Accuracy of single-tooth restorations based on intraoral digital and conventional impressions in patients.

Objectives: The purpose of this clinical study was to compare the marginal fit of dental crowns based on three different intraoral digital and one conventional impression methods.

Methods: Forty-nine teeth of altogether 24 patients were prepared to be treated with full-coverage restorations. Digital impressions were made using three intraoral scanners: Sirona CEREC AC Omnicam (OCam), Heraeus Cara TRIOS and 3M Lava True Definition (TDef).

Square-planar iridium(II) and iridium(III) amido complexes stabilized by a PNP pincer ligand.

Squaring the circle: the novel dienamido pincer ligand N(CHCHPtBu(2))(2)(-) affords the isolation of the unusual square-planar iridium(II) and iridium(III) amido complexes [IrCl{N(CHCHPtBu(2))(2)}](n) (n=0 (1), +1 (2)). In contrast, the corresponding iridium(I) complex of the redox series (n=-1) is surprisingly unstable. The diamagnetism of 2 is attributed to strong N→Ir π donation.

Synthesis of non-symmetrically sulphonated phosphine sulphonate based Pd(II) catalyst salts for olefin polymerisation reactions.

Direct sulphonation of 2-(diphenylphosphino)benzenesulphonic acid was extensively studied. The non-symmetrically functionalised reaction products obtained, related to the widely applied water soluble phosphine ligands m,m,m-TPPTS and m,m-TPPDS, display chelating κ(2)-(P,O)-coordination to Pd(II) metal centres. Phase transfer reaction of rac-o,m-TPPDS as the potassium salt with 18-crown-6 and complexation to Pd(II) gives the novel anionic catalyst precursor [K(18-crown-6)](2)[κ(2)(P,O){rac-o,m-TPPDS}PdMeCl] suitable for olefin polymerisation reactions.

Synthesis, X-ray single-crystal structure determination, and magnetic properties of [Rb(benzo[18]crown-6)](+) salts containing well-ordered fulleride trianions C60(3-).

Finally, a structure with well-resolved C(60) (3-) ions and S=1/2 spin system: The two novel title compounds have clearly S=1/2 and not S=3/2 electronic states, as expected for the occupation of the triply degenerate LUMO of C(60.) These structures with well-ordered fullerene trianions show that the expected Jahn-Teller distortion is not observable in X-ray diffraction experiments.Crystals of the composition [Rb(benzo[18]crown-6)](3)[eta(3)-C(60)](C(7)H(8))(C(3)H(7)NO)(4.