Chiral group 4 NHC-metal complexes were prepared in good yields by amine elimination from M(NR2)4 (M = Ti, Zr, Hf; R = Me, Et) and chiral pincer NHC-ligands, L4(L4a and L4b), L5 and L6, which are derived from (S,S)-diphenyl-1,2-ethanediamine. Treatment of M(NR2)4 with 1 equiv. of L4 in THF gives, after recrystallization from a benzene solution, the chiral titanium amides (L4)Ti(NMe2)(Br)(THF) (...

The basic weldability of the alloy Al-2.2Li-2.7Cu was investigated and compared with two common aluminum alloys: 2024 and 5083. The basic weldability was characterized by the susceptibility of the alloy to hot tearing as determined by the trans-Varestraint test. The hot tearing susceptibility was characterized through plots of total crack length and maximum crack length versus augmented strain....

NanoTiO2 , nanoZrO2 and TiO2 /ZrO2 nanocomposite were prepared via sol gel method by using ultrasonic irradiation. The precursor sol of zirconium was prepared from an aqueous solution of ZrCl4 and titanium tetra 2-propoxide was diluted by 2-propanol and deionized water The TiO2 /ZrO2 nanocomposite was synthesized from directly mixing Titanium dried gel into Zirconium gel. The reaction mixture w...

PURPOSE This study aimed to evaluate the correlation between microleakage and screw loosening at different types of implant-abutment connections and/or geometries measuring the torque values before and after the leakage tests. MATERIALS AND METHODS Three different abutment types (Intenal hex titanium, internal hex zirconium, morse tapered titaniuım) with different geometries were connected to...

Monomeric Ti(IV)/C3 trialkanolamine complexes are effective catalysts in the stereoselective sulfoxidation of alkyl aryl sulfides (ee’s up to 84%, 0.1% of catalyst). Such complexes were shown to have a biphilic nature, behaving as electrophilic oxidants towards sulfides while a nucleophilic pathway dominates the oxidation of sulfoxides. The analogous Zr(IV) complexes, likely dimeric, are even b...

Discrete ionic complexes {ONOSiMe2tBu}M(CH2Ph)((η6-Ph)CH2B(C6F5)3) (M = Ti, 2-Ti; Zr, 2-Zr) have been prepared from the parent neutral dibenzyl precursors and B(C6F5)3. Also, a neutral dichloro complex {ONOSiMe2tBu}ZrCl2(Me2NH) (3) was synthesized by the reaction of a proligand {ONOSiMe2tBu}H2 (1-H2) with (Me2N)2ZrCl2(DME). The compounds were characterized by NMR spectroscopy and X-ray crystall...

PURPOSE The aim of this study was to evaluate antibacterial activity and osteoblast-like cell viability according to the ratio of titanium nitride and zirconium nitride coating on commercially pure titanium using an arc ion plating system. MATERIALS AND METHODS Polished titanium surfaces were used as controls. Surface topography was observed by scanning electron microscopy, and surface roughn...

Osseointegrated dental implants play an important role in restorative dentistry. However, plaque accumulation may cause inflammatory reactions around the implants, sometimes leading to implant failure. In this in vivo study the influence of two physical hard coatings on bacterial adhesion was examined in comparison with a pure titanium surface. Thin glass sheets coated with titanium nitride (Ti...