Chemistry of boranes. III. Relationship between structure and chromatographic behaviour of boranes and their addition compounds with Lewis bases

1966 ◽  
Vol 31 (5) ◽  
pp. 1975-1984 ◽  
Author(s):  
S. Heřmánek ◽  
J. Plešek
Keyword(s):  
Chromatographic Behaviour ◽  
Lewis Bases

Cocrystals of 1,2-bis(chloromercurio) tetrafluorobenzene with netural bidentate Lewis bases

2007 ◽  
Vol 63 (a1) ◽  
pp. s166-s166
Author(s):  
M. Yu. Antipin ◽  
A. A. Yakovenko ◽  
J. H. Gallegos ◽  
T. V. Timofeeva
Keyword(s):  
Lewis Bases

scholarly journals Relativistic Effects on NMR Parameters of Halogen-Bonded Complexes

Molecules ◽  
2019 ◽  
Vol 24 (23) ◽  
pp. 4399 ◽  
Author(s):  
Ibon Alkorta ◽  
José Elguero ◽  
Manuel Yáñez ◽  
Otilia Mó ◽  
M. Merced Montero-Campillo
Keyword(s):  
Relativistic Effects ◽  
Lewis Base ◽  
Coupling Constants ◽  
Basic Site ◽  
Lewis Bases ◽  
Nmr Parameters ◽  
Quadrupolar Coupling ◽  
Binary Complexes ◽  
Computational Level ◽  
Bonded Complexes

Relativistic effects are found to be important for the estimation of NMR parameters in halogen-bonded complexes, mainly when they involve the heavier elements, iodine and astatine. A detailed study of 60 binary complexes formed between dihalogen molecules (XY with X, Y = F, Cl, Br, I and At) and four Lewis bases (NH3, H2O, PH3 and SH2) was carried out at the MP2/aug-cc-pVTZ/aug-cc-pVTZ-PP computational level to show the extent of these effects. The NMR parameters (shielding and nuclear quadrupolar coupling constants) were computed using the relativistic Hamiltonian ZORA and compared to the values obtained with a non-relativistic Hamiltonian. The results show a mixture of the importance of the relativistic corrections as both the size of the halogen atom and the proximity of this atom to the basic site of the Lewis base increase.

Urobiliverdin, a New Bile Pigment Deriving from Uroporphyrin

1983 ◽  
Vol 38 (9-10) ◽  
pp. 753-757 ◽  
Author(s):  
Eva Benedikt ◽  
Hans-Peter Köst
Keyword(s):  
Carboxylic Acid ◽  
Main Product ◽  
Aminolevulinic Acid ◽  
Chromic Acid ◽  
Bile Pigment ◽  
Enzyme Extract ◽  
Crude Enzyme Extract ◽  
Chromatographic Behaviour ◽  
Vis Spectroscopy ◽  
Rhodopseudomonas Spheroides

5-Aminolevulinic acid is incubated with a crude enzyme extract from Rhodopseudomonas spheroides, mutant R 26. The formed porphyrins (main product: uroporphyrin III) are isolated. Incorporation of iron, ring-splitting by coupled oxydation and subsequent iron removal leads to a mixture of pigments, from which urobiliverdin, a new bile pigment with eight carboxylic acid side chains, is isolated. It is characterized by its chromatographic behaviour, chromic acid degra­dation and UV-vis spectroscopy.

Addition of the oxirane derivatives to CO2 catalyzed by Lewis bases under mild conditions

2021 ◽  
Vol 70 (6) ◽  
pp. 1118-1123
Author(s):  
I. S. Gabov ◽  
V. A. Kuznetsov ◽  
I. S. Puzyrev ◽  
A. V. Pestov
Keyword(s):  
Lewis Bases ◽  
Mild Conditions

Cobalt(II) Mercury Tetrathiocyanate Complexes with Lewis Bases

1973 ◽  
Vol 51 (3) ◽  
pp. 438-447 ◽  
Author(s):  
R. Makhija ◽  
L. Pazdernik ◽  
R. Rivest
Keyword(s):  
Magnetic Susceptibility ◽  
Powder Diffraction ◽  
Elemental Analysis ◽  
Far Infrared ◽  
Crystalline Solid ◽  
Ultraviolet Spectroscopy ◽  
X Ray ◽  
Lewis Bases ◽  
Polydentate Ligands

A new series of octahedral cobalt(II) complexes are formed when CoX2(X = Cl, Br, I, SCN) reacts with Hg(SCN)2 in the presence of Lewis bases. These complexes of stoichiometry CoHg(SCN)4•2L (L = THF, dioxane, pyridine, aniline) are pink to violet solids which slowly decompose to the blue crystalline solid, CoHg(SCN)4, the stable magnetic susceptibility standard. On further reaction of CoHg(SCN)4•2THF with mono-, bi-, and polydentate ligands in dry ethanol, complexes of the following types are obtained: CoHg(SCN)4•2L (L = PΦ3), CoHg(SCN)4•2LL (LL = trien), CoHg(SCN)4•3LL (LL = en, bipy), and CoHg(SCN)4•4LL (LL = phen). The stoichiometry of these were determined by elemental analysis. Possible structures of these are discussed with the help of mid and far infrared, visible, and ultraviolet spectroscopy, magnetic susceptibility, and X-ray powder diffraction. Some new i.r. bands like Co—P, Co—N, and Hg—S are assigned in the low region.

Spontaneous bond dissociation cascades induced by Ben clusters (n = 2,4)

2021 ◽  
Author(s):  
Eva Vos ◽  
Inés Corral ◽  
M. Merced Montero-Campillo ◽  
Otilia Mó ◽  
José Elguero ◽  
...  
Keyword(s):  
Lewis Acids ◽  
Lewis Bases ◽  
Bond Dissociation ◽  
Multireference Methods

Be4 clusters are very powerful Lewis acids leading to the total dissociation of all the bonds of the Lewis bases interacting with them. The product of the bond dissociation cascade possesses a hyper-coordinated center. Multireference methods are needed to correctly describe these complexes.

Chromatographic behaviour and purification of N1.5-glycosyl enkephalins

1988 ◽  
Vol 25 (10) ◽  
pp. 891-894 ◽  
Author(s):  
J. L. Torres ◽  
P. Clapés ◽  
I. Haro ◽  
G. Valencia ◽  
F. Reig ◽  
...  
Keyword(s):  
Chromatographic Behaviour
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