The complex [Cu(en) 2 (H 2 O)](sy) 2 (en)(H 2 O) 2 has been synthesized and characterized by its electronic and vibrational spectra. The molecular structure of the complex has been determined by X-ray diffraction methods. The complex crystallizes in the orthorhombic space group Pnma with unit-cell parameters a = 10.7236 (5), b = 20.4660(10), c = 14.4523(11)Å and Z = 4. In the cation, the Cu(II) ion has a distorted square pyramidal coordination with two bidendate (en) ligands forming the basal plane and a H 2 O molecule in the apical position. The complex cations and syringate anions constitute chains along the b axis in -A-B-A-fashion. The members of the chains are linked by through N-H···O hydrogen bonds. The (en) molecules are responsible for connecting adjacent layers.

In this study, the hardness and wear behaviour of carburized and boronized AISI 8620 steels have been studied. The boronizing treatment increased the hardness of AISI 8620 steels from 395 HV0.1 to a maximal 1610 HV0.1 compared to the carburized steels and also significantly improved its wear behaviour. From obtained results, it can be concluded that boronizing is very effective surface hardening method for improving the wear properties of AISI 8620 steels.

Corrosion behaviour of boronized and unboronized AISI 1050 steel and chilled cast iron were investigated by the weight loss method. Corrosion studies were performed with 10 % H 2 S0 4 solution as a corrosive medium at temperatures 298, 333 and 353 Κ and 2 h immersion periods. The weight loss of AISI 1050 steel and chilled cast iron treated in the corrosive medium increased with increasing temperature. While the weight loss of the AISI 1050 steel increased exponentially with increasing temperature, the chilled cast iron showed continuously decreasing values. Very low weight losses were observed in boronized samples compared with unboronized samples. The boronizinig process significantly decreased the weight loss of both materials and improved the corrosion behaviour.