The title compound, C(26)H(30)N(4), was prepared by condensation of tetra-methyl-pyrazine and dimethyl-amino-benzaldehyde and crystallizes from chloro-form/methanol in two different forms. Block-shaped crystals belong to the monoclinic crystal system and plates to the triclinic system. The two crystal forms differ in the arrangement of the centrosymmetric mol-ecules, which have nearly identical...

The title compound, C18H18O4, is a triclinic polymorph of the previously reported monoclinic polymorph [Han & Zhen (2005 ▶). Acta Cryst. E61, o4358-o4359]. In the crystal of the triclinic polymorph, molecules are linked by two pairs of C-H⋯O hydrogen bonds, forming a two-dimensional network parallel to (102), and enclosing loops with graph set motifs of R2(2)(8) and R2(2)(6).

The preparation and characterization of the nBu4N+ salts of two bis-orotate(2-) complexes of cobalt, namely bis(tetra-n-butylammonium) diaquabis(2,4-dioxo-1,2,3,4-tetrahydropyrimidin-1-ide-6-carboxylato-κ2N1,O6)cobalt(II) 1.8-hydrate, (C16H36N)2[Co(C5H2N2O4)2(H2O)2]·1.8H2O, (1), and tetra-n-butylammonium (2,2'-bipyridine-κ2N,N')bis(2,4-dioxo-1,2,3,4-tetrahydropyrimidin-1-ide-6-carboxylato-κ2N1,...

sulphosalts in the system agsbs2-agass2 have been experimentally investigated using dry methods. the solid solutions which form between ?-miargyrite and smithite have different structures. the epma data for the solid solution series show that there is an inverse relation between sb and as. the cell parameters of the solid solution between ?-miargyrite and smithite increase up to about 50% of...

sulphosalts in the system agsbs2-agass2 have been experimentally investigated using dry methods. the solid solutions which form between ?-miargyrite and smithite have different structures. the epma data for the solid solution series show that there is an inverse relation between sb and as. the cell parameters of the solid solution between ?-miargyrite and smithite increase up to about 50% of ag...

The title compound, C(15)H(14)O(3), has been found to crystallize as a new triclinic polymorph. The asymmetric unit of the present structure, as in the previously reported monoclinic structure [Norment & Karle (1962 ▶). Acta Cryst. 15, 873-878], contains two independent mol-ecules, which differ slightly in the orientations of the two benzene rings. The crystal packing of the triclinic polymorph...