Binuclear 1,2,4,5-tetraimino-3,6-diketocyclohexane bis[bis(bipyridine)ruthenium(II)] redox series.

The reaction of the [Ru(bpy)2(MeOH)2]2+ cation (bpy = 2,2'-bipyridine) with 1,2,4,5-tetraaminobenzene in the presence of trace water and oxygen yields the cation [(bpy)2Ru(1,2,4,5-tetraimino-3,5-diketocyclohexane)Ru(bpy)2]4+. This binuclear species undergoes ligand-based reductions, giving the 3+ and 2+ charged species. The X-ray structure, electrochemistry, ZINDO calculations, and NMR, ESR, UV/vis, and IR spectra were analyzed where possible, giving an electronic model of the binuclear species and some of its redox products. The X-ray structure reveals the [(bpy)2Ru] fragments symmetrically disposed across the 1,2,4,5-tetraimino-3,5-diketocyclohexane bridge in a molecule with Cs symmetry.

A simplified procedure for survey and design of diagnostic casts.

The procedure described for survey and design of diagnostic casts is applicable to either dental arch. It is presented in a sequential manner, is not complex, and will produce uniformly acceptable results. The following steps should be followed: (1) locate a path by tilting the cast; (2) mark the survey lines and tripod the cast; (3) outline the rest and guide planes; (4) draw minor connectors; (5) draw major connectors; (6) draw retention mesh for acrylic resin; (7) draw acrylic resin base extension; and (8) draw direct retainers (clasps).

An individualized impression tray utilizing the patient's existing denture.

This technique utilizes patients' existing dentures to construct individualized impression trays. Some of the advantages are: (1) the trays are made within 30 minutes; (2) final impressions may be made at the first appointment; (3)it is an inexpensive and uncomplicated laboratory procedure readily taught to dental auxiliaries. (4) chair time is better utilized by both the dentist and patient.