Structural and Spectroscopic Characterization of Two New Cu(II)-Dipeptide Complexes

2000 ◽  
Vol 55 (12) ◽  
pp. 1157-1162 ◽  
Author(s):  
Gianella Facchin ◽  
María H. Torre ◽  
Eduardo Kremer ◽  
Oscar E. Piro ◽  
Eduardo E. Castellano ◽  
...  

Two new Cu(II) complexes of stoichiometry [Cu(L-dipept)], containing as ligands the dipeptides L-alanine-L-valine and L-alanine-L-phenylalanine were prepared. They were characterized by single crystal X-ray diffractometry, and infrared and electronic spectroscopy. Both crystallize in the orthorhombic space group P212121 with Z = 4. The Cu(II) ion has essentially the same elongated pyramidal coordination, being equatorially cis coordinated by a N2O2 arrangement of ligand atoms and axially by a carbonyl oxygen atom. The compounds show rather similar polymeric structures that differ from each other basically in the dihedral angle between adjacent N2O2 planes. The infrared and electronic spectra are briefly discussed on the basis of the structural characteristics of the complexes. Superoxide dismutase-like activity was tested for both compounds.

1998 ◽  
Vol 76 (7) ◽  
pp. 1050-1059 ◽  
Author(s):  
Scott Brownridge ◽  
T Stanley Cameron ◽  
Jack Passmore ◽  
Gabriele Schatte ◽  
George W Sutherland

Pentafluorophenyl-bis(pentafluorophenylthio)sulfonium hexafluoroarsenate, [(C6F5S)2SC6F5][AsF6], was prepared by the reaction of (C6F5)2S2 and AsF5 in liquid SO2 at room temperature. The compound has been characterized by single-crystal X-ray and powder diffraction, and IR and FT-Raman spectroscopy. Crystals of [(C6F5S)2SC6F5][AsF6] are orthorhombic, space group P212121 (cell dimensions measured at room temperature in brackets): a = 13.132(3) [13.157(2)] Å, b = 21.477(4) [21.575(3)] Å, c = 8.770(2) [8.775(1)] Å, α = ß = γ = 90.00°; V = 2473.3(9) Å3, Z = 4, temperature = 181 ± 1 K. The structure consists of [AsF6]- anions and [(C6F5S)2SC6F5]+ cations that have a different structure than the related [X2MMMX]+ cations (M = S, Se; X = Cl, Br), which contain a trichalcogen chain with a pronounced chalcogen-chalcogen bond alternation. Ab initio calculations suggest the observed [(C6F5S)2SC6F5]+ geometry is due to steric and solid state effects. Comparison of the Raman spectra of [(C6F5)S2SC6F5][AsF6], [Cl2SSSCl][AsF6], and [(CH3)2ClS3]+ implies that [(CH3)2ClS3]+ has a structure with equal sulfur-sulfur distances, and therefore the structure is likely [(CH3S)2SCl]+ and probably not the previously reported [(CH3)2SSSCl]+.Key words: [R3X3]+ cations, X-ray crystal structure, FT-Raman spectroscopy, [(C6F5S)2SC6F5]+, pentafluorophenyl-bis(pentafluorophenylthio)sulfonium cation, hexafluoroarsenate.


2001 ◽  
Vol 56 (2) ◽  
pp. 122-128 ◽  
Author(s):  
Athanassios K. Boudalis ◽  
Vassilios Nastopoulos ◽  
Aris Terzis ◽  
Catherine P. Raptopoulou ◽  
Spyros P. Perlepes

Abstract The reaction of Y(NO3)3 · 5H2O and 2,2':6',2"-terpyridine (terpy) in MeCN leads to [Y(N03 )3(terpy)(H2O )] (1) and [Y(N03 )3(terpy)(H2O )] terpy-3MeCN (2) in good yields depending on the isolation conditions. The structures of both complexes were determined by single-crystal X-ray crystallography. The YIII atom in 1 is 9-coordinate and ligation is provided by one terdentate terpy molecule, two chelating nitrates, one monodentate nitrate and one terminal H2O molecule; the coordination polyhedron about the metal may be viewed as a tricapped trigonal prism. The YIII atom in 2 is 10-coordinate and its coordination sphere consists of three nitrogen atoms from the terdentate terpy, six oxygen atoms from the three chelating nitrates (one of them being “anisobidentate”) and one oxygen atom from a terminal H2O molecule; the polyhedron about the metal may be viewed as a distorted sphenocorona. The interstitial terpy is strongly hydrogen-bonded to the O atom of the coordinated H2O molecule to form [Y(NO3 )3(terpy)(H20)] ··· terpy pairs. The new complexes were characterized by IR and 1H NMR spectroscopies. The YIII/NO3-/terpy chemistry is compared to the already well-developed LnIII/NO3-/terpy chemistry (Ln = lanthanide).


2019 ◽  
Vol 42 (1) ◽  
pp. 37-45
Author(s):  
Yichao Lin ◽  
Minghui Guo ◽  
Jin Liu ◽  
Laijin Tian ◽  
Xicheng Liu

AbstractThe complexes of 2-(menthoxycarbonyl)ethyltin chloride, MenOCOCH2CH2SnCl3⋅L (Men = Menthyl, L = benzyl phenyl sulfoxide (bpSO), 1; 2,2’-bipyridine (bpy), 2; 1,10-phenanthroline (phen), 3) and [MenOCOCH2CH2SnCl2(OCH3)]2 (4), have been synthesized and characterized by means of elemental analysis, FT-IR, NMR (1H, 13C and 119Sn) spectra. The crystal structures of 1, 3 and 4 have been determined by single crystal X-ray diffraction. The tin atoms in 1-4 are all hexa-coordinated. The tin atom in 1 adopts a distorted [CSnCl3O2] octahedral geometry with an oxygen atom of the ligand and an intramolecular coordination of the oxygen atom from the carbonyl group to the tin atom. Complex 3 possesses a distorted [CSnCl3N2] octahedral geometry with two nitrogen atoms of a chelating phen ligand. The carbonyl oxygen atom of the ester moiety is not coordinating. Compound 4 is a centrosymmetric dimer with a four-membered Sn2O2 ring, and the tin atom has a distorted [CSnCl2O3] octahedral geometry with an intramolecular C=O→Sn coordination and intermolecular methoxy bridging.


Molbank ◽  
10.3390/m1227 ◽  
2021 ◽  
Vol 2021 (2) ◽  
pp. M1227
Author(s):  
Bibi Hanifa ◽  
Muhammad Sirajuddin ◽  
Zafran Ullah ◽  
Sumera Mahboob ◽  
See Mun Lee ◽  
...  

The synthesis and spectroscopic characterization of the glutaric acid-amide derivative, 2,4-Cl2C6H3N(H)C(=O)(CH2)3C(=O)OH (1), are described. The X-ray crystal structure determination of (1) shows the backbone of the molecule to be kinked about the methylene-C–N(amide) bond as seen in the C(p)–N–C(m)–C(m) torsion angle of −157.0(2)°; m = methylene and p = phenyl. An additional twist in the molecule is noted between the amide and phenyl groups as reflected in the C(m)–N–C(p)–C(p) torsion angle of 138.2(2)°. The most prominent feature of the molecular packing is the formation of supramolecular tapes assembled through carboxylic acid-O–H…O(carbonyl) and amide-N–H…O(amide) hydrogen bonding.


1986 ◽  
Vol 41 (5-6) ◽  
pp. 618-626
Author(s):  
Alfred Gieren ◽  
Michail Kokkinidis

The crystal structures of the title compounds which display cholinergic activity at the ganglionic receptor have been determined by X-ray structure analysis. [(CH3)3N+C5H11]Cl- (1) crystallizes in the orthorhombic space group Pbnm with half a formula unit per asymmetric unit, a = 11.381(14). b = 12.871(17), c = 7.316(4) Å. The intensities of 1106 independent reflections were collected with an automatic diffractometer. The structure refinement converged at R = 0.133 for the 355 observed reflections. The cation of 1 is disordered. [(CH3)3N + (CH2)4-O-C(O)-CH3]I- (2) crystallizes in the orthorhombic space group P212121 with four formula units per unit cell, a = 16.783(8), b = 10.276(6), c = 7.427(10) Å. The intensities of 1469 independent reflections were collected. The structure refinement converged at R = 0.071 for 1383 observed reflections. In both compounds the trimethylammonio methyl groups are coordinated nearly tetrahedrally by four anions in the first coordination sphere. Anions which occupy a special face type (B) of the tetrahedron of the (CH3)3N+ -CH2-group may be treated as a “model binding site” of the receptor. In the crystal structure of 2 the anions occupying B-type faces form together with the ammonium nitrogen and the carbonyl oxygen so called “Activity triangles”. The almost equal geometries of these activity triangles are correlated with the mode of pharmacological action.


Biochemistry ◽  
1997 ◽  
Vol 36 (23) ◽  
pp. 7109-7113 ◽  
Author(s):  
Dolly Foti ◽  
Bruno Lo Curto ◽  
Giovanni Cuzzocrea ◽  
M. Elena Stroppolo ◽  
Francesca Polizio ◽  
...  

2010 ◽  
Vol 65 (1) ◽  
pp. 90-94 ◽  
Author(s):  
Thomas Harmening ◽  
Rainer Pöttgen

Samples of EuRu4B4 and of the new boride EuRuB4 were prepared from europium, RuB, and RuB4 precursor alloys, respectively, in sealed tantalum tubes in an induction furnace. EuRu4B4 crystallizes with the LuRu4B4 structure, a = 748.1(1), c = 1502.3(4) pm. The structure of EuRuB4 was refined on the basis of X-ray diffractometer data: Pbam, a = 599.7(1), b = 1160.7(3), c = 358.06(7) pm, wR2 = 0.0691, 474 F2 values, and 38 variables. The four crystallographically independent boron sites build up layers which consist of almost regular pentagons and heptagons which sandwich the ruthenium and europium atoms, respectively. Within the two-dimensional [B4] networks each boron atom has a slightly distorted trigonal-planar boron coordination with B-B distances in the range 172 - 186 pm. Temperature-dependent 151Eu Mössbauer spectra show stable trivalent europium for EuRu4B4 and EuRuB4


Author(s):  
Michael R. Jackson ◽  
Thomas L. Selby

A recombinant metal-dependent phosphatidylinositol-specific phospholipase C (PI-PLC) fromStreptomyces antibioticushas been crystallized by the hanging-drop method with and without heavy metals. The native crystals belonged to the orthorhombic space groupP222, with unit-cell parametersa= 41.26,b= 51.86,c = 154.78 Å. The X-ray diffraction results showed significant differences in the crystal quality of samples soaked with heavy atoms. Additionally, drop pinning, which increases the surface area of the drops, was also used to improve crystal growth and quality. The combination of heavy-metal soaks and drop pinning was found to be critical for producing high-quality crystals that diffracted to 1.23 Å resolution.


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