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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: The reaction of CdBr2·4H2O with ancillary ligands, N,N-bis(1H-pyrazolyl-1-methyl)aniline (L1), N, N-bis (1Hpyrazyl-1)-methyl)-p-methylaniline(L2) as discussed by the authors, showed a bromo-bridged dimeric species with crystallographic inversion symmetry.
Abstract: The reaction of CdBr2·4H2O with ancillary ligands, N,N-bis(1H-pyrazolyl-1-methyl)aniline (L1), N,N-bis(1H-pyrazolyl-1-methyl)-p-methylaniline (L2), N,N-bis(1H-pyrazolyl-1-methyl)-3,5-dimethylaniline (L3), N,N-bis(3,5-dimethyl-1H-pyrazolyl-1-methyl)aniline (L4) and N,N-bis(1H-pyrazolyl-1-methyl)-2,6-dimethylaniline (L5) in ethanol yields novel Cd(II) bromide complexes, [L1CdBr2]2, [L2CdBr2]2, [L3CdBr2]2, [L4CdBr2] and [L5CdBr2]. The X-ray crystal structures of [L1CdBr2]2, [L2CdBr2]2 and [L3CdBr2]2 reveal a bromo-bridged dimeric species with crystallographic inversion symmetry. Conversely, [L4CdBr2] and [L5CdBr2] exist as monomeric complexes, presumably due to the steric hindrance between the methyl substituents of the two pyrazole groups in the ligand and cadmium centre for [L4CdBr2], and crowding around the cadmium metal by methyl substituents on the aniline residue in the ligand for [L5CdBr2]. The geometry at each Cd(II) centre for [L1CdBr2]2, [L2CdBr2]2 and [L3CdBr2]2 is best described as a distorted trigonal bipyramid. A distorted trigonal bipyramid is achieved in [L4CdBr2] by coordinative interaction of the nitrogen atom of the aniline unit and the cadmium atom with a σ plane of symmetry, based on the bond length of Cd―Naniline (2.759(7) A). [L5CdBr2] exists with a distorted tetrahedral geometry involving non-coordination of the nitrogen atom of aniline and the Cd centre, resulting in the formation of an eight-membered chelate ring. The catalytic activity of monomeric, five-coordinated [L4CdBr2] in the polymerization of methyl methacrylate (MMA) in the presence of modified methylaluminoxane (MMAO) at 60°C resulted in a higher molecular weight and a narrower polydispersity index (PDI) than those obtained with dimeric [LnCdBr2]2 (Ln = L1, L2, L3) or monomeric tetrahedral [L5CdBr2]. Copyright © 2014 John Wiley & Sons, Ltd.
8 citations
TL;DR: Using the delocalised wavefunctions from Part 3, for a series of molecules of type MX 2 Y 2 where M is tetravalent, and X, Y are either H, Me or halogen, with a triple-zeta plus polarisation basis and either SCF of MP2 methods, the wave functions were converted to localised orbitals by the Foster-Boys method, which enabled the LMO to be subject to population analysis for changes in hybridisation in the individual total density of the MX and MY bonds.
8 citations
TL;DR: In this article, N-Methyl-2-piperidone adduct and dimethyl sulfoxide adduct of cobalt(II)mercury (II) thiocyanate (SCN) were synthesized and their crystal and molecular structures were determined by the single-crystal X-ray diffraction technique.
Abstract: N-Methyl-2-piperidone adduct and dimethyl sulfoxide adduct of cobalt(II)mercury(II) thiocyanate were synthesized and their crystal and molecular structures were determined by the single-crystal X-ray diffraction technique. The former adduct is triclinic with a space group P\bar1, a=8.488(3), b=17.206(7), c=8.466(3) A, α=103.72(1)°, β=90.00(1)°, γ=100.85(1)°, Z=2, while the latter adduct is orthorhombic with a space group P212121, a=8.418(3), b=27.389(10), c=8.407(3) A, Z=4, and the final R values obtained were 0.059 and 0.066, respectively. In these adducts each mercury atom is in the tetrahedral geometry, coordinated with four sulfur atoms of the thiocyanate (SCN) ions, and each cobalt atom is in the octahedral geometry, coordinated with four nitrogen atoms of SCN ions and two oxygen atoms of the Lewis-base molecules which occupy the trans-positions. Each pair of different kinds of metal atoms are bridged by an SCN ion forming a 16-membered ring of Co2Hg2(SCN)4; these are linked, forming a two-dimensiona...
8 citations
TL;DR: In this article, the zinc complex [Zn(P(py)3)2]2]+ was determined to have octahedral geometry with six pyridine N donor atoms.
8 citations
TL;DR: In this paper, three homoleptic complexes with formula [M(L1)2] [L1 = (C13H18N1O3S2−] with Zn, Cd and Hg have been designed, synthesized and characterized by elemental analysis, IR, 1H and 13C NMR and UV-visible absorption spectra.
8 citations