Crystal and Molecular Structure of Di-μ-phenoxido-bis-[N-{(2-hydroxybenzyl)-(S)-alaninato-κ3-O,O',N}copper(II)]. A Simple Homodimetallic Model for N-terminal Tyrosine Coordination with (S)-Alanine as a Second Amino Acid Residue

1998 ◽  
Vol 63 (3) ◽  
pp. 356-362 ◽  
Author(s):  
Svetlana Pakhomova ◽  
Jan Ondráček ◽  
František Jursík

Single-crystal X-ray diffraction study established the dimeric [Cu2(ohb-(S)-Ala)2] structure (ohb-(S)-Ala = N-(2-hydroxybenzyl-(S)-alaninate). The complex crystallizes in the tetragonal space group P43212 with a = b = 8.849(1) Å, c = 24.913(2) Å, V = 1950.8(3) Å3, Z = 8. The Cu(II) ion has distorted square-pyramidal geometry with the equatorial positions occupied by three oxygen and one nitrogen atom. Each copper atom is weakly coordinated at the apical position by carbonyl oxygen atom of the neighbouring molecule at the distance 2.329(2) Å. The Cu-Cu separation 3.0204(7) Å and the Cu-O3-Cu angle 100.8(1)° lead to antiferromagnetic coupling (at room temperature μeff = 1.35 μB). The O1-Cu-O3 angle (154.9(1)°) indicates distortion of the square pyramid toward a trigonal bipyramid (t = 0.23).

2020 ◽  
Vol 42 (6) ◽  
pp. 928-928
Author(s):  
Fouzia Chang Fouzia Chang ◽  
Najma Memon Najma Memon ◽  
Shahabuddin Memon Shahabuddin Memon ◽  
Muhammad Naeem Ahmed Muhammad Naeem Ahmed ◽  
Muhammad Nawaz Tahir Muhammad Nawaz Tahir ◽  
...  

A novel Poly [bis-and#181;-3,5-dinitro-2-oxidobenzoato) (py) Cu II]/(C12H7CuN3O7) was synthesized by a self assemble method at room temperature. The molecular structure was determined by single-crystal X-ray analysis. The compound crystallizes in the monoclinic system, space group P 2 1/c with lattice parameters of a = 10.2143, b = 5.1651 and c = 26.608, α = 90, β = 99.720, γ = 90, Z = 4, V = 1383.60 (18) and#197;3.Pore size depicted from single crystal XRD data was 47and#197;. The central metal atom Cu (II) is coordinated with oxygen of carboxylates group and nitrogen atom of pyridine. The coordination polyhedron posses square pyramidal geometry is manifested by the N— Cu—O angle of 90o. The structure is composed of monomeric coordination units with the central copper (II) ion is not occupying a centre of symmetry.


1984 ◽  
Vol 39 (2) ◽  
pp. 145-148 ◽  
Author(s):  
Ulf Thewalt ◽  
Konrad Holl

The compound S2N2 • 2AlBr3 has been prepared by reaction of S4N4 with AlBr3 in 1,2-dibromoethane at room temperature. Its crystal and molecular structure have been determined by X-ray diffraction; R = 0.068. Crystal data: monoclinic, P 21/n, a = 9.594(5), b = 9.975(4), c = 7.528(4) Å , β = 111.36(5)°. The S2N2 ring of the centrosymmetrical complex is bonded via its nitrogen atoms to two AlBr3 units thus completing coordination tetrahedra around the Al atoms. Bond distances and angles within the S2N2 ring are d(S-N) = 1.629(13) and 1.651(13) Å, ∢ (S-N-S) = 95.8, and ∢ (N-S-N) - 84.2°. Whereas the S-N bond lengths agree closely with those of free S2N2, the angle at N is enlarged by ca. 5° and the angle at S is decreased by ca. 5°. The sulfur atoms form two close S···Br contacts of length 3.149 (intramolecular) and 3.193 (intermolecular) Å , respectively. The intermolecular attractive nonbonded S···Br interactions tie the complexes together in a way that leads to infinite chains which run parallel to the crystallographic z axis


1986 ◽  
Vol 39 (5) ◽  
pp. 813 ◽  
Author(s):  
ERT Tiekink ◽  
G Winter

The crystal and molecular structure of the 1:1 adduct formed between bis (O- ethylxanthato )nickel(II) and triphenylphosphine is reported. The nickel atom is five-coordinate in a distorted square-pyramidal geometry with a sulfur atom, from an asymmetrically coordinating xanthate ligand , in the apical position. Crystals are triclinic, space group Pī, a 10.265(4), b 14.718(5), c 8.818(4) Ǻ, α 100.77(3), β 92.16(4), γ 89.56(3)° with Z 2. The structure was refined by a least-squares method; R 0.068 for 3301 reflections with I ≥ 3.0σ(I).


1989 ◽  
Vol 44 (1) ◽  
pp. 5-8
Author(s):  
Michel Mégnamisi-Bélombé

Abstract trans-Dichloro(ethanedial-dioximato)(ethanediaI-dioxime)rhodium (III), RhCl2(GH)(GH2), has been synthesized and its structure determined by single crystal X-ray diffraction at room temperature. C4H7Cl2N4O4Rh, Mr = 348.94. monoclinic space group P21/ɑ; a = 10.543(3), b = 8.363(2), c = 11.512(3)Å ; β = 92.79(2)°; V = 1024Å3; Z = 4; Dc = 2.26 Mg m-3. Final Rw = 0.075 for 2035 reflections and 139 parameters. The coordination geometry around Rh is a dis­torted (4+2) octahedron, with four chelating N atoms lying in the equatorial plane and the two Cl atoms in the apical positions. The H atoms of the oxime groups are involved in relatively weak intramolecular O-H-O bridgings, as well as in very strong intermolecular bridgings which extend throughout the crystal structure and propagate nearly parallel to the [101] crystallographic direction.


1982 ◽  
Vol 37 (10) ◽  
pp. 1230-1233 ◽  
Author(s):  
Günter Schmid ◽  
Roland Boese ◽  
Dieter Bläser

Abstract Tris(dimethylamino)borane, X-ray The crystal and molecular structure of tris(dimethylamino)borane, a liquid at room temperature, has been determined by single-crystal X-ray diffraction methods at - 116°C. The single-crystal growth was accomplished by means of a miniature zone melting process on the diffractometer. The structure data are compared with those of other aminoboranes.


2011 ◽  
Vol 66 (7) ◽  
pp. 752-754
Author(s):  
Oscar E. Piro ◽  
Gustavo A. Echeverría ◽  
Gabriel Arrambide ◽  
Dinorah Gambino ◽  
Enrique J. Baran

The crystal and molecular structure of the [VO(DLmeth)( NH2O)2]・H2O complex has been determined by X-ray diffraction methods (monoclinic, P21/c with a = 5.8138(2), b = 27.3496(8), c = 7.5663(2) A° , β = 103.059(3)◦, and Z = 4). The vanadium(V) cation is in a pentagonal bipyramidal environment axially coordinated to the oxo group and equatorially to two hydroxylamido groups in a side-on fashion. The fifth equatorial binding site and the other apical position are occupied by an N and an O atom, respectively, from the methioninate anion acting as a bidentate ligand.


2011 ◽  
Vol 34 (5-6) ◽  
pp. 127-130 ◽  
Author(s):  
Yaya Sow ◽  
Libasse Diop ◽  
Kieran C. Molloy ◽  
Gabrielle Kociok-Köhn

Abstract The title compounds [R2NH2][C2O4SnMe3](R=i-Bu, Cy), in which tin atoms adopt a distorted trigonal bipyramidal configuration, have been prepared and submitted to an X-ray diffraction study. These compounds have been obtained from the reaction of (Cy2NH2)2C2O4·H2O or (i-Bu2NH2)2C2O4 with SnMe3Cl. In both [R2NH2][C2O4SnMe3] compounds, the trans complex has an almost regular trigonal bipyramidal geometry around the tin atom. The SnMe3 residues are connected as a chain with bridging oxalate anions in a trans-SnC3O2 framework, the oxygen atoms being in axial positions. The cations connect linear adjacent chains through NH…O hydrogen bonds giving layered structures.


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