Ab initio calculation of strain effect on the magnetic properties of the thiogermanate [(CH3)4N]2FeGe4S10

The magnetic properties of the thiogermanate TMA(2)FeGe(4)S(10) (TMA=[(CH(3))(4)N](+)), and the influence of large strain are investigated by ab initio density functional theory calculations. An analysis of the electronic structure is provided considering antiferromagnetic (AFM), ferromagnetic (FM) and nonmagnetic configurations for the thiogermanate at the equilibrium states. A small difference in total energy between the FM and AFM states suggests that the thiogermanate TMA(2)FeGe(4)S(10) may possess a low Curie temperature. Changes in electronic structure and magnetic moment of the thiogermanate under strain are closely related to the distortion of FeS(4) tetrahedral units. With the help of a simplified molecule model, we show that, while the origin of the drastic change in magnetism under high isotropic compressions mainly originates from the decrease in the Fe-S interatomic bond length, the changes in the electronic structure between - 10% and + 15% isotropic strains are mainly due to the variations of the interatomic bond angles. Little effect of shear strain on the magnetic properties is found since the FeS(4) tetrahedral units rotate under shear, hence keeping their shape.     

BF3·Et2O catalyzed intramolecular cyclization of diethyl 2-(dialkoxyphosphorylethynyl)-2-arylaminomalonates to 3-phosphonylated indoles

The boron trifluoride diethyl etherate catalyzed intramolecular cyclization of diethyl 2-(dialkoxyphosphorylethynyl)-2-arylaminomalonates afforded a series of novel 3-phosphonylated indoles, diethyl 2-[3-(dialkoxyphosphoryl)-1H-indol-2-yl]propanedioates. Decarboxylation of the latter compounds resulted in the formation of ethyl 2-[3-(dialkoxyphosphoryl)-1H-indol-2-yl]acetates.     

Synthesis of 1,2-Diphenylpyrazolidin-4-ol and its Derivatives

A synthesis of 1,2-diphenylpyrazolidin-4-ol via direct heterocyclization of 1,2-diphenylhydrazine with 1-chloro-2,3-epoxypropane, its O-epoxypropyl-, O-ethyl-, and O-benzylderivatives are described. Novel hydrazone derivatives with pyrazolidine units were also synthesized. The compounds were characterized by spectroscopic methods as well as elemental analyses.     

The Complexation Properties of the Water-Soluble Tetrasulfonatomethylcalix[4]resorcinarene toward α-Aminoacids

The flexible bowl-type water-soluble molecule1, consisting of a resorcinol core and fourconvergent tetrasulfonatomethylene groups, existingas a tetraanion in neutral water solution, was studiedas the host molecule for recognition of-aminoacids. Out of 12 examined guestmolecules only those possessing aromatic hydrophobicmoieties or a long hydrophobic chain with a second ionogenic groupform inclusion complexes with 1. The complex formationwas considered with the help of both ¹H NMRand pH-metric titration in a broad range of pH.The role of host and guest geometric complementarity aswell as additional – and hydrophobic interactionsis discussed. The lack of these interactions inaqueous media provides domination of the guestsolvation by water over the 1 : 1 complexformation with 1.     

Synthesis of a Bifunctional 1,1′-Diphenyl-1,2,3,4-tetrahydroquinoline Derivative: 1,1′-Diphenyl-1,2,3,4,1′,2′,3′,4′-octahydro-6,6′-biquinolinyl-3,3′-diol

Summary. Intramolecular cyclization of N,N′-di(3-chloro-2-hydroxy)propyl-N,N′-diphenylbenzidine occurs to give bis-1,2,3,4-tetrahydroquinoline derivative 1,1′-diphenyl-1,2,3,4,1′,2′,3′,4′-octahydro-6,6′-biquinolinyl-3,3′-diol.