflections, 197 parameters, R1 = 0.049). The cation is made up from two independent Et2O molecules and one disordered proton on two split positions. Both ether molecules exhibit a W form, and their molecular planes include an angle of 74.1(7)°. Thus a distorted tetrahedron is formed by the four methyl carbon atoms of the two ether molecules. The distance O···O amounts to 237.7(1) pm. The proton of the cation was characterized both by 1H NMR (CDCl3, T = 23 °C: δ = 11.7 ppm, w1/2 = 100 Hz) and IR spectroscopy (3120 cm−1, ν vbr). The [Ti2Cl9]− ion consists of two face sharing octahedra. 47Ti and 49Ti NMR spectra were recorded in solution (CH2Cl2, T = 23 °C: δ 49Ti = 137 ppm, w1/2 = 175 Hz; δ 47Ti = −124 ppm, w1/2 = 250 Hz). The absence of a signal for TiCl4 at δ 49Ti = 0 ppm indicates the stability of the dinuclear anion in solution.


1985 ◽  
Vol 40 (4) ◽  
pp. 512-517 ◽  
Author(s):  
Udo Kunze ◽  
Hussain Jawad ◽  
Wolfgang Hiller ◽  
Regina Naumer

The tetracarbonyl chromium and molybdenum P,S-chelate complexes 1a, b and 2a, b are obtained by low-temperature photolysis of the metal hexacarbonyls with the neutral phosphinothioformamide ligands, Ph2PC(S)NHR (R = Me (a). Ph (b)), as stoichiometric 1/1 IHF adducts. A weak N-H···O(THF) hydrogen bond is deduced from the 1H NMR spectra which show a collapse of the N-methyl doublet in la (Tc -18 °C) but not in 2a. Unusually small P-C(S) couplings are observed in the 13C{1H} NMR spectra. The N-methyl chromium complex la crystal­lizes in the triclinic space group P1 (Z = 2) with the lattice constants a = 1076.6(3), b = 1235.8(3), c = 915.1(3) pm, α = 97.99(4)°, β = 92.73(5)°, γ = 87.63(5)°. The planar thioamide unit adopts the Z configuration and is linked to the tetrahydrofuran molecule by a hydrogen bond (N-H1-O31 164°) with an O···H contact distance of 191 pm.


Author(s):  
Christopher B. Hansen ◽  
Alexander S. Filatov ◽  
Gregory L. Hillhouse

The title compound, [Co2Na2{μ2-N(SiMe3)2}4](μ4-O), (I), represents a new entry in the class of inverse crown ethers. In the molecule, each Co atom is formally in the oxidation state +II. The structure contains one half of a unique molecule per asymmetric unit with the central μ4-oxido ligand residing on an inversion center, leading to a planar coordination to the Na and Co atoms. In the crystal, bulky trimethylsilyl substituents prevent additional interactions with cobalt. However, weak intermolecular Na...H3C—Si interactions form an infinite chain along [010]. The structure is isotypic with its Mg, Mn and Zn analogues.


1984 ◽  
Vol 39 (12) ◽  
pp. 1686-1695 ◽  
Author(s):  
Jürgen Hanich ◽  
Magda Krestel ◽  
Ulrich Müller ◽  
Kurt Dehnicke ◽  
Dieter Rehder

An improved synthesis for [VCl2(N3S2)]∞, was found in the reaction of VOCl3 with (NSCl)3; when the reaction is performed in H2CCl2 and (NSCl)3 is used in excess, the thiazyl-solvate [VCl2(N3S2) · NSCl]2 is obtained. [VCl2(N3S2)] reacts with AsPh4Cl to form (AsPh4)2[VCl3(N 3S2)]2; this reacts with AgN3 in CH2Cl2 suspension to yield (AsPh4)2[V (N3)3(N3S2)]2 · CH2Cl2. The compounds were characterized by their IR and 51V NMR spectra. The latter are compared with new 51V NMR data for [VO2Cl2]⊖ and [VOCl4]⊖ ; a decrease of 51V shielding in the order [VO2Cl2]⊖ > [VOCl4]⊖ > [VX3(N3S2)]22⊖ (X - N3 > Cl) is found, which is interpreted in terms of increasing polarizability of the ligands and of ring contributions to the extreme deshielding observed with the thiazenovanadates.The crystal structure of (AsPh4)2[V(N3)3(N3S2)]2 · CH2Cl2 was determined from X-ray diffraction data (1496 observed reflexions, R = 0.058). It crystallizes in the triclinic space group P 1̄ with one formula unit per unit cell and with the lattice constants a - 1087, b = 1317, c = 1350 pm, α = 58.8, β = 85.9, γ = 68.0°. The structure consists of AsPh4⊕ ions, CH2Cl2 molecules and centrosymmetric [V(N3)3(N3S2)]22⊖ anions. In the latter. N3S2 ligands are bonded to the V atoms in a chelate manner with short V = N bonds (189 and 172 pm) forming planar VN3S2 rings. The dimerization is accomplished by V -N donor-acceptor interactions (224 pm) involving one N atom of each VN3S2 ring. The vanadium coordination number of 6 is com pleted by three azido groups with V -N bond distances of 200 to 204 pm.


2004 ◽  
Vol 59 (11-12) ◽  
pp. 1438-1443 ◽  
Author(s):  
Adrienne Hammerschmidt ◽  
Illenora Beckmann ◽  
Mechtild Läge ◽  
Bernt Krebs

The title compound [H7O3(bis-dibromo-dibenzo-30-crown-10)][Se2Br9] ·1.5CH2Cl2 (1) was isolated from a solution of SeBr4 and dibenzo-30-crown-10 in CH3CN/CH2Cl2 containing a small amount of hydrobromic acid. During the reaction the crown ether is brominated by HBr. The compound crystallizes in the monoclinic space group P21/n with a = 17.688(11), b = 14.921(6), c = 20.521(12) Å , β = 97.71(5)°, and Z = 4. 1 is a novel example in the series of supramolecular halogenochalcogeno acids prepared in our group in which different oxonium cations are stabilized and encapsulated by crown ethers. Especially in this class of superacids complexation by cyclic polyethers offers covenient and variable possibilities for the controlled synthesis of oxonium cations. In the present case the large dibenzo-30-crown-10 ring systems are able to stabilize trinuclear [H7O3]+ cations within their cavities. Besides the macromolecular cations and some dichloromethane solvent molecules, the crystal structure of 1 contains molecular [Se2Br9]− ions with approximate D3h symmetry, each consisting of two face-sharing SeBr6 octahedra.


1990 ◽  
Vol 68 (1) ◽  
pp. 49-58 ◽  
Author(s):  
G. W. Buchanan ◽  
R. A. Kirby ◽  
J. P. Charland

For the cis–anti–cis isomer of dicyclohexano-13-crown-4 ether, disorder has been detected in the crystal structure, with two conformations being present in the ratio of ca. 3:2. Crystal structures for two Li+ complexes of the cis–syn–cis isomer have also been determined. Representative 13C solid phase NMR spectra are presented and discussed for these systems and the related dibenzo substituted compounds. Keywords: crown ethers, solids, NMR, conformation.


1985 ◽  
Vol 40 (11) ◽  
pp. 1457-1462 ◽  
Author(s):  
Jürgen Hanich ◽  
Wolfgang Willing ◽  
Ulrich Müller ◽  
Kurt Dehnicke

VBr2(N3S2) was synthesized by reaction of VCl2(N3S2) with Me3SiBr. It reacts with PPh4Br in dibromomethane solution to form (PPh4)2[VBr3(N3S2)]2. The compounds were characterized by their IR and 51V NMR spectra. The crystal structure of VBr2(N3S2) was determined by X-ray diffraction (2060 reflexions. R = 0.114). Crystal data: triclinic, space group P1̄, a = 586.4, b = 794.2, c = 744.6 pm. α - 89.25, β - 108.58, γ = 99.67°. Z = 2. The vanadium atoms form planar, six-membered rings wjith the N3S2 groups, with short VN distances (172 and 185 pm). Bromine- bridged dimers are associated via V−N links to form chains in a similar way as in some tetrahalides. The structure is similar to that of VCl2(N3S2), but the chains are rotated by 17° along their axes.


2015 ◽  
Vol 70 (2) ◽  
pp. 143-150
Author(s):  
Ernst-Christian Koch ◽  
Guido J. Reiss

AbstractIrradiation of tricarbonyl(η5-2,4-dimethyl-2,4-pentadien-1-yl)manganese (1) in tetrahydrofuran (THF) at 208 K affords the carmine solvent complex dicarbonyl(η5-2,4-dimethyl-2,4-pentadien-1-yl)(THF)manganese (2). Complex 2 thermally reacts with acetylene (3) to give tricarbonyl(η3:2-1,3-dimethyl-bicyclo[3.3.1]-3,6-nonadien-2-yl)manganese (4) and dicarbonyl(5-7,10-13-η-6,8-dimethyl-1,3,5,8,10,12-tridecahexaen-5-yl)manganese (5). The crystal structure of complex 4 was determined at room temperature [triclinic space group $P\bar 1,$a=7.6891(9), b=8.3860(8), c=10.5252(13) Å, α=93.000(9)°, β=93.390(10)°, γ= 108.032(8)°, V=642.43(13) Å3]. The manganese atom is trigonal-bipyramidally coordinated by three carbonyl ligands, one ethenylic and one allylic fragment. Consequently, the bicyclic olefin ligand 1,3-dimethyl-bicyclo[3.3.1]-3,6-nonadiene coordinates the manganese atom in a η3:2 mode. The constitution of complex 5 was deduced from IR data, elemental analysis, and 1H NMR spectra. For the formation of complexes 4 and 5, a reaction mechanism is proposed.


1994 ◽  
Vol 49 (6) ◽  
pp. 852 ◽  
Author(s):  
Peter G. Jones ◽  
Oliver Hiemisch ◽  
Armand Blaschette

Single crystals of the title complex were fortuitously grown from a dichloromethane solution containing 18-crown-6 and sulfur trioxide. Crystallographic data (at -130 °C): triclinic, space group P1̄, a = 819.1(7). b = 860.6(7), c = 905.8(7) pm. a = 63.98(3), β = 66.56(3), y = 74.95(3)°, V = 0.5236 nm3, Z = 1, Dx, = 1.377 Mgm-3. In the centrosymmetric formula unit, the two CH2Cl2 molecules are situated one above and one below the plane of the ether oxygen atoms. They are C-H···O hydrogen-bonded to two opposing oxygen atoms (H-O 237.1 and 270.6 pm, C-O 335.5 and 365.9 pm, C-H···O 171.7 and 161.8°). The crown ether molecule has approximate D3d symmetry


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