Structure-reactivity correlation in inclusion complexes: deoxycholic acid di-tert-butyl thioketone

1984 ◽  
Vol 62 (10) ◽  
pp. 2025-2028 ◽  
Author(s):  
K. Padmanabhan ◽  
K. Venkatesan ◽  
V. Ramamurthy
Keyword(s):  
Inclusion Complexes ◽  
Structure Analysis ◽  
Ultraviolet Irradiation ◽  
Deoxycholic Acid ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tert Butyl ◽  
Molecular Inclusion

Ultraviolet irradiation of crystalline molecular inclusion complexes of deoxycholic acid with di-tert-butyl thioketone results in no reaction. The structure of the above complex has been determined via X-ray diffraction. The absence of expected photoreactions, namely, photoreduction and photooxidation, is rationalized on the basis of the X-ray structure analysis of the complex.

Synthesis and Structure Analysis of N1,N4-di-tert-Butyl-3,6-Dimethyl-1,4-Dihydro-1,2,4,5-Tetrazine-1,4-Dicarboxamide

2012 ◽  
Vol 36 (3) ◽  
pp. 172-174 ◽  
Author(s):  
Guo-Wu Rao ◽  
Jia-Bin Ni ◽  
Qi Li
Keyword(s):  
Single Crystal ◽  
Structure Analysis ◽  
Title Compound ◽  
Boat Conformation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tert Butyl

N1, N4-Di- tert-butyl-3,6-dimethyl-1,4-dihydro-1,2,4,5-tetrazine-1,4-dicarboxamide was prepared from 3,6-dimethyl-1,6-dihydro-1,2,4,5-tetrazine, and its structure was confirmed by single-crystal X-ray diffraction. This reaction yields the 1,4-dicarboxamide derivative rather than the 1,2-dicarboxamide derivative. The central six-member ring of the title compound has a boat conformation and therefore, is not homoaromatic.

Studies on the Preparation, Characterization and Solubility of -Cyclodextrin-Roxythromycin Inclusion Complexes

2009 ◽  
Vol 2 (2) ◽  
pp. 523-530
Author(s):  
D. Nagasamy Venkatesh ◽  
S. Karthick ◽  
M. Umesh ◽  
G. Vivek ◽  
R.M. Valliappan ◽  
...  
Keyword(s):  
Dissolution Rate ◽  
Inclusion Complexes ◽  
Phase Solubility ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ir Studies ◽  
Poorly Soluble ◽  
Poorly Soluble Drug

Roxythromycin/ β-cyclodextrin (Roxy/ β-CD) dispersions were prepared with a view to study the influence of β-CD on the solubility and dissolution rate of this poorly soluble drug. Phase-solubility profile indicated that the solubility of roxythromycin was significantly increased in the presence of β-cyclodextrin and was classified as AL-type, indicating the 1:1 stoichiometric inclusion complexes. Physical characterization of the prepared systems was carried out by differential scanning calorimetry (DSC), X-ray diffraction studies (XRD) and IR studies. Solid state characterization of the drug β-CD binary system using XRD, FTIR and DSC revealed distinct loss of drug crystallinity in the formulation, ostensibly accounting for enhancement of dissolution rate.

scholarly journals Synchrotron Nano-Diffraction Study of Thermally Treated Asbestos Tremolite from Val d’Ala, Turin (Italy)

Minerals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 311 ◽  
Author(s):  
Carlotta Giacobbe ◽  
Jonathan Wright ◽  
Dario Di Giuseppe ◽  
Alessandro Zoboli ◽  
Mauro Zapparoli ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Heat Treatment ◽  
Risk Management ◽  
Structure Analysis ◽  
X Rays ◽  
X Ray Diffraction ◽  
X Ray ◽  
Adverse Health Effects ◽  
Nano Crystalline ◽  
Original Fibre

Nowadays, due to the adverse health effects associated with exposure to asbestos, its removal and thermal inertization has become one of the most promising ways for reducing waste risk management. Despite all the advances in structure analysis of fibers and characterization, some problems still remain that are very hard to solve. One challenge is the structure analysis of natural micro- and nano-crystalline samples, which do not form crystals large enough for single-crystal X-ray diffraction (SC-XRD), and their analysis is often hampered by reflection overlap and the coexistence of multiple fibres linked together. In this paper, we have used nano-focused synchrotron X-rays to refine the crystal structure of a micrometric tremolite fibres from Val d’Ala, Turin (Italy) after various heat treatment. The structure of the original fibre and after heating to 800 °C show minor differences, while the fibre that was heated at 1000 °C is recrystallized into pyroxene phases and cristobalite.

scholarly journals New Spiro-Tin Compounds: Reaction of N,N′-Dialkyl Sulfur Diimides with Cyclic Bis(amino)stannylenes - Unexpected Formation of a N-N Bond

1995 ◽  
Vol 50 (12) ◽  
pp. 1811-1817 ◽  
Author(s):  
Max Herberhold ◽  
Christian Köhler ◽  
Wolfgang Milius ◽  
Bernd Wrackmeyer
Keyword(s):  
Molecular Structure ◽  
Magnetic Resonance ◽  
Single Crystal ◽  
Structure Analysis ◽  
Membered Ring ◽  
Monoclinic Space Group ◽  
Unexpected Formation ◽  
Tin Compounds ◽  
X Ray ◽  
Tert Butyl

N,N′-Dialkyl sulfur diimides (1), R(NSN)R [R = Me (a), Et (b), nPr (c), nBu (d)] react with cyclic bis(amino)stannylenes such as 1,3-di-tert-butyl-4,4-dimethyl-1,3,4,2λ2-diazasilastannetedine (2) or 1,3-di-tert-butyl-4,4,5,5-tetramethyl-1,3,4,5,2λ2-diazadisilastannolidine (3) in a 2:1 ratio to give the new spiro-tin(IV) compounds 5a-d, 6b and 6c, built from the respective cyclic bis(amino)stannylene and a seven-membered ring in which the two sulfur diimide groups are coupled via a N-N bond and across the tin atom. A 1:1 adduct 4 is proposed as an intermediate which is the final product 4e in the case of R = tBu (1e). The products were characterized by multinuclear magnetic resonance (1H, 13C, 15N, 29Si, 119Sn NMR), and in the case of 5c the molecular structure was determined by single crystal X-ray structure analysis [monoclinic, space group C2/c ; a = 1504.1(3), b = 1393.3(3), c = 1688.6(3) pm; β = 115.71(3)°].

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