Synthesis of Mercury(II) and Palladium(II) Organometallic Derivatives of Terephthaldehyde by Metalation, Transmetalation, Oxidation, and Condensation Reactions. X-ray Crystal Structures oftrans-[PdCl{C6H3(CO2H)2-2,5}(PPh3)2]·Me2CO·2MeOH,trans-[PdCl{C6H3(CHO)-2-(CO2H)-5}(PPh3)2]·2CH2Cl2, and [Pd{C6H3(CHNC6H4NH2-4)-2-(CHO)-5}(N,N,N‘,N‘-Tetramethylethylenediamine)]CF3SO3. Molecular Assemblies through [Pd]−Cl···HO2C−Aryl and [Pd]−Cl···HOMe  HO(O)C−Aryl Hydrogen Bonds†

1997 ◽  
Vol 16 (24) ◽  
pp. 5269-5282 ◽  
Author(s):  
José Vicente ◽  
José-Antonio Abad ◽  
Barbara Rink ◽  
Francisco-Santos Hernández ◽  
M. Carmen Ramírez de Arellano
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Molecular Assemblies ◽  
X Ray ◽  
Condensation Reactions ◽  
Derivatives Of

The Through-Bond Interaction of a Sulfur Lone Pair with Oxygenated Substituents in the Thiacyclohexane Framework

2005 ◽  
Vol 58 (7) ◽  
pp. 531
Author(s):  
Laura Andrau ◽  
Jonathan M. White
Keyword(s):  
Low Temperature ◽  
Crystal Structures ◽  
Bond Distance ◽  
Lone Pair ◽  
X Ray ◽  
Ester Derivative ◽  
Bond Interaction ◽  
Derivatives Of ◽  
Electron Demand

Low-temperature X-ray crystal structures were determined on a range of derivatives of 4-thiacyclohexanol 5a of varying electron demand with a view to finding evidence for a through-bond interaction between the sulfur lone pair and the oxygenated substituent. In contrast to earlier suggestions, plots of C–OR bond distance versus pKa (ROH) showed that any interaction between the sulfur and the OR group is unlikely to be of a through-bond origin. Furthermore, unimolecular solvolysis rate measurements on the nosylate ester derivative 5g showed that the sulfur actually retards the reaction slightly in comparison with the corresponding sulfur-free analogue 6.

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.

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.

scholarly journals Frequency and hydrogen bonding of nucleobase homopairs in small molecule crystals

2020 ◽  
Vol 48 (15) ◽  
pp. 8302-8319
Author(s):  
Małgorzata Katarzyna Cabaj ◽  
Paulina Maria Dominiak
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Small Molecule ◽  
Base Pair ◽  
Base Pairs ◽  
Standard Pattern ◽  
Planar Structures ◽  
Structural Database ◽  
Derivatives Of

Abstract We used the high resolution and accuracy of the Cambridge Structural Database (CSD) to provide detailed information regarding base pairing interactions of selected nucleobases. We searched for base pairs in which nucleobases interact with each other through two or more hydrogen bonds and form more or less planar structures. The investigated compounds were either free forms or derivatives of adenine, guanine, hypoxanthine, thymine, uracil and cytosine. We divided our findings into categories including types of pairs, protonation patterns and whether they are formed by free bases or substituted ones. We found base pair types that are exclusive to small molecule crystal structures, some that can be found only in RNA containing crystal structures and many that are native to both environments. With a few exceptions, nucleobase protonation generally followed a standard pattern governed by pKa values. The lengths of hydrogen bonds did not depend on whether the nucleobases forming a base pair were charged or not. The reasons why particular nucleobases formed base pairs in a certain way varied significantly.

Methyl Tin(IV) Derivatives of HOTeF5and HN(SO2CF3)2:  A Solution Multinuclear NMR Study and the X-ray Crystal Structures of (CH3)2SnCl(OTeF5) and [(CH3)3Sn(H2O)2][N(SO2CF3)2]†

2004 ◽  
Vol 43 (10) ◽  
pp. 3189-3199 ◽  
Author(s):  
Ashwani Vij ◽  
William W. Wilson ◽  
Vandana Vij ◽  
Robert C. Corley ◽  
Fook S. Tham ◽  
...  
Keyword(s):  
Crystal Structures ◽  
X Ray ◽  
Multinuclear Nmr ◽  
Nmr Study ◽  
Derivatives Of

New insights into chalcogen bonding provided by co-crystal structures of benzisoselenazolinone derivatives and nitrogen bases

CrystEngComm ◽  
2019 ◽  
Vol 21 (10) ◽  
pp. 1539-1542 ◽  
Author(s):  
Thomas Fellowes ◽  
Jonathan M. White
Keyword(s):  
Crystal Structures ◽  
X Ray ◽  
Nitrogen Bases ◽  
X Ray Crystallography ◽  
Derivatives Of

A number of derivatives of benzisoselenazolinones, including the drug ebselen, have been synthesized, and their interactions with various nitrogen bases characterized through X-ray crystallography.

Sign in / Sign up

Export Citation Format

Share Document