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Tetrahedral molecular geometry
About: Tetrahedral molecular geometry is a research topic. Over the lifetime, 1795 publications have been published within this topic receiving 30706 citations.
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TL;DR: A series of substituted 2-hydroxysalicylidine benzohydrazides were converted into their phenyl-boron complexes in good yields upon reaction with phenylboronic acid as mentioned in this paper.
23 citations
TL;DR: In this article, X-ray diffraction showed that the M2+ cations are coordinated by two terminal N-bonded thiocyanato anions and two substituted pyridine ligands in a distorted tetrahedral geometry.
Abstract: Reaction of cobalt(II) thiocyanate or zinc(II) thiocyanate with 2-methylpyridine, 2-bromopyridine and 2-chloropyridine at room-temperature lead to tetrahedral complexes of composition M(NCS)2L2 (M = Co, Zn; 1: L = 2-methylpyridine, 2: L = 2-bromopyridine, 3: L = 2-chloropyridine). For all compounds, X-ray diffraction showed that the M2+ cations are coordinated by two terminal N-bonded thiocyanato anions and two substituted pyridine ligands in a distorted tetrahedral geometry. In all cases, complexes derived from cobalt and zinc with the same ligands are isomorphous. Eight crystalline solids were studied, which belong to only two different structure types: two polymorphs were obtained for the compounds with 2-chloropyridine: 3-Mα is isotypic with the 2-methylpyridine complexes 1-M and crystallizes in the orthorhombic space group P212121, whereas 3-Mβ and the isotypic 2-bromopyridine complexes 2-M adopt space group Pbcn. The structure types differ with respect to molecular conformation and packing: the complexes crystallizing in the former type are less distorted with respect to metal coordination; in the latter structure type, the angle subtended by the two ligands is by far the largest in the coordination sphere. P212121 allows for a more efficient intermolecular arrangement, whereas the complex geometry in Pbcn features shorter non-bonding distances between the ortho substituents of the pyridine ligands and comes closer to the gas phase geometry. DSC measurements gave no hints of a transformation between these modifications but from a melt of 3-Coα, 3-Coβ was obtained. Solvent mediated conversion experiments revealed that 3-Mα represents the thermodynamically stable form at room-temperature whereas 3-Mβ is metastable, in agreement with its lower density. Therefore, the thermodynamically stable phases with 2-chloropyridine as ligand adopt the crystal structure of the compounds with 2-methylpyridine, whereas the metastable forms are isotypic to the compounds with 2-bromopyridine.
23 citations
TL;DR: In this paper, a phenoxo-bridged zinc complex, Zn2(L)µ(O-O)2H2OCl2] [L= deprotonated salen ligand, 2,2′-((1E, 1′E)-((2,2-dimethylpropane-1,3-diyl)bis(azaneylylidene))bis(methaneyly lidene)diphenol), was reported.
23 citations
TL;DR: Two-, three-and four-coordinate silver(I) complexes, AgX (X = CN−, PF 6 -, and SbF 6 - ), with triphenyl phosphine, tricyclohexyl phosphines, diphenylcyclohexy phosphine and dicycloenylphenyl PHINE have been synthesised and characterised by single crystal X-ray diffraction, elemental analysis, infrared spectroscopy, and 13C and 31P NMR spectroscopic results as discussed by the authors.
23 citations
TL;DR: The global minimum structure of the Au102+ system has a highly symmetrical tetrahedral geometry and is clearly separated from the other isomers by a high relative energy gap.
Abstract: We propose that the global minimum structure of the Au102+ system has a highly symmetrical tetrahedral geometry and is clearly separated from the other isomers by a high relative energy gap. The large highest occupied molecular orbital-to-lowest unoccupied molecular orbital (HOMO–LUMO) gap as well as the superatom and spherical aromatic characters account for the high stability of this Td Au102+ geometry.
23 citations