The Atomic Geometry of the Reconstructed (001) Surface of the Rutile Phase of SnO2

1989 ◽  
Vol 159 ◽  
Author(s):  
Charles B. Duke ◽  
Michael R. Thompson
Keyword(s):  
Energy Barrier ◽  
Tight Binding ◽  
Rutile Phase ◽  
Tetrahedral Coordination ◽  
Surface Geometry ◽  
Coordinate Surface ◽  
Rutile Structure ◽  
Reconstructed Surface ◽  
Distorted Tetrahedral Coordination ◽  
Stable Structures

AbstractThe tight-binding total energy formalism developed for tetrahedrally coordinated compound semiconductors has been extended to rutile-structure oxides and applied to calculate the surface atomic geometry and electronic structure of SnO2 (001). Two stable structures, separated by an energy barrier, are found. The first consists of slightly relaxed surface geometry with the top layer oxygen atoms relaxed outward by approximately 0.12A, and cations inward by 0.25A. The second geometry is a more massively reconstructed surface in which the four-coordinate surface Sn atoms attain highly distorted tetrahedral coordination.

Bis(2,9-dimethyl-1,10-phenanthroline)copper(I) tetraphenylborate dichloromethane solvate

2007 ◽  
Vol 63 (3) ◽  
pp. m800-m802 ◽  
Author(s):  
William T. Eckenhoff ◽  
Tomislav Pintauer
Keyword(s):  
Bond Length ◽  
Dihedral Angle ◽  
Title Compound ◽  
Stacking Interactions ◽  
Coordination Geometry ◽  
Tetrahedral Coordination ◽  
Π Stacking ◽  
Distorted Tetrahedral Coordination

In the title compound, [Cu(C14H12N2)2]C24H20B·CH2Cl2, CuI is chelated by two 2,9-dimethyl-1,10-phenanthroline (2,9-Me2phen) ligands, in a distorted tetrahedral coordination geometry. The average Cu—N bond length is 2.032 Å, and the interligand dihedral angle is 77.60 (6)°. The complexes form π–π stacking interactions between 2,9-Me2phen ligands, with a perpendicular interplanar separation of 3.652 (5) Å.

scholarly journals Bis[μ-1,3-bis(1H-imidazol-1-yl)propane-κ2N3:N3′]bis(dichloridozinc) dihydrate

2014 ◽  
Vol 70 (5) ◽  
pp. m184-m184
Author(s):  
Xiao-Juan Wang ◽  
Yun-Long Feng
Keyword(s):  
Zinc Complex ◽  
Complex Molecule ◽  
Dimensional Structure ◽  
Water Molecules ◽  
Coordination Geometry ◽  
Tetrahedral Coordination ◽  
Lattice Water ◽  
Bridging Ligand ◽  
Cl Atoms ◽  
Distorted Tetrahedral Coordination

The title hydrated complex, [Zn2Cl4(C9H12N4)2]·2H2O, is a discrete dinuclear zinc complex with 1,3-bis(1H-imidazol-1-yl)propane as the bridging ligand. The complex molecule lies about a crystallographic inversion centre. The ZnIIatom exhibits a distorted tetrahedral coordination geometry defined by two imidazole N atoms and two Cl atoms. O—H...Cl hydrogen bonding between the lattice water molecules and the terminal Cl atoms of the molecule lead to a two-dimensional structure extending parallel to (100).

scholarly journals Crystal structures of two stilbazole derivatives: bis{(E)-4-[4-(diethylamino)styryl]-1-methylpyridin-1-ium} tetraiodidocadmium(II) and (E)-4-[4-(diethylamino)styryl]-1-methylpyridin-1-ium 4-methoxybenzenesulfonate monohydrate

2018 ◽  
Vol 74 (12) ◽  
pp. 1891-1894
Author(s):  
Priya Antony ◽  
S. Antony Inglebert ◽  
Jerald V. Ramaclus ◽  
S. John Sundaram ◽  
P. Sagayaraj
Keyword(s):  
Hydrogen Bonds ◽  
Rotation Axis ◽  
Stacking Interactions ◽  
Tetrahedral Coordination ◽  
Asymmetric Unit ◽  
Methyl Group ◽  
Diethyl Amine ◽  
Molecular Salts ◽  
Benzene Rings ◽  
Distorted Tetrahedral Coordination

The title molecular salts, (C18H23N2)2[CdI4], (I), and C18H23N2 +·C7H7O4S−·H2O, (II), are stilbazole, or 4-styrylpyridine, derivatives. The cation, (E)-4-[4-(diethylamino)styryl]-1-methylpyridin-1-ium, has a methyl group attached to pyridine ring and a diethyl amine group attached to the benzene ring. The asymmetric unit of salt (I), comprises one cationic molecule and half a CdI4 dianion. The Cd atom is situated on a twofold rotation axis and has a slightly distorted tetrahedral coordination sphere. In (II), the anion consists of a 4-methoxybenzenesulfonate and it crystallizes as a monohydrate. In both salts, the cations adopt an E configuration with respect to the C=C bond and the pyridine and benzene rings are inclined to each other by 10.7 (4)° in (I) and 4.6 (2)° in (II). In the crystals of both salts, the packing is consolidated by offset π–π stacking interactions involving the pyridinium and benzene rings, with centroid–centroid distances of 3.627 (4) Å in (I) and 3.614 (3) Å in (II). In the crystal of (II), a pair of 4-methoxybenzenesulfonate anions are bridged by Owater—H...Osulfonate hydrogen bonds, forming loops with an R 2 4(8) motif. These four-membered units are then linked to the cations by a number of C—H...O hydrogen bonds, forming slabs lying parallel to the ab plane.

One-dimensional CuIand AgIladder-like coordination polymers supported by 2-ethyl-1-(pyridin-3-ylmethyl)-1H-benzimidazole

2013 ◽  
Vol 69 (9) ◽  
pp. 1017-1021
Author(s):  
Liu-cheng Gui ◽  
Guang-ming Liang ◽  
Hua-hong Zou ◽  
Zhong Hou
Keyword(s):  
Hydrogen Bonds ◽  
Metal Ion ◽  
Three Dimensional ◽  
Coordination Geometry ◽  
Tetrahedral Coordination ◽  
Asymmetric Unit ◽  
Counter Anion ◽  
One Dimensional ◽  
Solvent Molecules ◽  
Distorted Tetrahedral Coordination

The title complexes, poly[[bis[μ2-2-ethyl-1-(pyridin-3-ylmethyl)-1H-benzimidazole-κ2N1:N3]copper(I)] tetrafluoroborate acetonitrile monosolvate], {[Cu(C15H15N3)2]BF4·CH3CN}n, (I), and poly[[bis[μ2-2-ethyl-1-(pyridin-3-ylmethyl)-1H-benzimidazole-κ2N1:N3]silver(I)] perchlorate methanol monosolvate], {[Ag(C15H15N3)2]ClO4·CH3OH}n, (II), are isostructural and exhibit one-dimensional ladder-like structures in which each asymmetric unit contains one metal ion (Cu+or Ag+), two 2-ethyl-1-(pyridin-3-ylmethyl)-1H-benzimidazole (bep) ligands, one counter-anion (tetrafluoroborate or perchlorate) and one interstitial molecule (acetonitrile or methanol). Each metal ion exhibits a distorted tetrahedral coordination geometry consisting of two pyridyl and two benzimidazole N atoms from four distinct ligands. Two metal ions are linked by two bep ligands to form a centrosymmetric 18-memberedM2(bep)2metallacycle, while adjacentM2(bep)2metallacycles are further interlinked by another two bep ligands resulting in a ladder-like array. In the extended structure, four adjacent ladder-like arrays are connected together through C—H...F, O—H...O and C—H...O hydrogen bonds between bep ligands, solvent molecules and counter-anions into a three-dimensional supramolecular structure.

Crystal and molecular structure of bis[methyltris(1-pyrazolyl)gallato]nickel(II)

1979 ◽  
Vol 57 (14) ◽  
pp. 1823-1825 ◽  
Author(s):  
Steven J. Rettig ◽  
Alan Storr ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Nickel Atom ◽  
Exact Formula ◽  
Coordination Geometry ◽  
Tetrahedral Coordination ◽  
Gallium Atom ◽  
Full Matrix ◽  
Distorted Tetrahedral Coordination

Crystals of bis[methyltris(1-pyrazolyl)gallato]nickel(II) are rhombohedral, a = 9.6670(5), c = 23.893(1) Å, Z = 3, space group [Formula: see text]. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to a final R of 0.030 and Rw = 0.035 for 925 reflections with I ≥ 3σ (I). The crystal structure consists of well separated molecules of [MeGa-(N2C3H3)3]2Ni having exact [Formula: see text] (S6) symmetry and approximate D3d symmetry. The coordination geometry about the nickel atom is octahedral with Ni—N = 2.109(2) Å, N—Ni—N = 90.65(6) and 89.35(6)°. The gallium atom has distorted tetrahedral coordination geometry with Ga—N = 1.939(2), Ga—C = 1.940(4) Å, N—Ga—N = 99.55(6), and N—Ga—C = 118.16(5)°.

scholarly journals Crystal structure of [bis(2,6-diisopropylphenyl) phosphato-κO]tris(methanol-κO)lithium methanol monosolvate

2015 ◽  
Vol 71 (5) ◽  
pp. 443-446 ◽  
Author(s):  
Mikhail E. Minyaev ◽  
Ilya E. Nifant'ev ◽  
Alexander N. Tavtorkin ◽  
Sof'ya A. Korchagina ◽  
Shadana Sh. Zeynalova
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Tetrahedral Coordination ◽  
Intermolecular Hydrogen Bonds ◽  
Coordination Environment ◽  
The Family ◽  
Phosphate Diesters ◽  
Distorted Tetrahedral Coordination

Crystals of the title compound, [Li{OOP(O-2,6-iPr2C6H3)2}(CH3OH)3]·CH3OH or [Li(C24H34O4P)(CH3OH)3]·CH3OH, have been formed in the reaction between HOOP(O-2,6-iPr2C6H3)2and LiOH in methanol. The title compound is of interest as it represents the first reported crystal structure of the family of lithium phosphate diesters. The {Li(CH3OH)3[O2P(O-iPr2C6H3)2]} unit displays the Li atom in a slightly distorted tetrahedral coordination environment and exhibits one intramolecular O—H...O hydrogen bond between a coordinating methanol molecule and the terminal non-coordinating O atom of the phosphate group. The unit is connected with two non-coordinating methanol molecules through two intermolecular O—H...O hydrogen bonds, and with a neighbouring unit through two other O—H...O interactions. These intermolecular hydrogen bonds lead to the formation of infinite chains along [100]. There are no significant interactions between the chains.

Redetermination of [bis(2-pyridyl)amine-N,N′]copper(II) diperchlorate

2000 ◽  
Vol 57 (1) ◽  
pp. m25-m27 ◽  
Author(s):  
Miao Du ◽  
Xian-He Bu ◽  
Lin-Hong Weng ◽  
Xue-Bing Leng ◽  
Ya-Mei Guo
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Coordination Sphere ◽  
Chain Structure ◽  
Title Complex ◽  
Coordination Geometry ◽  
Tetrahedral Coordination ◽  
A Chain ◽  
Distorted Tetrahedral Coordination ◽  
Close Contacts

In the crystal structure of the title complex, [Cu(C10H9N3)2](ClO4)2, the CuIIcenter is four-coordinated by the nitrogen donors of the pyridine rings of the ligand, bis(2-pyridyl)amine. The crystal structure reveals that the CuN4coordination sphere has a distorted tetrahedral coordination geometry with a crystallographicC2axis through the CuIIcenter. The perchlorate anions link the complex cations to form a chain structure through C—H...O close contacts and N—H...O hydrogen bonds.

catena-Poly[silver(I)-μ-4-aminobenzenesulfonato-μ-2,3-diethylpyrazine]

2007 ◽  
Vol 63 (11) ◽  
pp. m2707-m2707 ◽  
Author(s):  
Hai-Yan Liu ◽  
Ji-Cheng Ma ◽  
Jin Yang
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
Coordination Geometry ◽  
Dimensional Chain ◽  
Tetrahedral Coordination ◽  
One Dimensional ◽  
Distorted Tetrahedral Coordination

In the title compound, [Ag(C6H6NO3S)(C8H8N2)], the AgI cation is four-coordinated by three N atoms from two different 2,3-diethylpyrazine ligands and one –NH2 group of a 4-aminobenzenesulfonate ligand, and one sulfonate O atom in a distorted tetrahedral coordination geometry. The AgI centers are doubly bridged by both types of ligands, forming a one-dimensional chain. N—H...O hydrogen bonds complete the structure.

scholarly journals Poly[tetrakis(μ-1,1,1,3,3,3-hexafluoropropan-2-olato)iron(II)dipotassium]

2014 ◽  
Vol 70 (2) ◽  
pp. m32-m33 ◽  
Author(s):  
Andrew P. Purdy ◽  
Ray J. Butcher
Keyword(s):  
Hydrogen Bonding ◽  
Title Compound ◽  
Three Dimensional ◽  
The Other ◽  
Tetrahedral Coordination ◽  
Compound K ◽  
Coordination Environment ◽  
Weak Hydrogen Bonding ◽  
Alternating Chain ◽  
Distorted Tetrahedral Coordination

The title compound, [K2Fe{OCH(CF3)2}4]n, was formed from the reaction of potassium hexafluoroisopropoxide with iron(II) chloride in toluene. The FeIIatom has a highly distorted tetrahedral coordination environment. All four of the non-equivalent hexafluoroisopropoxy O atoms link the FeIIatoms to one of the K+atoms in an alternating chain of Fe—O—K—O fused four-membered rings, with K—Fe distances of 3.715 (2) and 3.717 (2) Å. This K+atom is also bridged to eight of the F atoms. The other K+atom is bonded to only two of the O atoms, but has seven short K...F contacts, one of which links the chains into a three-dimensional arrangement. Weak hydrogen bonding between the lone H atoms on the hexafluoroisopropoxy groups and F atoms is also present. The crystal studied was refined as an inversion twin.

Four (2,2′-bipyridyl)(ferrocenyl)boronium derivatives

2015 ◽  
Vol 71 (1) ◽  
pp. 26-31 ◽  
Author(s):  
Jan W. Bats ◽  
Kuangbiao Ma ◽  
Hans-Wolfram Lerner
Keyword(s):  
Hydrogen Bonding ◽  
Crystal Structures ◽  
Tetrahedral Coordination ◽  
Asymmetric Unit ◽  
Bond Lengths ◽  
Distorted Tetrahedral Coordination

Crystal structures are reported for four (2,2′-bipyridyl)(ferrocenyl)boronium derivatives, namely (2,2′-bipyridyl)(ethenyl)(ferrocenyl)boronium hexafluoridophosphate, [Fe(C5H5)(C17H15BN2)]PF6, (Ib), (2,2′-bipyridyl)(tert-butylamino)(ferrocenyl)boronium bromide, [Fe(C5H5)(C19H22BN3)]Br, (IIa), (2,2′-bipyridyl)(ferrocenyl)(4-methoxyphenylamino)boronium hexafluoridophosphate acetonitrile hemisolvate, [Fe(C5H5)(C22H20BN3O)]PF6·0.5CH3CN, (IIIb), and 1,1′-bis[(2,2′-bipyridyl)(cyanomethyl)boronium]ferrocene bis(hexafluoridophosphate), [Fe(C17H14BN3)2](PF6)2, (IVb). The asymmetric unit of (IIIb) contains two independent cations with very similar conformations. The B atom has a distorted tetrahedral coordination in all four structures. The cyclopentadienyl rings of (Ib), (IIa) and (IIIb) are approximately eclipsed, while a bisecting conformation is found for (IVb). The N—H groups of (IIa) and (IIIb) are shielded by the ferrocenyl andtert-butyl or phenyl groups and are therefore not involved in hydrogen bonding. The B—N(amine) bond lengths are shortened by delocalization of π-electrons. In the cations with an amine substituent at boron, the B—N(bipyridyl) bonds are 0.035 (3) Å longer than in the cations with a methylene C atom bonded to boron. A similar lengthening of the B—N(bipyridyl) bonds is found in a survey of related cations with an oxy group attached to the B atom.

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