scholarly journals Kristallstrukturen komplexer Metalate mit dem sterisch anspruchsvollen 1,3,5-Tri(tert-butyl)tropylium-Kation / X-Ray Crystal Structures of Complex Metallates Containing the Sterically Demanding 1,3,5-Tri(tert-butyl)tropylium Cation

2006 ◽  
Vol 61 (10) ◽  
pp. 1189-1197 ◽  
Author(s):  
Matthias Tamm ◽  
Thomas Bannenberg ◽  
Victoria Urban ◽  
Tania Pape ◽  
Olga Kataeva
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Transition Metal Complexes ◽  
Crystal Packing ◽  
Proton Donor ◽  
Close Inspection ◽  
X Ray ◽  
Tert Butyl ◽  
Sterically Demanding ◽  
Anions And Cations

The X-ray crystal structures of anionic transition metal complexes containing the sterically demanding 1,3,5-tri-tert-butyltropylium cation, [1,3,5-C7H4tBu3]+, as the compensating ion are presented. Bis(1,3,5-tri-tert-butyltropylium) hexachlorodiferrate(II), [1,3,5-C7H4tBu3]2[Fe2Cl6] (4), was obtained from the reaction of the 1,3,5-tri-tert-butyltropylium hydrogendichloride, [1,3,5- C7H4tBu3][HCl2] (3), with FeCl2, whereas the 1,3,5-tri-tert-butyltropylium tetrabromooxomolybdate( V) [1,3,5-C7H4tBu3][trans-Mo(O)Br4(CH3CN)] (7) was isolated from the reaction of the cycloheptatrienyl complex [(η7-1,3,5-C7H4tBu3)Mo(CO)2Br] (6) with elemental bromine. The crystal structures of 3, 4, 7 and 7 · CH3CN show in each case well separated anions and cations and the absence of any covalent anion-cation interactions. However, close inspection of the crystal packing reveals that the 1,3,5-tri-tert-butyltropylium cation can act as a CH-proton donor towards the counterion leading to the formation of weak C-H· · ·Cl-M and C-H· · ·O=M hydrogen bonds in 4 and in 7 and 7 ·CH3CN, respectively.

scholarly journals Crystal structures of crotonaldehyde semicarbazone and crotonaldehyde thiosemicarbazone from X-ray powder diffraction data

2015 ◽  
Vol 71 (2) ◽  
pp. 168-172 ◽  
Author(s):  
Atef Arfan ◽  
Mwaffak Rukiah
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Crystal Packing ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Semicarbazide Hydrochloride

Crotonaldehyde semicarbazone {systematic name: (E)-2-[(E)-but-2-en-1-ylidene]hydrazinecarboxamide}, C5H9N3O, (I), and crotonaldehyde thiosemicarbazone {systematic name: (E)-2-[(E)-but-2-en-1-yldene]hydrazinecarbothioamide}, C5H9N3S, (II), show the sameEconformation around the imine C=N bond. Compounds (I) and (II) were obtained by the condensation of crotonaldehyde with semicarbazide hydrochloride and thiosemicarbazide, respectively. Each molecule has an intramolecular N—H...N hydrogen bond, which generates anS(5) ring. In (I), the crotonaldehyde fragment is twisted by 2.59 (5)° from the semicarbazide mean plane, while in (II) the corresponding angle (with the thiosemicarbazide mean plane) is 9.12 (5)°. The crystal packing is different in the two compounds: in (I) intermolecular N—H...O hydrogen bonds link the molecules into layers parallel to thebcplane, while weak intermolecular N—H...S hydrogen bonds in (II) link the molecules into chains propagating in [110].

Influence of 3-{5-[4-(diethylamino)benzylidene]rhodanine}propionic acid on the conformation of 5-(4-chlorobenzylidene)-2-(4-methylpiperazin-1-yl)-3H-imidazol-4(5H)-one

2018 ◽  
Vol 74 (11) ◽  
pp. 1427-1433 ◽  
Author(s):  
Ewa Żesławska ◽  
Wojciech Nitek ◽  
Waldemar Tejchman ◽  
Jadwiga Handzlik
Keyword(s):  
Crystal Structures ◽  
Crystal Packing ◽  
Protonated Form ◽  
Acid Form ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
Basic Form ◽  
Piperazine Ring ◽  
X Ray ◽  
Intermolecular Contacts

The arylidene–imidazolone derivatives are a group of compounds of great interest in medicinal chemistry due to their various pharmacological actions. In order to study the possible conformations of an arylidene–imidazolone derivative, two new crystal structures were determined by X-ray diffraction, namely (Z)-5-(4-chlorobenzylidene)-2-(4-methylpiperazin-1-yl)-3H-imidazol-5(4H)-one, C15H17ClN4O, (6), and its salt 4-[5-(4-chlorobenzylidene)-5-oxo-4,5-dihydro-3H-imidazol-2-yl]-1-methylpiperazin-1-ium 3-{5-[4-(diethylamino)benzylidene]-4-oxo-2-thioxothiazolidin-3-yl}propionate, C15H18ClN4O+·C17H19N2O3S2 −, (7). Both compounds crystallize in the space group P\overline{1}. The basic form (6) crystallizes with two molecules in the asymmetric unit. In the acid form of (6), the N atom of the piperazine ring is protonated by proton transfer from the carboxyl group of the rhodanine acid derivative. The greatest difference in the conformations of (6) and its protonated form, (6c), is observed in the location of the arylidene–imidazolone substituent at the N atom. In the case of (6c), the position of this substituent is close to axial, while for (6), the corresponding position is intermediate between equatorial and axial. The crystal packing is dominated by a network of N—H...O hydrogen bonds. Furthermore, the crystal structures are stabilized by numerous intermolecular contacts of types C—H...N and C—H...Cl in (6), and C—H...O and C—H...S in (7). The geometry with respect to the location of the substituents at the N atoms of the piperazine ring was compared with other crystal structures possessing an N-methylpiperazine moiety.

Synthese und Kristallstrukturen einiger Tetramethylstibonium-Hydrogendicarboxylate / Synthesis and Crystal Structures of Some Tetramethylstibonium Hydrogendicarboxylates

1982 ◽  
Vol 37 (11) ◽  
pp. 1393-1401 ◽  
Author(s):  
Beatrix Milewski-Mahrla ◽  
Hubert Schmidbaur
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Spectroscopic Data ◽  
Molar Ratio ◽  
Ionic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carboxylate Oxygen ◽  
Donor Acceptor ◽  
New Compounds

Reactions of pentamethylantimony (CH3)5Sb with carboxylic acids in the molar ratio 1:2 afford one equivalent of methane and essentially quantitative yields of crystalline tetramothylstibonium hydrogendicarboxylates. Six new compounds of this series have been synthesized using benzoic, o-phthalic, salicylic, 4-ethoxy-salicylic, oxalic, and malic acid, and characterized by analytical and spectroscopic data. An ionic structure with strong hydrogen bonds in the anionic components is proposed.The crystal structures of the hydrogen-dibenzoato (1), hydrogen-ortho-plithalato (2) and 4-ethoxy-hydrogen-salicylate (3) were determined by single crystal X-ray diffraction. The compounds can be described as having ionic lattices with some donor-acceptor inter­actions between the stibonium centers and the carboxylate oxygen atoms. The anions are characterized by strong hydrogen bonds O...H...O. Thus, the (CH3)4Sb-tetrahedron in 1 is distorted by two benzoate oxygon atoms (at 304(2) and 340(2) pin). The cation in 2 is largely undistorted and the anion has a hydrogenphthalate hydrogen bond of d(O...H...O) = 232 pm. The cation-anion contact in 3 is as short as d(Sb-O) = 289 pm rendering the Sb atom pentacoordinate.

scholarly journals Crystal structures of 2-methylpyridinium hydrogen 2,3-bis(4-methylbenzoyloxy)succinate and bis-[4-methylpyridinium hydrogen 2,3-bis(4-methylbenzoyloxy)succinate] pentahydrate

2017 ◽  
Vol 73 (10) ◽  
pp. 1483-1487
Author(s):  
P. Sivakumar ◽  
S. Israel ◽  
G. Chakkaravarthi
Keyword(s):  
Hydrogen Bonds ◽  
Pyridine Ring ◽  
Crystal Packing ◽  
Water Molecules ◽  
Two Dimensional ◽  
Asymmetric Unit ◽  
Aromatic Rings ◽  
Π Interactions ◽  
Dimensional Network ◽  
Anions And Cations

The title salt (I), C6H8N+·C20H17O8−, comprises a 2-methylpyridinium cation and a 2,3-bis(4-methylbenzoyloxy)succinate mono-anion while the salt (II), 2C6H8N+·2C20H17O8−·5H2O, consists of a pair of 4-methylpyridinium cations and 2,3-bis(4-methylbenzoyloxy)succinate mono-anions and five water molecules of solvation in the asymmetric unit. In (I), the dihedral angle between the aromatic rings of the anion is 40.41 (15)°, comparing with 43.0 (3) and 85.7 (2)° in the conformationally dissimilar anion molecules in (II). The pyridine ring of the cation in (I) is inclined at 23.64 (16) and 42.69 (17)° to the two benzene moieties of the anion. In (II), these comparative values are 4.7 (3), 43.5 (3)° and 43.5 (3), 73.1 (3)° for the two associated cation and anion pairs. The crystal packing of (I) is stabilized by inter-ionic N—H...O, O—H...O and C—H...O hydrogen bonds as well as weak C—H...π interactions, linking the ions into infinite chains along [100]. In the crystal packing of (II), the anions and cations are also linked by N—H...O and O—H...O hydrogen bonds involving also the water molecules, giving a two-dimensional network across (001). The crystal structure is also stabilized by weak C—H...O and C—H...π interactions.

Hydrogen Bonds in "Carboxyoximes": the Case of Bomane Derivatives

2000 ◽  
Vol 55 (8) ◽  
pp. 677-684 ◽  
Author(s):  
Maciej Kubicki ◽  
Teresa Borowiak ◽  
Wiesław Z. Antkowiak
Keyword(s):  
Carboxylic Acid ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Carboxylic Acids ◽  
Supramolecular Structures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carboxylic Groups ◽  
Acid Function

Abstract The tendency of forming mixed carboxyl-to-oxime hydrogen bonds was tested on the series of bornane derivatives: one with the acid function only (bornane-2-endo-carboxylic acid), one with the oxime function (2,2′-diethylthiobomane-3-oxime), and one with both oxime and carboxylic functions (bornane-2-oxime-3-endo-carboxylic acid). The crystal structures of these compounds were determined by means of X-ray diffraction. In bornane-2-endo-carboxylic acid and 2,2′-diethylthiobornane-3-oxime 'homogenic' hydrogen bonds were found, and these hydrogen bonds close eight-and six-membered rings, respectively. By contrast, in bornane-2-oxime-3-endo-carboxylic acid 'heterogenic' hydrogen bonds between carboxylic and oxime bonds were found. This carboxylic-oxime, or 'carboxyoxime' system is almost always present in compounds which have both oxime and carboxylic groups; therefore it can be regarded as an element of supramolecular structures (synthon). The presence of such synthons can break the tendency of carboxylic acids and oximes towards crystallizing in centrosymmetric structures.

Crystal Structures of Seven Terephthaldiamide Derivatives

2002 ◽  
Vol 57 (8) ◽  
pp. 914-921 ◽  
Author(s):  
P. G. Jones ◽  
J. Ossowski ◽  
P. Kus
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Layer Structure ◽  
Inversion Symmetry ◽  
Asymmetric Unit ◽  
X Ray ◽  
Layer Structures ◽  
Structure Determinations ◽  
Independent Molecules

N,N′-Dibutyl-terephthaldiamide (1), N,N′-dihexyl-terephthaldiamide (2), N,N′-di(tert-butyl)- terephthaldiamide (3), N,N,N′,N′-tetrabutyl-terephthaldiamide (4), 1,1′-terephthaloylbis- pyrrolidine (5), 1,1′-terephthaloyl-bis-piperidine (6), and 4,4′-terephthaloyl-bis-morpholine (7) have been synthesised and physicochemically characterised. The X-ray structure determinations reveal imposed inversion symmetry for compounds 1-6; compound 3 has two independent molecules with inversion symmetry in the asymmetric unit. Compounds 1-3 form classical hydrogen bonds of the type N-H···O=C, leading to a ribbon-like arrangement of molecules (1 and 2) or a layer structure (3). Compound 3 also displays a very short C-H···O interaction, a type of hydrogen bond that is also observed in compounds 4-7, which lack classical donors; thereby compounds 4-6 form layer structures and 7 a complex threedimensional network.

Übergangsmetallkomplexe mit Schwefelliganden, LXXX. Synthese, Struktur, Oxotransfer- und redoxgekoppelte Kondensationsreaktionen von Molybdän-Oxo-Komplexen mit dem sterisch anspruchsvollen vierzähnigen Thioether-Thiolat-Liganden 'buS4'2- ('buS4'2- = 1,2-Bis(2-mercapto-3,5-di-t-butylphenylthio)ethan(2—))/Transition Metal Complexes with Sulfur Ligands, LXXX. Syntheses, Structures, Oxo Transfer and Redox Coupled Condensation Reactions of Molybdenum Oxo Complexes with the Sterically Demanding Tetradentate Thioether-Thiolato-Ligand 'buS4'2- ('buS4'2- = 1,2-Bis(2-mercapto-3,5-di-/-butylphenylthio)ethane(2—))

1992 ◽  
Vol 47 (1) ◽  
pp. 61-73 ◽  
Author(s):  
Dieter Sellmann ◽  
Franz Grasser ◽  
Falk Knoch ◽  
Matthias Moll
Keyword(s):  
Transition Metal ◽  
Transition Metal Complexes ◽  
Transfer Reaction ◽  
Parent Compound ◽  
Elimination Reaction ◽  
X Ray ◽  
Oxo Complexes ◽  
Sterically Demanding ◽  
Oxo Transfer ◽  
System 1

In order to obtain soluble molybdenum sulfur oxo complexes, [Mo(O)2('buS4')] (1) ('buS4'2- = 1,2-bis(2-mercapto-3,5-di-t-butylphenylthio)ethane(2-)) was synthesized by reaction of [Mo(O)2(acac)2] (acac- = acetylacetonate(1-) ) with 'buS4'-Li2. Treatment of 1 with PPh3 yielded [μ-O{Mo(O)('buS4')}2] (2) and OPPh3 in an oxo transfer reaction. [Mo(PMe3)2('buS2')2] (3) ('buS2'2- = 3,5-di-t-butyl-1,2 -benzenedithiolate(2-)) was obtained by twofold desoxygenation of 1 with excess PMe3 via a redox coupled addition elimination reaction. 2 reacts with the oxo group donor DMSO to yield 1 and Me2S. The system 1/2 then catalyses the oxo transfer reaction from DMSO to PPh3 and, therefore, shows properties modelling the co-factor in oxotransferases. In contrast to the parent compound [Mo(O)2('S4')] ('S4'2- = 1,2-bis(2-mercaptophenylthio)ethane(2-)), 1 is reactive towards hydrazine and its derivatives. Reactions with hydrazine and alkylhydrazines yield mixtures of products not containing nitrogen. By treatment of 1 with phenylhydrazine, the phenyldiazenido(1-) complex [Mo(NNPh)2('buS4')] (4) was formed in a redox coupled condensation. According to the X-ray structure analyses of 1, 2 and 4, the molybdenum centres in these complexes are coordinated pseudo-octahedrally by the four S-donors of the 'buS4'2- ligands, the oxo- and the N -donors.

Two polymorphs of 2-ethyl-3-hydroxy-6-methylpyridinium hydrogenN-acetyl-L-glutamate from powder diffraction data

2013 ◽  
Vol 69 (12) ◽  
pp. 1549-1552 ◽  
Author(s):  
Vladimir V. Chernyshev ◽  
Sergey Y. Efimov ◽  
Ksenia A. Paseshnichenko ◽  
Andrey A. Shiryaev
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Crystal Packing ◽  
Three Dimensional ◽  
Powder Diffraction Data ◽  
Screw Axis ◽  
Dimensional Network ◽  
Polymorphic Modifications

The title salt, C8H12NO+·C7H10NO5−, crystallizes in two polymorphic modifications,viz.monoclinic (M) and orthorhombic (O). The crystal structures of both polymorphic modifications have been established from laboratory powder diffraction data. The crystal packing motifs in the two polymorphs are different, but the conformations of the anions are generally similar. InM, the anions are linked by pairs of hydrogen bonds of the N—H...O and O—H...O types into chains along theb-axis direction, and neighbouring molecules within the chain are related by the 21screw axis. The cations link these chainsviaO—H...O and N—H...O hydrogen bonds into layers parallel to (001). InO, the anions are linked by O—H...O hydrogen bonds into helices along [001], and neighbouring molecules within the helix are related by the 21screw axis. The neighbouring helical turns are linked by N—H...O hydrogen bonds. The cations link the helicesviaO—H...O and N—H...O hydrogen bonds, thus forming a three-dimensional network.

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