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.

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.

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.

The vanadate garnet Ca2NaCd2V3O12: a single-crystal X-ray diffraction study

2018 ◽  
Vol 74 (4) ◽  
pp. 460-464 ◽  
Author(s):  
Makoto Tokuda ◽  
Akira Yoshiasa ◽  
Tsutomu Mashimo ◽  
Kazuake Iishi ◽  
Akihiko Nakatsuka
Keyword(s):  
Single Crystal ◽  
Edge Length ◽  
Geometric Constraints ◽  
Structural Studies ◽  
Floating Zone ◽  
X Ray Diffraction ◽  
Zone Method ◽  
X Ray ◽  
Atomic Coordinates ◽  
Shared Edge

Single crystals of the vanadate garnet Ca2NaCd2V3O12 (dicalcium sodium dicadmium trivanadate) were synthesized using the floating-zone method and the crystal structure was investigated using single-crystal X-ray diffraction. We considered the effectiveness of substitution of the Y-site cation with reference to previous structural studies of vanadate garnets. The structures of vanadate garnets are subject to geometric constraints similar to those of silicate garnets. These constraints force the tetrahedral–dodecahedral shared edge length in vanadate garnets to become shorter than the unshared dodecahedral edge length, as in ugrandite (uvarovite, grossular and andradite) garnets. However, the vanadate garnet Ca2NaCd2V3O12 exhibits the normal structural feature, similar to pyralspite (pyrope, almandine and spessartine) garnets, namely that the dodecahedral–dodecahedral shared edge length is shorter than the unshared dodecahedral edge length. With increasing ionic radius of the Y-site cation, the atomic coordinates x, y and z of oxygen adopt values which satisfy Pauling's third rule.

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.

Structural studies in the iron(III)/chloride/α,α'-diimine system. III. Crystal structures of Tris(2,2'-bipyridine)iron(II) μ-Oxo-bis[trichloroferrate(III)] and of 'Compound A', μ-Oxo-bis[cis-chlorobis(1 ,10-phenanthroline)iron(III)] chloride solvate

1983 ◽  
Vol 36 (10) ◽  
pp. 2057 ◽  
Author(s):  
PC Healy ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
Single Crystal ◽  
Least Squares ◽  
Structure Determination ◽  
Ionic Species ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
Compound A ◽  
X Ray

The crystal structure of [Fe(bpy)3] [CI3FeOFeCI3] (1) has been determined by single-crystal X-ray diffraction at 295 K, and refined by least squares to a residual of 0.058 for 2002 'observed' reflections. Crystals are monoclinic, P21/c, a 9.616(3), b 26.264(6), c 13.821(7) Ǻ, β 99.68(2)°, Z4. In the cation, Fe-N distances range from 1.956(9) to 1 .989(10) Ǻ; in the anion, Fe-Cl distances range from 2.196(5) to 2.225(5) Ǻ. Fe-O distances are 1.763(11) and 1.740(11) Ǻ, and the Fe-O-Fe angle is 148.9(7)°. Recrystallization of 'compound A' from methanolic aqueous solution yields crystals with stoichiometry [{cis-Fe(phen)2Cl}2O]Cl2.nH2O( n ≈ 4.5) as established by structure determination (hampered by serious disorder); R is 0.09 for 749 'observed' reflections. Crystals are orthorhombic, Pcn2, a 18.05(1), b 13.83(1), c 10.481(6) Ǻ, Z 2. The Fe-N distances trans to each other are 2.12(3) and 2.13(3) Ǻ; Fe-N distances trans to Cl and O are 2.20(2) and 2.28(2) Ǻ, respectively. Fe-CI is 2.34(1) and Fe-O 1.787(6) A; Fe-O-Fe is 161(1)°. For crystals from aqueous solution, an isomorphous but larger unit cell is obtained [2754(7), cf. 2616(3) Ǻ3]; it is believed that this is a consequence of variable occupancy of the disordered solvent layers which lie parallel to bc between the ionic species.

scholarly journals Analysis of LiKSO4 crystals in the temperature range from 573 to 943 K

2000 ◽  
Vol 56 (4) ◽  
pp. 607-617 ◽  
Author(s):  
Carlos Basílio Pinheiro ◽  
Marcos Assunção Pimenta ◽  
Gervais Chapuis ◽  
Nivaldo Lúcio Speziali
Keyword(s):  
Single Crystal ◽  
Phase Ii ◽  
Room Temperature ◽  
Structure Model ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Atomic Displacements ◽  
Disordered Models ◽  
Different Temperatures

The structural phases observed in LiKSO_4 crystals due to thermotropic transitions have been studied for more than a century. Nowadays many different phases are referenced, but some of the results are still controversial. Structural studies by single-crystal X-ray diffraction from room temperature to 803 K are presented here. Phase II (708 \lt T \lt 943 K) is extensively discussed on the basis of ordered and disordered models, using harmonic and anharmonic atomic displacements, and considering a twinned crystal composed of three orthorhombic domains. Analyses of the same phase at different temperatures determine the best structure model.

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

High-pressure structural studies of eskolaite by means of single-crystal X-ray diffraction

2012 ◽  
Vol 97 (10) ◽  
pp. 1764-1770 ◽  
Author(s):  
A. Kantor ◽  
I. Kantor ◽  
M. Merlini ◽  
K. Glazyrin ◽  
C. Prescher ◽  
...  
Keyword(s):  
High Pressure ◽  
Single Crystal ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
X Ray
Sign in / Sign up

Export Citation Format

Share Document