Vierfach Guanidinyl-funktionalisierte Aromaten: Synthese, Eigenschaften und Anwendung als organische Elektronendonoren und redoxaktive Liganden

This work focuses on the synthesis and characterization of the new guanidinyl-functionalized aromatic compounds (GFA-4) 1,4,5,8-tetrakis(N,N,N',N' - tetramethylguanidinyl)naphthalene (ttmgn) and 1,4,5,8-tetrakis(N,N,N',N'-dimethylethylenguanidinyl)naphthalene (tdmegn) as well as on the coordination chemistry of these ligands and the use of the new coordination compounds to stabilize monoanionic polyhalides. ttmgn and tdmegn represent strong electron-donors and redox-active ligands. Investigation of the redox behavior using cyclic voltammetry showed the existence of two reversible oxidation processes (oxida-tion to two and fourfold oxidized species) respectively, where tdmegn is a slightly better electron donor in CH3CN than ttmgn. Two and fourfold oxidized ligands were obtained fully characterized. Study of the basic properties showed ttmgn to be a double proton sponge. The protonation experiments on these "superbases" were supported by quantum chemical calculations. A general feature of the characterized coordination compounds was the displacement of the metals from the aromatic plane. The copper(I) complexes [ttmgn(CuI)2] and [ttmgn(CuBr)2] were synthesized and their redox chemistry analyzed. Magnetic superexchange through the ligand unit is studied for the binuclear Co(II) complexes trans-[ttmgn(CoCl2)2] and cis-[tdmegn(CoCl2)2]. SQUID measurements show an extremely weak antiferromagnetic coupling. The dynamic behavior of the metal centers was studied on the example of the Al(III) complex [ttmgn(AlMe2)2][BPh4]2 using NMR experiments. Furthermore, a number of new mono- and binuclear cationic boron complexes was prepared with the ligands ttmgn and btmgn (1,8-Bis(N,N,N',N'-tetramethylguanidinyl)naphthalene). The exchange process between the BF2 groups and BF4 anions in the salt [ttmgn(BF2)2][BF4]2 measured with 19F EXSY NMR spectroscopy points to a complexation equilibrium. It could be shown that the guanidine-boron bond is sufficiently weak to allow the presence of a small quantity of the redox-active ttmgn in solution. Finally, a strategy for the synthesis of polyhalide monoanions was introduced, in which the reducing agent ttmgn is in the cationic complex [ttmgn(BF2)2][BF4]2 "wrapped". Wrapped up in the cationic complex, the reduction power is evidently greatly reduced. Moreover, the relatively large size of the cationic complexes conduces to stabilize monoanionic polyhalides. So reaction of [ttmgn(BF2)2][BF4]2 with I2 and Br2 led respectively to the formation of [I7]‒ and [Br5]‒. This work provides the first complete characterization of the [Br5]‒ monoanion including X-Ray crystal structure

Fly ash particles spheroidization using low temperature plasma energy

The paper presents the investigations on producing spherical particles 65-110 [mu]m in size using the energy of low temperature plasma (LTP). These particles are based on flow ash produced by the thermal power plant in Seversk, Tomsk region, Russia. The obtained spherical particles have no defects and are characterized by a smooth exterior surface. The test bench is designed to produce these particles. With due regard for plasma temperature field distribution, it is shown that the transition of fly ash particles to a state of viscous flow occurs at 20 mm distance from the plasma jet. The X-ray phase analysis is carried out for the both original state of fly ash powders and the particles obtained. This analysis shows that fly ash contains 56.23 wt.% SiO[2]; 20.61 wt.% Al[2]O[3] and 17.55 wt.% Fe[2]O[3] phases that mostly contribute to the integral (experimental) intensity of the diffraction maximum. The LTP treatment results in a complex redistribution of the amorphous phase amount in the obtained spherical particles, including the reduction of O[2]Si, phase, increase of O[22]Al[20] and Fe[2]O[3] phases and change in Al, O density of O[22]Al[20] chemical unit cell

Fly ash particles spheroidization using low temperature plasma energy

The paper presents the investigations on producing spherical particles 65-110 [mu]m in size using the energy of low temperature plasma (LTP). These particles are based on flow ash produced by the thermal power plant in Seversk, Tomsk region, Russia. The obtained spherical particles have no defects and are characterized by a smooth exterior surface. The test bench is designed to produce these particles. With due regard for plasma temperature field distribution, it is shown that the transition of fly ash particles to a state of viscous flow occurs at 20 mm distance from the plasma jet. The X-ray phase analysis is carried out for the both original state of fly ash powders and the particles obtained. This analysis shows that fly ash contains 56.23 wt.% SiO[2]; 20.61 wt.% Al[2]O[3] and 17.55 wt.% Fe[2]O[3] phases that mostly contribute to the integral (experimental) intensity of the diffraction maximum. The LTP treatment results in a complex redistribution of the amorphous phase amount in the obtained spherical particles, including the reduction of O[2]Si, phase, increase of O[22]Al[20] and Fe[2]O[3] phases and change in Al, O density of O[22]Al[20] chemical unit cell

1,8-Bis(silylamido)naphthalene complexes of magnesium and zinc synthesized through alkane elimination reactions

The reactions between magnesium or zinc alkyls and 1,8-bis(triorganosilyl)diaminonaphthalenes afford the 1,8-bis(triorganosilyl)diamidonaphthalene complexes with elimination of alkanes. The reaction between 1,8-C10H6(NSiMePh2H)2 and one or two equivalents of MgnBu2 affords two complexes with differing coordination environments for the magnesium; the reaction between 1,8-C10H6(NSiMePh2H)2 and MgnBu2 in a 1:1 ratio affords 1,8-C10H6(NSiMePh2)2{Mg(THF)2} (1), which features a single magnesium centre bridging both ligand nitrogen donors, whilst treatment of 1,8-C10H6(NSiR3H)2 (R3 = MePh2, iPr3) with two equivalents of MgnBu2 affords the bimetallic complexes 1,8-C10H6(NSiR3)2{nBuMg(THF)}2 (R3 = MePh2 2, R3 = iPr3 3), which feature four-membered Mg2N2 rings. Similarly, 1,8-C10H6(NSiiPr3)2{MeMg(THF)}2 (4) and 1,8-C10H6(NSiMePh2)2{ZnMe}2 (5) are formed through reactions with the proligands and two equivalents of MMe2 (M = Mg, Zn). The reaction between 1,8-C10H6(NSiMePh2H)2 and two equivalents of MeMgX affords the bimetallic complexes 1,8-C10H6(NSiMePh2)2(XMgOEt2)2 (X = Br 6; X = I 7). Very small amounts of [1,8-C10H6(NSiMePh2)2{IMg(OEt2)}]2 (8), formed through the coupling of two diamidonaphthalene ligands at the 4-position with concomitant dearomatisation of one of the naphthyl arene rings, were also isolated from a solution of 7