Key indicators: single-crystal X-ray study; T = 173 K; mean (C-C) = 0.014 Å; R factor = 0.045; wR factor = 0.144; data-to-parameter ratio = 17.1.The title compound, [CdI 2 (C 12 H 8 N 2 ) 2 ], consists of two 1,10phenanthroline (phen) ligands, two I atoms and one Cd atom. The coordination geometry around the Cd atom, which lies on a twofold rotation axis, is slightly distorted octahedral. In the crystal structure, the dihedral angle between the two phen ligands is 89.03 (5) . The crystal packing is stabilized by intermolecularinteractions of phen rings, with a parallel distance of 3.362 Å , a centroid-centroid distance of 3.903 Å and a slip distance of 1.983 Å , and C-HÁ Á ÁI hydrogen bonding [IÁ Á ÁH = 3.091 and 2.990 Å ]. ] M r = 726.61 Orthorhombic, Pbcn a = 13.4833 (5) Å b = 9.5244 (3) Å c = 17.3385 (5) Å V = 2226.41 (13) Å 3 Z = 4 Mo K radiation = 3.77 mm À1 T = 173 (2) K 0.08 Â 0.07 Â 0.01 mm Data collection Rigaku R-AXIS SPIDER diffractometer Absorption correction: multi-scan (ABSCOR; Higashi, 1995) T min = 0.664, T max = 1.000 20141 measured reflections 2554 independent reflections 1786 reflections with I > 2(I) R int = 0.067

Key indicators: single-crystal X-ray study; T = 173 K; mean (C-C) = 0.006 Å; R factor = 0.033; wR factor = 0.085; data-to-parameter ratio = 19.7.A new mixed-metal complex, [CuI(C 12 H 8 N 2 ) 2 ] 2 [CdI 4 ], with an asymmetric unit consisting of one [CuI(phen) 2 ] + cation (phen = 1,10-phenanthroline) and half of a [CdI 4 ] 2À anion lying on a twofold rotation axis, has been synthesized. The Cu 2+ ion in the [CuI(phen) 2 ] + cation is five-coordinated by two bidentate phenanthroline ligands and an iodide ligand. The crystal packing is stabilized by intermolecular C-HÁ Á ÁI hydrogen bonds. 4 ] M r = 1721.70 Monoclinic, C2=c a = 21.0726 (5) Å b = 15.4727 (5) Å c = 15.5907 (4) Å = 90.991 (1) V = 5082.6 (2) Å 3 Z = 4 Mo K radiation = 4.93 mm À1 T = 173 (2) K 0.66 Â 0.41 Â 0.36 mm Data collection Rigaku R-AXIS SPIDER diffractometer Absorption correction: multi-scan (ABSCOR; Higashi, 1995) T min = 0.10, T max = 0.16 (expected range = 0.106-0.170) 24621 measured reflections 5821 independent reflections 5537 reflections with I > 2(I) R int = 0.061

Key indicators: single-crystal X-ray study; T = 298 K; mean (C-C) = 0.006 Å; R factor = 0.062; wR factor = 0.174; data-to-parameter ratio = 14.7.The title compound, [Cu 2 (C 5 H 3 N 6 ) 2 (N 3 ) 2 (C 10 H 8 N 2 ) 2 ], consists of isolated neutral centrosymmetric dinuclear units. Each molecule comprises two Cu atoms, two 2-tzpz À ligands [2-Htzpz = 2-(1H-tetrazol-5-yl)pyrazine], two 2,2 0 -bipyridine (bpy) ligands and two azide groups. The 2-tzpz À ligand is tridentate, utilizing N atoms from the tetrazole and pyrazine rings to chelate to one Cu 2+ ion and a second tetrazole N atom to form a bridge to the second Cu 2+ ion. The coordination geometry about each Cu 2+ center is slightly distorted octahedral. The crystal packing is stabilized by intermolecular C-HÁ Á ÁN hydrogen bonds. CommentConsiderable attention has been paid to the tetrazoles complex in recent years not only because of their structural and topological novelty but also because of their potential applications as molecular-based functional materials in fields such as

The title compound, C10H11N3O4, is a condensation product of 4-nitro­phenyl­hydrazine and methyl pyruvate. The complete mol­ecule except for the methyl groups can be considered as a conjugated π system. All non-H atoms are approximately coplanar (r.m.s. deviation 0.117 Å). The crystal packing involves an N—H⋯O hydrogen bond and a π–π inter­action between the aromatic rings, with a centroid–centroid distance of 3.617 Å.