Volume 70, Issue 6

Transparent colorless crystals of KCs[N(CN) 2 ] 2 and NaRb 2 [N(CN) 2 ] 3 · H 2 O were obtained by blending aqueous solutions of Na[N(CN) 2 ] and RbF or KF, respectively. After evaporation of the water, the remaining solid was extracted with absolute ethanol and the solvent was allowed to evaporate at r. t.. KCs[N(CN) 2 ] 2 crystallizes in the space group C 2/ c (no. 15) with the cell parameters a = 1382.7(2), b = 998.1(1) and c = 1455.4(2) pm, and β = 118.085(4) °. The structure of NaRb 2 [N(CN) 2 ] 3 · H 2 O is exhibiting the space group P 6 3 / m (no. 176) with the cell parameters a = 705.98(7) and c = 1462.89(12) pm. Single-crystalline α -K[N(CN) 2 ] was obtained while attempting to synthesize ‘NaK 2 [N(CN) 2 ] 3 ’, corroborating the results of previous X-ray powder diffraction experiments. Vibrational spectra and DSC/TGA analyses complete our results.

Abstract: The crystal structure of the title compound, K 2 [VO(C 7 H 3 O 4 N)(NH 2 O) 2 (H 2 O)] 2 , is composed of KO 9 and VO 5 N 2 polyhedra connected through pyridine-2,3-dicarboxylate (2,3-dipicolinate) bridges. The VO 5 N 2 coordination polyhedron is a pentagonal bipyramid, with hydroxylamido and dipicolinato ligands being bidentate. The axial positions are occupied by the terminal oxo ligand and one oxygen atom from a deprotonated carboxylate group. The oxygen atoms from hydroxylamido and the nitrogen atoms belonging either to the pyridine ring or to the hydroxylamido occupy the equatorial positions and form an approximate pentagonal plane. The irregular KO 9 polyhedra are linked, sharing edges and planes to form infinite chains. These chains are linked by the dipicolinate bridges to form layers. The distorted VO 5 N 2 polyhedron is grafted on to the layer by the dipicolinate carboxylate O atom. Adjacent layers are connected through N–H···O hydrogen bonds to form a three-dimensional supramolecular structure.

The phytochemical study of the EtOAc extract from Panzeria alaschanica resulted in the isolation of two new acylated flavone glycosides, 5,7,4′-trihydroxyflavone-7- O -(6″- O -[ E ]-coumaroyl)- β -glucopyranoside ( 1 ) and 5,7,4′-trihydroxyflavone-7- O -(2″,6″- O -[ E ]-dicoumaroyl)- β -glucopyranoside ( 2 ), as well as of a known phenylethanoid (verbascoside, 3 ). The structure of the isolated compounds was elucidated by spectroscopic methods, including ultraviolet spectrophotometry, infrared absorption spectroscopy, electrospray ionization mass spectrometry and 1D nuclear magnetic resonance spectroscopy, and by comparison with those reported in the literature. All compounds were investigated for their effect against inflammation induced by egg albumin and carrageenan in rats.

Dihydro-5 H -dibenzo[ b , g ]azonine-6,13-dione ( 2 ) has been used as a precursor in the synthesis of the indolo[2,3- e ]dibenzo[ b , g ]azonine and tribenzo[ b , g , j ][1,6]diazacyclododecine ring systems 6 and 7 respectively via a Fischer indolization/periodate oxidation sequence. Fischer indolization of the (1,4-phenylenedihydrazono) derivative 8 gave the polycyclic system 9 . The Schmidt reaction of 2 led to the formation of the benzimidazo[1,2- b ] [2]benzazepine ring system 11 . The Mannich reaction of 2 led to the spirocyclic system 15 . The reactions of 2 with aldimines and aromatic aldehydes were also investigated.

The mixed azines 3a–h and 4 were obtained by treating 3-hydrazonoindolin-2-one ( 2 ) with the appropriate aldehyde or dialdehyde. Treatment of 3b or 3c with formaldehyde or glutaric dialdehyde and the appropriate amine afforded the azine Mannich bases 5–7 . The condensation of isatin or its N -Mannich base 8 with 1-aminopiperidine, 4-aminomorpholine and 1,4-diaminopiperazine gave 10a–d , 12 and 13 . The Mannich bases 14 and 15 were obtained from 10a and 10b. Treatment of 2 with succinic, phthalic and quinolinic anhydride and pyromellitic dianhydride afforded compounds 16 , 17a , 17 b and 18 , respectively. The synthesis of isatin Schiff bases incorporating a benzoylpiperidine, benzoylmorpholine and 1,4-dibezoylpiperazine moiety and their N -Mannich bases was investigated.

Two new taraxastane-type triterpene saponins, named pittangretosides L ( 1 ) and C 1 ( 2 ), were isolated from the leaves of Pittosporum angustifolium Lodd. Their structures were established by NMR spectroscopic, mass spectrometric and chemical means. The in vitro cytotoxicity was evaluated against four cell lines. The compounds exhibited no cytotoxic activity up to a concentration of 130 μ m .

Sixteen new bisurea compounds incorporating versatile proteinogenic amino acids as well as nipecotic acid have been synthesized via addition reaction to aryl diisocyanates. The products were analytically characterized and their ability for anion recognition was studied by UV/Vis spectroscopy. In the presence of fluoride, acetate or dihydrogenphosphate ions, hyperchromic and bathochromic peak shifts were determined. By way of contrast, bromide, iodide, or hydrogensulfate ions cause no significant change of absorbance. The special effect of heterocyclic derivatives was explained by molecular modeling calculations. In addition, the crystal structure of the byproduct dimethyl N , N ′-(1,4-phenylene)dicarbamate is discussed.

Care should be taken on recording the sometimes elusive 13 C NMR signals for boron-bonded carbon atoms, since it is easy to extract information about coupling constants 1 J ( 13 C, 11 B) by measuring the respective line widths of 13 C(B-C) and 11 B NMR signals. This information can be confirmed by quantum-chemical calculations [B3LYP (6-311+G(d,p) level of theory] of n J ( 13 C, 11 B) in organoboranes and tetraorganoborates. For the latter, the signs for n = 2, 3, 4 were experimentally determined.

The Ce 3 Pd 6 Sb 5 -type rare earth stannides RE 3 Au 6 Sn 5 ( RE = La, Ce, Pr, Nd, Sm) were synthesized by arc-melting of the elements and subsequent annealing in open tantalum crucibles within sealed evacuated silica ampoules. The polycrystalline samples were studied by powder X-ray diffraction. The structures of three crystals were refined from single crystal X-ray diffractometer data: Pmmn , a = 1360.3(9), b = 455.9(2), c = 1023.6(4) pm, wR 2 = 0.0275, 1069 F 2 values, 48 variables for Ce 3 Au 6 Sn 5 , a = 1352.4(4), b = 455.1(1), c = 1023.7(3) pm, wR 2 = 0.0367, 1160 F 2 values, 48 variables for Nd 3 Au 6 Sn 5 , and a = 1339.8(2), b = 452.80(7), c = 1012.4(2) pm, wR 2 = 0.1204, 1040 F 2 values, 49 variables for Sm 3 Au 5.59(2) Sn 5.41(2) . One of the gold sites of the samarium compound shows a significant degree of Au/Sn mixing. The RE 3 Au 6 Sn 5 structures are composed of three-dimensional [Au 6 Sn 5 ] polyanionic networks with the two crystallographically independent rare earth atoms in larger cages, i.e., RE 1@Au 10 Sn 6 and RE 2@Au 8 Sn 8 . The [Au 6 Sn 5 ] network is stabilized by Au–Sn (266–320 pm), Au–Au (284–301 pm) as well as Sn–Sn (320 pm; distances given for the cerium compound) interactions. Temperature-dependent magnetic susceptibility measurements reveal an antiferromagnetic ordering only for Sm 3 Au 6 Sn 5 , while the other compounds exhibit Curie–Weiss paramagnetism. 119 Sn Mössbauer spectroscopy shows resonances in the typical range for intermetallic tin compounds where tin takes part in the polyanionic network [isomer shifts between 1.73(1) and 2.28(1) mm·s −1 ]. With the help of theoretical electric field gradient calculations using the WIEN2k code it was possible to resolve the spectroscopic contributions of all three crystallographically independent atomic tin sites in the 119 Sn spectra of RE 3 Au 6 Sn 5 ( RE = La, Ce, Pr, Nd, Sm).

PbBaGeO 4 was prepared by high-temperature solid-state synthesis at 900 °C in a platinum crucible from lead(II) oxide, barium carbonate, and germanium(IV) oxide. This compound crystallizes with the BaNdGaO 4 structure type in the orthorhombic space group P 2 1 2 1 2 1 (no. 19). The structure was refined from single-crystal X-ray diffraction data: a = 1021.6(2), b = 763.4(2), c = 618.1(2) pm, V = 482.1(2) Å 3 , and residuals of R 1 = 0.0373 and wR 2 = 0.0730 for all data. Next to structural data, Raman spectroscopic data of PbBaGeO 4 are reported.