Solid-State Hydration/Dehydration of Erythromycin A Investigated by ab Initio Powder X-ray Diffraction Analysis: Stoichiometric and Nonstoichiometric Dehydrated Hydrate

2013 ◽  
Vol 13 (5) ◽  
pp. 2060-2066 ◽  
Author(s):  
Kotaro Fujii ◽  
Masahide Aoki ◽  
Hidehiro Uekusa
Keyword(s):  
Solid State ◽  
Diffraction Analysis ◽  
Ab Initio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Erythromycin A

Bindung von Metall-Ionen an Dipeptide: Struktur von Thallium(I)-(3-benzyl-6-carboxylatomethyl-2,5-diketopiperazin) / Binding of Metal Ions by Dipeptides: Structure of Thallium(I) 3-Benzyl-6-carboxylatomethyl-2,5-diketopiperazine

1992 ◽  
Vol 47 (7) ◽  
pp. 952-956
Author(s):  
P. Mikulcik ◽  
P. Bissinger ◽  
J. Riede ◽  
H. Schmidbaur
Keyword(s):  
Solid State ◽  
Nitrogen Atom ◽  
Hydrogen Bonds ◽  
Diffraction Analysis ◽  
Carbonyl Oxygen ◽  
State Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystalline Product ◽  
Oxygen Atoms

Ester cleavage of aspartame (L-α-aspartyl-L-phenylalanine methylester) (1), by equimolar quantities of thallium ethoxide is accompanied by intramolecular cyclisation to give thallium 3-benzyl-6-(carboxylatomethyl)-2,5-dioxopiperazine (2). The solid state structure of the crystalline product was determined by single-crystal X-ray diffraction analysis. The cations were found to form four short and four elongated contacts to seven oxygen atoms and one nitrogen atom of a total of six neighbouring 3-benzyl-6-(carboxylatomethyl)-2,5-dioxopiperazine anions. There are inter-anionic hydrogen bonds only between the imino groups and the carbonyl oxygen atoms (O3, O4), featuring a pattern similar to that found for cytosine-guanosine contacts in DNA.

A Solid-State NMR, X-ray Diffraction, and ab Initio Computational Study of Hydrogen-Bond Structure and Dynamics of Pyrazole-4-Carboxylic Acid Chains

2001 ◽  
Vol 123 (32) ◽  
pp. 7898-7906 ◽  
Author(s):  
Concepción Foces-Foces ◽  
Aurea Echevarría ◽  
Nadine Jagerovic ◽  
Ibon Alkorta ◽  
José Elguero ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Solid State ◽  
Carboxylic Acid ◽  
Ab Initio ◽  
Solid State Nmr ◽  
Computational Study ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure And Dynamics

ChemInform Abstract: A Solid-State NMR, X-Ray Diffraction, and ab initio Investigation into the Structures of Novel Tantalum Oxyfluoride Clusters.

ChemInform ◽  
2008 ◽  
Vol 39 (26) ◽  
Author(s):  
Todd M. Alam ◽  
Jacalyn S. Clawson ◽  
Francois Bonhomme ◽  
Steven G. Thoma ◽  
Mark A. Rodriguez ◽  
...  
Keyword(s):  
Solid State ◽  
Ab Initio ◽  
Solid State Nmr ◽  
X Ray Diffraction ◽  
X Ray

A new aspect of the “pseudo water” concept of bis(trimethylsilyl)carbodiimide – “pseudohydrates” of aluminum

2018 ◽  
Vol 73 (11) ◽  
pp. 911-918
Author(s):  
Katrin Krupinski ◽  
Erica Brendler ◽  
Robert Gericke ◽  
Jörg Wagler ◽  
Edwin Kroke
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Diffraction Analysis ◽  
Quantum Chemical ◽  
Metal Salt ◽  
Similar Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
Positional Disorder ◽  
Cp Mas Nmr

AbstractBis(trimethylsilyl)carbodiimide (BTSC), so-called “pseudo water” because of some analogies such as similar (group)electronegativities of Me3Si– vs. H– and –N=C=N– vs. –O–, may form two different kinds of “pseudo hydrates” of metals (M), i.e. M–N(SiMe3)=C=N(SiMe3) and M–N≡C–N(SiMe3)2, derived from its carbodiimide and cyanamide isomeric forms, respectively. With anhydrous AlCl3 in Me3SiCl solution BTSC was shown to be capable of forming both kinds of solvates, i.e. Cl3Al–N(SiMe3)–C≡N(SiMe3) (1) and ((Cl3Al)(Me3Si)NCN)3–Al–(N≡C–N(SiMe3)2)3 (2). Both compounds were isolated as crystalline solids, which undergo condensation reactions upon storage. By single-crystal X-ray diffraction analysis the constitution of 1 was confirmed unambiguously, and quantum chemical calculations (B3LYP/6-311++g(d,p)) confirmed that compound 1 is 6 kcal mol−1 more stable than its hypothetical N,N-bis(trimethylsilyl)cyanamide isomer Cl3Al–N≡C–N(SiMe3)2. Compound 1 represents the first crystallographically confirmed disilylcarbodiimide complex of a metal salt. The molecules of compound 2 are heavily disordered in the solid state (positional disorder of N≡C–N(SiMe3)2 vs. N≡C–N(SiMe3)(AlCl3) and positional disorder of SiMe3 vs. AlCl3 groups in the latter). Therefore, the identity of 2 was additionally confirmed by 13C, 15N, 27Al and 29Si CP/MAS NMR spectroscopy.

Solid State of Polymolybdenum(VI) Phenylsiloxanes - Synthesis and Structure

2019 ◽  
Vol 806 ◽  
pp. 57-63 ◽  
Author(s):  
Nikolai P. Shapkin ◽  
Alevtina Kapustina ◽  
Natalya Dombai ◽  
Vitalii Libanov ◽  
Irina G. Khal'chenko ◽  
...  
Keyword(s):  
Solid State ◽  
Diffraction Analysis ◽  
Mechanical Activation ◽  
Cross Section ◽  
Mechanochemical Activation ◽  
Analysis Data ◽  
X Ray Diffraction ◽  
X Ray ◽  
Soluble Polymers ◽  
Activation Conditions

Interaction of molybdenyl(VI) bis(acetylacetonate) with polyphenylsiloxane in xylene and under mechanochemical activation conditions has been investigated. The interaction of the above reagents under mechanical activation conditions proceeds with formation of soluble polymers similar to those obtained in a solution with the silicon/molybdenum ratio equal to 2.6. The crystal chemistry parameters of the fraction obtained in solution with the ratio Si/Mo = 1:2 have been calculated on the basis of the X-ray diffraction analysis data using the Debye–Shearer equation. It has been demonstrated that the chain cross-section found using the Miller–Boyer method coincides with that calculated geometrically on the basis of literature data on bond lengths and angles.

Mechanism of Dehydration–Hydration Processes of Lisinopril Dihydrate Investigated by ab Initio Powder X-ray Diffraction Analysis

2012 ◽  
Vol 12 (12) ◽  
pp. 6165-6172 ◽  
Author(s):  
Kotaro Fujii ◽  
Hidehiro Uekusa ◽  
Naoko Itoda ◽  
Etsuo Yonemochi ◽  
Katsuhide Terada
Keyword(s):  
Diffraction Analysis ◽  
Ab Initio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mechanism Of Dehydration
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