Cu(II) and Pd(II) complexes of N-(2-hydroxybenzyl)aminopyridines

N-(2-Hydroxybenzyl)aminopyridines (Lⁱ) react with Cu(II) and Pd(II) ions to form complexes in the compositions Cu(Lⁱ)₂(CH₃COO)₂ · nH₂O (n = 0, 2, 4), Pd(Lⁱ)₂Cl₂ · nC₂H₅OH (n = 0, 2) and Pd(L²)₂Cl₂ · 2H₂O. In the complexes, the ligands are neutral and monodentate which coordinate through pyridinic nitrogen. Crystal data of the complexes obtained from 2-amino pyridine derivative have pointed such a coordinating route and comparison of the spectral data suggests the validity of similar complexation modes of other analog ligands. Cu(II) complex of N-(2-hydroxybenzyl)-2-aminopyridine (L¹), [Cu(L¹)₂(CH₃COO)₂] has slightly distorted square planar cis-mononuclear structure which is built by two oxygen atoms of two monodentate carboxylic groups disposed in cis-position and two nitrogen atoms of two pyridine rings. The remaining two oxygen atoms of two carboxylic groups form two Cu and H bridges containing cycles which joint at same four coordinated copper(II) ion. IR and electronic spectral data and the magnetic moments as well as the thermogravimetric analyses also specify on mononuclear octahedric structure of complexes [Cu(L²)₂(CH₃COO)₂ · 2H₂O] and [Cu(L³)₂(CH₃COO)₂ · 4H₂O] where L² and L³ are N-(2-hydroxybenzyl)-2- or 3-aminopyridines, respectively.     

Influence of the adsorption of residual gas phase molecules in a measuring chamber on the surface tension of liquid metals

The article physically substantiates the derivation of a formula, empirically derived earlier, which describes the adsorption relaxation of a newly-formed pure metal surface. The process variable is determined and its relation to other variables is established. It is demonstrated, that one of the reasons for the significant scattering of experimental surface tension values, as described in published works, may be the adsorption of residual gas phase molecules in a measuring chamber on the surface of pure metals.     

Undergraduate Engineering Majors' Beliefs About Mathematics

This study examined the mathematics beliefs of college students in 10 undergraduate mathematics classes at a large engineering school in the Midwest. The beliefs of 254 engineering majors were measured by the Indiana Mathematics Belief Scales and compared to the beliefs of elementary education majors and remedial college mathematics students obtained from earlier studies using the same instrument. The results were interpreted in terms of the students' daily attitudes towards their mathematics classes and corresponding academic and demographic parameters. The study showed that in many respects, the beliefs of the engineering majors were not that different from the other populations. The correlations among beliefs for the engineering group tended to be higher although there were relatively few significant correlations between belief and background variables. Attitude data were collected across a full semester for the engineering majors. The relatively modest day-to-day variation in those attitudes suggests that they are based on deeply seated beliefs.