Solvothermal Syntheses and Crystal Structures of Neodymium Thiostannates [Nd(dien)3]2[(Sn2S6)Cl2] and [Nd(dien)3]2[(Sn2S6)(SH)2]

Abstract  

Two neodymium thiostannates [Nd(dien)₃]₂[(Sn₂S₆)Cl₂] (1) and [Nd(dien)₃]₂[(Sn₂S₆)(SH)₂] (2) (dien = diethylenetriamine) were synthesized by the reaction of tin and sulfur in the presence of NdCl₃ and Nd₂O₃, respectively under solvothermal conditions. Compounds 1 and 2 crystallize in monoclinic space group P2₁/n. Crystallographic data for 1: a = 11.6722(16), b = 15.119(2), c = 14.1566(19) ?, β = 96.213(3)°, V = 2483.6(6) ?³, Z = 4. For 2: a = 11.7190(14), b = 15.2168(19), c = 14.2209(18) ?, β = 95.775(4)°, V = 2523.1(5) ?³, Z = 4. The nine-coordinate [Nd(trien)₃]³⁺ complex cation formed in situ acts as the counter ion to the [Sn₂S₆]⁴⁻ anion. The [Nd(dien)₃]³⁺, [Sn₂S₆]⁴⁻ and Cl^– (or SH^–) ions form a 3-dimensional network structure through the N–H···S and N–H···Cl hydrogen bonds.     

Crystal structures of (?)-(SS, 1R, 2S, 5R)-menthyl p-tolyl sulfinate and (+)-(SS)-[(p-tolyl)sulfinyl]ferrocene

The absolute configuration at the chiral sulfurs centers of (−)-(S _S , 1R, 2S, 5R)-menthyl-p-tolylsulfinate (1) and (S _S )-[(p-tolyl)sulfinyl]ferrocene (2) were determined by single crystal X-ray diffraction with anomalous dispersion effects and the corresponding calculation of Flack’s absolute structure parameters. Both compounds crystallize in the monoclinic crystal system in space group P2₁ (no. 4); chiral sulfinate ester 1: a = 8.2868(6), b = 6.1399(3), c = 16.366(2) ?, β = 91.816(6)°, V = 832.3(2) ?³, Z = 2 and absolute structure parameter −0.03(7); chiral ferrocenyl sulfoxide 2: a = 5.8371(3), b = 15.390(2), c = 16.143(2) ?, β = 97.748(6)°, V = 1436.9(3) ?³, Z = 4 and absolute structure parameter +0.01(1). The trigonal pyramidal geometry at the chiral sulfur atom of 2 is close to expected values while the one of 1 is slightly distorted. With direct determination of the absolute configuration at the chiral sulfur centers an important gap concerning the widely used precursors 1 and 2 for the syntheses of chiral sulfoxides and 1,2-disubstituted planar chiral ferrocenyl ligands is now closed. The latter substance class is playing a key role in enantioselective catalysis.     

Synthesis, Spectroscopic Studies and X-ray Crystal Structures of New Pyrazoline and Pyrazole Derivatives

Abstract  

The synthesis and characterization of some pyrazoline compounds of 1,3-diketones with hydrazine derivatives, namely, 1-(S-benzyldithiocarbazate)-3-methyl-5-phenyl-5-hydroxypyrazoline (1); 1-(2-thiophenecarboxylic)-3-methyl-5-phenyl-5-hydroxypyrazoline (2); 1-(2-thiophenecarboxylic)-3,5-dimethyl-5-hydroxypyrazoline (3); 1-(S-benzyldithiocarbazato)-3-methyl-5-phenylpyrazole (4); 1-(2-thiophenecarboxylic)-3-methyl-5-phenylpyrazole (5) and 1-(S-benzyldithiocarbazate)-3,5-dimethylpyrazole (6) are reported. Studies by IR, (¹H, ¹³C)-NMR spectroscopies and single crystal X-ray diffraction revealed that compounds (1)_, (2) and (3) are formed as pyrazoline, whereas (4) and (5) are formed as pyrazole derivatives only under acidic conditions. Compound (1) crystallizes in orthorhombic P2₁2₁2₁, a = 6.38960(10) ?, b = 12.9176(3) ?, c = 21.2552(5) ?, (2) crystallizes in monoclinic, P2₁/n, a = 11.3617(2) ?, b = 8.4988(2) ?, c = 92.8900(10) ? and β = 92.8900(5)°, (3) crystallizes in monoclinic, C2/c, a = 15.9500(5) ?, b = 9.3766(3) ?, c = 16.6910(5) ? and β = 113.825(2)°, (4) crystallizes in monoclinic, P2₁/c, a = 15.228(4) ?, b = 5.5714(13) ?, c = 19.956(5) ? and β = 91.575(7)° and (6) crystallizes in orthorhombic, P2₁2₁2₁, a = 5.3920(2) ?, b = 11.2074(5) ?, c = 21.885(1) ?. The (3) derivative represents the first pyrazoline compound prepared from 2,4-pentanedione and characterized crystallographically.     

Unusual Co-Crystallization of both Monomeric and Dimeric Forms of Cu[PhN(py)quin]Cl<Subscript>2</Subscript>

Abstract  

The aryl functionalized diquinolyl amine MesN(quin)₂ (1) and the pyridyl-quinolyl amine (2,6-iPr₂C₆H₃)N(py)quin (2) have been prepared via palladium catalyzed cross-coupling of substituted anilines with 2-chloroquinoline. The HBF₄ acid salts of (2,6-ⁱPr₂C₆H₃)N(quin)₂ (3) and MesN(py)quin (4), as well as the copper complex [Cu{PhN(py)quin}Cl₂] (5) have been prepared in order to probe the effect that ligand coordination has on its geometry. The molecular structures of each have been determined by X-ray crystallography. The free ligands 1 and 2 crystallize in three-bladed propellar conformations, having smaller degrees of “pitch” between the two heterocycles than either has with the aryl “blade”, allowing for greater heterocycle π-system overlap with the amine lone pair. Acid confinement of similar ligands in 3 and 4 results in forced coplanarity of the two heterocycles, which coordinate the HBF₄ proton in an asymmetric fashion. The copper complex 5 crystallizes with both monomeric and dimeric forms present in the asymmetric unit. Crystal data: (1) Space group P2₁/c, a = 14.058(3), b = 12.202(2), c = 12.831(3) ?, β = 104.61(3)°, V = 2129.8(8) ?³, Z = 4, R = 0.0596, wR₂ = 0.1453. (2) Space group P2₁/c, a = 22.250(4), b = 8.628(2), c = 23.031(5) ?, β = 92.88(3)°, V = 4370(2) ?³, Z = 8, R = 0.0514, wR₂ = 0.1323. (3) Space group Pbca, a = 13.886(3), b = 18.016(4), c = 21.347(4) ?, V = 5340(2) ?³, Z = 8, R = 0.0722, wR₂ = 0.1635. (4) Space group P2₁/c, a = 10.629(2), b = 18.489(4), c = 10.907(2) ?, β = 92.88(3), V = 2140.6(7) ?³, Z = 4, R = 0.0551, wR₂ = 0.1531. (5) Space group \text P[`1]{\text P}\bar{1}, a = 9.706(2), b = 11.325(2), c = 17.322(4) ?, α = 98.28(3), β = 94.85(3), γ = 91.83(3)°, V = 1875.6(7) ?³, Z = 1, R = 0.0481, wR₂ = 0.0946.     

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.     

Crystal Structure of [Zn(2-Bromobenzoato)<Subscript>2</Subscript>]<Subscript><Emphasis Type="Italic">n</Emphasis></Subscript> and [Zn(2-Bromobenzoato)<Subscript>2</Subscript>(<Emphasis Type="Italic">N</Emphasis>-Methylnicotinamide)]<Subscript>2</Subscript>

Abstract  

The syntheses and structural characterizations of two novel 2-bromobenzoatozinc(II) complexes—[Zn(2-BrC₆H₄COO)₂] _n (I) and [Zn(2-BrC₆H₄COO)₂(mnad)]₂ (II), where mnad is N-methylnicotinamide are reported. Compound (I) crystallized with a monoclinic lattice (space group P2₁/c) and is polymeric in solid state. Its cell parameters are: a = 7.37220(10) Å, b = 19.9639(3) Å, c = 30.2756(5) Å, β = 94.7510(7)°, V = 4440.59(12) ų, Z = 4. The coordination environments of all zinc atoms are distorted tetrahedra built from four carboxylate oxygen atoms coming from four 2-bromobenzoato ligands. Compound (II) crystallized with a monoclinic lattice (space group P2₁/c) with a = 11.7488(2) Å, b = 20.3683(3) Å, c = 9.30130(10) Å, β = 100.3941(11)°, V = 2189.30(5) ų, Z = 2. This dimeric molecule features a paddle-wheel [Zn₂O₈] cage in solid state; the coordination environment of the central atom is square pyramidal consisting of four carboxylate oxygen atoms and the pyridine N atom of the mnad ligand.     

Hydrogen Bonding in Proton-Transfer Compounds of 5-Sulfosalicylic Acid with a Series of Aliphatic Nitrogen Lewis Bases

Abstract  

The crystal structures of the proton-transfer compounds of 5-sulfosalicylic acid (3-carboxy-4-hydroxybenzenesulfonic acid) with the aliphatic nitrogen Lewis bases, hydroxylamine, triethylamine, pyrrolidine, morpholine, N-methylmorpholine and piperazine, viz. hydroxyammonium 3-carboxy-4-hydroxybenzenesulfonate (1), triethylaminium 3-carboxy-4-hydroxybenzenesulfonate (2), pyrrolidinium 3-carboxy-4-hydroxybenzenesulfonate monohydrate (3), morpholinium 3-carboxy-4-hydroxybenzenesulfonate monohydrate (4), N-methylmorpholinium 3-carboxy-4-hydroxybenzenesulfonate monohydrate (5) and piperazine-1,4-diium bis(3-carboxy-4-hydroxybenzenesulfonate) hexahydrate (6) have been determined and their comparative structural features and hydrogen-bonding patterns described. Crystals of 4 are triclinic, space group P-1 while the remainder are monoclinic with space group either P2₁/c (1–3) or P2₁/n (5, 6). Unit cell dimensions and contents are: for 1, a = 5.0156(3), b = 10.5738(6), c = 18.4785(9) ?, β = 96.412(5)^o, Z = 4; for 2, a = 8.4998(4), b = 12.3832(6), c = 15.4875(9) ?, β = 102.411(5)^o, Z = 4; for 3, a = 6.8755(2), b = 15.5217(4), c = 12.8335(3) ?, β = 92.074(2)^o, Z = 4; for 4, a = 6.8397(2), b = 12.9756(5), c = 15.8216(6) ?, α = 90.833(3), β = 95.949(3), γ = 92.505(3)^o, Z = 4; for 5, a = 7.0529(3), b = 13.8487(7), c = 15.6448(6) ?, β = 90.190(6)^o, Z = 4; for 6, a = 7.0561(2), b = 15.9311(4), c = 12.2102(3) ?, β = 100.858(3)^o, Z = 2. The hydrogen bonding generates structures which are either two-dimensional (2 and 5) or three-dimensional (1, 3 , 4 and 6). Compound 6 represents the third reported structure of a salt of 5-sulfosalicylic acid having a dicationic piperazine species.     

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.      

Synthesis and Crystal Structures of Two Novel Complexes with <Emphasis Type="Italic">N</Emphasis>-[2-(5-Bromo-2-Hydroxybenzylideneamino)Ethyl]-4-Methylbenzenesulfonamide as Ligand

Abstract  

Two novel complexes constructed from the sulfonamide Schiff base ligand H ₂ L, N-[2-(5-bromo-2-hydroxybenzylideneamino)ethyl]-4-methylbenzene-sulfonamide, [Cu(HL)₂] (1) and [CuL(H₂O)] (2) are synthesized and characterized via X-ray single-crystal diffraction, elemental analysis, FT-IR and UV–Vis. 1 and 2 both form 1-D supramolecular architectures by π–π stacking interactions. 1 and 2 both crystallize in monoclinic, with space group C2/c and P2/c for 1 and 2, with unit cell parameters a = 27.640(18) ?, b = 7.907(5) ?, c = 17.945(14) ?, β = 118.27(2)°, V = 3454(4) ?³, Z = 4 for 1, and a = 16.758(5) ?, b = 7.272(2) ?, c = 15.080(4) ?, β = 106.334(5)°, V = 1763.6(9) ?³, Z = 4 for 2.     

Oxazoles XXI. Three Ester Ammonium Salts Resulting from the Rupture of an Oxazoline Ring

Abstract  

The synthesis and characterisation of three ammonium salts that are formed via a ring opening of a 2-oxazoline (i.e., a 4,5-dihydro-1,3-oxazole) are described. Compound 1, derived from 2-phenyl-2-oxazoline (Phox), was isolated as a major reaction product during an unrelated synthesis using Phox which was being carried out in the presence of NO₃ ⁻ ions. The isolated compound is identified as the nitrate salt of the terminal ammonium ester [H₃NCH₂CH₂OC(=O)Ph]⁺ (1). The X-ray crystal structure (C₉H₁₂N₂O₅) of 1 is revealed to be orthorhombic (space group Pna2₁) with a = 21.1304(8), b = 7.5975(2) and c = 6.8629(3)?. The analogous material 2a, obtained from the related oxazole 4,4-dimethyl-2-phenyl-2-oxazoline (MePhox) under identical conditions to that of 1, contains the [H₃NCMe₂CH₂OC(=O)Ph]⁺ cation. The X-ray crystal structure (C₁₁H₁₆N₂O₅) of 2a is monoclinic with a = 6.1270(3), b = 6.3603(3), c = 16.1632(8)? and β = 90.662(3)o and of space group P2₁. Chiral derivative 2b, was isolated from a wet CH₂Cl₂/THF solution upon treatment of MePhox with (S)-mandelic acid. This material was shown to also contain the [H₃NCMe₂CH₂OC(=O)Ph]⁺ cation, a lattice water molecule and an (S)-mandalate anion. The X-ray crystal structure of 2b (C₁₉H₂₃NO₅·H₂O) is orthorhombic (space group P2₁2₁2₁) with a = 6.4733(3), b = 11.4661(5) and c = 24.5791(11)?. One proposed mechanism by which all three materials are formed was first presented in seminal work by Deslongchamps. The compounds reported herein are representatives of a class of rarely isolated intermediates in heterocyclic ring opening reactions and they are also the first examples of (ω-ammoniumethyl)(aryl) esters to be structurally characterised.     

Cross Coupling of Substituted Anilines with Quinoline: Synthesis and Structural Characterization of HN(py)quin,PhN(py)quin,MesN(py)quin,and [PhN(py)(H-quin)]BF<Subscript>4</Subscript>

Abstract  

The molecular structure of (2,6-ⁱPr₂C₆H₃)N(quin)₂ (1) and both the methanol and toluene solvates of its copper complex [Cu{(2,6-ⁱPr₂C₆H₃)N(quin)₂}₂]BF₄, 2·MeOH and 2.2(C₆H₅Me), respectively, have been determined. The quinolyl rings in 1 adopt anti-syn (C_Ar–N–C–N_quin) conformation as a result of π–π stacking. The cation in 2·MeOH crystallizes on a C₂ axis, while the cation in 2·2(C₆H₅Me) is crystallographically independent. As a result of intramolecular π–π stacking there are significant changes within the coordination geometry about the copper centers between the two solvates, suggesting that the coordination around copper is supple. Crystal data: 1 group P2₁/c, a = 8.614(1), b = 16.137(3), c = 17.601(4) ?, β = 93.32(3)°, V = 2,442.5(9) ?³, Z = 4, R = 0.0544, wR ₂ = 0.1340. 2·MeOH group P3₂21, a = 13.254(1), b = 13.254(1), c = 27.214(5) ?, V = 4,140(1) ?³, Z = 3, R = 0.0392, wR ₂ = 0.0917. 2.2(C₆H₅Me) group P1, a = 11.677(2), b = 16.261(3), c = 17.077(3) ?, α = 93.63(3), β = 97.30(3), γ = 96.26(3)°, V = 3,187(1) ?³, Z = 4, R = 0.0526, wR ₂ = 0.1221.     

Intramolecular Carbonyl–Carbonyl Interaction as the Directing Motif of the Opposed Conformational Preferences Among [4?+?2] Cycloadducts of 3-Ethoxycarbonyl- and 3-Acetyl-Coumarins with 2,3-Dimethyl-1,3-Butadiene

Abstract  

In this work, the molecular structures of the Diels–Alder adducts: ethyl (6aR/S,10aR/S)-6a,7,10,10a-tetrahydro-8,9-dimethyl-6-oxodibenzo[b,d]pyran-6a-carboxylate C₁₈H₂₀O₄ 1 and (6aR/S,10aR/S)-6a-acetyl-6a,7,10,10a-tetrahydro-8,9-dimethyl-6-oxodibenzo[b,d]pyran C₁₇H₁₈O₃ 2; and the epoxide of this last (6aR/S,7aR/S,8aS/R,9aR/S)-6a-acetyl-6a,7,7a,8a,9,9a-hexahydro-7a,8a-dimethyl-6-oxo-6H-5,8-dioxacyclopropa[b]phenanthrene C₁₇H₁₈O₄ 3, are comparatively analyzed. Compound 1 is triclinic, space group P-1 with a = 7.7529(6) ?, b = 9.8625(8) ?, c = 11.3103(9) ?, α = 109.387(9)°, β = 95.484(1)°, γ = 99.753(1)°, Z = 2. Compound 2 is monoclinic, space group Cc, a = 7.7285(7) ?, b = 16.6813(15) ?, c = 11.3213(10) ?, β = 92.470(2)°, Z = 4. Compound 3 is monoclinic, space group P2 ₁ /c a = 11.2036(10), b = 15.8326(14), c = 8.3182(7), β = 90.600(2)°, Z = 4. The molecular structures of compounds 1–3 show conformational differences between lactone and 6a-acyl carbonyls. CO···CO dipolar interactions stabilize the less favoured syn conformation in 2–3, conclusions are supported on theoretical calculations. The molecular structure of compound 3 demonstrates that epoxidation of 2 leads to the stereo-selective addition of the oxygen atom.     

Solvothermal Syntheses and Crystal Structures of Two Thiostannates(IV) [M(tepa)]<Subscript>2</Subscript>(<Emphasis Type="Italic">μ</Emphasis>-Sn<Subscript>2</Subscript>S<Subscript>6</Subscript>) (M = Fe<Superscript>2+</Superscript> and Co<Superscript>2+</Superscript>)

Abstract  

Two new thiostannates [M(tepa)]₂(μ-Sn₂S₆) (tepa = tetraethylenepentamine, M = Fe²⁺ 1 and Co²⁺ 2) were prepared by solvothermal method. Compounds 1 and 2 are isostructural. Both the compounds crystallize in the tetragonal system, space group I41/a (no. 88) with the crystal parameters of 1: a = 25.683(2) ?, b = 25.683(2) ?, c = 9.9860(9) ?, V = 6,586.7(11) ?³, Z = 8, and 2: a = 25.742(3) ?, b = 25.742(3) ?, c = 9.8977(12) ?, V = 6,558.5(14) ?³, Z = 8. The Sn₂S₆ ⁴⁻ anion acts as a bidentate bridging ligand connecting two transition metal complex cations by trans terminal S atoms to form neutral centrosymmetric [M(tepa)]₂(μ-Sn₂S₆) moieties.     

Preparation, Crystal Structure and Spectroscopic Properties of Dimeric [Zn(2-bromobenzoato)2(phenazone)]2 and Monomeric [Zn(2-bromobenzoato)2(thiourea)2]·2H2O

Abstract  

The binuclear zinc complex bis(2-bromobenzoato-O)-bis(μ ₂ -2-bromobenzoato-O,O′)-bis(phenazone-O)-dizinc(II) (I) and the mononuclear dihydrate bis(2-bromobenzoato-O)-bis(thiourea-S)-zinc(II) (II) have been synthesized and characterized by means of elemental analysis and spectroscopic methods (IR, ¹H and ¹³C NMR, EDS). The solid state structures of both compounds were determined by single-crystal X-ray diffractometry. Compound [Zn(2-BrC₆H₄COO)₂(phen)]₂ (phen—phenazone) (I) crystallized as a dimeric compound with a triclinic lattice (space group P − 1), where both zinc atoms, interconnected by two carboxylate groups, possess a distorted tetrahedral coordination environment. The crystallographic data of complex I: a = 9.9410(3) ?, b = 10.7309(3) ?, c = 12.9237(4) ?, α = 93.6004(17)°, β = 92.5898(11)°, γ = 116.2192(16)°, V = 1230.26(6) ?³, Z = 1. Complex [Zn(2-BrC₆H₄COO)₂(tu)₂]·2H₂O (tu—thiourea) (II) crystallized with an orthorhombic lattice (space group Aba2) as a monomeric compound, where the coordination environment of the central zinc atom is a distorted tetrahedron. The crystallographic data of complex II are: a = 9.8595(3) ?, b = 19.7052(5) ?, c = 12.5908(3) ?, V = 2446.18(11) ?³, Z = 4. The modes of the carboxylate binding were assigned from the IR spectra using the magnitude of the separation between the carboxylate stretches (Δ), which correlated well with the crystal structures. The computed theoretical IR spectrum agreed well with the experimental data.     

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.     

Absolute Configuration of Two Eudesmane Derivatives from <Emphasis Type="Italic">Verbesina turbacensis</Emphasis> H.B.K.

Abstract  

Two compounds isolated from the aerial parts of Verbesina turbacensis H.B.K, are reported in this work. Both compounds crystallize in the orthorhombic system, space group P2₁2₁2₁. Compound (1), 6β-[cinnamoyloxy]-3β,4α-dihydroxyeudesmane, formula C₂₄H₃₄O_4, has unit cell parameters a = 9.6234(2), b = 12.3137(3) and c = 18.6277(5) Å, V = 2207.38(9) Å³, Z = 4. On the other hand, 6β-[cinnamoyloxy]-eudesman-15-oic acid (2), formula C₂₄H₃₂O_4, has cell parameters a = 8.7035(3), b = 14.2020(4), c = 17.1590(5) Å, V = 2120.97(11) Å³, Z = 4.     

Synthesis and Crystal Structures of Anionic Gallium(II) and Gallium(III) Heterocyclic Compounds Derived from a Gallium(I) N-Heterocyclic Carbene Analogue

Abstract  

The addition of the N–H bond of the formamidine, ArN(H)C=NAr (Ar = C₆H₃Pr₂ⁱ-2,6), to the gallium(I) center of [K(tmeda)][:Ga(Ar-DAB)] (Ar-DAB={(Ar)NC(H)}₂) yields K[(Ar-DAB)Ga^III(H){N(Ar)C=NAr}] 1. The crystal structure of this and two other related anionic compounds, [K(18-crown-6)][(Ar-DAB)Ga^III{N(H)N=Fl}{(H)Fl}] (Fl = fluorendiyl) 2 and [K(OEt₂)₃][(Ar-DAB)Ga^II(CH₂Ph)Ga^II(Ar-DAB)] 3, have been determined. The cell parameters of the compounds are 1: P2₁/c, a = 20.2350(9), b = 14.1760(7), c = 19.6441(10), β = 111.307(1); 2: P2₁/c, a = 13.115(3), b = 21.799(4), c = 22.646(5), β = 90.20(3); 3: P2₁/n, a = 16.783(3), b = 21.635(4), c = 19.814(4), β = 92.34(3). The crystal structures of all complexes exhibit distorted tetrahedral gallium centers, and interactions between anion aryl substituents and the potassium cations.     

Synthesis and Crystal Structures of Two Binuclear Lanthanide [Ln = Pr,Dy] Complexes with 4-Quinolineacarboxylate

Abstract  

The reaction of the organic ligand, 4-quinolineacarboxylate (L) with Pr(ClO₄)₃·6H₂O and Dy(ClO₄)₃·6H₂O, leads to the formation of two novel complexes [Pr₂(L)₆(H₂O)₄]2H₂O 1 and [Dy₂(L)₆(H₂O)₄]2H₂O 2, which have been characterized by elemental analysis, IR and single-crystal X-ray diffraction analysis (monoclinic system, space group P2(1)/n, with a = 11.805(2), b = 16.645(3), c = 15.367(3) ?, β = 106.78(3)°, V = 2891.1(10) ?³, Z = 4 for 1, monoclinic system, space group P2(1)/n, with a = 11.629(2), b = 16.478(3), c = 5.336(3) ?, β = 105.83°, V = 2827.4(10) ?³, Z = 4). The two isostructure complexes are binuclear and possess an inversion center which is at the midpoint of the linkage of two symmetrical La(III) centers. In two complexes, each metal center adopts nine-coordinated mode coordinated by nine O atoms from two H₂O molecules and three carboxyls of three ligands, and L displays three different coordination modes. Hydrogen bonds join the binuclear complexes into 3D networks.     

Structure of 2-[(Phenyl)-(3,5-Dimethyl-Pyrazol-1-yl)-Methyl]-Malonic Acid Diethyl Ester

Abstract  

The titled new functionalized ligand of type 2-[(phenyl)-(3,5-dimethyl-pyrazol-1-yl)-methyl]-malonic acid diethyl ester (4) is prepared in good yield through condensation of 3,5-dimethyl-pyrazole, with 2-arylidene-malonic acid diethyl esters 3. The structure of 4 was determined by spectral (IR, ¹H and ¹³C NMR), elemental analyses and X-ray diffraction data. The title compound (4) crystallizes in the monoclinic space group P2₁/a, with a = 7.9253 (2), b = 17.1299 (5), c = 13.4522 (4) ?, β = 90.220 (2)°, V = 1,826.25 (9) ?³, Z = 4 and with R _int = 0.021. The molecular conformation shows two possible pockets ready to coordinate two metal atoms. The crystal structure of (4) is stabilized by inter-molecular C–H⋯O and C–H⋯N hydrogen bonding.     

Synthesis,Crystal Structure and IR Spectra of Complexes of Mn(II) by Indole-2-Carboxylic or Isoquinoline-1-Carboxylic Acids and 1,10-Phenanthroline

Abstract  

Two ternary complexes of manganese(II) indole-2-carboxylate (2-IC⁻) or isoquinolinecarboxylate (IQC⁻) with 1,10-phenanthroline (phen) in methanol or in dimethylacetamide (DMA) were synthesized and studied by X-ray diffraction and IR spectra. [Mn(C₉H₆NO₂)₂(C₁₂H₈N₂)₂]·CH₄O (1) crystallizes in the triclinic space group P-1 with cell parameters of a = 10.548(2) ?, b = 14.168(3) ?, c = 14.580(3) ?, α = 62.35(2)°, β = 69.16(2)°, γ = 78.61(2)°, V = 1802.4(6) ?³ and Z = 2; [Mn(C₁₀H₆NO₂)₂(C₁₂H₈N₂)].C₄H₉NO (2) crystallizes in the monoclinic space group P2₁/a with cell parameters of a = 15.304(5) ?, b = 12.871(5) ?, c = 17.421(5) ?, β = 114.39(1), V = 3125(2) ?³ and Z = 4. In 1, Mn is six-coordinate by two bidentate phen ligands and two 2-IC⁻ ligands and exhibits a very distorted octahedral geometry. This complex is solvated by methanol involved in hydrogen bonding. In 2, Mn atom is surrounded by one bidentate phen ligand and two bidentate IQC⁻ ligands. The complex exhibits a distorted octahedral geometry around the Mn^II atom. The crystal structure is completed by a disordered DMA solvate molecule. The IR spectra of both compounds are slightly different in the range 4000–2400 cm⁻¹ which may be attributed to hydrogen bond lack in 2.