4,4'-(Ethene-1,2-di-yl)dipyridinium 4-[2-(pyridin-4-yl)ethen-yl]pyridinium octa-cyanidomolybdate(V) tetra-hydrate.

The crystal structure of the title compound, (C12H12N2)(C12H11N2)[Mo(CN)8]·4H2O, consists of 4,4'-(ethene-1,2-di-yl)dipyridinium and 4-[2-(pyridin-4-yl)ethen-yl]pyridinium cations disordered over the same site, an [Mo(CN)8](3-) anion and four water mol-ecules of crystallization. The eight-coordinate [Mo(CN)8](3-) unit exhibits a slightly distorted square-anti-prismatic geometry. In the structure, the cations (crystallographic symmetry, 2) and anions (crystallographic symmetry, 222) are arranged alternately by N-H⋯O and O-H⋯N hydrogen bonds, forming layers parallel to the bc plane. These layers are further linked through O-H⋯N hydrogen bonds, generating a three-dimensional supra-molecular network.

Tris(3,4,7,8-tetra-methyl-1,10-phenanthrolin-1-ium) hexa-cyanidocobaltate(III) penta-hydrate.

The structure of the title compound, (C16H17N2)3[Co(CN)6]·5H2O, consists of three 3,4,7,8-tetra-methyl-1,10-phenanthrolin-1-ium cations, a [Co(CN)6](3-) anion and five water mol-ecules of crystallization, one of which is disordered over two sets of sites in a 0.587 (15):0.413 (15) ratio. The [Co(CN)6](3-) anion exhibits an octa-hedral geometry. In the structure, cations and anions are linked alternatively through O-H⋯O, O-H⋯N, N-H⋯O and N-H⋯N hydrogen bonds, π-π inter-actions [centroid-centroid distances = 3.523 (2)-4.099 (2) Å] and van der Waals forces, forming a three-dimensional supra-molecular network.

[Effect of surface modified nano-diamond on viscosity of dental adhesives].

PURPOSE: Different surface modified ultrafine-diamond (UFD) was added into dental adhesives as filler ,then the influence of dental adhesive properties was observed. The main matrix of dental adhesive was high polymer resin. METHODS: Different content of non-modified UFD(n-UFD) or modified UFD(m-UFD) were added into dental adhesives, then the viscosity of materials were measured. The data was processed with SPSS17.0 software package. RESULTS: The viscosity of dental adhesives was decreased when the proportion of UFD was less than 0.1wt%, especially when it was 0.1wt%; but was significantly improved when the proportion was more than 0.1wt%. The effect of UFD and surface-modified UFD on the viscosity was significantly different. CONCLUSIONS: The results show that silane coupling was chemically-grafted on the surface of UFD, the dispersion and stability of UFD in ethanol was improved; And a quantity of UFD with special content could reduce the viscosity of dental adhesives and improve the flowability obviously. The m-UFD was superior to n-UFD.