Activation of sp3-carbon-hydrogen bonds in a mono(pentamethylcyclopentadienyl)yttrium complex. X-ray crystal structures and dynamic behavior of Cp*Y(o-C6H4CH2NMe2)2 and Cp*Y[o-C6H4CH2NMe(CH2-.mu.)][.mu.-o-C6H4CH2NMe(CH2-.mu.)]YCp*[THF]

1989 ◽  
Vol 8 (10) ◽  
pp. 2454-2461 ◽  
Author(s):  
Martin. Booij ◽  
Niklaas H. Kiers ◽  
Auke. Meetsma ◽  
Jan H. Teuben ◽  
Wilberth J. J. Smeets ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Dynamic Behavior ◽  
X Ray ◽  
Carbon Hydrogen Bonds

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.

Surface Analysis of Carbon–Hydrogen Bonds in Diamondlike Carbon Films by X-ray Photoelectron Spectroscopy

2009 ◽  
Vol 48 (9) ◽  
pp. 092304 ◽  
Author(s):  
Susumu Takabayashi ◽  
Keishi Okamoto ◽  
Tatsuyuki Nakatani ◽  
Hiroyuki Sakaue ◽  
Takayuki Takahagi
Keyword(s):  
Hydrogen Bonds ◽  
Surface Analysis ◽  
Photoelectron Spectroscopy ◽  
Carbon Films ◽  
X Ray ◽  
Diamondlike Carbon ◽  
Carbon Hydrogen Bonds

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.

Supramolecular architectures in two 1:1 cocrystals of 5-fluorouracil with 5-bromothiophene-2-carboxylic acid and thiophene-2-carboxylic acid

2017 ◽  
Vol 73 (6) ◽  
pp. 481-485 ◽  
Author(s):  
Marimuthu Mohana ◽  
Packianathan Thomas Muthiah ◽  
Colin D. McMillen
Keyword(s):  
Solid State ◽  
Carboxylic Acid ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
X Ray Diffraction ◽  
Base Pairs ◽  
X Ray ◽  
Supramolecular Architectures ◽  
Acid Acid ◽  
Carboxylic Acid Dimer

In solid-state engineering, cocrystallization is a strategy actively pursued for pharmaceuticals. Two 1:1 cocrystals of 5-fluorouracil (5FU; systematic name: 5-fluoro-1,3-dihydropyrimidine-2,4-dione), namely 5-fluorouracil–5-bromothiophene-2-carboxylic acid (1/1), C5H3BrO2S·C4H3FN2O2, (I), and 5-fluorouracil–thiophene-2-carboxylic acid (1/1), C4H3FN2O2·C5H4O2S, (II), have been synthesized and characterized by single-crystal X-ray diffraction studies. In both cocrystals, carboxylic acid molecules are linked through an acid–acid R 2 2(8) homosynthon (O—H...O) to form a carboxylic acid dimer and 5FU molecules are connected through two types of base pairs [homosynthon, R 2 2(8) motif] via a pair of N—H...O hydrogen bonds. The crystal structures are further stabilized by C—H...O interactions in (II) and C—Br...O interactions in (I). In both crystal structures, π–π stacking and C—F...π interactions are also observed.

Heterocyclic Tautomerism. II. 4-Acylpyrazolones. X-Ray Crystal Structures of 4-Benzoyl-5-methyl-2-phenylpyrazol-3(2H)-one and 4-Acetoacetyl-3-methyl-1-phenylpyrazol-5-ol

1985 ◽  
Vol 38 (3) ◽  
pp. 401 ◽  
Author(s):  
MJ O'Connell ◽  
CG Ramsay ◽  
PJ Steel
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Room Temperature ◽  
Crystalline Form ◽  
Intermolecular Hydrogen Bonds ◽  
Intramolecular Hydrogen Bonds ◽  
X Ray ◽  
Intramolecular Hydrogen

The colourless crystalline form of the benzoylpyrazolone (2) has molecules with the NH structure (2c) stabilized by intermolecular hydrogen bonds. At room temperature crystals are monoclinic: P21/c, a 13.508(5), b 9.124(4), c 11.451(3)Ǻ, β 90.80(3)°, Z4; the structure was refined to R 0.059, Rw 0.048. The acetoacetylpyrazolone (3) has the OH structure (3c) with two intramolecular hydrogen bonds. At 193 K crystals are triclinic: Pī , a 7.142(2), b 13.704(8), c 14.699(7)Ǻ, α 117.36(3), β 96.87(3), γ 93.73(3)°, Z 4; the structure was refined to R 0.049, Rw 0.054.

Zur Kenntnis der Sulfite und Sulfithydrate des Zinks, Mangans, Magnesiums und Cobalts — Röntgenographische, spektroskopische und thermoanalytische Untersuchungen / Sulfites and Sulfite Hydrates of Zinc, Manganese, Magnesium and Cobalt-X-ray, Spectroscopic and Thermoanalytical Data

1977 ◽  
Vol 32 (11) ◽  
pp. 1230-1238 ◽  
Author(s):  
Heinz Dieter Lutz ◽  
Saleh M. El-Suradi ◽  
Bernward Engelen
Keyword(s):  
Thermal Analysis ◽  
Hydrogen Bonds ◽  
Ir Spectra ◽  
Single Crystal ◽  
Crystal Structures ◽  
Crystal Data ◽  
X Ray ◽  
Thermoanalytical Data ◽  
O 175 ◽  
Manganese Magnesium

IR, Raman, and X-ray data of ZnSO3 · 2½ H2O, ZnSO3 · 2 H2O, ZnSO3 ·½ H2O, ZnSO3, MnSO3 · 3 H2O, MnSO3 · H2O, MnSO3, MgSO3 · 6 H2O, MgSO3 · 3 H2O, CoSO3 · 3 H2O, CoSO3 · 2½ H2O, and CoSO3·2 H2O are presented. Except of MgSO3·6 H2O and ZnSO3 · 2½ H2O the crystal structures of these compounds are yet unknown. The following crystal data could be determined by single crystal measurements: ZnSO3 · 2 H2O (monoclinic, P21/n) : a = 642.1, b = 852.4, c = 757.4 pm, β = 98.93°, Z = 4, MnSO3 · 3 Η2Ο (monoclinic, Ρ21/n) : a = 665.0, b = 890.6, c = 879.3 pm, ß = 96.11°, Z = 4, MnSO3 · Η2Ο (orthorhombic) : a = 2565.1, b = 483.9, c = 576.0 pm, Z = 8, CoSO3 · 3 Η2Ο (orthorhombic, Pna21, isotype with MgSO3 · 3 H2O): a = 952.7, b = 942.0, c = 552.1 pm, Z = 4, CoSO3• 2½ H2O (tetragonal) : a = b = 946.4, c = 1021.1 pm, Z = 8, CoSO3 · 2 H2O (isotype with ZnSO3 · 2 H2O) : a = 639.7, b = 855.3, c = 753.7 pm, β = 98.85°, Z = 4. The IR spectra show that with exception of MnSO3· H2O strong hydrogen bonds are present in the sulfite hydrates. The decomposition of the sulfites has been examined by thermal analysis. Dehydration of the sulfite hydrates starts at 90 (ZnSO3 · 2½ H2O), 120 (ZnSO3 · 2 H2O), 175 (ZnSO3 · 1/2 H2O), 85 (MnSO3 · 3 H2O), 205 (MnSO3 · H2O), 70 (MgSO3 · 6 H2O), 130 (MgSO3 · 3 H2O), 120 (CoSO3 · 3 H2O), 140 (CoSO3 · 2½ H2O), and 150 °C (CoSO3 · 2 H2O). Decomposition of the anhydrous sulfites occurs at 300-350 (ZnSO3), 390-460 (MnSO3), and 400-530 °C (MgSO3).

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