The Ti(IV) Complex of a Benzannulated N-Heterocyclic Carbene

2004 ◽  
Vol 59 (3) ◽  
pp. 348-350 ◽  
Author(s):  
F. Ekkehardt Hahn ◽  
Thorsten von Fehren ◽  
Roland Fröhlich

The yellow titanium(IV) carbene complex [TiCl4(1)], 2 (1 = N,N’-bis(2,2-dimethylpropyl)benzimidazol-2-ylidene) was synthesized by reaction of TiCl4 and the benzannulated carbene 1 in toluene. The X-ray structure analysis revealed a mononuclear complex with a titanium(IV) center coordinated in a distorted trigonal-bipyramidal fashion by the carbene ligand in an equatorial position and four chloro ligands

2004 ◽  
Vol 59 (5) ◽  
pp. 544-546 ◽  
Author(s):  
F. Ekkehardt Hahn ◽  
Thorsten von Fehren ◽  
Lars Wittenbecher ◽  
Roland Fröhlich

Abstract The reaction of the dibenzotetraazafulvalene C6H4(NC2H5)2C=C(NC2H5)2C6H4, 1 = 1, with [(COD)Rh(μ-Cl)2Rh(COD)] proceeds via cleavage of the C=C double bond and yields the carbene complex [(COD)RhCl(1)], 2. The X-ray structure analysis shows 2 to be a mononuclear complex with a rhodium(I) center coordinated in a slightly distorted square-planar fashion.


2011 ◽  
Vol 34 (5-6) ◽  
pp. 127-130 ◽  
Author(s):  
Yaya Sow ◽  
Libasse Diop ◽  
Kieran C. Molloy ◽  
Gabrielle Kociok-Köhn

Abstract The title compounds [R2NH2][C2O4SnMe3](R=i-Bu, Cy), in which tin atoms adopt a distorted trigonal bipyramidal configuration, have been prepared and submitted to an X-ray diffraction study. These compounds have been obtained from the reaction of (Cy2NH2)2C2O4·H2O or (i-Bu2NH2)2C2O4 with SnMe3Cl. In both [R2NH2][C2O4SnMe3] compounds, the trans complex has an almost regular trigonal bipyramidal geometry around the tin atom. The SnMe3 residues are connected as a chain with bridging oxalate anions in a trans-SnC3O2 framework, the oxygen atoms being in axial positions. The cations connect linear adjacent chains through NH…O hydrogen bonds giving layered structures.


Author(s):  
Stephanie J. Hong ◽  
Jun Li ◽  
Mas A. Subramanian

The crystal structure of magnesium zinc divanadate, MgZnV2O7, was determined and refined from laboratory X-ray powder diffraction data. The title compound was synthesized by a solid-state reaction at 1023 K in air. The crystal structure is isotypic with Mn0.6Zn1.4V2O7 (C2/m; Z = 6) and is related to the crystal structure of thortveitite. The asymmetric unit contains two metal sites with statistically distributed magnesium and zinc atoms with the atomic ratio close to 1:1. One (Mg/Zn) metal site (M1) is located on Wyckoff position 8j and the other (M2) on 4h. Three V sites (all on 4i), and eight O (three 8j, four 4i, and one 2b) sites complete the asymmetric unit. The structure is an alternate stacking of V2O7 layers and (Mg/Zn) atom layers along [20\overline{1}]. It is distinct from other related structures in that each V2O7 layer consists of two groups: a V2O7 dimer and a V4O14 tetramer. Mixed-occupied M1 and M2 are coordinated by oxygen atoms in distorted trigonal bipyramidal and octahedral sites, respectively.


1981 ◽  
Vol 36 (5) ◽  
pp. 649-650 ◽  
Author(s):  
Joachim Pickardt

From an aqueous solution of cupric acetate containing an excess of KSCN and hexamethy- lenetetramine crystals of the title compound could be obtained. An X-ray structure analysis showed that the cuprate(II) anion has trigonal bipyramidal geometry. The three equatorial positions are occupied by NCS groups, the axial positions by the hexamethylenetetramine molecules


1995 ◽  
Vol 48 (4) ◽  
pp. 741 ◽  
Author(s):  
GB Deacon ◽  
TC Feng ◽  
BW Skelton ◽  
AH White

The X-ray crystal structure of Nd (Odpp)3 ( Odpp- = 2,6-diphenylphenolate), obtained by sublimation of Nd ( Odpp )3( thf )2 ( thf = tetrahydrofuran ) [triclinic, Pī , a 15.835(5), b 13.499(10), c 10.955(11) Ǻ, α 116.25(7), β 92.87(7), γ 101.66(6)°, V 2031 Ǻ3, Z2, No 5726 'observed' data (I > 3σ(I)) refined to conventional R 0.047 shows a near triangular array of oxygens surrounding neodymium { Nd -O} 2.169 Ǻ, ∑ O- Nd -O 353.2° with additional, intramolecular Nd-η6-Ph chelate interactions { Nd -C} 3.046 Ǻ and Nd-η1-Ph ( Nd -C 2.964(7)Ǻ). There is a pseudotrigonal bipyramidal arrangement of the oxygens, the centroid of the η6-Ph, and the η1-carbon. The complex Nd ( Odpp )3( thf ), obtained by crystallization of Nd ( Odpp )3( thf )2 from toluene (monoclinic, P21/c, a 12.213(4), b 21.447(4), c 17.744Ǻ, β 104.25(2)°, V 4505 Ǻ3, Z 4, R 0.042 for No 8014) also has pseudotrigonal bipyramidal stereochemistry, with a triangular equatorial array of aryl oxide oxygens { Nd -O} 2.193 Ǻ; ∑ O- Nd -O 358.7°, an apical thf oxygen (Nd -O 2.446(3)Ǻ), and an apical intramolecular chelating phenyl group. As the last has three Nd -C contacts (3.094(5), 3.144(5), 3.010(5)Ǻ) significantly shorter than the other three (3.300(5), 3.427(5), 3.377(5)Ǻ), an η3-Ph-Nd interaction seems likely. For [ Nd ( Odpp )3( thf )2].2( thf ), obtained by crystallization from tetrahydrofuran without drying of the crystals, the X-ray structure (monoclinic, P21, a 10.230(2), b 21.919(5), c 13.411(4) Ǻ, β 101.15(2)°, V 2950 A3, Z2, R 0.058 for No 3237) reveals a distorted trigonal bipyramidal arrangement of three aryl oxide oxygens (two equatorial 2.208(9), 2.16(1) Ǻ; one axial 2.203(9) Ǻ) and two thf oxygens (one equatorial 2.44(1) Ǻ; one axial (significantly distant) 2.62(1) Ǻ). The X-ray structure of [La( Odpp )3( thf )2].2( thf ) shows it to be isostructural with the neodymium analogue.


1990 ◽  
Vol 45 (6) ◽  
pp. 775-780 ◽  
Author(s):  
Hans H. Karsch ◽  
Michael Hollstein ◽  
Gerhard Müller

Stable germanium(II)-dithiocarbamate complexes Ge[S2C(NR2)]2 (R = Me, Et) have been obtained from GeCl2 · dioxane and Na[S2C(NR2)]. As an intermediate, Ge(Cl)[S2C(NEt2)] also could be isolated. Likewise, Ge[S2PMe2]2 was synthesized from GeCl2 · dioxane and Na[S2PMe2] and characterized by X-ray structure analysis. The germanium atom acts as a spiro-center for four sulfur atoms in a distorted ψ-trigonal bipyramidal configuration which is established by two anisobidentate dithiophosphinate ligands. The axial Ge—S bonds are significantly longer (mean: 2.722 A) than the equatorial ones (mean: 2.415 A). The variation in the axial bonds is more pronounced (0.058 A) than in the equatorial (0.013 A) Ge—S bonds, but this effect is much smaller than in the comparable Ge[(PMe2)2CPMe2]2 complex.


2007 ◽  
Vol 62 (6) ◽  
pp. 783-790 ◽  
Author(s):  
Carolin Wallenhorst ◽  
Kirill V. Axenov ◽  
Joseph S. M. Samec ◽  
Roland Fröhlich ◽  
Gerhard Erker

Reaction of the doubly deprotonated pyridine 2,6-dicarboxamido ligand (1) with (PCy3)2Cl2 Ru=CHPh (3a) in THF gave a mixture of (lig)(PCy3)Ru=CHPh isomers (4). The pentane soluble N,N,O-4 isomer was isolated by extraction and characterized by X-ray diffraction. The O,N, O-4 isomer was identified in the residue. Single crystals of the closely related complex (lig)(NHC) Ru=CHPh, O,N,O-5, were obtained from the reaction of 1 with (NHC)(PCy3)Cl2Ru=CHPh (3b) and used for the X-ray crystal structure analysis of the system


1978 ◽  
Vol 33 (12) ◽  
pp. 1393-1397 ◽  
Author(s):  
R. D. Fischer ◽  
E. Klähne ◽  
J. Kopf

Abstract The first two examples of a novel series of organo-actinide complexes, [Cp3UXL] (Cp = η5 -C5H5, X = halide or pseudohalide anion, L = uncharged Lewis base), are described. The X-ray structure analysis of the system with X = NCS and L = CH3CN confirms an almost linear alignment (H3)CCNUNCS along with the coplanarity of the three Cp ring normals. The remarkable Lewis acidity of certain Cp3UX-compounds appears to be essential for the formation of oligomeric species [Cp3UX]∞ as well as for specific reactions of monomeric CP3UX.


2017 ◽  
Vol 73 (11) ◽  
pp. 905-910 ◽  
Author(s):  
Zachary W. Schroeder ◽  
L. K. Hiscock ◽  
Louise Nicole Dawe

Benzothiazole derivatives are a class of privileged molecules due to their biological activity and pharmaceutical applications. One route to these molecules is via intramolecular cyclization of thioureas to form substituted 2-aminobenzothiazoles, but this often requires harsh conditions or employs expensive metal catalysts. Herein, the copper(II)- and gold(III)-mediated cyclizations of thioureas to substituted 2-aminobenzothiazoles are reported. The single-crystal X-ray structures of the thiourea N-(3-methoxyphenyl)-N′-(pyridin-2-yl)thiourea, C13H13N3OS, and the intermediate metal complexes aquabis[5-methoxy-N-(pyridin-2-yl-κN)-1,3-benzothiazol-2-amine-κN 3]copper(II) dinitrate, [Cu(C13H11N3OS)2(H2O)](NO3)2, and bis{2-[(5-methoxy-1,3-benzothiazol-2-yl)amino]pyridin-1-ium} dichloridogold(I) chloride monohydrate, (C13H12N3OS)2[AuCl2]Cl·H2O, are reported. The copper complex exhibits a distorted trigonal–bipyramidal geometry, with direct metal-to-benzothiazole-ligand coordination, while the gold complex is a salt containing the protonated uncoordinated benzothiazole, and offers evidence that metal reduction (in this case, AuIII to AuI) is required for the cyclization to proceed. As such, this study provides further mechanistic insight into the role of the metal cations in these transformations.


2011 ◽  
Vol 321 ◽  
pp. 127-130
Author(s):  
Xi Shi Tai

A novel ring-like zinc (II) complex of N-paratoluensulfonyl-glycine acid and 1,10-phenanthroline was synthesized and characterized by elemental analysis, IR spectrum and molar conductivity. The crystal structure of Zn (II) was determined by X-ray single crystal diffraction. The results show that each zinc (II) atoms is in a distorted trigonal bipyramidal geometry and form 16-membered chelate ring with the tridentate ligand. Intermolecular weak interactions in complex link molecules into a one-dimensional infinite chain supramolecular structure. The luminescence property of the complex was investigated in solid.


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