Finnish research on affect in mathematics: blended theories, mixed methods and some findings

Since the 1990s there has developed a strong cluster of research around the affect in mathematics in Finland. This review highlights some outcome of this work. It is argued that both theoretically and methodologically there has been a tendency to incorporate influences from several sources, which has provided a fertile ground for innovative research. Some of the empirical findings are also reviewed.     

Phase and Element Contents of the cBN Based Composites as Estimated by XPS

X-ray photoelectron spectroscopy (XPS) is used to estimate phase and element contents of the composites based on cubic boron nitride. A composite is a mixture of several compounds and the use of traditional X-ray diffraction for phase analysis in many cases can be difficult. By using XPS, we were able to evaluate the atomic concentration of elements and the content of different compounds of each element. SEM and XPS showed that samples are heterogeneous. The TiB₂ phase, expecting from thermodynamic calculations, was formed in both investigated samples of cBN/Ti₃SiC₂/TiC but in different amount. The Ti₃SiC₂ additive was found more chemically active then TiC.     

Thermal Decomposition of Copper(I) Thiocarbamide Chloride Hemihydrate

Two combinations of simultaneous thermoanalytical techniques (TG+DTA and TG+EGA) were used to study the thermal decomposition of the title compound in order to gain a better insight into the spray pyrolytic processes leading to Cu2-xS and CuInS2 thin films. After dehydration a complex sequence of reactions starts above 220°C leading through several intermediates to the formation of CuO in air at 1000°C. In an inert atmosphere Cu2S is formed which in helium above 800°C partly decomposes to Cu. XRD and FTIR were used to identify the intermediate solid phases which in air included CuCl, Cu2OSO4, Cu2OCl2 and CuSO4. EGA-FTIR confirmed the complex reaction mechanism with NH3, HCl, H2O, COS, CO2 and some HCN as main gaseous products under oxidative conditions. This revised version was published online in July 2006 with corrections to the Cover Date.     

Formation and structural characterization of novel polynuclear palladium selenolato complexes [Pd3Se(SePh)3(PPh3)3]Cl and [Pd6Cl2Se4(SePh)2(PPh3)6]

In addition to well-known dinuclear phenylselenolato palladium complexes, the reaction of [PdCl₂(PPh₃)₂] and NaSePh affords small amounts of novel trinuclear and hexanuclear complexes [Pd₃Se(SePh)₃(PPh₃)₃]Cl (1) and [Pd₆Cl₂Se₄(SePh)₂(PPh₃)₆] (2). Complex 1 is triclinic, P1?, a=13.6310(2), b=16.2596(2), c=16.9899(3) Å, α=83.1738(5), β=78.9882(5), γ=78.7635(5)°. Complex 2 is monoclinic, C2/c, a=25.7165(9), b=17.6426(8), c=27.9151(14) Å, β=110.513(2)°. There are no structural forerunners for 1, but the hexanuclear complex 2 is isostructural with [Pd₆Cl₂Te₄(TeR)₂(PPh₃)₆] (R=Ph, C₄H₃S) that have been observed as one of the products in the oxidative addition of R₂Te₂ to [Pd(PPh₃)₄]. Mononuclear palladium complexes may play a significant role as building blocks in the formation of the polynuclear complexes.     

A Thermal study of the precipitates formed in ammonia neutralization of acidic solutions of dissolved phlogopite

The precipitates containing mainly iron, aluminium and magnesium hydroxides, obtained from phlogopite dissolved in nitric acid by means of the neutralization procedure with ammonia, have been investigated by thermal analysis (TG, DTG and DTA). According to the present study, which is part of a larger investigation into the chemical utilization of Finnish mica minerals, the formation of solid solutions between iron and aluminium hydroxides in silt increases with an increasing neutralization temperature. Nitrogen exists mainly in the form of nitrate in silts, and magnesium forms mixed hydroxides with aluminium, which causes a separation between the iron hydroxide and magnesium aluminium hydroxide phases.

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Zusammenfassung Die von in Salpetersäure gelöstem Phlogopit durch Neutralisierung mit Ammoniak erhaltenen, hauptsächlich Eisen-, Aluminium- und Magnesiumhydroxid enthaltenden Niederschläge wurden thermoanalytisch (TG, DTG und DTA) untersucht. In der vorliegenden Arbeit, die Teil einer grossangelegten Untersuchung zur chemischen Nutzung finnischer Glimmermineralien ist, wird gezeigt, dass die Bildung fester Lösungen von Eisen- und Aluminiumhydroxiden in Schluff mit zunehmender Neutralisationstemperatur ansteigt. Stickstoff kommt in Schluff hauptsächlich in Form von Nitraten vor, und Magnesium bildet Mischhydroxide mit Aluminium, was eine Trennung der Eisenhydroxidphase von der Magnesium-Aluminium-Hydroxidphase bewirkt.

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A matrix infrared study of association of formamide

The association of formamide has been studied in argon. In the spectral region from 800 to 200 cm⁻¹ several characteristic bands due to association were found and assigned to the out-of-plane bending modes of the NH group. The widths of these low-frequency bands are of the same order of magnitude as those of the fundamental bands of the monomer. By comparing the spectra of self-associated species with spectra of heteroassociated species between formamide and N,N-dimethyl formamide, it was possible to assign association bands to the open dimers as well as to the cyclic dimers. A band appearing upon warming at about 230 cm⁻¹ has been assigned to a H-bond stretching mode. The results indicate that dimers trapped from the gas phase are predominantly open, and that both open and cyclic structures are formed upon diffusion-controlled association in the matrix.     

Synthesis,spectroscopic, magnetic properties and MMX force field study of two imidazolate-bridged dinuclear copper(II) complexes

Two new imidazolate-bridged dinuclear Cu^II complexes, Na[Cu₂(L¹)₂(im)] and K[Cu₂(L²)₂(im)] (where H₂L¹=6-amino-1,3-dimethyl-5(2-carboxyphenyl)azouracil and H₂L²=1,3-dimethyl-5(2-carboxyphenyl)azobarbituric acid) have been prepared and characterized by magnetic susceptibility and spectroscopic measurements. Both compounds exhibit the expected antiferromagnetic behaviour with 2J=−54.8 and −30.4 cm⁻¹, respectively. Because of the lack of suitable crystals for single crystal X-ray analysis, we have calculated the lowest energy structures using a program based on the MMX force field. On the basis of the results, the magnitude of the magnetic interaction is discussed. TMC 2623     

SYNTHESIS OF TRIFLUOROMETHYL-IMINES BY SOLID ACID/SUPERACID CATALYZED MICROWAVE ASSISTED APPROACH

A new solid acid/superacid catalyzed microwave assisted synthesis of trifluoromethyl-imines is described. Various α,α,α-trifluoromethylketones react readily with primary amines to produce the corresponding imines. Two different strategies have been employed; one is the application of microwave irradiation coupled with solvent-free solid acid catalysis. The other method, for highly deactivated substrates includes the use of a pressure vessel at 175 °C temperature, with solid superacid catalysis. Using the solid acid K-10 montmorillonite or the superacidic perfluorinated resinsulfonic acid Nafion-H, a wide variety of trifluoromethylated imines have been synthesized using the above methods. The products have been isolated in good to excellent yields and high selectivities. This new environmentally friendly synthetic methodology provides significantly higher yields than traditional methods during relatively short reaction times for the preparation of the target compounds.     

Neutralization of solvated protons and formation of noble-gas hydride molecules: matrix-isolation indications of tunneling mechanisms?

The (NgHNg)+ cations (Ng = Ar and Kr) produced via the photolysis of HFAr, HFKr, and HBrKr solid mixtures are studied, with emphasis on their decay mechanisms. The present experiments provide a large variety of parameters connected to this decay phenomenon, which allows us to reconsider various models for the decay of the (NgHNg)+ cations in noble-gas matrices. As a result, we propose that this phenomenon could be explained by the neutralization of the solvated protons by electrons. The mechanism of this neutralization reaction probably involves tunneling of an electron from an electronegative fragment or another trap to the (NgHNg)+ cation. The proposed electron-tunneling mechanism should be considered as a possible alternative to the literature models based on tunneling-assisted or radiation-induced diffusion of protons in noble-gas solids. As a novel experimental observation of this work, the efficient formation of HArF molecules occurs at 8 K in a photolyzed HFAr matrix. It is probable that the low-temperature formation of HArF involves local tunneling of the H atom to the Ar-F center, which in turn supports the locality of HF photolysis in solid Ar. In this model, the decay of (ArHAr)+ ions and the formation of HArF molecules observed at low temperatures are generally unconnected processes; however, the decaying (ArHAr)+ ions may contribute to some extent to the formation of HArF molecules.     

Studies on lanthanoid sulphites: V. thermal decomposition of cerium and neodymium sulphites

The preparation and thermal behaviour of Ce₂(SO₃)₃· 3H₂O, Nd₂(SO₃)₃·6H₂O and Nd₂(SO₃)₃ have been studied. Cerium sulphite undergoes first dehydration which is followed by decomposition to CeO₂ in the temperature range 500 – 850 °C. The decomposition involves two intermediate phases both in air and nitrogen. According to the TG curves the phases in air are Ce₂(SO₃)₂SO₄ and Ce₂SO₃(SO₄)₂. In nitrogen, Ce₂O₂SO₄ was identified and this provides a synthetic route to cerium oxysulphate.Neodymium sulphite decomposes to Nd₂O₂SO₄ when heated in air or in nitrogen up to 950°C. The intermediate levels observed do not correspond to single phases, and the reaction mechanism depends strongly on the experimental conditions.