Synthon preference in the cocrystal of 3,4,5-trifluorophenylboronic acid with urea

2017 ◽  
Vol 73 (11) ◽  
pp. 889-895 ◽  
Author(s):  
Karolina Kopczyńska ◽  
Paulina H. Marek ◽  
Bartłomiej Banaś ◽  
Izabela D. Madura
Keyword(s):  
Crystal Structure ◽  
Experimental Data ◽  
Hydrogen Bonds ◽  
Crystal Engineering ◽  
Boronic Acid ◽  
Theoretical Calculations ◽  
Boronic Acids ◽  
Vector Model ◽  
Comprehensive Description ◽  
Model Calculations

The comprehensive description of the crystal structure of a novel 1:1 cocrystal of 3,4,5-trifluorophenylboronic acid with urea, C6H4BF3O2·CH4N2O, is presented. Both components are good candidates for crystal engineering as they can create a variety of supramolecular synthons. The preference for the formation of different hetrosynthons is verified based on theoretical calculations. The syn–anti conformation of boronic acid has been found to be the most favourable in the formation of intermolecular interactions with urea. Moreover, the distortions present in the boron coordination sphere have been described quantitatively based on experimental data according to bond-valence vector model calculations. The results revealed that the deformation of the sphere is typical for a syn–anti conformation of boronic acids. The supramolecular structure of the cocrystal is composed of large synthons in the form of layers made up of O—H...O and N—H...O hydrogen bonds. The layers are joined via N—H...F hydrogen bonds which are unusual for urea cocrystal structures.

scholarly journals Enaminone Substituted Resorcin[4]arene—Sealing of an Upper-Rim with a Directional System of Hydrogen-Bonds

2020 ◽  
Vol 21 (20) ◽  
pp. 7494
Author(s):  
Anna Szafraniec ◽  
Marcin Grajda ◽  
Hanna Jędrzejewska ◽  
Agnieszka Szumna ◽  
Waldemar Iwanek
Keyword(s):  
Crystal Structure ◽  
Experimental Data ◽  
Solid State ◽  
Hydrogen Bonds ◽  
Theoretical Calculations ◽  
The Other ◽  
Thermally Activated ◽  
Intramolecular Hydrogen ◽  
Semi Empirical ◽  
Upper Rim

The paper presents the synthesis of an enaminone resorcin[4]arene via a thermally activated o-quinomethide. The crystal structure indicates that in the solid state all enaminone units participate in a unidirectional seam of 12 intramolecular hydrogen bonds that are formed around the cavity. The molecule exhibits C2 symmetry, with two opposite-laying enaminone units directed inside the cavity (“in”), and the other two units outside the cavity (“out”). In the solution the enaminone resorcin[4]arene exists as a mixture of conformers with distribution controlled by temperature and solvent. The experimental data are compared with the results of theoretical calculations using DFT B3LYP/6-31G(d,p) and fast semi-empirical DFTB/GFN2-xTB method in various solvents.

scholarly journals Molecular and Crystal Structure of a Chitosan−Zinc Chloride Complex

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1407
Author(s):  
Toshifumi Yui ◽  
Takuya Uto ◽  
Kozo Ogawa
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Theoretical Calculations ◽  
Chloride Complex ◽  
Fiber Axis ◽  
X Ray Diffraction ◽  
Intermolecular Hydrogen Bonds ◽  
Chain Packing ◽  
X Ray ◽  
Packing Structure

We determined the molecular and packing structure of a chitosan–ZnCl2 complex by X-ray diffraction and linked-atom least-squares. Eight D-glucosamine residues—composed of four chitosan chains with two-fold helical symmetry, and four ZnCl2 molecules—were packed in a rectangular unit cell with dimensions a = 1.1677 nm, b = 1.7991 nm, and c = 1.0307 nm (where c is the fiber axis). We performed exhaustive structure searches by examining all of the possible chain packing modes. We also comprehensively searched the positions and spatial orientations of the ZnCl2 molecules. Chitosan chains of antiparallel polarity formed zigzag-shaped chain sheets, where N2···O6, N2···N2, and O6···O6 intermolecular hydrogen bonds connected the neighboring chains. We further refined the packing positions of the ZnCl2 molecules by theoretical calculations of the crystal models, which suggested a possible coordination scheme of Zn(II) with an O6 atom.

scholarly journals Crystal structure ofN,N′-didecylpyromellitic diimide

2017 ◽  
Vol 73 (6) ◽  
pp. 838-841 ◽  
Author(s):  
Hansu Im ◽  
Myong Yong Choi ◽  
Cheol Joo Moon ◽  
Tae Ho Kim
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Density Functional Theory ◽  
Hydrogen Bonds ◽  
Density Functional ◽  
Theoretical Calculations ◽  
Asymmetric Unit ◽  
Functional Theory ◽  
Compound C ◽  
Herringbone Structure

The title compound, C30H44N2O4[systematic name: 2,6-didecylpyrrolo[3,4-f]isoindole-1,3,5,7(2H,6H)-tetraone], consists of a central pyromellitic diimide moiety with terminal decyl groups at the N-atom positions. The centre of the molecule lies on a crystallographic inversion centre so the asymmetric unit contains one half-molecule. The molecule exhibits a rod-shaped conformation, like other similar compounds of this type, the distance between the ends of terminal decyl groups being 32.45 Å. The packing is dominated by a lamellar arrangement of the molecules, which is reinforced by C—H...O hydrogen bonds and C—O...π interactions, forming a classic herringbone structure. The molecular structure is consistent with the theoretical calculations performed by density functional theory (DFT).

scholarly journals Statistical-model calculations for α-capture reactions relevant to the p process

2019 ◽  
Vol 26 ◽  
pp. 228
Author(s):  
C. Fakiola ◽  
I. Karakasis ◽  
I. Sideris ◽  
A. Khaliel ◽  
T. J. Mertzimekis
Keyword(s):  
Experimental Data ◽  
Statistical Model ◽  
Cross Sections ◽  
Theoretical Calculations ◽  
Reaction Network ◽  
Reaction Cross ◽  
Model Parameters ◽  
Model Calculations ◽  
Reaction Channels ◽  
Reaction Cross Sections

About 35 nuclides which lie on the neutron deficient side of the isotopic chart cannot be created by the two basic nucleosynthetic processes, the sand the rprocess. Due to scarce experimental data and the vast complexity of the reaction network involved, cross sections and reactions are estimated theoretically, using the Hauser–Feshbach statistical model. In the present work, theoretical calculations of cross sections of radiative α-capture reactions on the neutron–deficient Erbium and Xenon isotopes are presented in an attempt to make predictions inside the astrophysically relevant energy window (Gamow). The particular reactions are predicted to be sensitive branchings in the γprocess path.The most recent versions of TALYS (v1.9) and Fresco codes were employed for all calculations, initially focusing on investigating the influence of the default eight (8) α–nucleus optical potential models of TALYS on reaction cross sections. The theoretical results of both codes are compared and for the reactions where experimental data exist in literature, the optical model parameters were adjusted appropriately to best describe the data and were subsequently used for estimating (α,γ) reaction cross sections. Predictions for the (α,n) reaction channels have also been calculated and studied.

scholarly journals Synthesis, structure and characterization of a new noncentrosymmetric Zn(II) complex with the 2-amino-5-chloropyridine ligand (AClPy)

2014 ◽  
Vol 10 (9) ◽  
pp. 3116-3126 ◽  
Author(s):  
Wijdene Nbili ◽  
Kamel Kaabi ◽  
Valeria Ferretti ◽  
Frederic Lefebvre ◽  
Cherif Ben Nasr
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Theoretical Calculations ◽  
Mas Nmr ◽  
Coordination Pattern ◽  
X Ray Diffraction ◽  
Absorption Bands ◽  
Cp Mas Nmr ◽  
13C Cp Mas Nmr

A new noncentrosymmetric Zn(II) complex with the monodentate ligand 2-amino-5-chloropyridine (AClPy), ZnCl2(C5H5ClN2)2, has been prepared at room temperature and characterized by single crystal X-ray diffraction, 13C CP-MAS-NMR and IR spectroscopies. The basic coordination pattern of the AClPy coordinated metal cations is slighly distorted tetrahedral. The crystal structure is characterized by ZnCl2N2 tetrahedra interconnected via N-H···Cl hydrogen bonds generated by the NH2 amino group to form chains extending along the (a-c) direction. The exocyclic N atom is an electron receiving center, which is consistent with features of imino resonance as evidenced by bond lengths and angles. The crystal structure is stabilized by sets of intra and intermolecular hydrogen bonds. The 13C CP-MAS NMR spectrum is discussed and the vibrational absorption bands are identified by infrared spectroscopy and theoretical calculations.

Bis(triethanolamine)bis(μ2-trimesato)dicobalt(II): a CoIIdimer with an unreported two-dimensional supramolecular topology formed from triethanolamine and trimesic acid ligands

2016 ◽  
Vol 72 (2) ◽  
pp. 143-148 ◽  
Author(s):  
Min Xie ◽  
Guo-Hai Xu
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Crystal Engineering ◽  
Magnetic Measurements ◽  
Variable Temperature ◽  
Topological Analysis ◽  
Supramolecular Network ◽  
Two Dimensional ◽  
Engineering Research ◽  
Supramolecular Networks

Supramolecular networks are an important subset in the field of coordination polymer (CP) frameworks and are widely encountered in crystal engineering research. The search for novel topologies continues to be a significant goal in CP chemistry. The dimeric compound bis(μ-5-carboxybenzene-1,3-dicarboxylato-κ2O1:O3)bis[(triethanolamine-κ4N,O,O′,O′′)cobalt(II)], [Co2(C9H4O6)2(C6H15NO3)2], formed from the coligands 5-carboxybenzene-1,3-dicarboxylate (tmaH2−) and triethanolamine (teaH3), namely [Co(μ2-tmaH)(teaH3)]2, was synthesized and characterized by single-crystal and powder X-ray diffraction analyses, IR spectroscopy, thermogravimetric analysis (TGA) and magnetic measurements. The crystal structure features a zero-dimensional molecular structure consisting of centrosymmetric macrocyclic dinuclear complexes. Four classical hydrogen bonds between carboxylate groups and hydroxyethyl arms stabilize and extend the molecules into a two-dimensional supramolecular network. The topological analysis indicates that an unreported (3,5)-binodal supramolecular topology with a short Schläfli symbol of (4.5.6)(4.55.63.7) can be achieved by means of intermolecular hydrogen bonds. The crystal structure accounts for the potential to obtain unique topological types from two excellent hydrogen-bonding candidates,i.e.tmaH3and teaH3. A variable-temperature magnetic study shows the existence of antiferromagnetic behaviour in the complex.

Testing the core-cluster model calculations for some heavy deformed nuclei

2019 ◽  
Vol 28 (07) ◽  
pp. 1950049
Author(s):  
L. I. Abou-Salem ◽  
K. E. Abdelmageed ◽  
I. A. Elmashad ◽  
R. Al Allam
Keyword(s):  
Experimental Data ◽  
Cluster Model ◽  
Theoretical Calculations ◽  
Transition Probability ◽  
Parent Nucleus ◽  
Negative Parity ◽  
Excitation Energies ◽  
Model Calculations ◽  
The Core ◽  
Core Cluster

In this work, the spectra of some even–even isotopes are studied by selecting core-cluster decomposition of the parent nucleus. The considered nuclei lie in the rare-earth and the transition metal regions. The Schrödinger equation can be solved using Bohr–Sommerfeld relation and the modified Woods–Saxon beside Coulomb potentials to reproduce the spectra of these isotopes with mass number [Formula: see text]. The theoretical calculations of the excitation energies of the ground state rotational band are compared to the experimental data. The cluster model calculations show a good agreement with the experimental data for the transitional and rotational nuclei more than the vibrational nuclei. Some negative parity bands of the chosen nuclei are studied. The core-cluster charge products are correlated with the transition probability [Formula: see text].

scholarly journals Crystal Structure, Spectroscopy, SEM Analysis, and Computational Studies of N-(1,3-Dioxoisoindolin-2yl)benzamide

2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Hakan Bülbül ◽  
Yavuz Köysal ◽  
Necmi Dege ◽  
Sümeyye Gümüş ◽  
Erbil Ağar
Keyword(s):  
Crystal Structure ◽  
Ir Spectroscopy ◽  
Hydrogen Bonds ◽  
Theoretical Calculations ◽  
Sem Analysis ◽  
Monoclinic Space Group ◽  
Computational Studies ◽  
X Ray Diffraction ◽  
Ethanolic Solution ◽  
X Ray

The compound N-(1,3-dioxoisoindolin-2yl)benzamide, C15H10N2O3, was prepared by the heating of an ethanolic solution of 2-hydroxy-1H-isoindole-1,3(2H)-dione and 4-chloroaniline. The product was characterised using a combination of IR spectroscopy, SEM, and single crystal X-ray diffraction techniques. In addition to the experimental analysis, theoretical calculations were used to investigate the crystal structure in order to compare experimental and theoretical values. The X-ray diffraction analysis shows that the compound crystallises in the monoclinic space group P21/c with the geometric parameters of a=13.5324(11) Å, b=9.8982(8) Å, c=9.7080(8) Å, and β=95.425(6)°. The crystal structure is held together by a network of N-H⋯O hydrogen bonds involving the carboxamide group.

Synthesis, crystal structure and spectroscopic properties of a novel carbacylamidophosphate: N-(3-nitrobenzoyl)-N′,N′′-bis(tert-butyl)phosphoric triamide

2009 ◽  
Vol 65 (4) ◽  
pp. 502-508 ◽  
Author(s):  
Khodayar Gholivand ◽  
Hossein Mostaanzadeh ◽  
Tomas Koval ◽  
Michal Dusek ◽  
Mauricio F. Erben ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Vibrational Spectra ◽  
Theoretical Calculations ◽  
Spectroscopic Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Conformational Properties ◽  
Phosphoric Triamide ◽  
Butyl Amine

The new compound N-(3-nitrobenzoyl)-N′,N′′-bis(tert-butyl)phosphoric triamide was synthesized by reacting 3-nitrobenzoyl phosphoramidic dichloride and tert-butyl amine, and characterized by multinuclear (1H, 13C and 31P) NMR and FTIR spectroscopy techniques. Structural and conformational properties were analyzed using single-crystal X-ray diffraction, vibrational spectra and theoretical calculations. The crystal structure contains three symmetry-independent disordered molecules, connected via intermolecular N—H...O=P and N—H...O=C hydrogen bonds to form a centrosymmetric hexameric chain extended along the [2,1,\bar 1] direction. The disorder is mainly caused by rotation of the tert-butyl groups around the C—N bonds.

scholarly journals Hydrogen-bonding landscape of the carbamoylcyanonitrosomethanide anion in the crystal structure of its ammonium salt

2021 ◽  
Vol 77 (11) ◽  
Author(s):  
Kostiantyn V. Domasevitch ◽  
Ganna A. Senchyk ◽  
Andrey B. Lysenko ◽  
Eduard B. Rusanov
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Functional Groups ◽  
Surface Analysis ◽  
Crystal Engineering ◽  
Hirshfeld Surface ◽  
Simple Scheme ◽  
The Individual ◽  
Hydrogen Bonded

The structure of the title salt, ammonium carbamoylcyanonitrosomethanide, NH4 +·C3H2N3O2 −, features the co-existence of different hydrogen-bonding patterns, which are specific to each of the three functional groups (nitroso, carbamoyl and cyano) of the methanide anion. The nitroso O-atoms accept as many as three N—H...O bonds from the ammonium cations [N...O = 2.688 (3)–3.000 (3) Å] to form chains of fused rhombs [(NH4)(O)2]. The most prominent bonds of the carbamoyl groups are mutual and they yield 21 helices [N...O = 2.903 (2) Å], whereas the cyano N-atoms accept hydrogen bonds from sterically less accessible carbamoyl H-atoms [N...N = 3.004 (3) Å]. Two weaker NH4 +...O=C bonds [N...O = 3.021 (2), 3.017 (2) Å] complete the hydrogen-bonded environment of the carbamoyl groups. A Hirshfeld surface analysis indicates that the most important interactions are overwhelmingly O...H/H...O and N...H/H...N, in total accounting for 64.1% of the contacts for the individual anions. The relatively simple scheme of these interactions allows the delineation of the supramolecular synthons, which may be applicable to crystal engineering of hydrogen-bonded solids containing polyfunctional methanide anions.

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