Zinc Barbiturate Complexes with Bidentate N-Donor Ligands: Syntheses, Crystal Structures, Spectroscopic, Thermal and Voltammetric Studies

2006 ◽  
Vol 61 (3) ◽  
pp. 275-280 ◽  
Author(s):  
Fatih Yilmaz ◽  
Veysel T. Yilmaz ◽  
Ender Bicer ◽  
Orhan Büyükgüngör
Keyword(s):  
Hydrogen Bonds ◽  
Zinc Ion ◽  
Carbonyl Oxygen ◽  
Donor Ligands ◽  
Distorted Octahedral Geometry ◽  
Cyclic Voltammogram ◽  
X Ray Diffraction ◽  
Hydrogen Atoms ◽  
Space Groups ◽  
Voltammetric Behavior

Abstract Two new bis(5,5-diethylbarbiturato) (barb) complexes of zinc, [Zn(barb)2(en)] (1) and [Zn(barb)2(bpy)] ・H2O (2) [en = ethylenediamine, bpy = 2,2’-bipyridine], have been prepared and characterized by elemental analysis, IR spectroscopy, thermal analysis and single crystal X-ray diffraction. Complexes 1 and 2 crystallize in monoclinic space groups. The zinc(II) ions in complex 1 are tetrahedrally coordinated by two barb and an en ligand. The barb ligands are N-coordinated while the en ligand acts as a bidentate chelating ligand. One carbonyl oxygen atom of each barb ligands in complex 2 participates in the bonding with the zinc ion with remarkably long Zn-O bonds resulting in a highly distorted octahedral geometry. Molecules of complex 1 are connected via N-H ···O hydrogen bonds, involving hydrogen atoms of both barb and en ligands, while molecules of complex 2 are linked by N-H ···O and O-H ···O hydrogen bonds and also aromatic π(bpy) ···π(bpy) stacking interactions. The voltammetric behavior of complexes 1 and 2 was investigated in aqueous solution by cyclic voltammetry using a NH3/NH4Cl buffer. The cyclic voltammogram of 1 shows a cathodic peak at −1.260 V and an anodic peak at −1.068 V due to a quasi-reversible two-electron process. Complex 2 yields two reduction peaks at −1.312 and −1.412 V. The former corresponds to a quasi-reversible electrode process of the zinc(II) ions in complex 2, while the latter is attributed to the reduction of the coordinated bpy ligands.

Synthesis and structural elucidation of new complexes of 2,4- and 3,5-dimethyl diphenyldithiophosphates with cobalt(II)

2015 ◽  
Vol 71 (2) ◽  
pp. 221-227 ◽  
Author(s):  
Sandeep Kumar ◽  
Ruchi Khajuria ◽  
Amanpreet Kaur Jassal ◽  
Maninder S. Hundal ◽  
Sushil K. Pandey
Keyword(s):  
Chelate Ring ◽  
Bidentate Ligand ◽  
Donor Ligands ◽  
Distorted Octahedral Geometry ◽  
X Ray Diffraction ◽  
Triclinic Space Group ◽  
X Ray ◽  
Space Groups ◽  
Distorted Octahedral ◽  
Elemental Analyses

A new series of donor-stabilized addition complexes of cobalt(II) with disubstituted diphenyldithiophosphates [{(ArO)2PS2}2CoL2] {Ar = 2,4-(CH3)2C6H3[(1)–(3)] and 3,5-(CH3)2C6H3[(4)–(6)];L= C5H5N [(1), (4)], 3,4-(CH3)2C5H3N [(2), (5)] and 4-(C2H5)C5H4N [(3), (6)]} were successfully isolated and characterized by elemental analyses, magnetic moment measurements, IR and single-crystal X-ray analysis. Complexes (3), (4) and (5) crystallize in the monoclinic space groupsP21/n,P21/nandP21/c, respectively, whereas complex (6) crystallizes in the triclinic space group P\bar 1. X-ray diffraction analysis of complexes (3)–(6) reveals a six-coordinated distorted octahedral geometry for the CoS4N2chromophore defined by two chelating diphenyldithiophosphate anions as well as two N-donor ligands. Two diphenyldithiophosphate ligands are coordinated to the cobalt ion as a bidentate ligand chelatingviathe two thiolate S atoms. Each of them forms a four-membered chelate ring in the equatorial plane. The N atoms from two donor ligands are axially coordinated to the Co atom in a mutuallytransposition.

Distinguishment of Weak Interactions of Hydrogen Atoms Bound to Carbon Atoms: X-Ray Crystal Structural and Hirshfeld Surface Analyses of 2-Hydroxy-7-methoxy-3-(2,4,6-trimethylbenzoyl)naphthalene with the 2-Methoxylated Homologue

2021 ◽  
Vol 19 ◽  
Author(s):  
Kikuko Iida ◽  
Toyokazu Muto ◽  
Miyuki Kobayashi ◽  
Hiroaki Iitsuka ◽  
Kun Li ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
Molecular Conformation ◽  
Weak Interactions ◽  
Carbonyl Oxygen ◽  
Hirshfeld Surface ◽  
Molecular Surface ◽  
Hydrogen Atoms ◽  
X Ray ◽  
Classical Hydrogen Bond

Abstract: X-ray crystal and Hirshfeld surface analyses of 2-hydroxy-7-methoxy-3-(2,4,6-trimethylbenzoyl)naphthalene and its 2-methoxylated homologue show quantitatively and visually distinct molecular contacts in crystals and minute differences in the weak intermolecular interactions. The title compound has a helical tubular packing, where molecules are piled in a two-folded head-to-tail fashion. The homologue has a tight zigzag molecular string lined up behind each other via nonclassical intermolecular hydrogen bonds between the carbonyl oxygen atom and the hydrogen atom of the naphthalene ring. The dnorm index obtained from the Hirshfeld surface analysis quantitatively demonstrates stronger molecular contacts in the homologue, an ethereal compound, than in the title compound, an alcohol, which is consistent with the higher melting temperature of the former than the latter. Stabilization through the significantly weak intermolecular nonclassical hydrogen bonding interactions in the homologue surpasses the stability imparted by the intramolecular C=O…H–O classical hydrogen bonds in the title compound. The classical hydrogen bond places the six-membered ring in the concave of the title molecule. The hydroxy group opposingly disturbs the molecular aggregation of the title compound, as demonstrated by the distorted H…H interactions covering the molecular surface, owing to the rigid molecular conformation. The position of effective interactions predominate over the strength of the classical/nonclassical hydrogen bonds in the two compounds.

Carbacylamidophosphates: Synthethis and Structure of N,N'-Tetramethyl-NM-benzoylphosphoryltriamide and Dimorpholido-N-benzoylphosphorylamide

2000 ◽  
Vol 55 (6) ◽  
pp. 495-498 ◽  
Author(s):  
Katerina E. Gubina ◽  
Vladimir A. Ovchynnikov ◽  
Vladimir M. Amirkhanov ◽  
Viktor V. Skopenkoa ◽  
Oleg V. Shishkinb
Keyword(s):  
Nmr Spectroscopy ◽  
Hydrogen Bonds ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Hydrogen Atoms ◽  
Sodium Salts ◽  
Space Group ◽  
X Ray ◽  
Centrosymmetric Dimers ◽  
Oxygen Atoms

N,N′-Tetramethyl-N"-benzoylphosphoryltriamide (I) and dimorpholido-N-benzoylphosphorylamide (II), and their sodium salts Nal, Nall were synthesized and characterized by means of IR and 1H, 31P NMR spectroscopy. The structures of I, II were determined by X-ray diffraction: I monoclinic, space group P2i/c with a = 10.162(3), b= 11.469(4), c = 12.286(4) Å , β = 94.04°, V = 1428.4(8) A 3, Z = 4, p(calcd) = 1.187 g/cm3; II monoclinic, space group C2/c with a = 15.503(4), b = 10.991(3), c = 22.000(6) Å, β = 106.39°, V = 3596.3(17) Å3, Z = 8, p(calcd.) = 1.253 g/cm3. The refinement of the structures converged at R = 0.0425 for I, and R = 0.068 for II. In both structures the molecules are connected into centrosymmetric dimers via hydrogen bonds formed by the phosphorylic oxygen atoms and hydrogen atoms of amide groups.

Bindung von Metall-Ionen an Dipeptide: Struktur von Thallium(I)-(3-benzyl-6-carboxylatomethyl-2,5-diketopiperazin) / Binding of Metal Ions by Dipeptides: Structure of Thallium(I) 3-Benzyl-6-carboxylatomethyl-2,5-diketopiperazine

1992 ◽  
Vol 47 (7) ◽  
pp. 952-956
Author(s):  
P. Mikulcik ◽  
P. Bissinger ◽  
J. Riede ◽  
H. Schmidbaur
Keyword(s):  
Solid State ◽  
Nitrogen Atom ◽  
Hydrogen Bonds ◽  
Diffraction Analysis ◽  
Carbonyl Oxygen ◽  
State Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystalline Product ◽  
Oxygen Atoms

Ester cleavage of aspartame (L-α-aspartyl-L-phenylalanine methylester) (1), by equimolar quantities of thallium ethoxide is accompanied by intramolecular cyclisation to give thallium 3-benzyl-6-(carboxylatomethyl)-2,5-dioxopiperazine (2). The solid state structure of the crystalline product was determined by single-crystal X-ray diffraction analysis. The cations were found to form four short and four elongated contacts to seven oxygen atoms and one nitrogen atom of a total of six neighbouring 3-benzyl-6-(carboxylatomethyl)-2,5-dioxopiperazine anions. There are inter-anionic hydrogen bonds only between the imino groups and the carbonyl oxygen atoms (O3, O4), featuring a pattern similar to that found for cytosine-guanosine contacts in DNA.

The crystal structure of C.I. Pigment Red 2, 1′-(2,5-dichlorophenyl)azo-2′hydroxy-3′-phenylamidonaphthalene

1977 ◽  
Vol 146 (4-6) ◽  
Author(s):  
A. Whitaker
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Crystal And Molecular Structure ◽  
X Ray Diffraction ◽  
Hydrogen Atoms ◽  
Monoclinic System ◽  
X Ray ◽  
Cell Parameters ◽  
Intramolecular Hydrogen

AbstractThe crystal and molecular structure of C.I. Pigment Red 2, l′-(2,5-dichlorophenyl)azo-2′-hydroxy-3′-phenylamidonaphthalene has been determined by x-ray diffraction techniques. It crystallizes in the monoclinic system with cell parametersThe hydrogen atoms have been found and included but not refined. The final residual is 15.3%. The molecule is probably in the form of the hydrazone tautomer. The intramolecular hydrogen bonds keep most of the molecule approximately planar while it appears that the remainder is held in the same plane due to steric hinderence between the molecules. The molecules are packed in columns with alternate molecules antiparallel and are linked by van der Waals forces.

Carbacylamidophosphates: Synthesis, Properties, and Structure of Dimorfolido-N-trichloroacetylphosphorylamide

1998 ◽  
Vol 53 (4) ◽  
pp. 481-484 ◽  
Author(s):  
Vladimir A Ovchynnikov ◽  
Vladimir M Amirkhanov ◽  
Taras P Timoshenko ◽  
Tadeusz Glowiak ◽  
Henryk Kozlowskib
Keyword(s):  
Ir Spectroscopy ◽  
Hydrogen Bonds ◽  
X Ray Diffraction ◽  
Hydrogen Atoms ◽  
Space Group ◽  
X Ray ◽  
Synthesis Properties ◽  
First Time ◽  
Centrosymmetric Dimers ◽  
Ir Bands

Abstract Dimorpholido-N-trichloroacetylphosphorylamide: CCl3C(O)NHP(O)[N(CH2CH2)2O]2 [HL] and its sodium [NaL] and morpholine [HN(CH2-CH2)2O•HL] salts were synthesized for the first time. The compounds were studied by IR spectroscopy and assignments of the characteristic IR bands have been made. The structure of [HL] was determined by X-ray diffraction. Crystals are monoclinic, a = 11.412(2) Å, b = 16.056(3) Å, c = 9.622(2) Å, β = 108.55(3)°, space group P21/c; Z = 4. The refinement of the structure converged at R = 0.066. The molecules are connected into centrosymmetric dimers via hydrogen bonds formed by the phosphorylic oxygen atoms and hydrogen atoms of amide groups.

Syntheses and structures of four new mixed-amide phosphoric triamides

2016 ◽  
Vol 72 (3) ◽  
pp. 251-259 ◽  
Author(s):  
Mojtaba Keikha ◽  
Mehrdad Pourayoubi ◽  
Atekeh Tarahhomi ◽  
Arie van der Lee
Keyword(s):  
Hydrogen Bonds ◽  
Electron Donor ◽  
Donor Ligands ◽  
Spectroscopic Methods ◽  
X Ray Diffraction ◽  
X Ray ◽  
Phosphoric Triamide ◽  
Phosphoric Triamides ◽  
Cyclohexyl Methyl

Phosphoric triamides have extensive applications in biochemistry and are also used asO-donor ligands. Four new mixed-amide phosphoric triamide structures, namelyrac-N-tert-butyl-N′,N′′-dicyclohexyl-N′′-methylphosphoric triamide, C17H36N3OP, (I),rac-N,N′-dicyclohexyl-N′-methyl-N′′-(p-tolyl)phosphoric triamide, C20H34N3OP, (II),N,N′,N′′-tricyclohexyl-N′′-methylphosphoric triamide, C19H38N3OP, (III), and 2-[cyclohexyl(methyl)amino]-5,5-dimethyl-1,3,2λ5-diazaphosphinan-2-one, C12H26N3OP, (IV), have been synthesized and studied by X-ray diffraction and spectroscopic methods. Structures (I) and (II) are the first diffraction studies of acyclic racemic mixed-amide phosphoric triamides. The P—N bonds resulting from the different substituent –N(CH3)(C6H11), (C6H11)NH–, 4-CH3-C6H4NH–, (tert-C4H9)NH– and –NHCH2C(CH3)2CH2NH– groups are compared, along with the different molecular volumes and electron-donor strengths. In all four structures, the molecules form extended chains through N—H...O hydrogen bonds.

Crystal chemistry and location of hydrogen atoms in prehnite

2008 ◽  
Vol 72 (6) ◽  
pp. 1163-1179 ◽  
Author(s):  
T. A. Detrie ◽  
N. L. Ross ◽  
R. J. Angel ◽  
M. D. Welch
Keyword(s):  
Single Crystal ◽  
Powder Diffraction ◽  
Rietveld Analysis ◽  
Neutron Powder Diffraction ◽  
X Ray Diffraction ◽  
Fourier Synthesis ◽  
Hydrogen Atoms ◽  
Space Groups ◽  
Neutron Powder Diffraction Data ◽  
Difference Fourier

AbstractThe structure of prehnite Ca2Al(AlSi3O10)(OH)2, including H positions, has been determined by a combination of single-crystal X-ray diffraction and neutron powder diffraction on four natural samples. The symmetry of the average structure with Al/Si disordered at the T2 siteis Pncm. However, for four of the crystals studied, numerous violations of the n- and c-glide reflection conditions indicate lower symmetry corresponding to space groups P2cm and P2/n and Al-Si ordered structures, possibly as domains of different symmetries and ordering within a single crystal. Time-of-flight neutron powder diffraction was carried out on a sample from Mali at 293 K and 2 K. The structure was refined in space group Pncm by Rietveld analysis. Although it was not possible to locate the missing H using the 293 K neutron data, these data were used to refine the H position located approximately by single-crystal XRD and to refine Uiso. For the 2 K neutron powder diffraction data, H was located directly by difference-Fourier synthesis and its refined position found to be in close agreement with that obtained by the combined XRD/neutron 293 K dataset.

scholarly journals Site Selectivity of Halogen Oxygen Bonding in 5- and 6-Haloderivatives of Uracil

Crystals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 467 ◽  
Author(s):  
Portalone
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Packing ◽  
Halogen Bond ◽  
Halogen Bonding ◽  
Carbonyl Oxygen ◽  
X Ray Diffraction ◽  
General Ability ◽  
Site Selectivity ◽  
Electron Donating Groups ◽  
Derivatives Of

Seven 5-and 6-halogenated derivatives of uracil or 1-methyluracil (halogen = Cl, Br, I) were studied by single crystal X-ray diffraction. In contrast with pure 5-halouracils, where the presence of N-H…O and C-H…O hydrogen bonds prevents the formation of other intermolecular interactions, the general ability of pyrimidine nucleobases to provide electron donating groups to halogen bonding was confirmed in three crystals and cocrystals containing uracil with the halogen atom at the C6 position. In the latter compounds, among the two nucleophilic oxygen atoms in the C=O moiety, only the urea carbonyl oxygen O1 can act as halogen bond acceptor, being not saturated by conventional hydrogen bonds. The halogen bonds in pure 6-halouracils are all rather weak, as supported by Hirshfeld surface analysis. The strongest interaction was found in the structure of 6-iodouracil, which displayed the largest (13%) reduction of the sum of van der Waals (vdW) radii for the contact atoms. Despite this, halogen bonding plays a role in determining the crystal packing of 6-halouracils, acting alongside conventional hydrogen bonds.

NEUTRON DIFFRACTION DETERMINATION OF THE HYDROGEN POSITIONS IN NATROLITE

1964 ◽  
Vol 42 (2) ◽  
pp. 229-240 ◽  
Author(s):  
B. H. Torrie ◽  
I. D. Brown ◽  
H. E. Petch
Keyword(s):  
Hydrogen Bonds ◽  
Neutron Diffraction ◽  
Oxygen Atom ◽  
Water Molecule ◽  
Neutron Diffraction Data ◽  
X Ray Diffraction ◽  
Hydrogen Atoms ◽  
X Ray ◽  
Diffraction Determination

Neutron diffraction data obtained with single crystals of natrolite, Na2Al2Si3O10.2H20, have been analyzed using Fourier difference synthesis arid least squares methods. The details of the aluminosilicate framework were found to be in agreement with the results of earlier X-ray diffraction studies. The oxygen atom of the water molecule is linked by bent hydrogen bonds to two oxygen atoms in the framework, making an O—O—O angle of 134°. Lying almost in the O—O—O plane, the hydrogen atoms are located at distances of 0.94 ± 0.03 and 0.98 ± 0.02 Å from the oxygen of the water molecule and make with it an H—O—H angle of 108°. Natrolite thus provides an excellent example of the ability of the water molecule to resist the influence of the environment in opening the H—O—H angle.

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