The system magnesium oxide—silica

Abstract

The system MgO-Si02 has been studied at temperatures up to 1800". The polymorphic relationships in magnesium metasilicate are discussed and evidence is offered for the possible existence of an additional phase in the high-temperature region of the system. London, S.W.7THE MgO-SiO, system has frequently been investigated.Early work on the melt equilibrium of the system showed,l by optical methods, that magnesium orthosilicate (Mg,SiO,) (forsterite), and the clinoenstatite modification of magnesium metasilicate (MgSiO,) crystallised from the melt. The incongruent melting of clino-

Preparation, characterization and thermal investigation of polymeric and monomeric binuclear complexes of dianils derived from 6-formylkhellin with cobalt(II), nickel(II) and copper(II)

“…The molar conductivity values for complexes 3 and 6 are commensurated with their non-electrolytic nature. Complexes 1, 2 and 10 display higher molar conductance values (230, 206 and 171.9 cm 2 V À1 mol À1 , respectively), indicating 1:2 electrolyte [12]. The observed molar conductivity value (141 cm 2 V À1 mol À1 ) for complex 4, corresponds to a 1:1 electrolyte [13].…”

The synthesis and characterization of 1,2-O-cyclohexylidene-4-aza-8-aminooctane and some of its transition metal complexes

“…Analytical data for the complexes are given in the Tables 1-5. According to the aforementioned results, a tetrahedral geometry for the Ni(II) and Cu(II) complexes and a distorted octahedral high-spin geometry for the Co(II) is proposed [11][12][13][14][15]26]. The suggested structures of the complexes are shown in Figure 3 and Figure 4.…”

“…The preparation and structures of the complexes of benzenediamines recently have been reported [11][12][13][14][15]. Mostly, these complexes have been prepared by direct mixing of solutions containing appropriate amounts of the metal salt and the ligand.…”

Synthesis of β-D-ribofuranosylbenzazoles using nitrile oxide addition chemistry

“…Work-up of the reaction mixture was aided by washing with 4% aq. CuSO 4 , which removed excess DAB as its copper complex, 31 thus reducing time-consuming chromatographic separations. The 1 H and 13 C NMR spectra in CDCl 3 showed the presence of both the ribofuranose and benzimidazole units.…”