Volume 70, Issue 3

Vanandium trifluoride reacts with dry liquid ammonia under the formation of lilac plate-shaped crystals of mer -triammine trifluorido vanadium(III) ( 1 ), mer -[VF 3 (NH 3 ) 3 ]. Single-crystal X-ray analysis was carried out at low temperature to elucidate the structure. The compound crystallizes in the monoclinic space group P 2 1 / c with a = 5.7284(4), b = 9.2033(5), c = 10.5271(6) Å, β = 91.795(6)°, and V = 554.72(6) Å 3 at 123 K with Z = 4. The discrete [VF 3 (NH 3 ) 3 ] molecules are interconnected by hydrogen bonds.

The synthesis of two new copper(II) complexes with benzimidazole type ligands, Cu(tta) 2 ( L 1 ) 2 ( 1 ) and Cu(tta) 2 ( L 1 ) ( 2 ) (where L 1 is 3-(4-(1 H -benzo[ d ]imidazol-1-yl)-4-methoxy phenyl)-1-phenylprop-2-en-1-one; tta is 2-thenoyltrifluoroacetonate), are reported. Their structures have been characterized by infrared spectroscopy, elemental analyses and single-crystal X-ray diffraction. The copper(II) ion of 1 is in a distorted octahedral environment, while that of 2 is in a distorted square-pyramidal environment. In both cases, the donor atoms are provided by oxygen atoms of the tta ligands and nitrogen atoms of the L 1 ligands.

A green, efficient and simple protocol was developed for the synthesis of dihydropyrimido[4,5- d ]pyrimidinetrione derivatives via a coupling reaction of 6-aminouracils, aromatic aldehydes and urea in aqueous media in the presence of nano-crystalline CuI at room temperature. The products were obtained in high yields. CuI nanoparticles can be recycled three times without significant loss of catalytic activity.

Transparent, light blue crystals of Cu[C(CN) 3 ] 2 ·2 NH 3 were obtained by dissolving Cu[C(CN) 3 ] 2 in aqueous ammonia and subsequent evaporation of the solvent under ambient conditions. Cu[C(CN) 3 ] 2 ·2 NH 3 crystallizes in the space group C 2/ c (no. 15, Z = 4) with the cell parameters a = 1291.9(3), b = 753.18(15) and c = 1200.8(2) pm, and β = 92.68(3)°. The nature of the tricyanomethanide anion and the ammonia molecules were verified by Raman spectroscopy. Single crystals of Ag[C(CN) 3 ] and Cu[C(CN) 3 ] 2 were synthesized, the known structures were confirmed and their Raman spectra were recorded for the first time for comparison.

Single crystals of the hydrous cadmium borate Cd 6 B 22 O 39 ·H 2 O were obtained through a high-pressure/high-temperature experiment at 4.7 GPa and 1000 °C using a Walker-type multianvil apparatus. CdO and partially hydrolyzed B 2 O 3 were used as starting materials. A single crystal X-ray diffraction study has revealed that the structure of Cd 6 B 22 O 39 ·H 2 O is similar to that of the type M 6 B 22 O 39 ·H 2 O ( M =Fe, Co). Layers of corner-sharing BO 4 groups are interconnected by BO 3 groups to form channels containing the metal cations, which are six- and eight-fold coordinated by oxygen atoms. The compound crystallizes in the space group Pnma (no. 62) [ R 1=0.0379, wR 2=0.0552 (all data)] with the unit cell dimensions a =1837.79(5), b =777.92(2), c =819.08(3) pm, and V =1171.00(6) Å 3 . The IR and Raman spectra reflect the structural characteristics of Cd 6 B 22 O 39 ·H 2 O.

The new compounds LiK[C(CN) 3 ] 2 and Li[C(CN) 3 ]·½ (H 3 C) 2 CO were synthesized and their crystal structures were determined. Li[C(CN) 3 ]·½ (H 3 C) 2 CO crystallizes in the orthorhombic space group Ima 2 (no. 46) with the cell parameters a =794.97(14), b =1165.1(2) and c =1485.4(3) pm, while LiK[C(CN) 3 ] 2 adopts the monoclinic space group P 2 1 / c (no. 14) with the cell parameters a =1265.7(2), b =1068.0(2) and c =778.36(12) pm and the angle β =95.775(7)°. Single crystals of K[C(CN) 3 ] were also acquired, and the crystal structure was refined more precisely than before corroborating earlier results.

The cadmium intermetallics RE PtCd ( RE = La, Ce, Pr, Nd, Eu) and CeAuCd were synthesized by induction-melting of the elements in sealed niobium ampoules followed by annealing in muffle furnaces. The samples were characterized by powder X-ray diffraction. The structures of CePtCd (ZrNiAl type, P6¯2m,$P\bar 62m,$ a = 763.8(6), c = 409.1(4) pm, wR 2 = 0.0195, 298 F 2 values, 14 variables) and EuPtCd (TiNiSi type, Pnma , a = 741.3(2), b = 436.4(1), c = 858.0(4) pm, wR 2 = 0.0385, 440 F 2 values, 20 variables) were refined from single-crystal data. The RE PtCd structures exhibit three-dimensional networks of corner- and edge-sharing Cd@Pt 2/6 Pt 2/3 and Cd@Pt 4/4 tetrahedra, which leave cages for the rare earth atoms. Temperature-dependent magnetic susceptibility data of CeAuCd reveal a paramagnetic to antiferromagnetic phase transition at T N = 3.7(5) K.

[Bi(bt Me )(phen)Cl 2 ] (bt Me = dihydrobis(2-mercapto-4-methylthiazolyl)borate), a mixed-ligand bismuth complex, was prepared from BiCl 3 , phenanthroline and Na(bt Me ) and characterized by nuclear magnetic resonance spectroscopy as well as single-crystal X-ray diffraction. It possesses a BiS 2 N 2 Cl 2 core with distorted octahedral environment constituted by two sulfur atoms of the dipodal boron-centered soft ligand (bt Me ) – , two nitrogen atoms of the phenanthroline ligand and two chloro ligands.