Structure of Methyl N-(4-methoxyphenylmethyl)-N′-cyano-carbamimidothioate and Methyl N-[1-(phenylmethyl)-4-piperidinyl]-N′-cyanocarbamimidothioate

Abstract  

The title compounds, Methyl N-(4-methoxyphenylmethyl)-N′-cyanocarbamimidothioate, I, and Methyl N-[1-(phenylmethyl)-4-piperidinyl]-N′-cyanocarbamimidothioate, II, have been designed and synthesized for use as new potential organic molecular electronic materials. The crystal structure of I and II were determined with crystal data (I: Monoclinic, P2₁/c, a = 4.746(2) ?, b = 5.737(3) ?, c = 17.399(7) ?, β = 91.667(7)o, R _all = 0.0703; II: Orthorhombic, Pna2₁, a = 18.209(8) ?, b = 11.463(5) ?, c = 7.539(3) ?, β = 90.00 o, R _all = 0.0481). N–H···N hydrogen bonds were responsible for the formation of one-dimensional zigzag molecular chains of I, and trifurcated hydrogen-bonded molecular chains were indicated in structure of II. C–H···π and C–H···N hydrogen bonds were found in both structures. All these types of interaction together form an extended three-dimensional network and stabilize the title crystals.     

Structure of 2-(1-phenylimidiazolidin-2-ylidene)- malononitrile and 2-(hexahydropyrimidinyl-2-ylidene)- malononitrile

The crystal structure of 2-(1-phenylimidazolidin-2-ylidene)-malononitrile, I, and 2-(hexahydropyrimidin-2-ylidene)-malononitrile, II, were determined with crystal data (I: Monoclinic, P2₁/n, a=8.116(3) ?, b=7.650(3) ?, c=17.399(7) ?, β=93.065(6)°, R _all=0.0980; II: Monoclinic, P2₁/n, a=9.169(2) ?, b=8.103(2) ?, c=10.337(3) ?, β=99.853(4)°, R _all=0.0877). N−H···N hydrogen bonds were responsible for the formation of centrosymmetric dimers of I and one-dimensional zigzag molecular chains of II.     

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.     

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.     

Crystal Structures of Two Aromatic Zinc(II) Carboxylates: [Zn(4-Chlorosalicylato)2(H2O)4]·2theophylline·(H2O)2 and Unique [Zn(5-Chlorosalicylato)2(isonicotinamide)2(H2O)]

Abstract  

The crystal structures of two zinc(II) 4-chloro- and 5-chlorosalicylate complexes, [Zn(4-ClC₆H₃-2-(OH)COO)₂(H₂O)₄]·2tph·(H₂O)₂ (I) and [Zn(5-ClC₆H₃-2-(OH)COO)₂(ina)₂(H₂O)] (II), where tph is theophylline and ina is isonicotinamide, have been determined using X-ray diffraction methods. Crystals of both (I) and (II) are triclinic, space group P-1, with Z = 1 in a cell with a = 7.2220(3), b = 8.59700(10), c = 16.0210(5) ?, α = 75.990(2), β = 83.959(2), γ = 68.455(2)°, V = 897.54(5) ?³ (I) and with Z = 2 in a cell with a = 11.4148(11), b = 11.5327(10), c = 12.0685(13) ?, α = 63.458(6), β = 87.547(8), γ = 89.387(7)°, V = 1419.9(2) ?³ (II). The coordination environment of the zinc(II) atom of compound (I) consists of two unidentate carboxylate oxygen atoms and four oxygen atoms of aqua ligands, forming a distorted octahedral configuration. Two theophylline molecules and the remaining water molecules are bound only by hydrogen bonds. The Zn atom of compound (II) is pentacoordinated with two unidentate carboxylate oxygen atoms, two pyridine nitrogen atoms of isonicotinamide ligands, and the oxygen atom of the aqua ligand, forming a distorted configuration between square pyramid and trigonal bipyramid. In both complexes intramolecular O–H···O hydrogen-bonding interactions are present. In the crystal structures, molecules are linked by intermolecular O–H···O and N–H···O hydrogen bonds. The structures are analyzed and compared to the similar Zn(II) complexes, with the chromophores ZnO₆ and ZnO₃N₂.     

Crystal and Molecular Structures of Two Triazole Derivatives: 4-Cyclopropyl-4,5-dihydro-1H-1,2,3-triazole and Methyl 1-benzyl-1H-1,2,3-triazole-4-carboxylate

Abstract  

The molecule in 4-cyclopropyl-4,5-dihydro-1H-1,2,3-triazole (I) is disposed about a mirror plane with the triazole ring lying in the plane and being orthogonal to the cyclopropyl ring. Considerable delocalization of π-electron density within the triazole ring is indicated by the pattern of bond distances in (I). The molecule of methyl 1-benzyl-1H-1,2,3-triazole-4-carboxylate (II) adopts a curved shape with the dihedral angle formed between the triazole and benzene rings being 63.23(8)°. By contrast to (I), localization of π-electron density within the triazole ring in (II) is indicated. Both (I), via N–H···N hydrogen bonding, and (II), via C–H···O and C–H···N interactions, associate in the solid state to form supramolecular chains. In (I), the chain is a zigzag with a flat topology, whereas in (II) the linear chain has a curved topology. Compound (I) crystallizes in the orthorhombic space group Pnma with a = 5.6470(2) ?, b = 7.3359(4) ?, c = 13.4404(7) ?, and Z = 4. Compound (II) crystallizes in the monoclinic space group P2₁/c with a = 12.1314(5) ?, b = 5.5951(2) ?, c = 16.4339(7) ?, β = 111.269(2)°, and Z = 4.     

Synthesis and Crystal Structures of 4-(3-Nitropyridin-2-ylamino)phenol and 4-(3-Aminopyridin-2-ylamino)phenol

Abstract  

The title compounds, 4-(3-nitropyridin-2-ylamino)phenol (I) and 4-(3-aminopyridin-2-ylamino)phenol (II), are two intermediates for the synthesis of a potential antitumor agent ABT-751. The reaction of 4-aminophenol with 2-chloro-3-nitropyridine yielded I which was converted into II by reduction. Instead of the Pd/C catalytic hydrogenation described in many literature, reduction with cheap sodium sulfide in aqueous media was utilized for shorting the reaction time and simplifying the operation. The crystal structures of the resultant compounds were determined by single-crystal X-ray diffraction. The compound I is crystallized in P2₁/c space group of monoclinic system, with a = 11.5236(19) ?, b = 8.7389(17) ?, c = 10.684(3) ? and α = 90.00°, β = 107.76(3)°, γ = 90.00°. The compound II is crystallized in Cc space group of monoclinic system, with a = 10.688(2) ?, b = 14.2181(18) ?, c = 7.9836(15) ? and α = 90.00°, β = 125.801(7)°, γ = 90.00°. In both crystal structures, the intermolecular N–H–O and O–H–N hydrogen bonds link the molecules, which effectively stabilize the structures.     

Structures and Characterization of [Zn(n-chlorosalicylato)2(N-methylnicotinamide)2(H2O)2] (n?=?4 or 5) Ligand Isomers

Abstract  

Two ligand isomers [Zn{4-ClC₆H₃-2-(OH)COO}₂(Menia)₂(H₂O)₂] (I) and [Zn{5-ClC₆H₃-2-(OH)COO}₂(Menia)₂(H₂O)₂] (II) (Menia = N-methylnicotinamide) were prepared and characterized by elemental analysis, IR spectroscopy and thermal analysis. The X-ray crystal structures of complexes (I) and (II) were determined. Compound (I) crystallizes in the triclinic space group P[`1] P\bar{1} with a = 8.105(1) ?, b = 10.036(2) ?, c = 10.545(2) ?, α = 109.088(9)°, β = 91.416(8)°, γ = 102.757(9)°, V = 786.2(2) ?<sup>3</sup>, Z = 1. Compound (II) crystallizes in the triclinic space group P[`1] P\bar{1} . Its cell parameters are: a = 8.133(1) ?, b = 10.119(2) ?, c = 10.428(1) ?, α = 66.44(1)°, β = 74.32(1)°, γ = 80.16(1)°, V = 755.5(2) ?³, Z = 1. The molecular structure of both isomers is monomeric. Each Zn(II) atom is hexacoordinated by three pairs of unidentate ligands in trans-positions (ZnO₄N₂). The 5-Clsal complex is somewhat less distorted than 4-Clsal complex (Cl-sal = chlorosalicylate). The structural data are compared with those found in similar [Zn(RCOO)₂(NL)₂(H₂O)₂].     

Crystal structures of substituted imidazolidine derivatives

The crystal structures of isoxazole, 3-[[dihydro-2-[(Z)-2-oxohyrazono]-1H-imidazol-1-(3H)-yl]methyl-5-phenyl-,N-oxide] (C₁₃H₁₃N₅O₃) (I), isoxazole,3-[[dihydro-2-[(Z)-2-oxohyrazono]-1H-imidazol-1-(3H)-yl]-methyl-5-(4-methylphenyl)-,N-oxide] (C₁₄H₁₅N₅O₃) (II) and isoxazole, 3-[[dihydro-2-[(Z)-2-oxohyrazono]-1H-imidazol-1-(3H)-yl]-methyl-5-(2-methoxyphenyl)-,N-oxide] (C₁₄H₁₅N₅O₄) (III) have been determined by X-ray diffraction studies. The compound I, crystallized in triclinic space group with unit cell dimensions a = 7.2405(7) ?, b = 7.9936(8) ?, c = 11.6573(11) ?, α = 97.801(2)°, β = 90.884(2)°, γ = 96.250(2)° and Z = 2. Compound II crystallized in orthorhombic space group Pna2₁ with unit cell dimensions a = 10.1778(10) ?, b = 28.228(3) ?, c = 5.1206(5) ?, and Z = 4. Compound III crystallized in monoclinic space group P2₁/n with unit cell dimensions a = 7.8439(9) ?, b = 7.8544(9) ?, c = 23.534(3) ?, β = 99.464(2)° and Z = 4. For all three compounds, the five-membered imidazolidine ring adopts an envelope conformation. The crystal structures are stabilized by both the intramolecular N–H···O and intermolecular N–H···N hydrogen bonding.     

Structures of Two (<Emphasis Type="Italic">E</Emphasis>)-3-Substituted Cinnamoylbenzotriazole 1-Oxides

Abstract  

The molecule of (E)-3-(3-MeOC₆H₄CH=CHCO)-benzotriazole 1-oxide, 2, has a very near planar structure, while the 2-nitrophenyl ring is rotated out of the plane of the remaining atoms in (E)-3-(2-O₂NC₆H₄CH=CHCO)-benzotriazole 1-oxide, 1. The nitrogen oxide bond lengths in 1 and 2 are 1.258 (6) and 1.2683 (15) ?, respectively, and are in the region found for related compounds. There are no strong intermolecular hydrogen-bonds in either compound, instead there are weak C–H···O intermolecular hydrogen-bonds and π···π stacking interactions in 1, and C–H···O, C–H···π, and π···π stacking interactions in 2. Different three-dimensional arrays are generated in each case. Compound 1 crystallises in the orthorhombic space group Pna2₁, with a = 25.061 (2) ?, b = 3.6997 (2) ?, c = 14.2623 (12) ? and Z = 4. Compound 2 crystallises in the triclinic space group P-1, with a = 5.7297 (3) ?, b = 10.8440 (6) ?, c = 11.4965 (6) ?, α = 89.689 (3)°, β = 76.019 (3)°, γ = 75.047 (3)°, Z = 2.     

Crystal and Molecular Structure of the 1:2 Adduct Formed Between <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>′-Butylenebis(imidazole) and Carboxylic Acid Derivatives

Abstract  

Two imidazolyl derived complexes [N,N′-butylenebis(imidazole): (fumaric acid)₂ (1), and N,N′-butylenebis(imidazole): (2,4,6-trinitrophenol)₂ (2)] were prepared and structurally characterized by X-ray crystallography. Compound 1 crystallizes in the triclinic, space group P−1, with a = 5.9990(12) ?, b = 8.1772(16) ?, c = 10.419(2) ?, α = 86.88(2)°, β = 84.73(3)°, γ = 77.03(4)°, V = 495.67(17) ?³, Z = 1. For 1, two dimensional network structure is formed through imidazolium moieties forming hydrogen bonds to di-ionic carboxylate groups of fumarate chains. In the same network layers and adjacent layers, C–H···O contact also accompanies the N⁺–H···O⁻ hydrogen bonds, all these lead the extended architecture to show a three-dimensional lamellar structure. Compound 2 crystallizes in the triclinic, space group P − 1, with a = 7.0236(14) ?, b = 8.2831(17) ?, c = 12.053(2) ?, α = 106.05(4)°, β = 99.13(2)°, γ = 98.84(3)°, V = 650.8(2) ?³, Z = 1. In 2, two parallel imidazolium cations and two antiparallel 2,4,6-trinitrophenolate anions formed 32-membered rings through hydrogen bonding interaction, these rings extended along the c axis direction to form one dimensional railway structure. Adjacent parallel railways connect further through C–H···O hydrogen bonds between the 2-CH of the imidazole ring and the NO₂ group O atoms. These weak interactions combined, the complex showed 3D layer structure.     

Synthesis, Crystal Structure and Magnetic Property of a Cyano-Bridged Two-Dimensional Heterometallic Assembly [Mn(salen)]2[Fe(CN)5NO]·2H2O

Abstract  

A cyano-bridged bimetallic assembly, [Mn^III(salen)]₂[Fe^II(CN)₅NO]·2H₂O [salen = N,N′-1,2-ethylenebis(salicylideneiminato)dianion], has been prepared and characterized structurally and magnetically. It crystallizes in the tetragonal space group P4/ncc with a = b = 14.813(2) ?, c = 17.093(5) ?, V = 3750.6(13) ?³, Z = 4. In this complex, each [Fe(CN)₅NO]²⁻ unit connects four [Mn(salen)]⁺ units with its four co-planar cyanide groups, and each [Mn(salen)]⁺ unit is linked to two [Fe(CN)₅NO]²⁻ ions in trans-form, which results in a two-dimensional (2-D) network consisting of pillow-like octanuclear [–Fe^II–CN–Mn^III–NC–]₄ units with dimensions: Fe–C = 1.943(3) ?, C≡N– = 1.139(4) ?, Mn–N = 2.326(3) ?, Fe–C≡N = 178.0(3)°, Mn–N≡C = 161.7(3)°. The NO group of [Fe(CN)₅NO]²⁻ remains monodentate and the bond angle of Fe–N–O is linear (180.0°). The variable temperature magnetic susceptibilities, measured in the 1.8–300 K range, show a weak Mn^III···Mn^III antiferromagnetic interaction through the diamagnetic –NC–Fe^II–CN– bridges.     

The Zolmitriptan-Pyridine (1:1) and Zolmitriptan-Propiophenone (3:2) Inclusion Complex

Abstract  

The crystal structures of zolmitriptan with pyridine (I) and propiophenone (II) solvates have been determined by single crystal X-ray diffraction studies. Compound (I) crystallizes in the orthorhombic space group P2₁2₁2₁ with a = 8.5610(5) ?, b = 12.2709(7) ?, c = 19.6201(12) ?, V = 2061.1(2) ?³, and Z = 4, while compound (II) crystallizes in the monoclinic space group P2₁ with a = 15.085(1) ?, b = 19.656(12) ?, c = 21.0860(13) ?, β = 92.068(1)°, V = 6248(4) ?³ and Z = 4. The asymmetric unit of (I), C₁₆H₂₁N₃O₂·C₅H₅N, contains one zolmitriptan molecule and one pyridine solvate, while the asymmetric unit of (II), 3(C₁₆H₂₁N₃O₂)·2(C₉H₁₀O) comprises six zolmitriptan molecules and four propiophenone solvates. In both structures, the N–H···N hydrogen bonds, form an infinite helical chain and generate a C(11)-type motif in (I) and a D₂²(13)-type motif in (II). Both the complexes have layer structures, the layers being constructed from rings (cavity) of four zolmitriptan molecules, hydrogen bonded through N–H···N and N–H···O bonds, where the pyridine (I) and propiophenone (II) solvates are included in an R₄⁴(33) ring.     

Persistence of layer motifs in the crystal structures of [1,4-bis-(2-methoxy-2-carbonylethyl)piperazinium (2’)] chloride and [1,4-bis-(2-amidoethyl)piperazinium (2’)] perchlorate

Two structures of the closely related piperazinium salts, [1,4-bis-(2-methoxy-2-carbonylethyl)piperazinium (2+)] chloride (1) and [1,4-bis-(2-amidoethyl)piperazinium (2+)] perchlorate (2) reveal the persistence of a layer structure, interspersed with anions, held in place by N–H···Cl, C–H···O and C–H···Cl interactions in the case of 1, and N–H···O and C–H···O interactions in the case of 2. Compound 1 crystallizes in the triclinic space group P-1 with a=6.7667(6) ?, b = 6.9467(6) ?, c=9.3880(18) ?, α=105.845(9)°, β=99.896(16)°, γ=103.600(9)°, and Z=1. Compound 2 crystallizes in the monoclinic space group P2₁/c with a = 9.0930(8) ?, b=10.0525(11) ? c=10.2104(13) ?, β=114.279(9)°, and Z=2.     

Crystal Structure of (E)-2,3-Dihydro-2-(R-Phenylacylidene)-1,3,3-Trimethyl-1H-Indole (R?=?4-CN, 4-Cl)

Abstract  

Two new 1,3,3-trimethyl-2-methylene-2,3-dyhidro-1H-indole derivatives, (E)-2,3-dihydro-2-(4-cyanophenylacylidene)-1,3,3-trimethyl-1H-indole, (I), and (E)-2,3-dihydro-2-(4-chlorophenylacylidene)-1,3,3-trimethyl-1H-indole, (II), have been synthesized and their crystal structure determined by single crystal X-ray diffraction. (I), C₂₀H₁₈N₂O, crystallizes in a monoclinic space group, P2₁/c, with unit cell parameters a = 9.882 (3), b = 15.614(4), c = 11.181(3) ?, β = 106.691(4)°, Z = 4. (II), C₁₉H₁₈Cl N O, crystallizes in a monoclinic space group, P2₁/n, with unit cell parameters a = 14.6722(19), b = 7.2597(9), c = 16.304(2) ?, β = 111.249 (2)°, Z = 4. The molecules consist of a enaminoketone group formed by a Fischer base 1,3,3-trimethyl-2-methylene-2,3-dihydro-1H-indole bonded, at the exocyclic electron-rich β-carbon atom of the indole moiety, with the benzoyl chloride derivatives substituted at para-positions with cyano and chloro groups. The molecules adopt a s-cis conformation with respect to the C=O bond towards the C=C bond, and a E configuration about the latter indole exocyclic alkene C–C bond. Intermolecular arrangement of the crystals show, for (I) an antiparallel stacking mode favored by the formation of weak C–H···π interactions involving the phenyl ring attached to the carbonyl group and the phenyl of the indole fragment in a head-to-tail mode, whereas, (II) present an weak C–H···Hal interaction.     

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.     

Histamine Molecule and Dianion Oxalate are Efficient Blocks for Building 2D Supramolecular Networks

Abstract  

One salt and two Cu(II) complexes (H₂hsm)(ox), 1, [Cu(hsm)(ox)], 2, and [Cu(hsm)(ox)H₂O], 3, have been synthesized and X-ray characterized (hsm is histamine and ox²⁻ is the oxalate dianion). Starting from the prochiral tetracoordinated complex 2, pentacoordinated complex 3 crystallizes as a racemic mixture of the enantiomeric Δ and Λ isomers, in space group P2₁/c. In all cases, the side chain of the hsm group is gauche, allowing the formation of strong hydrogen bonds in the salt 1, and to chelate the metal center in complexes 2 and 3. The combination hsm/ox seems to favor the formation of 2D supramolecular structures (planes or wavy planes), through efficient networks of N–H···O hydrogen bonds. Cell parameters: 1, P2₁/c, a = 6.260 (2) ?, b = 11.500 (4) ?, c = 12.525 (4) ?, β = 104.047 (17)o; 2, C2/c, a = 10.7966 (13) ?, b = 15.5622 (16) ?, c = 11.3996 (15) ?, β = 106.261 (11)o; 3, P2₁/c, a = 7.0627 (6) ?, b = 7.1323 (6) ?, c = 20.0296 (19) ?, β = 91.529 (7)o.     

Syntheses and Crystal Structures of Two CuII Coordination Isomers [Cu(pmt)2] · 4H2O (1) and {[Cu(pmt)2] · 2H2O} n (2)

Abstract  A pair of Cu^II coordination isomers [Cu(pmt)₂] · 4H₂O (1) and {[Cu(pmt)₂] · 2H₂O} _n (2) [Hpmt = 2-(2-pyridylmethylamino) ethanesulfonic acid] have been prepared by reaction of the same proportion CuCl₂ · 2H₂O and Hpmt but with different experimental methods in water–methanol mixed solution, and were characterized by X-ray diffraction, elemental analysis, IR spectrum. X-ray analysis indicates that complex (1) is a mononuclear complex in which two deprotonated pmt ligands coordinate in a facial tridentate arrangement about the Cu^II atom. While complex (2) is a coordination polymer, in which four N atoms of pmt ligands coordinate to one Cu^II atom but its sulfonate O atoms bond to adjacent Cu^II atom. Thus 12-membered rings (–Cu–N–C–C–S–O–)₂ are obtained between two neighbouring Cu^II atoms and they connect one another to form this new polymer. Crystal data: [Cu(pmt)₂] · 4H₂O (1), Mr = 566.10, monoclinic, P2 ₁/c, a = 9.1950(8) ?, b = 11.5093(10) ?, c = 11.2304(10) ?, β  = 105.5550(10)°, Z = 2, V = 1144.96(17) ?³, R ₁  = 0.0407, wR ₂  = 0.1242 [I > 2σ (I)]; {[Cu(pmt)₂] · 2H₂O} _n (2), Mr = 530.07, triclinic, P-1, a = 7.6165(19) ?, b = 8.806(2) ?, c = 9.592(4) ?, α = 104.933(4)°, β = 106.732(4)°, γ = 109.503(3)°, Z = 1, V = 534.2(3) ?³, R ₁ = 0.0470, wR ₂ = 0.1082 [I > 2σ(I)]. Index Abstract  A pair of Cu^II coordination isomers [Cu(pmt)₂] · 4H₂O (1) and {[Cu(pmt)₂] · 2H₂O} _n (2) [Hpmt = 2-(2-pyridylmethylamino) ethanesulfonic acid] have been prepared by reaction of the same proportion CuCl₂ · 2H₂O and Hpmt but with different experimental methods in water–methanol mixed solution.      

Metal Ion Interactions with Pyridinecarboxylates in Tripodal tris(2-Aminoethyl)amine Ligand System: Crystal Structures of [Ni(tren)(pic)]2(ClO4)2·CH3OH and [Co(tren)(dipic)]ClO4·CH3OH

Abstract  

Two new complexes [Ni(tren)(pic)]₂(ClO₄)₂·CH₃OH (1) and [Co(tren)(dipic)]ClO₄·CH₃OH (2), (tren is tris(2-aminoethyl)amine, pic is the anion of picolinic acid, dipic is the dianion of 2,6-pyridinedicarboxylic acid) have been synthesized and structurally characterized. X-ray analysis indicates that the two complexes are mononuclear with tren acting as a quadridentate ligand. In complex 1, the nickel(II) ion is further coordinated with picolinate in μ₂-N, O bidentate chelating mode. In complex 2, the cobalt(III) ion is coordinated with the pyridine nitrogen and one carboxylic oxygen of 2,6-pyridinedicarboxylate in μ₂-N, O chelating form. The metal atoms in both cases have distorted octahedral geometry. Crystal data: [Ni(tren)(pic)]₂(ClO₄)₂·CH₃OH (1), Mr = 869.03, monoclinic, C2/c, a = 26.354(5) ?, b = 10.407(2) ?, c = 25.839(5) ?, β = 96.24(3)°, Z = 8, V = 7045(2) ?³, R ₁ = 0.0418, wR ₂ = 0.1063 [I > 2σ(I)]; [Co(tren)(dipic)]ClO₄·CH₃OH (2), Mr = 501.77, Triclinic, P-1, a = 8.3667(2) ?, b = 10.4434(2) ?, c = 11.9431(16) ?, α = 73.9590(10)°, β = 88.0240(10)°, γ = 75.5890°, Z = 2, V = 969.97(4) ?³, R ₁ = 0.0408, wR ₂ = 0.1063 [I > 2σ(I)].     

Synthesis and Characterization of Nickel(II) Complex of 3,14-Dimethyl-2,6,13,17-Tetraazatricyclo[14,4,01.18,07.12]Docosane Containing Pyrazine-2-Carboxylate Ligand

Abstract  

The reaction of [Ni(L)]Cl₂·2H₂O (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0^1.18,0^7.12]docosane) with pyrazine-2-carboxylic acid (H-pyc) yields mononuclear nickel(II) complex, [Ni(L)(pyc)₂]·2H₂O (1). This complex has been characterized by X-ray crystallography, electronic absorption and cyclic voltammetry. The crystal structure of 1 exhibits a distorted octahedral geometry with four nitrogen atoms of the macrocycle and two pyrazine-2-carboxylate ligands. It crystallizes in the triclinic system P-1 with a = 9.6643(17), b = 10.116(3), c = 16.99(4) ?, V = 1633(3) ?³, Z = 2. Electronic spectrum of 1 also reveals a high-spin octahedral environment. Cyclic voltammetry of 1 undergoes two waves of a one-electron transfer corresponding to Ni^II/Ni^III and Ni^II/Ni^I processes.