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 of strontium aqua(ethylenediaminetetraacetato)cobaltate(II) tetrahydrate Sr[CoEdta(H2O)] · 4H2O

The complex Sr[Co^II Edta] · 5H₂O (I) (where Edta ^4? is the ethylenediaminetetraacetate ion) has been synthesized. The crystal structure of this compound is determined by X-ray diffraction. Crystals are monoclinic, a = 7.906(2) Å, b = 12.768(2) Å, c = 18.254(3) Å, β = 95.30(3)°, V = 1834.8 ų, space group P2₁/n, Z = 4, and R = 0.036. The structure is built up of the binuclear complex fragments {Sr(H₂O)₃[CoEdta(H₂O)]}, which consist of the anionic [CoEdta(H₂O)]^2? and cationic [Sr(H₂O)₃]²⁺ units linked by the Sr-O bonds into a three-dimensional framework. The coordination polyhedra of the Co and Sr atoms are mono-and bicapped trigonal prisms. The coordination sphere of the Co atom (the coordination number is equal to 6 + 1) involves six donor atoms (2N and 4O) of the Edta ^4? ligand and the O_w atom of water molecule. One of the Co-O distances (2.718 Å) is considerably longer than the other Co-O_lig distances (2.092–2.190 Å) and the Co-O_w(1) distance (2.079 Å). The Sr coordination polyhedron (the coordination number is eight) contains three water molecules, three carbonyl O atoms of the three different anionic complexes, and two O atoms of one acetate group of the fourth anionic complex. The Sr-O distances fall in the range 2.535–2.674 Å. The structural formula of the compound is {Sr(H₂O)₃[CoEdta(H₂O)]}_3∞ · H₂O.     

Crystal structures of acid ethylenediaminetetraacetates [Cd(H2 Edta)(H2O)] · 2H2O and [Mn(H2O)4][Mn(HEdta)(H2O)]2 · 4H2O

The crystal structures of [Cd(H₂ Edta)(H₂O)] · 2H₂O (I) and [Mn(H₂O)₄][Mn(HEdta)(H₂O)]₂ · 4H₂O (II) are studied by X-ray diffraction [R ₁ = 0.0209 (0.0272), wR ₂ = 0.0571 (0.0730) for 2551 (4025) reflections with I > 2σ(I) in I (II), respectively]. Structure I contains mononuclear [Cd(H₂ Edta)(H₂O)] complexes with the C ₂ symmetry, and structure II contains centrosymmetric trinuclear [Mn(H₂O)₄][Mn(HEdta)(H₂O)]₂ complexes. In I and II, the protonated ligands are hexadentate (2N + 4O), and the water molecule increases the coordination number of the metal atom to seven. The acid protons participate in short intermolecular hydrogen bonds, which are symmetric in II and asymmetric in I.     

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 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.     

Interferometric study of the growth kinetics of K2Co(SO4)2 · 6H2O and K2Ni(SO4)2 · 6H2O crystals

Crystallography Reports - The growth kinetics of the (001) and (110) faces of K2Co(SO4)2 · 6H2O and K2Ni(SO4)2 · 6H2O crystals in the kinetic mode has been in situ investigated for the...     

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.     

Crystal structure and nonlinear optical properties of the K2UO2(SO4)2 · 2H2O compound at 293 K

Single crystals of potassium uranyl sulfate are grown, and their atomic structure is determined using X-ray diffraction analysis. The compound crystallizes in the orthorhombic crystal system with space group Pna2₁ [a = 13.773(4) Å, b = 7.288(2) Å, c = 11.556(4) Å, R ₁ = 0.033, wR ₂ = 0.0892 for 2630 reflections with I > 2σ(I)]. The crystal structure of the K₂UO₂(SO₄)₂ · 2H₂O compound is built up of two-dimensional infinite, negatively charged layers of the composition [UO₂(SO₄)₂·H₂O] _2∞ ^δ? ], which are linked together through the K⁺ ions. The specific features of the atomic arrangement in the structure of this compound are analyzed, and the second harmonic generation of laser radiation is investigated.     

Crystal structure of Zn4Na(OH)6SO4Cl·6H2O

The structure of Zn₄Na(OH)₆SO₄Cl·6H₂O, a secondary mineral from Hettstedt, Germany, was determined by single-crystal X-ray diffraction. The crystals are hexagonal,a=8.413(8),c=13.095(24) Å, space group $P\bar 3$ , Z=2. The structure was refined to R=0.0554 and R_w=0.0903 for 970 reflections with I≥3σ(I). The structure can be described as zinc hydroxide layers perpendicular toc, from which sulfates and chlorides extend. The layers are held together by a system of hydrogen bonds involving hexaaquo Na⁺ ions which occupy the interlayer space.     

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.     

Synthesis and structure of (H2O·HBF4)2(18-crown-6)

The title compound has been prepared by the addition of fluoroboric acid to 18-crown-6 in toluene. The compound crystallizes in the triclinic space group P¯1 witha=7.341(2),b=8.364(2),c=10.631(3)Å,=71.48(2),=67.91(2), =67.94(2)°, andD _c =1.44 g cm^–3 forZ=1. The final conventionalR value was 0.079 based on 1575 observed reflections. The molecule resides on a center of inversion. The (H₂O·HBF₄) moieties are best viewed as fluoroboric acid monohydrate molecules hydrogen bonded to the crown ether, one above and one below the plane of the crown. The FO(water) hydrogen bond separation is 2.474(5)Å, and the O(crown)O(water) separations are 2.834(5) and 2.841(6) Å. The oxygen atoms of the crown ether are planar to 0.23 Å.     

Synthesis and structure of (NH4)3[UO2(C3H2O4)2(NCS)] · 2H2O

Malonate-thiocyanate complex (NH₄)₃[UO₂(C₃H₂O₄)₂(NCS)] · 2H₂O is synthesized and studied by X-ray diffraction. The compound crystallizes in the monoclinic system: a = 13.9983(4) Å, b = 8.1947(2) Å, c = 16.4678(4) Å, β = 100.846(1)°, space group Cc, Z = 4, and R = 0.0158. The main structural units of the crystal are mononuclear [UO₂(C₃H₂O₄)₂(NCS)]^3? groups belonging to the AB ₂ ⁰¹ M ₁ crystal chemical group of uranyl complexes (A = UO ₂ ²⁺ , B ⁰¹ = C₃H₂O ₄ ^2? , M ¹ = NCS^?). Discrete uranium-containing groups are connected by electrostatic interactions with ammonium ions and by hydrogen bonds. Some specific structural features of crystals containing [UO₂(L)₂(NCS)]^3? complexes, where L is the oxalate or malonate ion, are discussed.     

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 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 neptunium(V) sulfate hexahydrate, (NpO2)2SO4 · 6H2O

Single crystals of (NpO₂)₂SO₄ · 6H₂O are obtained, and their structure is determined. The structure is built of NpO ₂ ⁺ dioxo cations, SO ₄ ^2? anions, and molecules of coordination and crystallization water. The NpO ₂ ⁺ ions are linked into cationic ribbons stretched along the [001] direction. In the ribbons, neptunoyl ions of one type act as monodentate ligands, whereas neptunoyl ions of the other type coordinate the neighboring neptunoyl groups by two oxygen atoms. The Np(1) and Np(2) atoms have oxygen environments in the shape of a pentagonal bipyramid whose equatorial plane consists of oxygen atoms of the neighboring dioxo cations, sulfate ions, and water molecules. The sulfate ion acts as a bidentate ligand bridging the two neighboring atoms Np(1) and Np(2). Six water molecules are revealed in the structure; one of them is a crystallization water molecule. Hydrogen bonds link cationic ribbons into a three-dimensional network.     

Peculiarities of the micromorphology of the CaC2O4 · H2O crystal faces

Crystallography Reports - Peculiarities of the faceted microrelief formed during the growth of CaC2O4 · H2O calcium oxalate monohydrate (whewellite) crystals are investigated to gain insight...     

Metal-hydroxycarboxylate interactions: syntheses and structures of K2[VO2(C6H6O7)]2·4H2O and (NH4)2[VO2(C6H6O7)]2·2H2O

Potassium and ammonium dimeric (citrato)dioxovanadium(V) hydrate K₂[VO₂(H₂cit)]₂·4H₂O1 and (NH₄)₂[VO₂(H₂cit)]₂·2H₂O2 (H₄cit=citric acid) have been prepared and characterized by X-ray structure analyses. Vanadate1 crystallizes in the monoclinic space groupP2₁/n (No. 14) with unit cell parameters:a=9.304(2),b=11.756(2),c=11.911(2)Å, =111.72(3)°, andD _c=1.911 g/cm³,Z=2; Vanadate2 also crystallizes in the monoclinic space groupP2₁/n with unit cell parameters:a=9.719(2),b=11.111(3),c=11.294(2)Å, =109.03(2)°, andD _c=1.781 g/cm³,Z=2. Each dimer contains a centro-symmetric planar four-member V₂O₂ ring with two exocyclic citrate entities coordinated by the oxygen atoms of the hydroxy-and -carboxylate ligands, while the other two -carboxylate groups remain uncomplexed. Principal dimensions of the V–O bonds are 1.986(4)_av (hydroxy) and 1.980(3)Å(-carboxyl) for vanadate1, 1.988(2)_av (hydroxy) and 1.974(3)Å(-carboxyl) for vanadate2.     

Crystal and molecular structure of β-resorcylidene aminoguanidine copper(II) complex

The tridentate Schiff base, -resorcylidene aminoguanidine (RAG)1 was synthesized from 2,4-dihydroxybenzaldehyde and aminoguanidine and complexed with copper(II) to form a copper(II)--resorcylidene aminoguanidine (Cu-RAG)2 complex. X-ray diffraction analysis of compound2 (orthorhombic, Pnma,a=11.674(1);b=6.7198(7);c=17.836(2) ) revealed a square-planar copper(II) cation with a tridentate·ligand bound through two nitrogen atoms (N1 and N3) of the aminoguanidine moiety and an oxygen (O1) of the monodeprotonated dihydroxybenzaldehyde function. The remaining coordination site was occupied by chloride and the structure was rigidly planar as demanded by the restrictions of the crystallographic space group. The unit cell contents exhibited an extended sheet-like structure constructed via hydrogen bonds both intermolecularly and involving two water molecules (O3 and O4) also restricted by the same mirror symmetry. The remaining water (O5) provided for interlayer hydrogen bonding.