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.

Synthesis, structures, and property studies on Zn(II), Ni(II), and Cu(II) complexes with a Schiff base ligand containing thiocarbamide group

Abstract: A Schiff base ligand containing thiocarbamide group of 4-phenyl-1-(4-methoxyl-1-phenylethylidene)thiosemicarbazide (HL) and its three mononuclear metal complexes of ZnL2 (1), NiL2 (2), and CuL2 (3) have been synthesized. Elemental analysis, IR, and X-ray single crystal diffraction characterizations for the ligand and the three complexes have been carried out. In the three complexes, the central metallic ions of Zn2+, Ni2+, and Cu2+ coordinate with two deprotonated ligands of L−, respectively. In 1, Zn2+ ion adopts a distorted tetrahedral geometry, while in 2 and 3, both the Ni2+ and Cu2+ ions possess distorted square planar configurations. For the four compounds, UV–Vis spectra have been measured and DFT calculations at B3LYP/LANL2DZ level of theory prove that the electronic spectra of HL and 1 are corresponding with electronic transitions of n → π* and π → π* in the ligand itself and the electronic spectra of 2 and 3 are attributed to intraligand electronic transitions as well as d–d electronic transitions. Electrochemical investigations reveal that the different metal–ligand interactions have changed the peak shapes and peak locations, which are corresponding with the DFT-B3LYP/LANL2DZ calculational results. Fluorescence spectra measurements indicate that the ligand emits purple fluorescence and the complex 1 emits stronger blue fluorescence, while the complexes 2 and 3 quench fluorescence. The thermal analyses result show that the three complexes undergo two similar decomposition processes because of their similar geometric configurations.

Pyramidal Inversion at Phosphorus Facilitated by the Presence of Proximate Lewis Acids. Coordination Chemistry of Group 13 Elements with the Macrocyclic Bis(amidophosphine) Ligand [P2N2] ([P2N2] = [PhP(CH2SiMe2NSiMe2CH2)2PPh])

Abstract: Investigations on the preparation of four- and five-coordinate aluminum and gallium bis(amidophosphine) derivatives are reported. The reaction of the macrocyclic ligand precursor anti-Li2(THF)2[P2N2] ([P2N2] = [PhP(CH2SiMe2NSiMe2CH2)2PPh]) with AlCl3 or GaCl3 in toluene at 25 °C leads to the formation of the four-coordinate species anti-MCl[P2N2] (M = Al (1), Ga (2)). An X-ray diffraction study of anti-GaCl[P2N2] shows it to be monomeric with a distorted tetrahedral geometry at Ga; only one of the phosphine donors of the [P2N2] ligand binds to the gallium, resulting in the retention of the anti-configuration. The solution NMR spectra are consistent with Cs symmetry. The addition of AlCl3 or GaCl3 to the macrocyclic ligand precursor syn-Li2(dioxane)[P2N2] in toluene at 25 °C yields the five-coordinate complexes syn-MCl[P2N2] (M = Al (3), Ga (4)). The X-ray crystal structure of syn-GaCl[P2N2] reveals a trigonal bipyramidal geometry about the metal atom, necessitating the coordination of both phosphorus atom...

Is regular tetrahedral geometry possible in gold(I)–phosphine complexes? X-Ray crystal structures of three modifications of (PPh3)4Au+BPh4–

Abstract: X-Ray crystal structures of three modifications of tetrakis(triphenylphosphine)gold(I) tetraphenylborate have been determined, one at –150 °C; none shows the expected simple tetrahedral geometry.