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Distorted Tetrahedral Geometry (distorted + tetrahedral_geometry)
Selected AbstractsA novel cobalt(II) coordination polymer with an unusual four-connected 42.63.8 topologyACTA CRYSTALLOGRAPHICA SECTION C, Issue 7 2008Guo-Hua Wei In the cobalt(II) coordination polymer poly[[(,2 -benzene-1,3-dicarboxylato){,2 -1,1,-[2,2,-oxybis(ethane-2,1-diyl)]di-1H -imidazole}cobalt(II)] monohydrate], {[Co(C10H14N4O)(C8H4O4)]·H2O}n, two crystallographically distinct CoII cations are four-coordinated by N2O2 donor sets in distorted tetrahedral geometries. The CoII centers are connected by benzene-1,3-dicarboxylate (m -BDC) anions, giving two types of linear chains, which are further joined via meso -helical 1,1,-[2,2,-oxybis(ethane-2,1-diyl)]di-1H -imidazole ligands to yield a thick two-dimensional slab. The compound displays a two-dimensional four-connected 42.63.8 topology, which is unprecedented in coordination polymers. [source] Design of Neutral Metallomesogens from 5,5-Dimethyldipyrromethane: Metal Ion Mediated Control of Folding and Hairpin StructuresEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 32 2008Kelly A. Ames Abstract New ligands derived from 5,5-dimethyldipyrromethane and their corresponding neutral complexes with ZnII and PdII are described. The ligands incorporate either a hexacatenar [H2(1n), n = 1, 10, 12, 14 and 16], tetracatenar [H2(2n), n = 1 and 16] or an extended dicatenar structure [H2(3n), n = 1and 16]. Single-crystal X-ray structure determinations of [Zn2(11)2] and [Zn2(31)2] confirm a distorted tetrahedral geometry at ZnII to afford double-stranded helical structures, while the PdII species [Pd(31)] shows a distorted square-planar geometry with the ligand adopting an alternative hairpin conformation. The metal-free hexacatenar ligands H2(1n) (n = 10, 12, 14, 16) and the corresponding complexes [Zn2(116)2] and [Pd(1n)] (n = 12, 14, 16) are not mesomorphic. However, the tetracatenar complex [Zn2(216)2] generates a smectic mesophase, as confirmed by X-ray diffraction, while [Pd(216)] and the metal-free ligand H2(216) show no mesomorphic behaviour. Two of the extended dicatenar compounds, H2(316) and [Zn2(316)2] are non-mesomorphic, while [Pd(316)] displays a smectic A phase.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Concomitant polymorphic behavior of di-,-thiocyanato-,2N:S;,2S:N -bis[bis(tri- p -fluorophenylphosphine-,P)silver(I)]ACTA CRYSTALLOGRAPHICA SECTION B, Issue 1 2010Bernard Omondi The structures of two polymorphs, both monoclinic P21/n [polymorph (I)] and P21/c [polymorph (II)], of di-,-thiocyanato-,2N:S;,2S:N -bis[bis(tri- p -fluorophenylphosphine-,P)silver(I)] complexes have been determined at 100,K. In both polymorphs the complex has a dinuclear structure where the silver(I) coordinates to two phosphine ligands and two bridging thiocyanate anions to form complexes with distorted tetrahedral geometry. Polymorph (I) has just one half of the [Ag2(SCN)2{P(4-FC6H4)3}4] molecule at (0, ½, 0) from the origin in the asymmetric unit. Polymorph (II) has one and a half molecules of [Ag2(SCN)2{P(4-FC6H4)3}4] in the asymmetric unit; the half molecule is situated at (0, 1, ½), while the full molecule is located at (1/3, ½, 1/3) from the origin. The Ag,P bond distances range from 2.4437,(4) to 2.4956,(7),Å in both polymorphs. The Ag,S distances are 2.5773,(7),Å in (I) and 2.5457,(5), 2.5576,(5) and 2.5576,(5),Å in (II). The full molecule in polymorph (II) has slightly shorter Ag,N bond distances [2.375,(1) and 2.367,(2),Å] compared with the half molecules in both polymorphs [2.409,(2),Å in (II) and 2.395,(2),Å in (I)]. The two polymorphs are compared using r.m.s. overlay calculations as well as half-normal probability plot analysis. [source] Ethyl[tris(3- tert -butyl-5-methylpyrazol-1-yl)hydridoborato]zinc(II)ACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2010Mukesh Kumar The X-ray crystal structure of the title compound, [Zn(C2H5)(C24H40BN6)], or TptBu,MeZnEt [TptBu,Me is tris(3- tert -butyl-5-methylpyrazolyl)hydridoborate], reveals a distorted tetrahedral geometry around the Zn atom. The Zn center is coordinated by three N atoms of the borate ligand and by one C atom of the ethyl group. The present structure and other tetrahedral Tp zinc alkyl complexes are compared with similar Ttz ligands (Ttz is 1,2,4-triazolylborate), but no major differences in the structures are noted, and it can be assumed that variation of the substitution pattern of Tp or Ttz ligands has little or no influence on the geometry of alkylzinc complexes. Refinement of the structure is complicated by a combination of metric pseudosymmetry and twinning. The metrics of the structure could also be represented in a double-volume C -centered orthorhombic unit cell, and the structure is twinned by one of the orthorhombic symmetry operators not present in the actual structure. The twinning lies on the borderline between pseudomerohedral and nonmerohedral. The data were refined as being nonmerohedrally twinned, pseudomerohedrally twinned and untwinned. None of the approaches yielded results that were unambiguously better than any of the others: the best fit between structural model and data was observed using the nonmerohedral approach which also yielded the best structure quality indicators, but the data set is less than 80% complete due to rejected data. The pseudomerohedral and the untwinned structures are complete, but relatively large residual electron densities that are not close to the metal center are found with values up to three times higher than in the nonmerohedral approach. [source] Crystallographic report: The [bis(,5 -cyclopentadienyl)titanium(IV)-bis(L -methionine)] dichlorideAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 6 2004Radim Bína Abstract The structure of ionic complex [Cp2Ti(L -Met)2]2+[Cl,]2 (where Cp = ,5 -C5H5) possessing C2 symmetry is presented. Discrete cationic units with distorted tetrahedral geometry around the central titanium atom are connected through intermolecular H···Cl bonds between ammonium group protons of ,-amino acid ligands and chloride anions. Copyright © 2004 John Wiley & Sons, Ltd. [source] Crystallographic report: (2,9-Dimethyl-1,10-phenanthroline)bis-(N,N -pyrrolidinedithiocarbamato)zinc(II) chloroform hemihydrateAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 4 2003Chian Sing Lai Abstract The mononuclear structure of Zn(S2C(N(CH2)2)4)2(2,9-Me2 -1,10-phen) shows monodentate coordination by the dithiocarbamate ligands and a distorted tetrahedral geometry for zinc, defined by an N2S2 donor set, results. Copyright © 2003 John Wiley & Sons, Ltd. [source] Crystallographic report: Crystal structure of a one-dimensional zinc(II) coordination polymer containing 4,4,-biphenyldicarboxylate hemihydrateAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 4 2003Wei Yuan Abstract A one-dimensional zinc(II) coordination polymer has been constructed from zinc(II), 4,4,-biphenyldicarboxylate and pyridine in which each zinc(II) atom is coordinated by two pyridine ligands and two monodentate 4,4,-biphenyldicarboxylate ligands that define a distorted tetrahedral geometry. Copyright © 2003 John Wiley & Sons, Ltd. [source] (2,2,-Bipyridine-,2N)bis[N -(2-pyridyl-,N)- p -toluenesulfonamido-,N]zinc(II)ACTA CRYSTALLOGRAPHICA SECTION C, Issue 3 2000Santiago Cabaleiro The structure of the title compound, [Zn(C12H11N2O2S)2(C10H8N2)], consists of monomeric molecules in which the central ZnN2N,N,, unit has a distorted tetrahedral geometry, with bond lengths ranging from 2.020,(3) to 2.109,(3),Å. The anionic ligands are potential bidentate donors and thus there are two secondary Zn,N interactions. The shorter of these is 2.317,(3),Å and completes at the Zn atom an irregular five-coordinated geometry, which can be described as a square pyramid showing 30% distortion towards the trigonal bipyramid; the other Zn,N contact is much longer at 2.549,(3),Å. [source] Crystal Structures and Characterizations of Bis (pyrrolidinedithiocarbamato) Cu(II) and Zn(II) ComplexesCHINESE JOURNAL OF CHEMISTRY, Issue 1 2003Jian Fang-Fang Abstract The structures of [Cu (S2CN (CH2)4)2] (1) and [Zn2(S2CN-(CH2)4)4] (2) have been determined by X-ray crystallography analysis. They are all isomorphous and triclinic, space group of P1,, with Z = 1. The lattice parameters of compound 1 is: a = 0.63483(2) nm, b = 0.74972(3) nm, c=0.78390(1) mn, , = 75.912(2)°, , = 78.634(2)° and , = 86.845(2)°; compound 2: a = 0.78707(6) nm, b=0.79823(6) nm, c = 1.23246(9) nm, , = 74.813(2)°, , = 73.048(2)° and , = 88.036(2)°. The copper atom is located on a crystallographic inversion center and zinc atom lies across centers of symmetry. The Cu(II) ion has a square-planar geometry while Zn(II) has a distorted tetrahedral geometry. The thermal gravity (TG) data indicate that no structural transitions in the two compounds were abserved and the decomposition products can adsorb gas. Also they all have a high thermal stability. [source] | ||||||||||