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.

Counting levels within vibrational polyads: Generating function approach

Abstract: Simple analytical formulas for the number of energy levels in the vibrational polyads are given. These formulas account for the resonances between the vibrational modes, and for the symmetry of the problem, so that the number of states of a particular symmetry type can be computed. The formulas are used to estimate the differential and integral densities of states from the minimum initial information about the molecule. Examples of the vibrational structure of triatomic molecules A3, tetrahedral molecules AB4, and linear molecules AB2 are considered. The analytical formulas are compared to the ab initio results for H3+ [J. R. Henderson et al., J. Chem. Phys. 98, 7191 (1993)].

Bis(melaminium) sulfate dihydrate.

Abstract: The crystals of a new melaminium salt, bis(2,4,6-tri­amino-1,3,5-triazin-1-ium) sulfate dihydrate, 2C3H7N6+·SO42−·2H2O, are built up from monoprotonated melaminium(1+) residues, sulfate(2−) anions and water mol­ecules. The SO42− ion has a slightly distorted tetrahedral geometry. The melaminium residues are interconnected by N—H⋯N hydrogen bonds, forming chains. The chains of melaminium residues develop a three-dimensional network through multiple donor–acceptor hydrogen-bond interactions with sulfate anions and water mol­ecules.

Stepwise Synthesis of Charged and Neutral Two-Dimensional Networks via One-Dimensional Silver(I) Coordination Polymer Based on Bis(4-pyridylmethyl)sulfide

Abstract: Stepwise synthesis and structural characterization of two-dimensional (2-D) coordination polymer frameworks with positive charged or neutral cavities are reported. First, reactions of bis(4-pyridylmethyl)sulfide (L) with silver salts (1: nitrate and 2: perchlorate) afforded the respective double-stranded one-dimensional (1-D) chains [Ag(L)NO3]n (1) and {[Ag2(L)2](ClO4)2}n (2), both of which are stabilized by face-to-face π−π interactions. In this case, the silver(I) center in the nitrato complex 1 shows four-coordinated distorted tetrahedral geometry, whereas that of the perchlorato complex 2 exhibits a distorted trigonal planar geometry. The difference of these structures indicates that the coordination ability of the anions has important effects on the silver(I) coordination environments. Interestingly, the perchlorato 1-D complex 2 allows further reactions with bridging ligands such as 4,4′-bipyridine (bpy) and terephthalate (tp2−) to give a 2-D positive-charged network {[Ag2(L)2(bpy)]·(ClO4)2·C6H6}n (...