Structure of a Cu(II)-containing peptide,diaquo-gly-l-tyr Cu(II) dihydrate, [Cu(C11N2O4H13)(H2O)2·2H2O

The structure of the Cu(II) complex of gly-l-tyr [Cu(C₁₁N₂O₄H₁₃) (H₂O)₂]·2H₂O has been solved by X-ray diffraction methods. The compound crystallizes in the orthorhombic space groupP2₁2₁2₁ witha=11.970(2) Å,b=12.485(2) Å andc=10.418(3) Å, respectively, (MoK)=0.710 Å,D _c =1.59 Mgm^–3,D _m =1.59 Mgm^–3, finalR=0.04. The structure was solved by heavy atom (Cu) phased Fourier and refined by full-matrix least squares methods. The coordination geometry of the ligand around the Cu(II) ion has been established as a distorted tetragonal pyramid. The peptide molecule behaves as a tridentate ligand via its amino (N2), amido (N1) nitrogens and carboxyl (O2) oxygens. The peptide nitrogen is found to be deprotonated.     

Crystal structure of aqua[S-prolinato-N-monoacetato)copper(II) dihydrate [Cu(Proma)H2O] ⋅ 2H2O

The crystal structure of [Cu(C₇H₉NO₄)H₂O] ? 2H₂O is determined by X-ray diffraction (λMo, R = 0.0316 for 857 reflections). The crystals are tetragonal, a = 8.219(1) Å, c = 17.449(3) Å, Z = 4, ρ_calcd = 1.627 g cm^?3, and space group P4₃. The coordination polyhedron of the Cu atom is a tetragonal pyramid with the O atom of the acetate arm of the prolinatomonoacetate ion (Proma) in the apical position [Cu-O 2.312(6) Å]. The O atom of the water molecule and the N and O atoms of the prolinate group of the Proma ligand lie in the basal plane. The Cu-N bond length is 2.044(6) Å, and the Cu-O bond lengths are 1.932(7) and 1.927(6) Å. The O atom of the acetate arm of the neighboring Proma ion completes the basal plane [Cu-O 1.951(6) Å], thus linking the copper complexes into infinite chains.     

Crystal and molecular structure of four copper(II) ethylenediaminedisuccinates, [Cu2(RR,SS-Edds)] · 6H2O, Ba2[Cu(RR,SS-Edds)](ClO4)2 · 8H2O, Ba[Cu(SS-HEdds)]ClO4 · 2H2O, and Ba3[Cu2(RR,SS-Edds)2](ClO4)2 · 6H2O

Four Cu(II) complexes with the RR,SS-Edds ^4? and SS-HEdds ^3? anions are synthesized, and their crystal structures are studied. In the compounds [Cu2(RR,SS-Edds)] · 6H₂O (I) and Ba2[Cu(RR,SS-Edds)](ClO₄)₂ · 8H₂O (II), the ligand forms hexacoordinate chelate [Cu(Edds)]^2? complexes with the N atoms and O atoms of the propionate groups in the equatorial positions and the O atoms of the acetate groups in the axial vertices. In the compounds Ba[Cu(SS-HEdds)]ClO₄ · 2H₂O (III) and Ba3[Cu2(RR,SS-Edds)₂](ClO₄)₂ · 6H₂O (IV), one of the propionate arms, the protonated arm in III and the deprotonated arm in IV, does not enter into the coordination sphere of the Cu atom. An acetate arm moves to its position in the equatorial plane, and the free axial vertex is occupied by an O atom of the perchlorate ion. In I–IV, the lengths of the equatorial Cu-N and Cu-O bonds fall in the ranges 1.970–2.014 and 1.921–1.970 Å, respectively. The axial Cu-O bonds with the acetate groups and ClO ₄ ^? anions are elongated to 2.293–2.500 and 2.727–2.992 Å, respectively. In structure I, the second Cu atom acts as a counterion forming bonds with the O atoms of two water molecules and three O atoms of the Edds ligands. In II–IV, the Ba²⁺ cations are hydrated and bound to the O atoms of the anionic complexes and (except for one of the cations in IV) ClO ₄ ^? anions. The coordination number of the Ba cations is nine. The structural units in I–IV are connected into layers. In I, an extended system of hydrogen bonds links the layers into a framework. In II and III, the layers are linked only by weak hydrogen bonds, one bond per structural unit. In IV, ClO ₄ ^? anions are bound to the Ba and Cu atoms of neighboring layers, thus serving as bridges between the layers.     

Structure and conformation of the monohydrate of N-t-boctyrosyl-proline (Boc-Tyr-Pro·H2O)

The structure and conformation of the monohydrate of N-t-boc-tyrosyl-proline (Boc-Tyr-Pro·H₂O) (C₁₉H₂₆O₆N₂·H₂O) has been investigated with X-ray crystallographic and spectroscopic methods. Boc-Tyr-Pro crystallized in an extendedtrans conformation in the space group P2₁2₁2₁ with cell dimensionsa=8.566(1),b=9.996(1),c=24.734(1). The conformation of Boc-Tyr-Pro reflex -helix type prolines. Three intermolecular hydrogen bonds are observed. Crystal water is involved in two hydrogen bonds (to the hydroxyl group of the C-terminal of the proline residue; to the carbonyl group of the t-Boc functionality) while the hydroxyl group of the tyrosyl residue (to the carbonyl group of the amide bond) is involved in one hydrogen bond. The puckering mode of the pyrrolidine ring of the proline residue is similar to what has been previously observed for other proline-containing peptides.Cis-trans isomerism is observed in the NMR spectra of Boc-Tyr-Pro with a predominance for the extended side chain for the tyrosyl residue.     

Synthesis, crystal structure, and thermal analyses of triaqua-(1,10-phenanthroline-N,N′) succinatomanganese(II) dihydrate, [Mn(H2O)3(phen)(C4H4O4)]·2H2O

[Mn(H₂O)₃(phen)(C₄H₄O₄)]·2H₂O was obtained by reaction of freshly prepared MnCO₃, phen and succinic acid in CH₃OH/H₂O (1:1 v/v), and its crystal structure has been determined by single crystal X-ray diffraction methods. The title mixed ligand complex crystallizes in the triclinic space group with cell dimensions a = 7.590(1) Å, b = 9.324(1) Å, c = 13.917(1) Å, = 85.64(1)°, = 74.56(1)°, = 77.10(1)°, and D _calc = 1.584 g/cm³ for Z = 2. The crystal structure consists of the [Mn(H₂O)₃(phen)(C₄H₄O₄)] complex molecules and lattice H₂O molecules. The Mn atoms are each octahedrally coordinated by two N atoms of one phen ligand and four O atoms of three H₂O molecules and one succinato ligand with d(Mn—N) = 2.271 and 2.299 Å, and d(Mn—O) = 2.133–2.239 Å. Through intermolecular hydrogen bondings, the complex molecules are interlinked to form 2D layers, which are assembled by – stacking interactions into 3D framework with tunnels occupied by the lattice H₂O molecules. Thermal analyses showed that the title compound decomposes in two steps over the range 25–600°C upon heating in flowing Ar.     

The Crystal Structure and Magnetic Susceptibility of Tetrakis-(μ2-phenylacetato-O,O′)-bis(caprolactam-O)copper(II)

Abstract  

Tetrakis-(μ₂-phenylacetato-O,O′)-bis(caprolactam-O)copper(II) (1) was synthesized and characterized by X-ray crystallography, magnetic susceptibility and FT-IR spectroscopy. The title compound (1) crystallized in the monoclinic space group P2₁/n with unit cell parameters a = 18.2242(4) ?, b = 10.0994(2) ?, c = 23.0696(5) ?, β = 101.117(2)°; V = 4166.37(15) ?³; Z = 4. The molecular structure of (1) consists of a copper dimer bridged by four phenylacetate ligands in the paddlewheel geometry with caprolactam coordinated in both axial sites. The copper dimers of (1) are organized into one-dimensional columns by N–H···O interactions between bound caprolactam ligands. Magnetic susceptibility studies indicate antiferromagnetic coupling between the Cu⁺² ions with a singlet ground-state and triplet excited-state separated by |2J = 319(1) cm⁻¹ |.     

Crystal and molecular structure of bis(o-phenylenethiourea)selenium(II)chloride dihydrate,C14H12N4S2Cl2Se·2H2O

The synthesis and crystal structure ofbis(o-phenylenethiourea)selenium(II)-chloride dihydrate, Se(C₇H₆N₂S)₂Cl₂·2H₂O are reported. The compound crystallizes in the monoclinic space group, P2₁/n, with four molecules per unit cell, the dimensions of which area=10.243(3),b=13.341(4),c=14.273(4) Å,=93.00(3)°,U=1947.76 ų. The structure was solved by direct methods and refined by full-matrix least-squares toR=0.039 andR _w =0.040 for 3314 unique reflections. Selenium displays two strong coordinations arising from the two sulfurs, Se-S(1)=2.191(1), Se-S(2)=2.206(1) Å, and S(1)-Se-S(2)=101.0(1)°, and four secondary interactions involving three chlorines and one sulfur. The complex occurs as a dimer with two sets of very weakly interacting bridging pairs S(2), S(2)^a; and Cl(2), Cl(2)^a, where a denotes the inversion related atom. Lattice stabilization is ensured by the extensive network of hydrogen bonds involving chlorines, water oxygens, and nitrogens of phenylenethiourea ligands.     

Crystal structure of aminoguanidinium hexahydro-closo-hexaborate dihydrate, (CN4H7)2B6H6 · 2H2O

The (HAgu)₂B₆H₆ · 2H₂O compound was synthesized and its crystal structure was determined [R = 0.0385 for 2018 reflections with I > 2σ(I)]. The structure consists of HAgu ⁺ cations, centrosymmetric B₆H ₆ ^2? anions, and water molecules. The anions have an almost regular octahedral structure. The bond lengths and angles lie within the following narrow ranges: B-B, 1.715–1.726(2) Å; B-H, 1.08–1.14(2) Å; B-B-B, 59.72°–60.29(9)° and 89.63°–90.20(11)°; and B-B-H, 133.2°–137.0(9)°. The HAgu ⁺ cations and water molecules are involved in the O-H?O, N-H?O, and N-N?N hydrogen bonds and participate in numerous (N, O)-H?H-B specific interactions with the B₆H ₆ ^2? anions, which results in splitting and high-frequency shift of the band of B-H stretching vibrations in the IR spectrum.     

Structure,bonding, and magnetic behavior of bis(μ-chloro)-and (μ-bromo)-bridged Cu(II) dimers

It has been previously reported that dimeric compounds of the general formula [L₃Cu(II)]₂(-Cl)₂ exhibit a correlation between their magnetic coupling constantJ and the bridging Cu-Cl-Cu angle. A full survey of the published structural and magnetic data on these compounds confirms this correlation but leads to the conclusion that its physical significance is questionable. EHMO calculations on Cu₂Cl ₈ ^4– and its bromo analog show that the molecular orbitals responsible for the magnetic behavior of the dimers are not the orbitals responsible for the bonding interactions in these dimers. Therefore, they are very weakly affected by variations of the molecular structure, and no significant correlation betweenJ and any of the structural parameters is theoretically predicted. However, this situation changes when the coordination around the Cu atoms is strongly and dissymmetrically pyramidalized.     

Growth,Properties, and Structure of Cadmium Sulfamate Cd(NH2SO3)2 · 2H2O

Crystallography Reports - The temperature dependence of the solubility of Cd(NH2SO3)2 compound in the range from 25 to 80°C has been determined. It is found that Cd(NH2SO3)2 · 2H2O and...     

Crystal structure of dicesium thorium trisulfate dihydrate,Cs2Th(SO4)3·2H2O

Dicesium Di--sulfatosulphatobisaquothorate(IV), H₄O₁₄S₃Cs₂Th, (M _r =821.8) crystallized from water in the monoclinic space groupP2₁/c (No. 14), witha=6.415(2),b=15.95(1),c=13.078(8) Å,=90.88(4)°,V=1338(14) ų,Z=4,D _x =4.08 g cm^–3, MoK (=0.71069 Å),=195.8 cm^–1,F(000)=1407.3, room temperature, finalR=0.086 for 1699 unique observed reflexions. Two of the sulfate groups are tridentate (chelating and bridging) and the other is bidentate chelating. As the waters are both coordinated the thorium is 10-coordinate. It shows an unusual 2/4/2/2 geometry.     

Synthesis and crystal structure of [Cu(azpy)(H2O)4][Cu2(nta)2(azpy)]····6H2O: A two-dimensional network solid

The copper(II) complex [Cu(azpy)(H₂O)₄][Cu₂(nta)₂(azpy)]····6H₂O (nta = nitrilotriacetate, azpy = 4,4-azobispyridine) has been synthesized and structurally characterized. It crystallizes in the triclinic space group P , a = 8.6985(3) Å, b = 9.4776(3) Å, c = 14.6544(5) Å, = 71.5360(10)°, = 85.7600(10)°, = 88.1420(10)°, V = 1142.74(7) ų, Z = 1. The crystal structure consists of one-dimensional linear chain cations and dimeric anions. The copper centers in the anion possess distorted trigonal bipyramidal geometry, while Cu(2) has a distorted octahedral geometry in the cation. Coordinated water molecules in the one-dimensional chain form interionic hydrogen bonds with the oxygen atoms of the carboxylate of nta of the dimmer anion. These hydrogen bonds result in the formation of a two-dimensional network.     

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.      

Crystal structure of tetrabutylammonium nitroprusside dihydrate, [(C4H9)4N]2[Fe(CN)5NO]·2H2O, and vibrational spectra of ground and metastable excited states of the dihydrate and the anhydrate

The crystal structure of tetrabutylammonium nitroprusside dihydrate (TBANPDH, [(C₄H₉)₄N]₂[Fe(CN)₅NO]·2H₂O) was determined by single crystal X-ray diffraction (XRD) and the compound was also studied, as well as the anhydrous salt (TBANP), by room and low temperature Fourier Transform Infra-Red (FTIR) and room temperature Fourier Transform Near Infra-Red Raman (FTNIRR) spectroscopies. In addition to the ground states (GS), the metastable excited states (MSI and MSII) generated by laser excitation (488 nm) at low temperature were IR studied, both of the dihydrate and the anhydrate. TBANPDH crystallizes in the trigonal space group P3₂21, D ⁶ ₃, with a = b = 13.777(2), c = 22.039(2) Å, and Z = 3. The structure was solved employing 1273 independent XR reflections, with I > 2(I), by Patterson and Fourier methods and refined by full-matrix least-squares to R1 = 0.054.     

Synthesis and structure of [(nitrito-O,O′) bis(di-2-pyridylamine)copper(II)] nitrite

The synthesis and molecular structure of the title compound, [(nitrito-O,O) (dpa)₂Cu(II)] (NO₂), 1, is reported. Compound 1 crystallized in the orthorhombic space group Pccn with a = 11.397(5) Å, b = 12.256(6) Å, c = 14.876(8) Å, and V = 2077.9(17) ų with Z = 4. The distorted octahedral copper(II) cations are linked through a hydrogen-bonded polymer network. The polymer network is formed through the amine N–H of the cations and hydrogen bonded to the N–HO nitrite anions.     

Crystal structure of triaquamaleatostrontium(II) monohydrate, [Sr(C4H2O4)(OH2)3]·H2O

[Sr(C₄H₂O₄)(OH₂)₃]·H₂O is monoclinic, P2₁/n, witha=11.476(2),b=7.027(1),c=12.344(2) Å, =115.74(3)°,V=896.67 ų,Z=4. The Sr atom is surrounded by nine oxygen atoms which come from four different maleate anions and three water molecules. The Sr–O distances range from 2.546(2) to 2.808(2) Å. The C–O distances are equal within the standard deviation 1.263(3) to 1.258(3) Å). In the maleate anion, the planes that contain the carboxylate groups form an angle of 74.44(9)°. Both carboxylate groups deviate significantly from planarity. The different coordination modes of the carboxylate group and the extensive hydrogen bonding present are responsible for the polymeric nature of the structure.     

Crystal structure and magnetic properties of bis(2,2′-bipyridine) azido copper(II) perchlorate

The title compound has been synthesized and its crystal structure has been solved at room temperature. It crystallizes in the triclinic system, space groupP, witha=7.853(1) Å,b=10.177(1) Å,c=13.651(4) Å,=74.57(1)°,=88.49(1)°, =80.675(4)°, andZ=2. The structure consists of isolated [Cu(bipy)₂N₃]⁺ cations (bipy=2,2-bipyridine) and perchlorate anions. The metallic cation environment has a distorted trigonal-bipyramidal geometry. The EPR spectrum is rhombic, which indicates that the distortion with respect to the perfect trigonal bipyramid is sufficiently pronounced to mixz ²- andx ²–y ²-type orbitals in the ground state. The temperature dependence of the molar magnetic susceptibility has been investigated in the 300-2.2 K temperature range.     

C–H···F Hydrogen-Bonded Assembly of Ni(II) and Cu(II) Complexes Generate 3D Supramolecular Frameworks

Abstract  Syntheses and X-ray structural characterizations of two new complexes [Ni(imi)₆](pfbz)₂ (1) and Cu(imi)₂(pfbz)₂ (2) (imi = imidazole, pfbz = pentafluorobenzoate) are reported. The first complex crystallizes in the triclinic space group P-1 with the crystal cell parameters a = 9.180(2) ?, b = 9.742(3) ?, c = 11.466(3) ?, α = 76.947(18)°, β = 80.629(18)°, γ = 78.043(19)°, V = 970.0(4) ?³ and Z = 1. The second complex crystallizes in the triclinic space group P-1 with the crystal cell parameters a = 7.3250(12) ?, b = 7.6685(10) ?, c = 10.888(4) ?, α = 92.80(2)°, β = 101.92(2)°, γ = 115.038(12)°, V = 535.7(2) ?³ and Z = 1. Examination of the structures shows that both complexes form three-dimensional hydrogen bonded networks in which C–H···F hydrogen bonds play significant roles. Index Abstract   C–H···F Hydrogen-Bonded Assembly of Ni(II) and Cu(II) Complexes Generate 3D Supramolecular Frameworks Chun-Hua Ge, Xiao-Yan Zhang, Fang Yu, Ya-Nan Guo, Xiang-Dong Zhang* and Qi-Tao Liu C–H···F interactions link simple complexes to form intricate three-dimensional supramolecular networks.      

4-Methoxypyridine-(pyridine-2,6-dicarboxylato-N,O,O′) copper(II)

The synthesis and X-ray crystal structure of [Cu(C₇H₃NO₄)(C₆H₇NO)], [Cu(dipic)(4-MeO-Py)], (dipic = pyridine-2,6-dicarboxylate, 4-MeO-Py = 4-methoxypyridine), is described. Molecules of [Cu(dipic)(4-MeO-Py)] are formed {via} coordination of the copper(II) cation to two nitrogen atoms, from the dipic and 4-MeO-Py ligands respectively, and to two oxygen atoms from the carboxylate groups of the dipic ligand. The molecules pack in a non-centrosymmetric manner, stacked eclipsed with respect to one another along the b-axis and aligned parallel in a head-to-tail motif. The title compound crystallizes in the orthorhombic space group, Pca2(1), with a = 27.339(3) Å, b = 3.7130(4) Å, c = 11.6859(12) Å, V = 1186.2(2) ų, and Z = 4. The structure was solved by direct methods and refined by least-squares methods to a final R-factor of 0.0327 for 2648 independent reflections.