Unoccupied Electron States and the Formation of Interface between Films of Dimethyl-Substituted Thiophene–Phenylene Coolygomers and Oxidized Silicon Surface

Physics of the Solid State - The unoccupied electron states and the boundary potential barrier during deposition of ultrathin films of dimethyl-substituted thiophene–phenylene coolygomers of...     

Density functional theory versus quantum Monte Carlo simulations of Fermi gases in the optical-lattice arena

We benchmark the ground state energies and the density profiles of atomic repulsive Fermi gases in optical lattices (OLs) computed via density functional theory (DFT) against the results of diffusion Monte Carlo (DMC) simulations. The main focus is on a half-filled one-dimensional OLs, for which the DMC simulations performed within the fixed-node approach provide unbiased results. This allows us to demonstrate that the local spin-density approximation (LSDA) to the exchange-correlation functional of DFT is very accurate in the weak and intermediate interactions regime, and also to underline its limitations close to the strongly-interacting Tonks–Girardeau limit and in very deep OLs. We also consider a three-dimensional OL at quarter filling, showing also in this case the high accuracy of the LSDA in the moderate interaction regime. The one-dimensional data provided in this study may represent a useful benchmark to further develop DFT methods beyond the LSDA and they will hopefully motivate experimental studies to accurately measure the equation of state of Fermi gases in higher-dimensional geometries.     

Synthesis of Phosphorus Containing Polymers by Phase Transfer Catalysis (PTC). I. Comparative Study between Liquid-Liquid and Liquid-Vapor Systems

Abstract

Polyphosphonates were synthesized by interfacial alkaline polycondensation of bispheml A (BA) with phenyldichlorophosphonate (PPD) and cyclohexyl-dichlorophosphonate (CPD) in liquid-liquid[1] (1–1) and Iiquid-vapoR[2] (I-v) systems.     

Unexpected radical substitution of the dichlorine-containing iron(II) clathrochelate with 1,4-dioxane derivatives: Novel approach to functionalization of its macrobicyclic framework

The dichlorine-containing tris-dioximate iron(II) clathrochelate undergoes a radical addition-elimination reaction with the radical derivatives of 1,4-dioxane to yield ribbed-functionalized C-alkylated macrobicyclic complexes. The clathrochelates obtained have been characterized using elemental analysis, MALDI-TOF mass, IR, UV-Vis and multinuclear NMR spectra, as well as X-ray crystallography. This unexpected and previously unknown radical reaction is a novel approach to the ribbed functionalization of tris-dioximate d-metal clathrochelates, and it can be extended to other cyclic ethers.