scholarly journals INTRAMOLECULARLY HYPERCOORDINATED ORGANOLEAD COMPOUNDS: (o-MeOC6H4-CH2)PbPh2R, R = Ph, Cl, WITH Pb–O SECONDARY BONDING

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Hemant K. Sharma ◽  
Alejandro J. Metta-Magaña ◽  
Laura I. Saucedo ◽  
Marcela López-Cardoso ◽  
Keith H. Pannell
Keyword(s):  
Structural Analysis ◽  
Organic Ligand ◽  
Phenyl Group ◽  
Group 14 ◽  
Tetrahedral Geometry ◽  
Trigonal Bipyramidal ◽  
Internuclear Distances ◽  
Organolead Compounds ◽  
Oxygen Functionality ◽  
Secondary Bonding

Abstract The tetrahedral geometry of organolead(IV) compounds can be readily transformed by using an organic ligand containing a dangling-arm oxygen functionality. The acidity of the Pb center results in so-called secondary bonding between O and Pb thereby pushing the geometry at Pb toward a trigonal bipyramidal (tbp) structure. Replacing a phenyl group by a chlorine atom dramatically enhances this phenomenon. Thus for (o-methoxybenzyl) triphenyllead (4), and (o-methoxybenzyl)diphenyllead chloride (5), the Pb–O internuclear distances are 3.362(4) and 2.845(3) Å, respectively; 83% (4) and 70% (5) of the sum of the van der Waals Pb and O radii. Within the group 14 element congeners the structural analysis of the (o-methoxybenzyl)triphenylE compounds, E = Si, Ge, Sn, and now Pb, demonstrates the relative acidities of E are Si < Ge < Sn < Pb.

scholarly journals Polymeric coordination complex of lithium(I) with aqua and cyanurate ligands

2021 ◽  
Vol 77 (10) ◽  
Author(s):  
Anjapuli Ponnuvel ◽  
Arumugam Pillai Kala ◽  
Karachalacherevu Seetharamiah Nagaraja ◽  
Chandran Karnan
Keyword(s):  
Three Dimensional ◽  
Water Ligand ◽  
Water Molecules ◽  
Equatorial Position ◽  
Tetrahedral Geometry ◽  
Trigonal Bipyramidal ◽  
Dimensional Network ◽  
Vis Spectroscopy ◽  
Dta Analysis ◽  
Water Ligands

The polymeric title complex, poly[hexa-μ-aqua-diaquatetra-μ-cyanurato-tetralithium] [Li4(C3H2N3O3)4(H2O)7] n , synthesized at room temperature from an aqueous solution of lithium hydroxide and cyanuric chloride, crystallizes in the triclinic space group P\overline{1}. There are two distinct Li+ cations in the asymmetric unit, one of which, Li1, has distorted trigonal–bipyramidal geometry and is coordinated via oxygen to two cyanurate anions occupying equatorial positions, and three water molecules, two in the axial positions and the third in an equatorial position. One of the axial water ligands and the equatorial water ligand are involved in bridging to a crystallographically equivalent Li1 cation. A centre of inversion lies between the two Li1 cations and the Li1...Li1 distance is 3.037 (5) Å. The remaining axial water ligand bridges to the second Li cation, Li2, which is disordered over two crystallographic sites with approximately equal occupancy, and has an Li1...Li2 distance of 3.438 (7) Å. The terminal Li2 cation is coordinated to three water molecules and an oxygen atom from a cyanuric anion and has a distorted tetrahedral geometry. A three-dimensional network of intermolecular hydrogen bonds involving N—H...O, O—H...O and O—H...N interactions serves to hold the structure together, as confirmed by a Hirshfeld surface analysis. The title compound was further characterized using IR and UV–vis spectroscopy and TG–DTA analysis.

scholarly journals The phase transition in bis(methyl(2-phenylethyl)ammonium) tetrabromidocuprate(II)

2014 ◽  
Vol 70 (a1) ◽  
pp. C1688-C1688
Author(s):  
Marcus Bond
Keyword(s):  
Transition Temperature ◽  
Ambient Temperature ◽  
Color Change ◽  
Phenyl Group ◽  
Exothermic Peak ◽  
Steady Increase ◽  
Organic Layer ◽  
Tetrahedral Geometry ◽  
Square Planar ◽  
Axis Length

Bis(methyl(2-phenylethyl)ammonium) tetrachloridocuprate(II) is a well-known thermochromic compound that exhibits an abrupt color change (from green to yellow) at 353 K that is caused by a change in coordination geometry from square planar to flattened tetrahedral [1]. As part of a reinvestigation of established thermochromic chloridocuprate(II) and their related compounds, the bromide analog [bis(methyl(2-phenylethyl)ammonium) tetrabromidocuprate(II)] has been studied anew. The structure redetermination at ambient temperature agrees with the original [2] (CSD refcode: FUTTIX), i.e. alternating layers of flattened tetrahedral tetrabromidocuprate(II) complexes and of organic cations stacked along the a-axis of the monoclinic C2/c unit cell. A DSC scan from ambient temperature to 183 K reveals an exothermic peak (and corresponding endothermic peak upon heating) at 215 K. Single crystal structures, determined from ambient temperature to 120 K in steps of ~20 K, track a steady increase in b-axis length on cooling to the transition temperature. Across the transition temperature abrupt 1.1% and 0.74% increases in lengths of the b- and c-axes, respectively. and a 0.23% decrease in the a-axis length are observed with no change in space group. Slight changes of the organic cation phenyl group conformation are observed across the transition temperature that cause the organic layer to spread out and become thinner so that neighbouring layers are stacked more closely together along a. However, the flattened tetrahedral geometry of the tetrabromidocuprate(II) complex remains essentially unchanged across the transition.

The synthesis, molecular and crystal structure of the 1:1 adduct of triphenyltin chloride with 2,3-diphenylthiazolidin-4-one

1995 ◽  
Vol 73 (1) ◽  
pp. 95-99 ◽  
Author(s):  
Frank E. Smith ◽  
Rosemary C. Hynes ◽  
John Tierney ◽  
Ying Z. Zhang ◽  
George Eng
Keyword(s):  
Crystal Structure ◽  
Structural Analysis ◽  
Oxygen Atom ◽  
Dutch Elm Disease ◽  
Monoclinic Space Group ◽  
Monodentate Ligand ◽  
X Ray ◽  
Trigonal Bipyramidal ◽  
Triphenyltin Chloride ◽  
Mössbauer Data

The title compound was synthesized as part of an effort to produce a more effective fungicide to combat Dutch Elm Disease (DED), which is caused by the fungus Ceratocystisulmi. A full X-ray structural analysis of the 1:1 adduct has been carried out and the results are reported along with the Mössbauer data for the compound. The crystals are monoclinic, space group P21/a with a = 19.240(3) Å, b = 9.1463(24) Å, c = 19.3512(24) Å, β = 118.874(8)°, V = 2982.0(10) Å3, z = 4, and Dcalc = 1.427 Mg m−3. The final discrepancy factors are RF = 0.056 and Rw = 0.058 for 1915 significant reflections. The QS and IS values in the Mössbauer spectrum of the complex are 3.08 mm s−1 and 1.28 mm s−1, respectively. The 2,3-diphenylthiazolidin-4-one behaves as a monodentate ligand and coordinates to the tin through the oxygen atom. The complex exhibits a trigonal bipyramidal configuration with the three phenyl groups in equatorial positions and the chloride and ligand oxygen occupying the apical sites. Keywords: triorganotin, fungicide, Dutch Elm Disease, thiazolidin-4-one.

Organoamido- and Aryloxo-Lanthanoids. XI. Syntheses and Crystal Structures of Nd(Odpp)3, Nd(Odpp)3(thf) and [Nd(Odpp)3(thf)2].2(thf) (Odpp-=2,6-Diphenylphenolate): Variations in Intramolecular π-Ph-Nd Interactions

1995 ◽  
Vol 48 (4) ◽  
pp. 741 ◽  
Author(s):  
GB Deacon ◽  
TC Feng ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Crystal Structures ◽  
Phenyl Group ◽  
Triangular Array ◽  
The Other ◽  
X Ray ◽  
Trigonal Bipyramidal ◽  
Distorted Trigonal Bipyramidal

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.

scholarly journals Tetra-μ3-iodido-tetrakis[(tri-n-butylphosphane-κP)copper(I)]

2014 ◽  
Vol 70 (4) ◽  
pp. m117-m118
Author(s):  
Simon Klenk ◽  
Wolfgang Frey ◽  
Martina Bubrin ◽  
Sabine Laschat
Keyword(s):  
Site Symmetry ◽  
Asymmetric Unit ◽  
Tetrahedral Geometry ◽  
Trigonal Bipyramidal ◽  
The Face ◽  
Symmetry Operators ◽  
Anisotropic Displacement Parameters ◽  
Axial Site ◽  
Geometric Consequence ◽  
Distorted Trigonal Bipyramidal

The title complex, [Cu4I4(C12H27P)4], crystallizes with six molecules in the unit cell and with three independent one-third molecule fragments, completed by application of the relevant symmetry operators, in the asymmetric unit. The tetranuclear copper core shows a tetrahedral geometry (site symmetry 3..). The I atoms also form a tetrahedron, with I...I distances of 4.471 (1) Å. Both tetrahedra show an orientation similar to that of a pair of self-dual platonic bodies. The edges of the I-tetrahedral structure are capped to the face centers of the Cu-tetrahedron andvice versa. The Cuface...I distances are 2.18 Å (averaged) and the Iface...Cu distances are 0.78 Å (averaged). As a geometric consequence of these properties there are eight distorted trigonal–bipyramidal polyhedra evident, wherein each trigonal face builds up the equatorial site and the opposite Cu...I positions form the axial site. As expected, then-butyl moieties are highly flexible, resulting in large elongations of their anisotropic displacement parameters. Some C atoms of then-butyl groups were needed to fix alternative discrete disordered positions.

Two new zinc(II) and mercury(II) complexes based on N,N′-(cyclohexane-1,2-diylidene)bis(4-fluorobenzohydrazide): synthesis, crystal structures and antibacterial activities

2020 ◽  
Vol 76 (5) ◽  
pp. 476-482
Author(s):  
Al-Ameen Bariz OmarAli ◽  
Ahmed Jasim M. Al-Karawi ◽  
Adil A. Awad ◽  
Necmi Dege ◽  
Sevgi Kansız ◽  
...  
Keyword(s):  
Organic Ligand ◽  
Antibacterial Activities ◽  
Structural Features ◽  
Bacterial Strains ◽  
Tetrahedral Geometry ◽  
X Ray ◽  
X Ray Crystallography ◽  
Growth Inhibitory ◽  
The Difference

Reaction of N,N′-(cyclohexane-1,2-diylidene)bis(4-fluorobenzohydrazide), C20H18F2N4O2, (LF ), with zinc chloride and mercury(II) chloride produced different types and shapes of neutral coordination complexes, namely, dichlorido[N,N′-(cyclohexane-1,2-diylidene)bis(4-fluorobenzohydrazide)-κ2 N,O]zinc(II), [ZnCl2(C20H18F2N4O2)], (1), and dichlorido[N,N′-(cyclohexane-1,2-diylidene)bis(4-fluorobenzohydrazide)-κ4 O,N,N′,O′]mercury(II), [HgCl2(C20H18F2N4O2)], (2). The organic ligand and its metal complexes are characterized using various techniques: IR, UV–Vis and nuclear magnetic resonance (NMR) spectroscopies, in addition to powder X-ray diffraction (PXRD), single-crystal X-ray crystallography and microelemental analysis. Depending upon the data from these analyses and measurements, a typical tetrahedral geometry was confirmed for zinc complex (1), in which the ZnII atom is located outside the bis(benzhydrazone) core. The HgII atom in (2) is found within the core and has a common octahedral structure. The in vitro antibacterial activities of the prepared compounds were evaluated against two different bacterial strains, i.e. gram positive Bacillus subtilis and gram negative Pseudomonas aeruginosa bacteria. The prepared compounds exhibited differentiated growth-inhibitory activities against these two bacterial strains based on the difference in their lipophilic nature and structural features.

Interaction of Metal Ions with 7-Deaza-8-aza-and 8-Aza-purines Preparation and X-Ray Structural Analysis of Copper(II) Complexes

1987 ◽  
Vol 42 (2) ◽  
pp. 195-202 ◽  
Author(s):  
W. S. Sheldrick ◽  
P. Bell
Keyword(s):  
Structural Analysis ◽  
Ph Value ◽  
Pyrimidine Ring ◽  
Polymeric Chain ◽  
Subsequent Formation ◽  
X Ray ◽  
Pyramidal Geometry ◽  
Trigonal Bipyramidal ◽  
Distorted Octahedral ◽  
Hcl Solution

Abstract The reaction of 8-aza-and 7-deaza-8-aza-purines with Cu2+ cations in acid solution has been studied. At a pH value of 2, the 8-azaadenine complex [Cu(H2O)4(AAdH)2](NO3)2 (1), which displays Cu-N9 coordination, may be isolated from solution. The reaction of CuCl2 with 8-aza-hypoxanthine in concentrated HCl solution leads to ring opening at C2 of the azapurine with subsequent formation of dichlorobis[(5-amino-4-carboxamide)[1 - 3]triazole] copper(II) dihydrate 2, in which the triazole ligands display a chelating function, coordinating the metal via N7 and O6. The results for 1 and 2 suggest that copper coordination of the azapurine base is not a prerequisite for opening of the pyrimidine ring. Respectively N9-and N8-coordinated complexes [CUCl3(AllH3)]n 3 and [CuCl2(H2O)(MAllH)]n (4) of allopurinol (AllH2) and 9-methylallopurinol (MAllH) may be prepared by the reaction of CuCl2 with the respective bases in HCl solution. In contrast, with the analogous 1-methyl-4-aminopyrazolo[3,4-d]pyrimidine MAPP, only the salt (MAPPH)4(CU2Cl8) (5) could be isolated under similar conditions, indicating that N8 is less attractive as a binding site in this 7-deaza-8-azaadenine derivative. The structures of 1-5 have been established by X-ray structural analysis. A distorted octahedral [4+2]geometry is found for the copper atoms in 1 and 2. Chlorine bridged polymeric chain structures are adopted by the complexes 3 and 4. An intermediate coordination geometry between trigonal bipyramidal and square-pyramidal is observed for the metal atoms in 3, a distorted square-pyramidal geometry in 4.

scholarly journals Poly[hydrazin-1-ium [diaquabis(μ4-pyridazine-3,6-dicarboxylato)trilithate] monohydrate]

2012 ◽  
Vol 68 (4) ◽  
pp. m496-m497 ◽  
Author(s):  
Wojciech Starosta ◽  
Janusz Leciejewicz
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
Water Molecules ◽  
Extended System ◽  
Tetrahedral Geometry ◽  
Crystal Water ◽  
Distorted Tetrahedral Geometry ◽  
Trigonal Bipyramidal ◽  
Distorted Trigonal Bipyramidal

The structure of the title compound, {(N2H5)[Li3(C6H2N2O4)2(H2O)2]·H2O}n, is composed of molecular dimers, each built up of two symmetry-related LiIions with distorted trigonal–bipyramidal coordinations bridged by two deprotonated ligand moleculesviatheirN,O-bonding sites. Doubly solvated LiIions with a distorted tetrahedral geometry link adjacent dimers, forming a polymer generated by bridging bidentate carboxylato O atoms to LiIions in adjacent dimers, forming anionic layers parallel to theacplane with monoprotonated hydrazinium cations and crystal water molecules positioned between them. The layers are held together by an extended system of hydrogen bonds in which the hydrazinium cations and coordinated and crystal water molecules act as donors and carboxylate O atoms act as acceptors.

Pentacoordinated Molecules. 107. Axial Preference of a Phenyl Group in a Trigonal Bipyramidal Tetraoxyphosphorane. A Unique Five-Coordinated Geometry

1995 ◽  
Vol 34 (18) ◽  
pp. 4525-4526 ◽  
Author(s):  
Natalya V. Timosheva ◽  
T. K. Prakasha ◽  
A. Chandrasekaran ◽  
Roberta O. Day ◽  
Robert R. Holmes
Keyword(s):  
Phenyl Group ◽  
Trigonal Bipyramidal

Darstellung und Kristallstrukturen von Phenyliodoantimonaten(III). Strukturkorrelation für Halogenoantimonate(III) / Preparation and Crystal Structures of Phenyliodoantimonates(III). Structural Correlation for Haloantimonates(III)

1991 ◽  
Vol 46 (5) ◽  
pp. 639-646 ◽  
Author(s):  
W. S. Sheldrick ◽  
C. Martin
Keyword(s):  
Structural Analysis ◽  
Crystal Structures ◽  
Iodine Atom ◽  
Trans Position ◽  
X Ray ◽  
Trigonal Bipyramidal ◽  
Structural Correlation ◽  
Bipyramidal Structure ◽  
In Trans

The phenyliodoantimonates(III) [Et4N][Ph2SbI2] (1), [Et4N]2[Ph2Sb2I6] (2) and [Hpy]3[Ph2Sb2I7] (3) have been prepared and their structures established by X-ray structural analysis. The anion [Ph2SbI2]⁻ displays a ψ-trigonal bipyramidal structure with axial Sb–I distances of 2.925(1) and 3.109(1) A. In the dimeric anions [Ph2Sb2I6]2- and [Ph2Sb2I7]3- the antimony atoms exhibit ψ-octahedral geometries. As observed for [Ph2SbI2]⁻, terminal Sb–I bonds in trans-position to one another display significantly different lengths. The anion [Ph2Sb2I7]3- displays Ci- symmetry with a bridging iodine atom at the crystallographic centre of symmetry. Long Sb—I distances of 3.404(1) A are observed to this atom. A structural correlation of opposite Sb–X distances (X = Cl, Br, I) in linear three centre X–Sb ··· X interactions is presented. The sum of the bond valences in iodoantimonates(III) is a minimum for symmetrical I–Sb–I three centre bonds, reflecting thereby the antibonding influence of the Sb 5 s-orbital. This influence is considerably smaller for bromoantimonates(III) and may be effectively neglected for chloroantimonates(III).

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