On the Synthesis and Addition Reactions of Chiral N-Heterocyclic Diphosphines

2012 ◽  
Vol 67 (8) ◽  
pp. 765-773 ◽  
Author(s):  
Daniela Förstera ◽  
Ingo Hartenbach ◽  
Martin Nieger ◽  
Dietrich Gudat
Keyword(s):  
Single Crystal ◽  
Optically Active ◽  
Molecular Structures ◽  
Addition Reactions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Chiral Induction

Reaction of chiral N-heterocyclic chlorophosphines with lithium diphenylphosphide or of achiral N-heterocyclic chlorophosphines with optically active lithium menthyl phosphide produces chiral N-heterocyclic diphosphines which can be utilized in subsequent diphosphination reactions with activated alkenes or alkynes. The reaction with alkynes proceeds stereospecifically to produce Zethylene- 1,2-bisphosphines which are readily converted to nickel(II) or palladium(II) complexes. Reactions with alkenes are synthetically less useful as the addition proceeds without any chiral induction at the newly formed stereocenters to yield inseparable mixtures of diastereomeric products. The molecular structures of chiral Z-ethylene-1,2-bisphosphine complexes and of a chiral N-heterocyclic chlorophosphine have been determined by single-crystal X-ray diffraction

Lewis-Base Adducts of Group 1B Metal(I) Compounds. XXI The Crystal and Molecular Structures of the Unsolvated Forms of Dibromotris(triphenylphosphine)dicopper(I) and 'step' Tetrabromotetrakis(triphenyl-phosphine)tetracopper(I)

1985 ◽  
Vol 38 (8) ◽  
pp. 1243 ◽  
Author(s):  
JC Dyason ◽  
LM Engelhardt ◽  
C Pakawatchai ◽  
PC Healy ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Molecular Structures ◽  
Lewis Base ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
Triphenyl Phosphine ◽  
X Ray ◽  
Crystal And Molecular Structures

The crystal structures of the title compounds have been determined by single-crystal X-ray diffraction methods at 295 K. Crystal data for (PPh3)2CuBr2Cu(PPh3) (1) show that the crystals are iso-morphous with the previously studied chloro analogue, being monoclinic, P21/c, a 19.390(8), b 9.912(5), c 26.979(9) Ǻ, β 112,33(3)°; R 0.043 for No 3444. Cu( trigonal )- P;Br respectively are 2.191(3); 2.409(2), 2.364(2) Ǻ. Cu(tetrahedral)- P;Br respectively are 2.241(3), 2.249(3); 2.550(2), 2.571(2) Ǻ. Crystals of 'step' [PPh3CuBr]4 (2) are isomorphous with the solvated bromo and unsolvated iodo analogues, being monoclinic, C2/c, a 25.687(10), b 16.084(7), c 17.815(9) Ǻ, β 110.92(3)°; R 0.072 for No 3055. Cu( trigonal )- P;Br respectively are 2.206(5); 2.371(3), 2.427(2) Ǻ. Cu(tetrahedral)- P;Br are 2.207(4); 2.446(2), 2.676(3), 2.515(3) Ǻ.

scholarly journals Structural Study of Three 1,2,4-triazole Derivatives Prepared by Oxidative Cyclization of Thiosemicarbazides

Proceedings ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 20
Author(s):  
Mirian Artime ◽  
Alfonso Castiñeiras ◽  
Isabel García-Santos ◽  
Manuel Saa
Keyword(s):  
Acetic Acid ◽  
Single Crystal ◽  
Structural Study ◽  
Supramolecular Assembly ◽  
Oxidative Cyclization ◽  
Molecular Structures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Triazole Derivatives

In the present research, 5,5-dimethyl-4-phenyl-4,5-dihydro-3H-1,2,4-triazole-3-thione (1) was prepared by condensation from N-phenylhydrazinecarbothioamide, while 4-phenyl-5-(pyrazin-2-yl)-2,4-dihydro-3H-1,2,4-triazole-3-thione (2) and 2-((5-(pyridin-2-yl) -4H-1,2,4-triazol-3-yl)thio)acetic acid (3) was prepared by oxidative cyclization from 2-(amino(pyrazin-2-yl)methylene)-N-phenylhydrazine-1-carbothioamide and 2-(amino(pyridine-2-yl)methylene)hydrazine-1-carbothioamide, respectively. The three compounds have been well characterized and their molecular structures studied by single-crystal X-ray diffraction. The supramolecular assembly of each crystal has also been analyzed and discussed.

Syntheses and molecular structures of some di(amidino)monosilanes

2021 ◽  
Vol 44 (1) ◽  
pp. 228-238
Author(s):  
Markus Bös ◽  
Marcus Herbig ◽  
Uwe Böhme ◽  
Edwin Kroke
Keyword(s):  
Raman Spectroscopy ◽  
Single Crystal ◽  
High Field ◽  
Structural Features ◽  
Molecular Structures ◽  
X Ray Diffraction ◽  
One Pot ◽  
X Ray ◽  
Field Shift ◽  
Nmr Signals

Abstract The syntheses of three different amidinosilanes of the type Me2Si[N=C(Ph)R]2 with R = pyrrolidino, morpholino, and diethylamino and one derivative with the composition R2Si[N=C(Ph)R]2 with R = morpholino are reported. These compounds were prepared in one-pot syntheses including three consecutive steps. All products are analysed by single crystal X-ray diffraction, NMR, and Raman spectroscopy. The Si–N=C–N units of these compounds show characteristic structural features and cause a significant high field shift of the 29Si NMR signals.

Synthesis and Structural Characterization of Palladium Dicarbene Complexes Bearing Labile Co-Ligands

2009 ◽  
Vol 62 (9) ◽  
pp. 983 ◽  
Author(s):  
Han Vinh Huynh ◽  
Hui Xian Seow
Keyword(s):  
Single Crystal ◽  
Structural Characterization ◽  
Molecular Structures ◽  
X Ray Diffraction ◽  
Metathesis Reaction ◽  
X Ray ◽  
Low Activity

Dicarbene complexes [Pd(OAc)2(diNHC)] (2), [Pd(O2CCF3)2(diNHC)] (3), and [Pd(CNCH3)2(diNHC)](SO3CF3)2 (4) bearing labile acetato, fluoroacetato, and acetonitrile co-ligands have been synthesized via metathesis reaction of the respective precursor [PdBr2(diNHC)] (1) with Ag-salts. All complexes are stable towards air and moisture and have been fully characterized by spectroscopic and spectrometric methods. Notably and in comparison to diphosphine analogues, they resist ligand disproportionation in solution. Their molecular structures have also been determined by single crystal X-ray diffraction. A preliminary catalytic study showed low activity in the hydroamination reaction, but revealed an interesting co-ligand influence.

A Speculative Discussion of the Structural Details of 1-Bromo-2-iodo-benzenes

2004 ◽  
Vol 59 (3) ◽  
pp. 264-268 ◽  
Author(s):  
Hubert Schmidbaur ◽  
Oliver Minge ◽  
Stefan Nogai
Keyword(s):  
Single Crystal ◽  
Van Der Waals ◽  
Visible Region ◽  
Molecular Structures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
Structural Details ◽  
Steric Crowding ◽  
Speculative Discussion

The crystal and molecular structures of 2,4-dibromo-1-iodo-benzene (1) and 1,3-dibromo-2-iodobenzene (2) have been determined by single crystal X-ray diffraction. The proximity of two or three large halogen substituents (Br/I) induces only minor distortions of the C-C-Br/I angles (ca. 2°) and the halogen atoms remain in the plane of the molecules. These undistorted structures lead to short intramolecular, sub-van-der-Waals Br-I contacts [in the range 3.465(4) to 3.530(4) Å ]. The results suggest that the peripheral Br-I interactions have an attractive component which alleviates the repulsion out of steric crowding. The influence is associated with an absorption in the visible region and is possibly responsible for the enhanced reactivity of the 1,2-dihalobenzene molecules

Preparation and Structural Studies of Non-Symmetric Guanidinate-Supported Zirconium Complexes

2014 ◽  
Vol 67 (7) ◽  
pp. 1063 ◽  
Author(s):  
Rafael Fernández-Galán ◽  
Juan-Antonio Navarro ◽  
Fernando Carrillo-Hermosilla ◽  
Antonio Antiñolo ◽  
Isabel López-Solera ◽  
...  
Keyword(s):  
Single Crystal ◽  
Molecular Structures ◽  
Insertion Reaction ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
Metathesis Reaction ◽  
X Ray ◽  
Zirconium Complexes

The new lithium guanidinate salt [Li{μ-κ1,κ2,N,N′-(NEt)(N-t-Bu)CNMe2}(THF)]2 (1) was obtained by the reaction of HNMe2 with n-BuLi and further reaction with the asymmetric carbodiimide EtN=C=N-t-Bu. Guanidinate-supported zirconium complexes [Zr{κ2,N,N′-(NEt)(N-t-Bu)CNMe2}(μ-Cl)Cl2]2 (2), [Zr{κ2,N,N′-(NEt)(N-t-Bu)CNMe2}3Cl] (4), [Zr{κ2,N,N′-(NEt)(N-t-Bu)CNMe2}2(η5-C5H5)Cl] (5) and [Zr{κ2,N,N′-(NEt)(N-t-Bu)CNMe2}(η5-C5H5)2Cl] (6) were prepared. Complexes 2, 4, and 6 were synthesized by the metathesis reaction of ZrCl4 or [ZrCl2(η5-C5H5)2] with 1. The previously described complex [Zr{κ2,N,N′-(NEt)(N-t-Bu)CNMe2}2Cl2] (3), which was prepared by the insertion reaction of EtN=C=N-t-Bu into a metal–amido bond of [Zr(NMe2)2Cl2(THF)2], allowed the new complex 5 to be obtained by reaction with NaC5H5. All of the new complexes were characterized spectroscopically and the molecular structures of 1, 4, and 6 were determined by single-crystal X-ray diffraction.

Molecular structures of organotin tropolonato complexes with tin coordination numbers 5-7, seen by single-crystal x-ray diffraction and solid- and solution-state119Sn NMR

2001 ◽  
Vol 40 (1) ◽  
pp. 31-40 ◽  
Author(s):  
Carlos Camacho-Camacho ◽  
Rosalinda Contreras ◽  
Heinrich Nöth ◽  
Matthias Bechmann ◽  
Angelika Sebald ◽  
...  
Keyword(s):  
Single Crystal ◽  
Molecular Structures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Coordination Numbers ◽  
Tin Coordination

Reactions between ruthenium chlorides and trimethyl phosphite : crystal and molecular structures of RuCI3(NH3)[P(OMe)3]2

1980 ◽  
Vol 33 (1) ◽  
pp. 195 ◽  
Author(s):  
MI Bruce ◽  
DA Kelly ◽  
GM Mclaughlin ◽  
GB Robertson ◽  
IB Tomkins ◽  
...  
Keyword(s):  
Single Crystal ◽  
Diffraction Study ◽  
Molecular Structures ◽  
Trimethyl Phosphite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
A Minor

The reaction between RuCl3,nH2O and P(OMe)3 affords RuCl2[P(OMe)3]4; one batch of RuCl3,-nH2O also gave amminetrichlorobis(trimethyl phosphite)ruthenium(III), RuCl3(NH3)[P(OMe)3]2, as a minor product. The structure of this complex has been determined from a single-crystal X-ray diffraction study (4598 data, R 0.065, Rw 0.090): the ruthenium is approximately octahedrally coordinated by the three mer chloro, two trans P(OMe)3 and one NH3 ligands. Crystals are monoclinic,P21/n, a 8.725(3), b 18.286(7), c 10.936(4)Ǻ, β 94.57(3)°, Z 4.

Structural and spectroscopic characterization of isotypic sodium, rubidium and cesium acesulfamates

2015 ◽  
Vol 70 (7) ◽  
pp. 491-496 ◽  
Author(s):  
Oscar E. Piro ◽  
Gustavo A. Echeverría ◽  
Eduardo E. Castellano ◽  
Beatriz S. Parajón-Costa ◽  
Enrique J. Baran
Keyword(s):  
Aqueous Solutions ◽  
Single Crystal ◽  
Potassium Salt ◽  
Spectroscopic Characterization ◽  
Molecular Structures ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystal And Molecular Structures

AbstractThree new acesulfamate salts, NaC4H4NO4S, RbC4H4NO4S and CsC4H4NO4S, were prepared by reactions in aqueous solutions and thoroughly characterized. Their crystal and molecular structures were determined by single crystal X-ray diffraction methods. They crystallize in the monoclinic space group P21/a with a = 7.2518(2), b = 8.9414(4), c = 10.5929(4) Å, β = 99.951(3)°, V = 676.52(4) Å3 for the Na salt; a = 7.4663(3), b = 9.6962(4), c = 10.4391(4) Å, β = 95.150(3)°, V = 752.68(5) Å3 for the Rb salt and a = 7.5995(4), b = 9.9439(4), c = 10.8814(6) Å, β = 91.298(5)°, V = 822.08(7) Å3 for the Cs salt, and Z = 4 molecules per unit cell. The three compounds are isotypic to each other and to the previously reported potassium salt. The metal ions are in irregular polyhedral coordination with six neighboring acesulfamate anions through their nitrogen and carbonyl and sulfoxide oxygen atoms. The FTIR spectra of the compounds were also recorded and are briefly discussed.

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