Topic
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 structure of ionic complex [Cp2Ti(L-Met)2]2+[Cl−]2 (where Cp = η5-C5H5) possessing C2 symmetry is presented in this article.
Abstract: The structure of ionic complex [Cp2Ti(L-Met)2]2+[Cl−]2 (where Cp = η5-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 α-amino acid ligands and chloride anions. Copyright © 2004 John Wiley & Sons, Ltd.
12 citations
TL;DR: In this paper, the reaction profiles of three cyclic disulfide species with model zinc finger domains in the HIV-1 nucleocapsid protein (NCp7) have been analyzed.
Abstract: By using quantum chemistry methods, including ab initio Hartree−Fock (HF), as well as the Density Functional Theory approach employing B3LYP approximation, the reaction profiles of three cyclic disulfide species with model zinc finger domains in the HIV-1 nucleocapsid protein (NCp7) have been analyzed. It is shown that the disulfide molecules can act as efficient agents destroying the tetrahedral coordination sphere of the zinc finger domains. The consequence of the reaction is a break of one of the Zn−S bonds and removal of the corresponding molecular thiolate group from the domain by forming a new S−S bond between sulfur atoms from the withdrawing fragment and of the electrophilic agent. As a result of this process the zinc-containing site transforms from the initial tetrahedral geometry to a planar geometry configuration. This transformation further facilitates destruction of the metal binding site. The calculations explicitly show correlations between redox potentials of the electrophilic agents, thei...
12 citations
TL;DR: In this article, the lowest energy electronic structure of neutral, cationic and anionic Rhn (n = 2-8) clusters in the gas phase is performed with an all electron relativistic method using density functional theory within the generalized gradient approximation.
Abstract: A systematic investigation on the lowest energy electronic structure of neutral, cationic and anionic Rhn (n = 2–8) clusters in the gas phase is performed with an all electron relativistic method using density functional theory within the generalized gradient approximation. The lowest energy structures of neutral and ionic rhodium clusters are evaluated with different multiplicities. Neutral clusters with even atoms of rhodium and ionic clusters containing odd atoms of rhodium are optimized with multiplicities M = 1, 3 and 5, while neutral clusters containing odd rhodium atoms and ionic clusters with even atoms of rhodium are allowed to relax with multiplicities M = 2, 4 and 6. The bond length, binding energy, coordination number, bond dissociation energy, stability function, ionization potential, electron affinity, electrophilicity, LUMO–HOMO gap, chemical hardness, dipole moment and magnetic moment are evaluated from the lowest energy geometry. These studies reveal that even atom rhodium clusters are more stable than odd atom clusters. Calculated electronic properties such as the LUMO–HOMO gap, bond dissociation energy, stability function, electron affinity and electrophilicity suggest that Rh4 with a tetrahedral geometry is the most stable among all Rhn (n = 2–8) clusters. Hence, tetrahedral Rh4 may be considered as the magic number cluster.
11 citations
TL;DR: Redox orbitals are shown to be almost exclusively ligand in nature, with a HOMO based heavily on the electron-rich maleonitriledithiolate ligand, and a LUMO comprised mostly of the electrons-deficient dithione ligand.
11 citations
TL;DR: In this article, a modified spin Hamiltonian was introduced to account for all energetically favorable spatial distributions of the valence electrons along the exchange bridges connecting the constituent magnetic ions.
Abstract: We investigate the spectroscopic magnetic excitations in molecular magnets with complex intermediate structure among the magnetic ions. Our approach consists in introducing a modified spin Hamiltonian that allows for discrete coupling parameters accounting for all energetically favorable spatial distributions of the valence electrons along the exchange bridges connecting the constituent magnetic ions. We discuss the physical relevance of the constructed Hamiltonian and derive its eigenvalues. The model is applied to explore the magnetic excitations of the tetrameric molecular magnet Ni$_4$Mo$_{12}$. Our results are in a very good agreement with the available experimental data. We show that the experimental magnetic excitations in the named tetramer can be traced back to the specific geometry and complex chemical structure of the exchange bridges leading to the splitting and broadness of the peaks centered about 0.5 meV and 1.7 meV.
11 citations