Piperazine Molecules Research Articles

A New Copper (II) Complex with the N,N'-Bis(antipyryl-4-methyl)-piperazine (BAMP) Ligand: [Cu(BAMP)](ClO4)2

The synthesis of the Mannich base N,N’-bis(antipyryl-4-methyl)-piperazine (BAMP) (1), its crystal structure as well as the synthesis and the crystal structure of the copper complex Cu(BAMP)(ClO4)2 (2) are reported. C28H34N6O2 ∙ 4H2O (BAMP ∙ 4H2O) crystallizes with triclinic symmetry, space group P1̄, lattice parameters: a = 704,9(2), b = 983,4(2), c = 1198,9(3) pm, α = 68,72°, β = 73,62°, γ = 78,49°. The copper-complex Cu(BAMP)(ClO4)2 crystallizes with tetragonal symmetry, space group P42/n, lattice parameters: a = 2295,1(3), c = 1412,2(2) pm. The copper(II) atom is five-coordinate by the two nitrogen atoms belonging to the piperazine ring and the oxygen atoms of the antipyrinemoieties. The geometry of the copper(II) atom can be described as a square-based pyramid with the N2O2 donor atoms of BAMP forming the basal plane and an oxygen atom of the neighbouring complex molecule occupying the apical position. BAMP acts as a tetradentate ligand, which incorporates a piperazine-fused ring. The structural parameters illustrate well the reinforcing effect exerted by the double “straps” of the piperazine molecule.

Synthesis and structure of an open-framework cobalt zincophosphate

Introducing cobalt into a Zn–P–O–amine system and using oxalates as starting materials, an amine containing open-framework cobalt zincophosphate, [C4N2H12][Co0.14Zn1.86(PO4)(H1.5PO4)2] (1), has been hydrothermally synthesized and structurally determined. It crystallizes in the monoclinic space group C2/c (No. 15) with cell parameters a = 13.374(3) A, b = 12.827(3) A, c = 8.1940(16) A, β = 94.77(3)°, V = 1400.9(5) A3, Z = 4, Dcal = 2.399 g cm−3. The linkages of ZnO4 and PO4 give rise to four-membered rings, which serve as the secondary building unit for compound 1. The four-membered rings (four-MR) share their corners leading to chains. Connection of these chains results in a complex three-dimensional channel system. Eight-MR, twelve-MR and highly distorted twelve-MR channels can be observed along the [010], [110] and [101] directions, respectively. The prominent feature of compound 1 is the clover-like 16-MR channel along the [001] direction. The channel spaces are occupied by the diprotonated piperazine molecules with H-bonds to the framework.

Two polymorphs of a piperazinium zincophosphate with different interrupted SOD-type frameworks

Two polymorphous forms of the piperazinium zincophosphate (ZnPO) (C 4N 2H 12)[Zn 2P 3O 12H 3] have been obtained under mild hydrothermal conditions from mixtures of ZnCl 2, H 3PO 4 piperazine and H 3BO 3 in ethylene glycol/water solvents. Single-crystal X-ray structure analyses revealed that both polymorphs possess an open-framework structure with sodalite (SOD) topology. While polymorph I (formulation (C 4N 2H 12)[Zn 2(HPO 4) 3], space group P2 1/c, Z=8) is reported for the first time, polymorph II (formulation (C 4N 2H 12)[Zn 2(PO 4)(H 1.5PO 4) 2], space group C2/c, Z=4) is a known phase. Its structure has been reinvestigated in order to unambiguously determine the hydrogen bonds. The interruptions in the ZnPO host structures possess the form of distorted tetrahedral [H 3O 4(P) 4] groupings (hydroxyl nests). A diprotonated piperazine molecule is enclosed in every [4 66 8] cage. The polymorphs differ in the host–guest N–H⋯O and C–H⋯O interactions, the degree of condensation of the distinct phosphate tetrahedra, the hydrogen-bonding systems in the interruptions, and the long-range ordering of interruptions in the host frameworks. Considerable differences are seen for the donor–acceptor O⋯O distances (ranging from 2.47 to 3. 14 Å) in the total of three distinct [H 3O 4(P) 4] groupings.

Synthesis and Structure of a New Organic–Inorganic Framework with Tetranuclear Clusters, [Co4(OH)2(H2O)2](C4H11N2)2[C6H2(COO)4]2·3H2O

A new hybrid organic–inorganic three-dimensional compound, [Co4(OH)2(H2O)2](C4H11N2)2[C6H2(CO2)4]2·3H2O 1, has been synthesized via hydrothermal reactions and characterized by single-crystal X-ray diffraction, infrared spectroscopy, thermogravimetric analysis, and magnetic techniques. Compound 1 crystallizes in the monoclinic space group P21/n (no. 14) with a=6.3029(9) Å, b=16.413(2) Å, c=17.139(2) Å, β=98.630(2)°, V=1735.0(4) Å3, Z=2. Compound 1 contains tetranuclear Co4(μ3-OH)2(H2O)2 clusters that are inter-linked by pyromellitate bridging ligands into a three-dimensional structure containing one-dimensional tunnels along the a-axis with water and pendant monoprotonated piperazine molecules in the center. The variable temperature magnetic susceptibility was measured from 2 to 300 K at 5000 Oe showing a predominantly anti-ferromagnetic interaction in 1, and the field dependence of magnetization was measured at 2, 5, 15, and 20 K indicating the competition of magnetic interactions in the tetranuclear centers.

Hydrothermal synthesis of the first iron arsenate-oxalate [C4N2H12]2[Fe4(HAsO4)6( C2O4)2], possessing open architecture

The hydrothermal synthesis and structural characterization of the first iron arsenate-oxalate [C4N2H12]2[Fe4(HAsO4)6(C2O 4)2], I, with open-framework structure has been described. Crystal data for I: triclinic, space group P(−1) (no. 2), a=11.1066(2), b=12.9842(1), c=13.4294(1) Å, α=111.345(1), β=93.688(1), γ=93.879(1)°, V=1706.33(4) Å3, Z=2, ρcalc=2.755 g cm−3, μ(MoKα)=7.567 mm−1, R1=0.0441 and wR2=0.113 for 3861 reflections with I>2σ(I). The framework structure of I consists of neutral inorganic sheets formed by the linkages between strictly alternating FeO6 octahedra and AsO4 tetrahedra cross-linked by the oxalate units forming an anionic three-dimensional network with channels. The charge compensating doubly protonated piperazine molecules occupy these channels and interact with the framework through strong hydrogen bonds. The compound shows strong anti-ferromagnetic interactions with TN∼40 K.

Hydrothermal synthesis and structure of organically templated one-dimensional and three-dimensional iron fluorophosphate

Two new open-framework iron fluorophosphates, [C(4)N(2)H(12)](0.5) [FeF(HPO(4))(H(2)PO(4))] (I) and [C(4)N(2)H(12)][Fe(4)F(2)(H(2)O)(4)(PO(4))(4)]. 0.5H(2)O (II), were synthesized hydrothermally using piperazine as a templating agent. The structures were determined by single-crystal X-ray diffraction. Compound I crystallizes in the orthorhombic space group Pbca, a = 7.2126(2) Angstrom, b = 14.2071(4) Angstrom, c = 17.1338(2) Angstrom, Z = 8. The structure is composed of infinite anionic chains of [FeF(HPO(4))(H(2)PO(4))](n)(-) built by trans-fluorine sharing FeF(2)O(4) octahedra. These chains are similar to those found in tancoite-type minerals. Compound II crystallizes in the monoclinic space group P2(1)/n, a = 9.9045(3) Angstrom, b = 12.3011(3) Angstrom, c = 17.3220(4) Angstrom, beta = 103.7010(10)degrees, Z = 4. The structure of compound II has a three-dimensional (3D) architecture with an eight-membered channel along the b axis, in which protonoted piperazine molecules reside. The complex framework is built from two types of secondary building unit (SBU): one hexamer [Fe(3)F(2)(H(2)O)(2)(PO(4))(3)] (SBU6), and one dimer [FeO(4)(H(2)O)(2)PO(4)] (SBU2). The vertex sharing between these SBUs create the 3D structure.

Synthesis, structure determination and characterization of a new layered aluminophosphate templated by piperazinium ions

The synthesis and the crystal structure of a new layered aluminophosphate templated with doubly protonated piperazine molecules are reported. The aluminophosphate has the composition (C 4N 2H 12) 4.5[Al 3P 4O 16] 3·5H 2O and crystallizes in space group P2 1/c(no. 14) with a=22.04(3), b=19.11(2), c=16.479(12) A ̊ and β=99.91(7)°. The aluminophosphate sheets contain PO 4 tetrahedra linked to three AlO 4 tetrahedra in a strictly alternating fashion, the fourth bond being a PO bond. These sheets consist of two types of chains (A and B) running along the [0 0 1] direction in the sequence AABAAB. The part of the sheets formed by chains A is identical to that already found in a layered aluminophosphate prepared with 1,2-diaminopropane. Chain B consists of phosphate-capped 6-MR units linked along the [0 0 1] direction. The connection of the different chains along [1 0 0] forms a new 4.6 net with rows of fused six rings. The inorganic sheets are separated by and hydrogen bonded to doubly protonated piperazine molecules which adopt two types of orientation. The compound was characterized by solid-state NMR and the 2D 27 Al NMR spectrum was partially assigned to the different crystallographic sites of the structure.

2:1 Complex of 4-methylphenol with piperazine, structure in the solid and solution state

The title complex has been obtained from the solution of 4-methylphenol and piperazine, and the crystal structure has been determined by X-ray diffraction analysis. The complex crystallizes in space group P-1, each piperazine molecule linking two 4-methylphenol molecules via H-bonding between the amine N atoms and the phenol hydroxyl group. 1H NMR spectra indicate that the complex formed with the aid of H-bonding exists also in the solution. The proton peaks assigned to the hydroxyl and amine groups in pure 4-methylphenol and piperazine merge into one in the title complex, which implies that the H-bond between the hydroxyl O and the amine N atoms is involved in a fast proton exchange process. The ESI-MS spectrum of the solution of the title complex also provides evidence for the existence of the 2:1 complex in the solution.

The synthesis and crystal structure of two novel 3D open-framework zinc phosphates UiO-21 and UiO-22

Two open-framework zinc phosphate materials denoted by UiO-21 and UiO-22 have been prepared by hydrothermal methods and characterised by single crystal X-ray diffraction. UiO-21, Zn 7(PO 4) 6N 6C 12H 34, crystallises in the trigonal space group R-3 (No. 148) with a=13.7249(2) Å, c=15.3316(1) Å, V=2501.13(5) Å 3 and Z=3. The structure has the zeolite topology CHA with double six-ring units stacked in an AABBCC stacking sequence. At the centre of each double six-ring unit there is a zinc atom octahedrally coordinated to six out of the 12 oxygen atoms in the unit. Each cage of the structure contains two 1-(2-aminoethyl)piperazine molecules, each of which being disordered over three positions around the trigonal axis. Each molecule is doubly protonated to compensate for the negative charge of the zinc phosphate framework. There are no hydrogen bonding interactions between the organic templates and the inorganic framework. UiO-22, Zn 4(PO 4) 3(OH)N 3C 6H 17, crystallises in the triclinic space group P-1 with a=5.2697(1) Å, b=12.1400(2) Å, c=13.9161(3) Å, α=115.439(1)°, β=98.392(1)°, γ=91.157(1)°, V=791.91(3) Å 3 and Z=2. The structure consists of vertex sharing PO 4 and ZnO 4 tetrahedra and is of the interrupted type by having terminal Zn–OH bonds and trigonally coordinated oxygen atoms. The structure can be viewed as built from columns of edge-sharing three and four rings running along [1 0 0] which interconnects into a framework exhibiting a two-dimensional eight and 12-ring channel system. Terminal OH groups are located in the staggered eight-ring channel running along [0 0 1]. In the 12-ring channel running along [1 0 0] there are highly disordered organic templates, probably 1-(2-aminoethyl)piperazine molecules that are doubly protonated in order to compensate for the negative charge of the zinc phosphate framework. The disordered nature of the organic templates in UiO-21 and UiO-22 indicates that the organic molecules play the role as space fillers in the crystallisation of these phases.

Synthesis and structural characterization of a new open-framework tin(II) phosphate: [Sn4(PO4)3]-.0.5[C4N2H12]2+.

A three-dimensional open-framework tin(II) phosphate [Sn4(PO4)3]-·0.5[C4N2H12]2+ has been synthesized under hydrothermal conditions using piperazine as the template. Its framework is built up from strictly alternating SnO3 and PO4 units that form eight-membered-ring channels along the [100] direction in which the diprotonated piperazine molecules are entrapped.

Photochemical and photobiological properties of new bispsoralen derivatives (Bis[PsCn]PIP, n = 4, 6, 8).

Bispsoralen derivatives possessing two psoralens and one piperazine molecule, 1,4-bis[n'-(8-psoralenoxy) alkyl] piperazine (Bis[PsCn]PIP, n = 4, 6, 8), show high water solubility, efficient intercalation into DNA and good photocrosslinking efficiency of DNA. Bis(PsC4)PIP shows high lethality on bacteriophage T7 and can effectively inhibit the amplification of DNA by stopping the polymerase chain reactions in a short period of irradiation time.

Vibrational spectra of the solid solution of (piperazine-pinacol) hexahydrate and polarons

Raman and infrared spectra of crystals obtained from an aqueous solution of piperazine and pinacol with an arbitrary molar ratio were observed and confirm the formation of a solid solution of (piperazine–pinacol) hexahydrate, for which the infrared and Raman bands due to piperazine molecules change as the molar fraction of piperazine, x, changes. The Raman spectra of the deuterated system with x=0.80 were also observed in the temperature range 296–25 K. One of two N–D stretches, the lower wavenumber one, increased in intensity as the temperature decreases and was assigned to polarons. It was found that the Raman intensity of the polarons is stronger in the solid solution than the parent compound, which can be qualitatively explained in terms of the difference in structure between them. © 1997 John Wiley & Sons, Ltd.

Crystal Engineering Using Trisphenols. Three-Dimensional Hydrogen-Bonding Networks in 1,1,1-Tris(4-hydroxyphenyl)ethane, its Hydrated Adduct with 1,4-Diazabicyclo[2.2.2]octane (1/1/1) and its Adduct with Piperazine (4/3)

In 1,1,1-tris(4-hydroxyphenyl)ethane, C20H18O3 (1), monoclinic la, a = 7.9781 (10), b = 18.558 (3), c = 11.1995 (13) Å, \beta–101.668 (9)°, with Z = 4, each of the hydroxyl groups acts as both a donor and an acceptor of hydrogen bonds of the type O—H...O. The molecules are thus connected into square nets, graph set R^4_4(38), pairs of which are then interwoven; the nets are themselves interconnected by further hydrogen bonds to give a continuous three-dimensional network. In 1,1,1-tris(4-hydroxyphenyl)ethane-l,4-diazabicyclo[2.2.2]octane–water (1/1/1), C20H18O3.C6H12N2.H2O (2), triclinic P\overline 1, a = 10.421 (2), b = 10.734 (2), c = 10.9756 (13) Å, \alpha = 76.645 (12), \beta 74.513 (11), \gamma = 89.305 (13)°, with Z = 2, the water molecules are linked to the trisphenol and the diamine units by O—H...O and O—H...N hydrogen bonds, respectively, to form a linear aggregate. These aggregates are linked into chains by the formation of O—H...N hydrogen bonds between the trisphenol and the neighbouring diamine; however, alongside hydrogen-bond formation between the trisphenol and the diamine, there is also partial transfer of a proton, so that the intra-chain links between trisphenol and diamine units are in fact a mixture of O—H...N and N—H...O hydrogen bonds. These chains in the [101] direction are cross-linked by further O—H...O hydrogen bonds, involving only trisphenol O atoms, which form chains in both the [010] and [001] directions, thus generating a continuous three-dimensional network. Adduct (3), 1,1,1-tris(4-hydroxyphenyl)ethane–piperazine (4/3), (C20H18O3)4.(C4H10N2)3, triclinic P\overline 1, a = 12.5049 (11), b = 12.7046 (10), c = 14.6226 (9) Å, \alpha = 113.738 (6), \beta = 100.839 (6), \gamma = 102.438 (7)°, with Z = 1, has two independent trisphenol molecules in general positions and three independent piperazine molecules lying about centres of inversion. The five independent components of the asymmetric unit are linked together by means of three O—H...N and one O—H...O hydrogen bonds to form an open aggregate containing no hydrogen-bonded rings. These aggregates are connected into three sets of interlinked chains in the [010], [001] and [\overline 110] directions: the [010] and [\overline 110] chains employ only O—H...O hydrogen bonds, while the [001] chains employ both O—H...N and N—H...O hydrogen bonds. Additionally, the inversion symmetry at each piperazine unit gives rise to further interlinks.

Small angle X-ray scattering and IR spectroscopy study of metal carbonyl complexes immobilized on a silica gel surface chemically modified with piperazine

The carbonyl complexes [WCl(CO) 3(bipy)(HgCl)] ( 1), Fe(CO) 4(HgCl) 2] ( 2 and [W(CO) 6] ( 3) were immobilized on a silica gel surface organofunctionalized with piperazine groups. The products obtained were studied by IR spectroscopy and small angle X-ray scattering (SAXS) techniques. The IR data show that the immobilization of heterobimetallic compounds 1 and 2, on the functionalized surface, occured through the mercury atom, while for 3 the displacement of one CO group by the nitrogen of a piperazine molecule was observed. The data obtained from SAXS indicate that particles have a uniform size and reveal suitable modifications on the functionalized surface after immobilization of metal carbonyl complexes. The average intermolecular distance l ij for piperazine ligands on support is 8.7 Å, for the metal carbonyl complex 1 it is 18.8 Å, for complex 2 it is 16.2 Å and for complex 3 it is 15.3 Å.

Trimethyl(1-methyl-4-phenylpiperazine-N1)aluminium

The X-ray single-crystal structure determination of the title compound, [Al(CH 3 ) 3 (C 11 H 16 N 2 )], reveals that the Al atom is four-coordinate in a distorted tetrahedral environment and is bonded to the N atom of the piperazine molecule carrying the methyl group, with an Al-N bond length of 2.050 (2)A. The piperazine ring adopts a chair conformation.

Piperazine Metavanadate

The structure of the title compound {piperazinediium poly[trioxovanadate(2-)], (C4H12N2)(VO3)2} is monoclinic, space group P21/c, and contains infinite (VO3−)n chains running parallel to the c axis. These chains form layers running parallel to the (100) plane. The protonated piperazine molecules are located between the (VO3−)n chains and form hydrogen bonds which contribute to the stabilization of the structure.

Piperazine Metavanadate Trihydrate

The structure of piperazine-1,4-diium piperazin-1-ium metavanadate trihydrate, (C 4 H 11 N 2 )(C 4 H 12 N 2 )V 3 O 9 .-3H 2 O, is orthorhombic, space group Pbca, and contains infinite (V 3 O 9 3- ) n chains running along the b axis of the unit cell. These chains form layers running parallel to the (100) plane. The protonated piperazine molecules and three molecules of water are located between the (V 3 O 9 3- ) n chains, forming hydrogen bonds which contribute to the stabilization of the structure.

Hydrogen-bonded adducts of ferrocene-1,1′-diylbis(diphenylmethanol): crystal and molecular structures of 1 : 1 adducts with 4,4′-bipyridyl, piperazine and dimethylformamide, the 2 : 1 : 1 hydrated adduct with morpholine, and two adducts with 1,4-dioxane, 1 : 1 at 150 K and 1 : 2 at 298 K

Host–guest adducts formed by ferrocene-1,1′-diylbis(diphenylmethanol)1 with oxygen- and/or nitrogen-containing guests exhibited a wide range of hydrogen-bonding patterns as determined by X-ray crystallography. The 1 : 1 adduct 2 formed with 4,4′-bipyridyl comprises a centrosymmetric hydrogen-bonded aggregate involving two molecules of the diol and one of the bipyridyl and contains intramolecular O–H ⋯ O and intermolecular O–H ⋯ N hydrogen bonds; the second molecule of the bipyridyl, also centrosymmetric, is trapped in a cavity, but is not hydrogen bonded to any other part of the structure. The structure of the 1 : 1 adduct formed with piperazine 3 is chiral and consists of infinite spiral chains, with alternating diol and piperazine molecules, which contain only O–H ⋯ N hydrogen bonds. Morpholine forms both anhydrous 4a and hydrated adducts 4b with the host diol, both having host: guest ratios of 2 : 1 : the hydrated adduct contains infinite ribbons comprising ferrocene units on the outside edges and disordered water and morpholine components in the body of the ribbon. With 1,4-dioxane a 1 : 1 5a and a 1 : 2 adduct 5b are formed. The centrosymmetric hydrogen-bonded aggregate of 5a consists of two molecules of the diol and one of dioxane and contains both intra- and inter-molecular O–H ⋯ O hydrogen bonds: the second dioxane molecule is also centrosymmetric and is trapped in a structural cavity and not bonded to the rest of the structure. Adduct 5b is isomorphous with the 1 : 2 diol : pyridine adduct. The diol component lies on a two-fold rotation axis, forming hydrogen bonds to the dioxane molecules which are highly disordered and readily lost from the structure. In the 1 : 1 complex formed with dimethylformamide 6 inter- and intra-molecular O–H ⋯ O hydrogen bonds link a finite host–guest pair, which also includes an intermolecular C–H ⋯π(arene) interaction. The hydrogen-bonding patterns are analysed and codified using a graph-set approach.

Structural studies of analgesics and their interactions. Part 4. Crystal structures of phenylbutazone and a 2 : 1 complex between phenylbutazone and piperazine

The X-ray crystal structures of 4-butyl-1,2-diphenylpyrazolidine-3,5-dione (phenylbutazone)(I). and its 2 : 1 complex (II) with piperazine have been determined by direct methods and the structures refined to R 0.096 (2 300 observed reflections measured by diffractometer) and 0.074 (2 494 observed reflections visuallyestimated). Crystals are monoclinic, space group P21/c; for (I)a= 21.695(4), b= 5.823(2), c= 27.881(4)A, β= 108.06 (10)°, Z= 8, and for (II)a= 8.048(4), b= 15.081(4), c= 15.583(7)A, β= 95.9(3)°, Z= 2. The two crystallographically independant molecules in the structure of (I) are similar except for the conformation of the butyl group, which is disordered in one of the molecules. In the pyrazolidinedione group, the two C–C bonds are single and the two C–O bonds double. The two nitrogen atoms in the five-membered ring are pyramidal with the attached phenyl groups lying on the opposite sides of the mean plane of the ring. The phenylbutazone molecule in (II) exists as a negative ion owing to deprotonation of C-4. C-4 is therefore trigonal and the orientation of the Bu group with respect to the pyrazolidinedione group is considerably different from that in (I); there is also considerable electron delocalization along the C–O and C–C bonds. These changes in geometry and electronic structure may relate to biological activity. The doubly charged cationic piperazine molecule exists in the chair form with the nitrogen atoms at the apices. The crystal structure of (II) is stabilized by ionic interactions and N–H ⋯ O hydrogen bonds.

Structure of Piperazine Hexahydrate

Piperazine hexahydrate, C4N2H10·6H2O, forms monoclinic pseudo-tetragonal and usually strongly twinned crystals, melting at 44°C. The structure has been determined using x-ray counter data obtained at room temperature. The space group is P21 / n, with Z = 2, and cell dimensions are a = 6.309, b = 6.323, and c = 14.912 Å, β = 94.96°. The hydrogen-bonded water molecules form puckered layers of almost tetragonal symmetry composed of edge-sharing pentagons, which are joined into a three-dimensional framework by hydrogen bonds to the nitrogen atoms of the piperazine molecules. The twin laws are explained as stacking faults of the water layers. The hydrogen atoms are disordered within the water layers and ordered between the oxygen and nitrogen atoms. The bond lengths and angles of the piperazine molecule are normal. The structure is related to the clathrate hydrate structures because of the pentagonal geometry of the water structure.