Structure of antitumor agents 2-acetylpyridinethiosemicarbazone hemihydrate and 2-acetylpyridinethiosemicarbazone hydrochloride

The structures of two antitumor agents, 2-acetylpyridinethiosemicarbazone hemihydrate (1), C₁₈H₁₁N₄O_0.5S, colorless,M _r 203.3, monoclinic,P2₁ lc,a=16.713(3),b=9.460(2),c=12.642(2) Å, β=97.60(1)°,V=1981.2(6) ų,Z=8,R=0.054,R _w =0.085 and 2-acetylpyridinethiosemicarbazone hydrochloride (2), C₁₈H₁₂N₄SCl, yellow,M _r =230.7, monoclinic,P2₁ ln,a=7.676(2),b=7.889(1),c=17.452(4), Å, β=100.96(2)°,V=1037.5(4) ų Z=4,R=0.041,R _w =0.076, have been determined. Both compounds exhibit an E configuration(S atomtrans to the N atom of the hydrazine group). Three hydrogen bonds link the two crystallographically independent molecules in a pairwise fashion in the hemihydrate. An intramolecular N?H...Cl bond lends extra conformational stability to the hydrochloride salt.     

The preparation and crystal structures of [Ru(bpy) (η2-tpy)(CO)CH2OAc]PF6 and [Ru(η3-tpy)(CO)CH2OAc] PF6 (bpy = 2,2′-bipyridine; tpy = 2,2′:6′,2″ terpyridine)

The first titled compound, 1, was obtained by treating [Ru(bpy)(η²-tpy)(CO)CH₂OH]PF₆ with acetic anhydride. Heating 1 in acetonitrile afforded 2, [Ru((η³-tpy)(MeCN)(CO) CH₂OAc]PF₆. Allowing 2 to stand in CH₂Cl₂ followed by concentration and precipitation afforded the second titled compound, 3 ([Ru((η³-tpy)(CO)–CH₂OAc]PF₆), in which the acetoxymethyl group had become bidentate. Crystal data for 1, monoclinic crystal system, space group C2/c, a=26.001(4) ?, b=13.0395(18) ?, c=20.718(3) ?, β=107.700(2)°, V=6691.7(16) ?³, Z=8; for 3, monoclinic crystal system, space group P2₁/n, a=10.864(2) ?, b=16.922(4) ?, c=11.127(2) ?, β=90.907(3)°, V=2045.4(8) ?³, Z=4.     

The molecular structures of three germacrolides related to parthenolide

The germacrolide-class sesquiterpene lactone, 1,10-epoxyparthenolide, C₁₅H₂₀O₄,1, crystallizes with two independent molecules in monoclinic space groupP2₁ witha=10.6845(5),b=9.0763(4),c=15.4326(7) ?, β=105.887(4)°,V=1439.4(3) ?³,Z=4.R=0.037 for 2425 observed data. Its 11βH, 13-dihydro-derivative 1,10-epoxydihydroparthenolide, C₁₅H₂₂O₄,2, crystallizes in orthorhombic space groupP2₁2₁2₁ witha=7.6414(10),b=12.559(2),c=14.6821(14) ?,V=1409.0(3) ?³ Z=4.R=0.031 for 1555 observed data. The corresponding unexposidized compound, 11βH,13-dihydrocostunolide, C₁₅H₂₂O₂,3, crystallizes with three independent molecules in orthorhombic space groupP2₁2₁2₁ witha=7.3576(5),b=23.505(3),c=24.185(2) ?,V=4182(1) ?³,Z=12.R=0.070 for 2767 observed data. In all, the 10-membered rings adopt approximate chair-chair conformations. In all, the double bonds or epoxidized double bonds are E, both methyl groups on the 10-ring are β, and the α-methylene-γ-lactone (or α-methyl-γ-lactone) istrans-fused at C6 and C7 with H6 β and H7 α. In the dihydro compounds, the H at C11 is β.     

Synthetic and structural studies of the trans bis(2-N-H-pyrrolylcarbaldimine) complexes of nickel(II) and palladium(II)

The molecular bis(2-N-H-pyrrolylcarbaldimine)nickel(II) and palladium(II) complexes are isolated in moderate yield (30–35%) from in situ assembly of the Schiff base with metal(II) salt, base, and pyrrole-2-carbaldehyde in aqueous ammonia solution. The nickel(II) complex, 1, is monoclinic, space group P2₁/c, with a=11.289(6) ?, b=5.611(3) ?, c=8.287(5) ?, β=111.620(6)°, and V=488.0(5) ?³ with Z=2, for d _calc=1.667 Mg/m³. The palladium analog, 2, is isomorphous, space group P2₁/c, with a=11.481(3) ?, b=5.5738(10) ?, c=8.276(2) ?, β=110.923(12)°, and V=494.7(2) ?³ with Z=2, for d _calc=1.965 Mg/m³. In both crystal structures, the metal resides on an inversion center. In the IR spectra, ν(C=N) appears at 1561 cm⁻¹ in 1, and 1557 cm⁻¹ in 2, while ν(N–H) shows at 3345 cm⁻¹ and 3335 cm⁻¹, respectively. The ¹H-nmr spectra reveal the C–H and N–H protons of the imine group as sharp and broad doublets, respectively, at 7.62 and 8.38 δ in 1 and at 7.92 and 9.73 δ in 2.     

The molecular structures of two furanoheliangolides

The heliangolide-class sesquiterpene lactone 8β-angeloyloxy-9α-acetoxycalyculatolide, C₂₂H₂₆O₈,1, crystallizes in orthorhombic space groupP2₁2₁2₁ witha=12.455(3),b=12.601(3),c=14.023(5) ?,V=2200(1)?,³ Z=4.R=0.059 for 1735 observed data. The 11,13-dihydro-11α, 13-epoxyatripliciolide-8β-angelate, C₂₀H₂₂O₇. 1/2 H₂O,2, crystallizes as the hemihydrate with two molecules in the asymmetric unit in triclinic space groupP1 witha=9.422(1),b=9.559(1),c=12.358(3) ?, α=101.62(2)°, β=91.30(2)°, γ=117.80(1)°,V=955.6(7)?³,Z=2.R=0.046 for 3607 observed data. In both, the 10-membered rings adopt approximate chair-boat conformations. Their conformations are typical for heliangolides. The methyl group C14 is α, while the C-15 has a β-orientation. The α-methylene-γ-lactone istrans-fused at C6 and C7 with H6 β and H7 α. In compound2, the epoxide at C11–C13 has an α orientation.     

Structural and Spectral Analyses of 2-[(2-Benzothiazolylmethyl)thio]-benzenamine and 2-[(2-Benzothiazolylmethyl)thio]-benzenamine hydrobromide

Abstract  

2-[2-benzothiazoylmethyl)thio]-benzenamine, which was first reported in 1898, was isolated from the reaction of bromoacetyl bromide and 2-aminothiophenol [1]. The product crystallized from an aqueous methanol solution of the reaction mixture to which nickel(II) acetate had been added. 2-[(2-benzothiazolylmethyl)thio]-benzenamine crystallized in the monoclinic system, in space group C2/c, with cell dimensions of a = 27.392 (19) ?, b = 4.730 (3) ?, and c = 23.686 (16) ?, β = 122.465 (6)°, V = 2589(3) ?³, Z = 8 and refined to R = 0.0343 and R _w  = 0.0844. Crystallization from methanol yielded the product as the hydrobromide salt in the monoclinic space group Cc, with cell dimensions of a = 10.488 (3) ?, b = 33.404 (9) ?, c = 5.2578 (14) ?, β = 116.769(2)°, V = 1644.7(8) ?³, Z = 4 and refined to R = 0.0296 and R _w  = 0.0600. Mass spectral and NMR analyses confirmed that the bulk and crystalline compound were all 2-[(2-benzothiazolylmethyl)thio]-benzenamine.     

Synthesis,Characterization and Crystal Structures of <Emphasis Type="Italic">N</Emphasis>′-(5-Bromo-2-hydroxybenzylidene)-2-fluorobenzohydrazide in Unsolvated and Monohydrate Forms

Abstract  

A new hydrazone derivative, N′-(5-bromo-2-hydroxybenzylidene)-2-fluorobenzohydrazide (BFBH), has been prepared and crystallized from absolute methanol and 95% ethanol, respectively, yielding unsolvated and monohydrate forms of the compound, viz. BFBH (1) and BFBH·H₂O (2). The two forms of the compound were characterized by elemental analysis, IR spectra, ¹HNMR spectra, and X-ray single crystal structural determination. The unsolvated form of the compound crystallizes in the monoclinic space group P2₁/c with unit cell dimensions a = 6.879(1) ?, b = 28.911(2) ?, c = 8.724(1) ?, β = 127.685(2)o, V = 1373.1(3) Ǻ³, Z = 4, R ₁ = 0.0569, and wR ₂ = 0.1352. The monohydrate forms of the compound crystallizes in the monoclinic space group P2₁/c with unit cell dimensions a = 14.873(3) ?, b = 7.265(1) ?, c = 13.043(2) ?, β = 96.281(2)o, V = 1400.9(4) Ǻ³, Z = 4, R ₁ = 0.0402, and wR ₂ = 0.0890. The two structures are similar to each other, except for the presence of a water molecule in (2).     

Syntheses and Crystal Structures of Two 2-Aminoisoflavones

Abstract  

2-Amino-7,4′-dimethoxyisoflavone (I), C₁₇H₁₅NO₄ and 2-amino-7-methoxy-4′-hydroxyisoflavone (II), C₁₆H₁₃NO₄ were synthesized and their crystal structures were determined by single-crystal X-ray diffraction. They all crystallize in the monoclinic crystal system, space group P21/c. The cell dimensions of I are a = 15.6673(17) ?, b = 7.3998(8) ?, c = 13.2919(14) ?, β = 111.4460(10)°, D _c = 1.377 mg/mm³, V = 1,434.3(3) A³, Z = 4 and those of II are a = 10.990(7) ?, b = 11.879(7) ?, c = 10.422(6) ?, β = 96.904(11)°, D _c = 1.393 mg/mm³, V = 1,350.8(14) A³, Z = 4. A combination of F-type and T-type aromatic–aromatic interaction and hydrogen bonding links the molecules of I into a tri-dimensional framework structure. In the crystal structure of II, paired tri-centered hydrogen bond generates a R₄²(21) ring and the R₄²(21) rings link the molecules into a sheet.     

Synthesis and molecular structure of 4,4,5,5-tetramethyl-2-(1-(phenylsulfonyl)propan-2-yl)-1,3,2-dioxaborolane

The compound 4,4,5,5-tetramethyl-2-(1-(phenylsulfonyl)propan-2-yl)-1,3,2-dioxabo- rolane has been prepared by the rhodium catalyzed hydroboration of allyl phenyl sulfone and characterized by a single crystal X-ray diffraction study. The title compound crystallized in the monoclinic space group P2₁/c, with cell parameters a=16.0728(8) ?, b=9.8884(5) ?, and c=10.1926(5) ?, β=92.067(1)°, Z=4, and V=1618.90(14) ?³. The structure was solved by direct methods and refined to a final R=0.0449 for 3627 reflections with I>2σ(I). No significant intramolecular or intermolecular interaction is observed with the Lewis acidic boron atom.     

Synthesis and Structural Characterization of [2-(2-1H-Imidazoly)-1H-imidazolium nitrate] and [2-(2-1H-Imidazoly)-2H-imidazolium phthalyl glycinate] Based on the 2,2′-bi-1H-Imidazole Molecule

Abstract  

Two new compounds (H₃biim)(NO₃)(1) and (H₄biim)(phthgly)₂ (2) (H₂biim=biimidazole; Hphthgly=N-phthaloylglycine) have been synthesized and characterized by luminescence and single crystal X-ray diffraction study. Compound 1 crystallizes in the monoclinic space group C2/c, where a = 14.8078(15), b = 5.9233(6), c = 20.028(2) ?, β = 92.7910(10)°, V = 1754.6(3) ?³ and Z = 8. Compound 2 crystallizes in the monoclinic space group P2(1)/n, where a = 15.3775(14), b = 5.3200(6), c = 6.4689(18)?, β = 115.418(2)° V = 1216.9(2)?³ and Z = 4. In 1, the N–H groups of H₃biim⁺ and the oxygen atoms of NO₃ ⁻ are linked by hydrogen bonds leading to H₃biim⁺(N,N)–R₂²(10) and N–H···O interactions forming infinite 1D helical chains along the b-axis. Compound 2 consists of a planar diprotonated biimidazole moiety and two phthgly anions which connect to the dication by hydrogen bonds phthgly⁻(O,O)–R₂²(9).     

Synthesis and crystal structures of two new complexes [M(OH2)(HDPA)2]·3H2O (M = Mn, Co)

Two new transition metal complexes of [M(OH₂)(HDPA)₂]·3H₂O (M=Mn(1); M=Co(2)) (H₂DPA, 2,6-pyridine-dicarboxylic acid) have been prepared at room temperature from the reaction of MCl₂·6H₂O (M=Mn or Co) and H₂DPA in the mixed solvent of H₂O and EtOH in the presence of piperazine, and were characterized by X-ray analysis, elemental analysis. X-ray analysis reveals that the coordination geometries of Mn²⁺ and Co²⁺ are of octahedron and severely distorted square-based pyramid, respectively. Crystal data: [Mn(OH₂)(HDPA)₂]·3H₂O (1), Mr=459.23, monoclinic, P2(1)/n, a=7.0056(3), b=(23.8125(12), c=10.7444(3) ?, β=99.834(2)°, Z=4, V=1766.28(13) ?³, R ₁=0.0586, wR ₂=0.1448 [I>2σ(I)]; Co(OH₂)(HDPA)₂]·3H₂O (2), Mr=463.22, monoclinic, P2(1)/n, a=7.0014(2), b=23.8346(7), c=10.7212(4) ?, β=99.8540(10)°, Z=4, V=1762.71(10) ?³, R ₁=0.0474, wR ₂=0.1366 [I>2σ(I)].     

Molecular Association of Almotriptan with Oxalate and Terephthalate Anions

Abstract  

Crystal structures of anti-migraine drug almotriptan were crystallized with oxalic acid (I) and with terephthalic acid (II) and their crystal structures and molecular associations were determined using X-ray diffraction methods. Crystals of both (I) and (II) are monoclinic, space group P2₁/c, with a = 5.6270(4) ?, b = 27.6419(19) ?, c = 13.6228(9) ?, β = 93.057(1)°, V = 2115.9(3) ?³, Z = 4 (I) and a = 13.3756(15) ?, b = 15.6065(17) ?, c = 10.7238(12) ?, β = 98.017(2)°, V = 2216.7(4) ?³, Z = 4 (II). In almotriptan oxalate {systematic name: N,N-dimethyl-2-[5-(pyrrolidin-1-ylsulfonyl-methyl)-1H-indol-3-yl]-ethanaminium semioxalate}, C₁₇H₂₆N₃O₂S⁺, C₂HO₄ ⁻, (I) and in almotriptan hemi terephthalate hydrate {systematic name: N,N-dimethyl-2-[5-(pyrrolidin-1-ylsulfonyl-methyl)-1H-indol-3-yl]-ethanaminium hemi terephthalate monohydrate}, C₁₇H₂₆N₃O₂S⁺, 0.5(C₈H₄O₄ ²⁻), H₂O, (II), both the almotriptan cations form a trimer with the corresponding anions via N–H···O hydrogen bonds. In (I), the oxalate salt is monoprotonated and in (II), the terephthalic acid is located across the inversion centre and exists as doubly protonated anion. In (I), the cation and anion are interlinked by the N–H···O and O–H···O hydrogen bonds into continuous two-dimensional layers generate an R₆⁶(34) hydrogen-bonded motif tetramers running parallel to the (0 0 1) plane. In (II), the cation and water form a centrosymmetric tetramer of R₄⁴(22) hydrogen-bonded motif via N–H···O and O–H···O hydrogen bonds and further cross-linked by centrosymmetric anions to form an infinite three-dimensional supramolecular hydrogen-bonded networks.     

The Crystal Structures of Some 1-Aryl-5-methyl-1,2,3-triazole Derivatives

Abstract  The two 1-aryl-5-methyl-1,2,3-triazole derivatives were prepared by the 1-aryl-5-methyl-1,2,3-triazol-4-carboxylic acids 3. The yielded products 4a–b were confirmed by NMR, MS, IR spectra. We investigated the crystalline structure of compounds 4a and 4b. Compound 4a, C₉H₈BrN₃, Mr = 238.09, crystallizes in the monoclinic space group P2(1)/n with unit cell parameters a = 11.660(2), b = 7.668(2), c = 11.818(2) ?, α = 90.00, β = 116.01(3), γ = 90.00o. V = 949.6(3) ?³, Z = 4, Dx = 1.665 Mg m⁻³. The final R was 0.0477. Compound 4b, C₁₃H₁₁N₃, Mr = 209.25, crystallized in the orthorhombic space group Pbca with unit cell parameters a = 10.373(2) ?, b = 11.691(2) ?, c = 17.579(4) ?, α = 90.00o, β = 90.00o, γ = 90.00o, V = 2131.8(7) ?³, Z = 8, D _m = 1.304 Mg m⁻³. The final R was 0.0565. Index Abstract  The two 1-aryl-5-methyl-1,2,3-triazole derivatives were prepared by the 1-aryl-5-methyl-1,2,3-triazol-4-carboxylic acids 3. The yielded products 4a–b were confirmed by NMR, MS, IR spectra. We investigated the crystalline structure of compounds 4a and 4b. Compound 4a, C9H8BrN3, Mr = 238.09, crystallizes in the monoclinic space group P2(1)/n with unit cell parameters a = 11.660(2), b = 7.668(2), c = 11.818(2)  ?, α = 90.00, β = 116.01(3), γ =90.00o. V = 949.6(3) ?³, Z = 4, Dx = 1.665 Mg m⁻³. The final R was 0.0477. Compound 4b, C13H11N3, Mr = 209.25, crystallized in the orthorhombic space group Pbca with unit cell parameters a = 10.373(2) ?, b = 11.691(2) ?, c = 17.579(4) ?, α = 90.00o, β = 90.00o, γ = 90.00o, V = 2131.8(7) ?³, Z = 8, D _m = 1.304 Mg m⁻³. The final R was 0.0565.      

Structure of “bis(methoxymagnesium)diselenide”: A reagent for the introduction of selenium into organic molecules

The reaction of magnesium and selenium in dry methanol has been reported to yield a reagent tentatively identified as bis(methoxymagnesium) diselenide. The dark red-brown solution obtained from this reaction yielded red crystals that crystallized in the monoclinic space group C2/c, a=17.391(4) ?, b=15.823(3) ?, c=21.626(4) ?, β=110.71(3)°, V=5566.5(19) ?³, Z=4, R=0.0350, wR₂=0.0850 for 4930 reflections. X-ray crystallographic analysis of this reagent showed it to be dodecamethanol-tetramethoxy-di(μ₄-hydroxy)tetra(μ₃-methoxy)hexamagnesium hexaselenide, Mg₆(μ₄-OH)₂(μ₃-OCH₃)₄(OCH₃)₄(CH₃OH)₁₂]Se₆·2CH₃OH (1), not the bis(methoxymagnesium) diselenide as previously described. The structure of 1 is composed of six magnesium ions and six bridging oxygen-containing ligands in a face-sharing cubic arrangement.     

Synthesis and Crystal Structures of 4-Chloro-<Emphasis Type="Italic">N′</Emphasis>-(4-hydroxy-3-nitrobenzylidene)benzohydrazide monohydrate and 4-Chloro-<Emphasis Type="Italic">N′</Emphasis>-(4-hydroxy-3-methoxybenzylidene)benzohydrazide monohydrate

Abstract  

Two new hydrazone compounds, 4-chloro-N′-(4-hydroxy-3-nitrobenzylidene)benzohydrazide monohydrate (1) and 4-chloro-N′-(4-hydroxy-3-methoxybenzylidene)benzohydrazide monohydrate (2), were synthesized and characterized by physico-chemical methods and single crystal X-ray diffraction. Compound 1 crystallizes in the monoclinic space group P2₁/c with unit cell parameters a = 23.257(3) ?, b = 4.829(1) ?, c = 12.763(2) ?, β = 96.017(2)°, V = 1425.5(5) ?³, Z = 4, R ₁ = 0.0525, and wR ₂ = 0.1120. Compound 2 crystallizes in the monoclinic space group P2₁/c with unit cell parameters a = 8.103(3) ?, b = 21.321(3) ?, c = 10.594(3) ?, β = 120.281(2)°, V = 1580.5(8) ?³, Z = 4, R ₁ = 0.0480, and wR ₂ = 0.1078. Both compounds contains a hydrazone molecule and a water molecule. The crystals of the compounds are stabilized by N–H···O, O–H···O, and O–H···N hydrogen bonds.     

Crystal structure of M4[(UO2)2C2O4(SO4)2(NCS)2] ( M = K+, Rh+) and K4[(UO2)2C2O4(SeO4)2(NCS)2]

Three heteroacidoligand uranyl complexes M ₄[(UO₂)₂C₂O₄(SO₄)₂(NCS)₂] (M = K⁺ (I), Rb⁺ (II)) and K₄[(UO₂)₂C₂O₄(SeO₄)₂(NCS)₂] (III) have been synthesized and their crystal structure has been determined by X-ray diffraction analysis. The compounds I–III are isostructural and crystallized in the monoclinic system, sp. gr. P2₁/c, Z = 2, a = 11.5548(3) ?, b = 7.0847(1) ?, c = 13.5172(3) ?, β = 93.130(1)°, V = 1104.90(4), R = 0.015 (I); a = 11.5854(9) ?, b = 7.3841(6) ?, c = 13.9072(9) ?, β = 95.754(3)°, V = 1183.74(15), R = 0.0235 (II); a = 11.6715(3) ?, b = 7.1418(2) ?, c = 13.8546(1) ?, β = 93.539(1)°, V = 1152.66(5), R = 0.0126 (III). Basic structural units of these crystals are [(UO₂)₂C₂O₄(XO₄)₂(NCS)₂]⁴⁻ chains, which belong to the crystallochemical group A ₂ K ⁰² B ₂² M ₂¹ (A = UO₂²⁺, K ⁰² = C₂O₂₋⁴, B ² = SO₄²⁻ or SeO₄²⁻, M ¹ = NCS⁻) of uranyl complexes. Uranium-containing chains are connected into a 3D framework via a system of electrostatic interactions with potassium or rubidium cations from outer spheres. Original Russian Text ? I.V. Medrish, E.V. Peresypkina, A.V. Virovets, L.B. Serezhkina, 2008, published in Kristallografiya, 2008, Vol. 53, No. 3, pp. 495–498.     

Synthesis and Crystal Structures of pH-Dependent Ni(II) Coordination Polymers with 3-Pyrid-3-ylbenzoic Acid

Abstract  

Two pyridinecarboxylato-bridged coordination polymers[Ni(pbc)₂(H₂O)₂]_n(1) and {[Ni(pbc) ₂ (H₂O)]·H₂O}_n (2)(Hpbc = 3-Pyrid-3-ylbenzoic acid) have been synthesized by the hydrothermal method and characterized by elemental analysis, IR spectrum and single crystal X-ray diffraction. Compound 1 crystallizes in monoclinic, space group P2₁/c with a = 9.519(5) ?, b = 9.417(5) ?, c = 11.701?, β = 98.086(5)°, V = 1038.5(9) ?³, Z = 2. Compound 2 crystallizes in monoclinic, space group P2₁/c with a = 10.490(2) ?, b = 12.920(3) ?, c = 16.074?, β = 95.97(3)°, V = 2166.7(8) ?³, Z = 4. X-ray diffraction analysis reveals that all pbc⁻ ligands act as diconnectors to link two Ni(II) centers and adopt one coordination mode: μ₂−N, O in compound 1 and the ligands adopt two coordination modes: μ ₂ −N, O and μ ₃ − N, O, O in compound 2.     

Hydrogen Bonded 3D Supramolecular Architectures of Three Saccharinate Salts

Abstract  

Three saccharinate salts (2-aminopyrimidine): (saccharin) (1), (4-phenylthiazol-2-amine): (saccharin) (2), and (2-methylquinoline): (saccharin) (3) were prepared and structurally characterized by X-ray crystallography. Salt 1 crystallizes in the monoclinic, space group P2(1)/c, with a = 7.1782(9) ?, b = 13.5105(16) ?, c = 12.2251(12) ?, β = 93.3410(10)°, V = 1183.6(2) ?³, Z = 4. Compound 2 crystallizes in the triclinic, space group P-1, with a = 7.4584(7) ?, b = 8.6930(9) ?, c = 12.9179(14) ?, α = 108.952(2)°, β = 91.7510(10)°, γ = 97.2280(10)°, V = 783.57(14) ?³, Z = 2. Compound 3 crystallizes in the monoclinic, space group P2(1)/c, with a = 7.781(8) ?, b = 19.4209(19) ?, c = 10.9719(12) ?, β = 107.7390(10)°, V = 1579.2(16) ?³, Z = 4. The different hydrogen bonding interaction modes of the saccharinate anions and the cations lead to 3D network structure, 3D staircase structure, and 3D ABAB layer structure for 1, 2, and 3 respectively. Despite variations in the cation shape on the aromatic N–heterocyclic compounds, there all existed strong intermolecular N–H⋯O(carbonyl) hydrogen bonds. In compounds 1, and 3 the N⁺–H⋯O interaction between the N⁺–H group of the cation and the C=O group of the saccharinate anion is the most important interaction in this family of salts. However, in 2, there was a N–H⋯O interaction between the amino proton and the C=O group of the saccharinate anion. At the next level, the aromatic C–H proton interacts with the sulfonyl O atom. There are also π–π interactions in compounds 1–2, there is CH₃–π interaction in 3. Under these interactions the three compounds exhibit synthons I–III respectively. These interactions are responsible for the high-yielding supramolecular assembly of N-containing aromatic bases and the saccharinate into salts.     

Crystal Structures of Dipeptides Derived from the β-Amino Acids (1R,2S)-2-Aminocyclopentanecarboxylic Acid and (1S,2R,3S)-2-Amino-3-methylcyclopentanecarboxylic Acid

Abstract  

Crystals of the dimeric β-peptides 13 and 20, derived from (1R,2S)-2-aminocyclopentanecarboxylic acid and (1S,2R,3S)-2-amino-3-methylcyclopentanecarboxylic acid, respectively, were synthesised and studied by X-ray diffraction in order to establish their solid state secondary structural characteristics. Compound 13 crystallises in the monoclinic space group P 2 ₁ with cell parameters of a = 5.2682(1) ?, b = 9.1211(2) ?, c = 22.4467(6) ?, β = 91.3855(9)°, V = 1078.29(4) ?³ and Z = 2. Compound 20 crystallizes in the orthorhombic space group P 2 ₁ 2 ₁ 2 ₁ with cell parameters of a = 5.0968(1) ?, b = 11.5546(2) ?, c = 43.5414(8) ?, V = 2564.22(8) ?³ and Z = 4. In both cases adjacent molecules are linked by a series of N–H···O=C hydrogen bonds to form β-sheet like structures.