scholarly journals Synthesis, Crystal Structures, and Spectroscopic Properties of Novel Gadolinium and Erbium Triphenylsiloxide Coordination Entities

Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 147
Author(s):  
Patrycja Wytrych ◽  
Józef Utko ◽  
Julia Kłak ◽  
Maciej Ptak ◽  
Mariusz Stefanski ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Variable Temperature ◽  
Magnetic Interaction ◽  
Spectroscopic Properties ◽  
Lanthanide Ions ◽  
Oxidation States ◽  
Crystal Field Effect ◽  
Spectroscopy Studies ◽  
Behavior Characteristics

In alkali metal and lanthanide coordination chemistry, triphenylsiloxides seem to be unduly underappreciated ligands. This is as surprising as that such substituents play a crucial role, among others, in stabilizing rare oxidation states of lanthanide ions, taking a part of intramolecular and molecular interactions stabilizing metal-oxygen cores and many others. This paper reports the synthesis and characterization of new lithium [Li4(OSiPh3)4(THF)2] (1), and sodium [Na4(OSiPh3)4] (2) species, which were later used in obtaining novel gadolinium [Gd(OSiPh3)3(THF)3]·THF (3), and erbium [Er(OSiPh3)3(THF)3]·THF (4) triphenylsiloxides. Crystal structures were determined for all 1–4 compounds, and in addition, IR, Raman, absorption spectroscopy studies were conducted for 3 and 4 lanthanide compounds. Furthermore, direct current (dc) variable-temperature magnetic susceptibility measurements on polycrystalline samples of 3 and 4 were carried out in the temperature range 1.8–300 K. The 3 shows behavior characteristics for the paramagnetism of the Gd3+ ion. In contrast, the magnetic properties of 4 are dominated by the crystal field effect on the Er3+ ion, masking the magnetic interaction between magnetic centers of neighboring molecules.

Iridium(I) complexes containing bidentate pyrazolylgallate ligands. X-ray crystal structures of [Me2Gapz2]Ir(COD), [Ir(μ-pz)(CO)2]2, and [Ir(μ-3,5-Me2pz)(CO)2]2

1985 ◽  
Vol 63 (3) ◽  
pp. 692-702 ◽  
Author(s):  
Sophia Nussbaum ◽  
Steven J. Rettig ◽  
Alan Storr ◽  
James Trotter
Keyword(s):  
Crystal Structures ◽  
Variable Temperature ◽  
Hydrogenation Reaction ◽  
Synthesis And Characterization ◽  
Nmr Studies ◽  
X Ray ◽  
H Nmr ◽  
Measurable Activity

The synthesis and characterization of a number of Ir(I) complexes incorporating bidentate, chelating, pyrazolylgallate ligands are described. Non-rigidity for some of the complexes in solution has been demonstrated by variable temperature 1H nmr studies. Crystal structures of three complexes, [Me2Gapz2]Ir(COD), [Ir(μ-pz)(CO)2]2, and [Ir(μ-3,5-Me2pz)(CO)2]2 are reported and confirm the expected boat conformations for the six-membered M—(N—N)2—Ir rings (where M = Ir or Ga) in the compounds. One of the complexes studied has exhibited measurable activity as a catalyst in the hydrogenation reaction of cyclohexene.

Synthesis and characterization of dimethyl- and dimethoxyphenylbis(N,N-dialkyldithiocarbamato)tellurium(IV) and chlorodimethyl- and chlorodimethoxyphenyl-(N,N-dialkyldithiocarbamato)tellurium(IV). Crystal structures of Me2Te[S2CNMe2]2 and (p-MeOC6H4)2Te[S2CNMe2]2

1993 ◽  
Vol 71 (1) ◽  
pp. 42-50 ◽  
Author(s):  
Jane H. E. Bailey ◽  
John E. Drake
Keyword(s):  
Nmr Spectroscopy ◽  
Crystal Structures ◽  
Variable Temperature ◽  
Reductive Elimination ◽  
Synthesis And Characterization ◽  
Space Group ◽  
Cell Parameters

The compounds Me2Te[S2CNR2]2, Me2TeCl[S2CNR2], (p-MeOC6H4)2Te[S2CNR2]2, and (p-MeOC6H4)2TeCl[S2CNR2], where R = Me, Et, have been prepared and characterised primarily by vibrational and NMR spectroscopy. Variable temperature NMR spectroscopy and qualitative time studies indicate that in solution the dimethoxyphenyltellurium derivatives undergo the reductive-elimination noted for analogous phenyl derivatives but the reductive-elimination does not occur with the dimethyl tellurium derivatives. The crystal structures of Me2Te[S2CNMe2]2, 1, and (p-MeOC6H4)2-Te[S2CNMe2]2, 5, were completed. The cell parameters for 1, which crystallizes as monoclinic in space group P21/n, are a = 13.550(2), b = 13.034(2), c = 17.854(2) Å, β = 106.61(1)°, V = 3021.6(7) Å3, Z = 8, R = 0.0368, and Rw = 0.0402 and for 5, which crystallizes as monoclinic in space group C2/c, are a = 35.36(1), b = 11.063(3), c = 12.778(3) Å, β = 96.16(3)°, V = 4963(3) Å3, Z = 8, R = 0.0627, and Rw = 0.0646.

scholarly journals Solvatomorphism of Moxidectin

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4869
Author(s):  
Toni Grell ◽  
Mauro Barbero ◽  
Franco Pattarino ◽  
Giovanni Battista Giovenzana ◽  
Valentina Colombo
Keyword(s):  
Diffraction Analysis ◽  
Crystal Structures ◽  
Variable Temperature ◽  
Thermal Characterization ◽  
Active Pharmaceutical Ingredient ◽  
X Ray Diffraction ◽  
X Ray ◽  
Anthelmintic Drug

The solvatomorphism of the anthelmintic drug moxidectin is investigated, and a new solvatomorph with nitromethane is reported. Moreover, the hitherto unknown crystal structures of the solvatomorphs with ethanol and 2-propanol are reported and discussed. The thermal characterization of these solvatomorphs through variable-temperature powder X-ray diffraction analysis (VT-PXRD) is also described, providing new insights into the crystallochemistry of this active pharmaceutical ingredient.

Catalytic Fluorination of Boron Compounds at a Bismuth Redox Platform

2019 ◽  
Author(s):  
Oriol Planas ◽  
Feng Wang ◽  
Markus Leutzsch ◽  
Josep Cornella
Keyword(s):  
Transition Metal ◽  
Main Group ◽  
Group Element ◽  
Oxidation States ◽  
Boron Compounds ◽  
Main Text ◽  
Main Group Element ◽  
Rational Ligand Design ◽  
Supplementary Material

The ability of bismuth to maneuver between different oxidation states in a catalytic redox cycle, mimicking the canonical organometallic steps associated to a transition metal, is an elusive and unprecedented approach in the field of homogeneous catalysis. Herein we present a catalytic protocol based on bismuth, a benign and sustainable main-group element, capable of performing every organometallic step in the context of oxidative fluorination of boron compounds; a territory reserved to transition metals. A rational ligand design featuring hypervalent coordination together with a mechanistic understanding of the fundamental steps, permitted a catalytic fluorination protocol based on a Bi(III)/Bi(V) redox couple, which represents a unique example where a main-group element is capable of outperforming its transition metal counterparts.<br>A main text and supplementary material have been attached as pdf files containing all the methodology, techniques and characterization of the compounds reported.<br>

Radially π-Extended Pyrrole-Fused Azacoronene: A Series of Crystal Structures of HPHAC with Various Oxidation States

2021 ◽  
Vol 86 (5) ◽  
pp. 4290-4295 ◽  
Author(s):  
Yoshiki Sasaki ◽  
Masayoshi Takase ◽  
Nagao Kobayashi ◽  
Shigeki Mori ◽  
Keishi Ohara ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Oxidation States
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