X-ray diffraction and packing analysis on vintage crystals: Wilhelm Koerner's nitrobenzene derivatives from the School of Agricultural Sciences in Milano

2004 ◽  
Vol 60 (5) ◽  
pp. 609-620 ◽  
Author(s):  
Francesco Demartin ◽  
Giuseppe Filippini ◽  
Angelo Gavezzotti ◽  
Silvia Rizzato
Keyword(s):  
Crystal Structures ◽  
Molecular Structures ◽  
X Ray Diffraction ◽  
Factors Affecting ◽  
Correct Assignment ◽  
Molecular Electron ◽  
Structural Database ◽  
Potential Methods ◽  
The University ◽  
Crystal Packings

The crystal structures of six nitrotoluene derivatives, synthesized by Wilhelm Koerner about a century ago and retrieved from a depository at the University of Milano, were determined. The correct assignment of molecular structures is verified. The geometry of the nitro groups and factors affecting the orientation of nitro groups with respect to the benzene ring are discussed, also using an auxiliary set of crystal structures retrieved from the Cambridge Structural Database. The crystal packings have been analyzed, and lattice energies have been calculated by atom–atom potential methods and by the newly proposed Pixel method. This method allows a more complete description of intermolecular potentials in terms of the interaction between molecular electron densities and separate Coulombic, polarization, dispersion and overlap repulsion energies. Lattice vibrations and external entropies were calculated by lattice-dynamical procedures. The results of the Pixel energy calculations allow a reliable, quantitative assessment of the relative importance of stacking interactions and hydrogen bonding in the rationalization of the recognition modes of nitrobenzene derivatives, which is impossible to attain using only qualitative atom– atom geometry concepts.

Lewis-Base Adducts of Group 1B Metal(I) Compounds. XXI The Crystal and Molecular Structures of the Unsolvated Forms of Dibromotris(triphenylphosphine)dicopper(I) and 'step' Tetrabromotetrakis(triphenyl-phosphine)tetracopper(I)

1985 ◽  
Vol 38 (8) ◽  
pp. 1243 ◽  
Author(s):  
JC Dyason ◽  
LM Engelhardt ◽  
C Pakawatchai ◽  
PC Healy ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Molecular Structures ◽  
Lewis Base ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
Triphenyl Phosphine ◽  
X Ray ◽  
Crystal And Molecular Structures

The crystal structures of the title compounds have been determined by single-crystal X-ray diffraction methods at 295 K. Crystal data for (PPh3)2CuBr2Cu(PPh3) (1) show that the crystals are iso-morphous with the previously studied chloro analogue, being monoclinic, P21/c, a 19.390(8), b 9.912(5), c 26.979(9) Ǻ, β 112,33(3)°; R 0.043 for No 3444. Cu( trigonal )- P;Br respectively are 2.191(3); 2.409(2), 2.364(2) Ǻ. Cu(tetrahedral)- P;Br respectively are 2.241(3), 2.249(3); 2.550(2), 2.571(2) Ǻ. Crystals of 'step' [PPh3CuBr]4 (2) are isomorphous with the solvated bromo and unsolvated iodo analogues, being monoclinic, C2/c, a 25.687(10), b 16.084(7), c 17.815(9) Ǻ, β 110.92(3)°; R 0.072 for No 3055. Cu( trigonal )- P;Br respectively are 2.206(5); 2.371(3), 2.427(2) Ǻ. Cu(tetrahedral)- P;Br are 2.207(4); 2.446(2), 2.676(3), 2.515(3) Ǻ.

Crystal structures of 1-(m-nitrophenyl)-2,2-dicarboethoxy-3-phenyl-pyrrolidin-5-one (C22H22N2O7) (I) and 1-(p-chlorophenyl)-2,2-dicarboethoxy-3-phenyl-pyrrolidin-5-one (C22H22NO5Cl) (II)

1989 ◽  
Vol 189 (3-4) ◽  
Author(s):  
G. D. Nigam ◽  
G. Mattern ◽  
R. Fröhlich
Keyword(s):  
Crystal Structures ◽  
Molecular Structures ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Crystal And Molecular Structures

AbstractThe crystal and molecular structures of 1-(m-nitrophenyl)-2,2-dicarboethoxy-3-phenyl-pyrrolidin-5-one (I) and 1-(p-chlorophenyl)-2,2-dicarboethoxy-3-phenyl-pyrrolidin-5-one (II) have been determined by X-ray diffraction methods. (I) crystallizes in the monoclinic space group

scholarly journals Crystal structures of diiodidobis[(1S,5S)-4-mesityl-1,2,8,8-tetramethyl-2,4-diazabicyclo[3.2.1]octan-3-ylidene-κC3]palladium(IV) and dichlorido[(1S,5S)-4-mesityl-1,2,8,8-tetramethyl-2,4-diazabicyclo[3.2.1]octan-3-ylidene-κC3](triphenylphosphane-κP)palladium(IV)

2015 ◽  
Vol 71 (8) ◽  
pp. 919-922
Author(s):  
Eduard Rais ◽  
Ulrich Flörke ◽  
René Wilhelm
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Molecular Structures ◽  
Square Planar ◽  
Crystal Packings

The molecular structures of the chiral title compounds, [Pd(C19H28N2)2I2], (I), and [Pd(C19H28N2)Cl2(C18H15P)], (II), show a distorted square-planar coordination around the PdIIatoms with two halogenide (Hal) ligands each and two N-heterocyclic carbene (NHC) ligands in (I) or one NHC and one triphenylphosphane ligand in (II). The deviations of the PdIIatoms from theL2Hal2best plane (L= NHC or triphenylphosphane ligand) are 0.206 (1) Å for (I) and 0.052 (1) Å for (II). The crystal packings exhibit intermolecular C—H...Hal hydrogen bonds.

Two crystal structures of 10,10′-(l,4-phenylene-dimethylidene)-bis-9,10-H-anthracenone

1992 ◽  
Vol 200 (3-4) ◽  
Author(s):  
G. Dewald ◽  
M. Hanack ◽  
E.-M. Peters ◽  
L. Walz
Keyword(s):  
Crystal Structures ◽  
Diffraction Data ◽  
Molecular Structures ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Hydrogen Atoms ◽  
Space Group ◽  
X Ray ◽  
Crystal And Molecular Structures

AbstractThe crystal and molecular structures of dimorphic 10,10′-(1,4-phenylene-dimethylidene)-bis-9,10-H-anthracenone (1) have been determined using X-ray diffraction data. The compound crystallizes either in the monoclinic space groupSince all non-hydrogen atoms are of pure

scholarly journals π–π Noncovalent Interaction Involving 1,2,4- and 1,3,4-Oxadiazole Systems: The Combined Experimental, Theoretical, and Database Study

Molecules ◽  
2021 ◽  
Vol 26 (18) ◽  
pp. 5672
Author(s):  
Sergey V. Baykov ◽  
Alexander S. Mikherdov ◽  
Alexander S. Novikov ◽  
Kirill K. Geyl ◽  
Marina V. Tarasenko ◽  
...  
Keyword(s):  
Crystal Structures ◽  
13C Nmr Spectroscopy ◽  
Data Bank ◽  
Noncovalent Interaction ◽  
X Ray Diffraction ◽  
1H And 13C Nmr ◽  
Nci Analysis ◽  
Equilibrium Structures ◽  
Structural Database ◽  
Anti Hiv

A series of N-pyridyl ureas bearing 1,2,4- (1a, 2a, and 3a) and 1,3,4-oxadiazole moiety (1b, 2b, 3b) was prepared and characterized by HRMS, 1H and 13C NMR spectroscopy, as well as X-ray diffraction. The inspection of the crystal structures of (1–3)a,b and the Hirshfeld surface analysis made possible the recognition of the (oxadiazole)···(pyridine) and (oxadiazole)···(oxadiazole) interactions. The presence of these interactions was confirmed theoretically by DFT calculations, including NCI analysis for experimentally determined crystal structures as well as QTAIM analysis for optimized equilibrium structures. The preformed database survey allowed the verification of additional examples of relevant (oxadiazole)···π interactions both in Cambridge Structural Database and in Protein Data Bank, including the cocrystal of commercial anti-HIV drug Raltegravir.

scholarly journals The Cambridge Structural Database in chemical education: analysis of hydrogen-bonded networks in salts of hexaaqua metal ions with organic counter-ions

2020 ◽  
Vol 53 (6) ◽  
pp. 1593-1602
Author(s):  
Massimo Moret
Keyword(s):  
Metal Ions ◽  
Crystal Structures ◽  
Structure Analysis ◽  
Structural Information ◽  
Crystal Structure Analysis ◽  
Molecular Structures ◽  
Intramolecular Interactions ◽  
Cambridge Structural Database ◽  
Counter Ions ◽  
Structural Database

This paper describes a laboratory course that introduces basic crystallographic data analysis to chemistry students encountering for the first time the world of crystals and crystal structures. The aim of the course is to provide students with direct contact with crystal structures and hands-on experience in structure analysis. To this end, a set of appropriately simple inorganic molecular structures was selected, consisting of salts of hexaaqua metal ions with organic counter-ions. By exploiting the crystallographic tools available in the Cambridge Structural Database program Mercury, students learn how to visualize and analyse a set of atomic coordinates. In this way they learn how to extract bonding and structural information concerning intramolecular interactions in both salt components. Intermolecular interactions are next analysed by looking closely at supramolecular motifs and packing patterns generated by hydrogen bonds. This pragmatic approach turned out to be effective and extremely useful for summarizing many chemical concepts learned by students during a bachelor degree course in chemistry. The experience provides at the same time some basic capabilities for properly managing crystal structure analysis.

scholarly journals CO2 Derivatives of Molecular Tin Compounds. Part 1: Hemicarbonato and Carbonato Complexes

Inorganics ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 31
Author(s):  
Laurent Plasseraud
Keyword(s):  
Elevated Pressure ◽  
Molecular Structures ◽  
X Ray Diffraction ◽  
Tin Compounds ◽  
X Ray ◽  
Synthesis Conditions ◽  
Structural Database ◽  
Carbonate Salts ◽  
Derivatives Of ◽  
Nickel Cluster

This review focuses on organotin compounds bearing hemicarbonate and carbonate ligands, and whose molecular structures have been previously resolved by single-crystal X-ray diffraction analysis. Most of them were isolated within the framework of studies devoted to the reactivity of tin precursors with carbon dioxide at atmospheric or elevated pressure. Alternatively, and essentially for the preparation of some carbonato derivatives, inorganic carbonate salts such as K2CO3, Cs2CO3, Na2CO3 and NaHCO3 were also used as coreagents. In terms of the number of X-ray structures, carbonate compounds are the most widely represented (to date, there are 23 depositions in the Cambridge Structural Database), while hemicarbonate derivatives are rarer; only three have so far been characterized in the solid-state, and exclusively for diorganotin complexes. For each compound, the synthesis conditions are first specified. Structural aspects involving, in particular, the modes of coordination of the hemicarbonato and carbonato moieties and the coordination geometry around tin are then described and illustrated (for most cases) by showing molecular representations. Moreover, when they were available in the original reports, some characteristic spectroscopic data are also given for comparison (in table form). Carbonato complexes are arbitrarily listed according to their decreasing number of hydrocarbon substituents linked to tin atoms, namely tri-, di-, and mono-organotins. Four additional examples, involving three CO2 derivatives of C,N-chelated stannoxanes and one of a trinuclear nickel cluster Sn-capped, are also included in the last part of the chapter.

Factors affecting charge transfer in tetraiodide dianions

2018 ◽  
Vol 42 (13) ◽  
pp. 10661-10669 ◽  
Author(s):  
Anita M. Grześkiewicz ◽  
Maciej Kubicki
Keyword(s):  
Charge Transfer ◽  
Crystal Structures ◽  
Intermolecular Interactions ◽  
Cambridge Structural Database ◽  
Factors Affecting ◽  
Factors Influencing ◽  
Structural Database

Thirty-one examples of crystal structures containing discrete tetraiodide I42−dianions were identified from the Cambridge Structural Database (CSD) and analyzed in detail in order to find the factors influencing the geometry of this rare fragment. The intermolecular interactions are at least partially responsible for the changes in the geometry of the dianion.

Syntheses and crystal structures of ruthenium complexes with bidentate salicylaldiminato and dithiophosphato ligands

2018 ◽  
Vol 73 (5) ◽  
pp. 329-335
Author(s):  
Li-Hua Tang ◽  
Fule Wu ◽  
Hui Lin ◽  
Ai-Quan Jia ◽  
Qian-Feng Zhang
Keyword(s):  
Schiff Base ◽  
Single Crystal ◽  
Crystal Structures ◽  
Schiff Bases ◽  
Ruthenium Complexes ◽  
Molecular Structures ◽  
Carbonyl Complexes ◽  
X Ray Diffraction ◽  
X Ray

AbstractTreatment of the bidentate Schiff base 2-[(2,6-diisopropyl-phenylimino)-methyl]-phenol (HL1) with one equivalent of (Et4N)[RuCl4(MeCN)2] in the presence of triethylamine afforded (Et4N)[RuCl3(κ2-N,O-L1)(MeCN)] (1), which reacted with two equivalents of K[S2P(OiPr)2] to produce a neutral ruthenium(III) complex [Ru(κ2-N,O-L1){η2-S2P(OiPr)2}2] (2) bearing both salicylaldiminato and dithiophosphato ligands. Reactions of the bidentate Schiff bases 2-[(3-chloro-phenylimino)-methyl]-phenol (HL2) and 2-[(2,4,6-trimethyl-phenylimino)-methyl]-phenol (HL3) with one equivalent of [Ru(CO)2Cl2] in the presence of triethylamine led to formation of the corresponding anionic ruthenium(II) carbonyl complexes (Et3NH)[RuCl2(κ2-N,O-L2)(CO)2] (3) and (Et3NH)[RuCl2(κ2-N,O-L3)(CO)2] (4). The molecular structures of complexes 2–4 have been determined by single-crystal X-ray diffraction.

Hydrogen-bond directionality and symmetry in [C(O)NH](N)2P(O)-based structures: a comparison between X-ray crystallography data and neutron-normalized values, and evaluation of reliability

2021 ◽  
Vol 77 (3) ◽  
Author(s):  
Maryam Taherzadeh ◽  
Mehrdad Pourayoubi ◽  
Banafsheh Vahdani Alviri ◽  
Samad Shoghpour Bayraq ◽  
Maral Ariani ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Crystal Structures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Maximum Percentage ◽  
Bond Lengths ◽  
X Ray Crystallography ◽  
Percentage Difference ◽  
Structural Database

For [C(O)NH](N)2P(O)-based structures, the magnitude of the differences in the N—H...O, H...O=P and H...O=C angles has been evaluated when the N—H bond lengths, determined by X-ray diffraction, were compared to the neutron normalized values and the maximum percentage difference was obtained, i.e. about 3% for the angle even if the N—H bond lengths have a difference of about 30% (0.7 Å for the X-ray and 1.03 Å for the neutron-normalized value). The symmetries of the crystals are discussed with respect to the symmetry of the molecules, as well as to the symmetry of hydrogen-bonded motifs, and the role of the most directional hydrogen bond in raising the probability of obtaining centrosymmetric crystal structures is investigated. The work was performed by considering nine new X-ray crystal structures and 204 analogous structures retrieved from the Cambridge Structural Database.

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