Volume 60, Issue 4

In order to examine the possibility of using yttrium(III) in the crystal engineering of hydrogenbonded coordination complexes and to compare the molecular and supramolecular YIII/Cl 3 or NO 3 - /DMU chemistry with the already well-developed Ln III /Cl − or NO 3 − /DMU chemistry (Ln III = lanthanide, DMU = N,N’-dimethylurea), compounds [Y(DMU) 6 ][YCl 6 ] (1) and [Y(NO 3 ) 3 (DMU) 3 ] (2) have been prepared. The structures of both compounds have been determined by single-crystal Xray diffraction. The structure of 1 consists of octahedral [Y(DMU) 6 ] 3+ and [YCl 6 ] 3− ions. The Y III ion in 2 is nine-coordinate and ligation is provided by three O-bonded DMU ligands and three bidentate chelating nitrato groups; the coordination polyhedron about the metal can be viewed as a distorted, monocapped square antiprism. The [Y(DMU) 6 ] 3+ cations and [YCl 6 ] 3− anions self-assemble to form a hydrogen-bonded 3D architecture in 1. Most of the hydrogen-bonding functionalities on the components of 2 create also a 3D network. Two motifs of interionic/intramolecular hydrogen-bonds have been observed: N-H···Cl in 1 and N-H···O(NO 3 − ) in 2. The IR data are discussed in terms of the nature of bonding and the structures of the two complexes

Crystals of diiodo-2,2’-dipyridyldisulfide mercury(II) [HgI 2 (C 5 H 4 N) 2 S 2 ], dichloro-2,2’-dipyridyldisulfide zinc(II) [ZnCl 2 (C 5 H 4 N) 2 S 2 ], dibromo-2,2’-dipyridyldisulfide cadmium(II) [CdBr 2 (C 5 H 4 N) 2 S 2 ], diiodo-2,2’-dipyridyldisulfide cadmium(II) [CdI 2 (C 5 H 4 N) 2 S 2 ], and diaquo 2,2’-dipyridyldisulfide cadmium(II) trifluoromethanesulfonate [Cd(H 2 O) 2 (C 5 H 4 N) 2 S 2 ](CF 3 SO 3 ) 2 , were obtained by evaporation of solutions of the ligand and the appropriate metal salts, and their X-ray crystal structures determined

The ion exchange reaction between ammonium cyanoureate NH 4 [H 2 NC(=O)NCN] and zinc chloride yielded single crystals of the urea derivative cyanoguanylurea H 2 NC(=O)NHC(NH 2 )NCN, which was obtained as a by-product alongside zinc cyanoureate and traces of ammonium chloride. It is assumed that owing to its Lewis and Brønsted acidity, the hydrated Zn 2+ ion acts as a catalyst, promoting the degradation of the cyanoureate anion with subsequent formation of the title compound. The crystal structure was solved in the centrosymmetric space group P2 1 /n (a = 476.7(1), b = 965.3(2), c = 1165.6(2) pm, β = 97.75(3)°, V = 531.4(2) 10 6 pm 3 , Z = 4, T = 200 K). In the solid there are non-planar cyanoguanylurea molecules with a dicyandiamide-type C-N system, building up a layered structure with sparse interlayer contacts and significant hydrogen bonding within the layers

5-Bromo-1,2,3,4-tetraphenyl-5-p-tolyl-1,3-cyclopentadiene (1a), 5-Bromo-1,4-di-phenyl-2,3,5- tri-p-tolyl-1,3-cyclopentadiene (1b), 5-Bromo-1,2,3,4,5-penta-p-tolyl-1,3-cyclopentadiene (1c), 5- Bromo-1,2,3,4-tetraphenyl-5-p-bromophenyl-1,3-cyclopentadiene (1d), and 5-Bromo-1,2,3,4-tetraphenyl- 5-p-anisyl-1,3-cyclopentadiene (1e) react with ironpentacarbonyl in m-xylene to yield the corresponding ferrocenes 2a - 2e. In the course of the purification procedure, reactions with HCl and the solvent m-xylene are observed which yield the mixed ionic sandwich complexes [(C 5 Ph 4 C 6 H 4 Me)Fe(C 6 H 4 Me 2 )] + Cl − (3a), [(C 5 Ph 2 (C 6 H 4 Me) 3 )Fe(C 6 H 4 Me 2 )] + Cl − (3b), [(C 5 (C 6 H 4 Me) 5 )Fe(C 6 H 4 Me 2 )] + Cl − (3c), [(C 5 Ph 4 C 6 H 4 Br)Fe(C 6 H 4 Me 2 )] + Cl − (3d), and [(C 5 Ph 4 C 6 H 4 OMe)Fe(C 6 H 4 Me 2 )] + Cl − (3e), respectively, along with the corresponding cyclopentadienes 1,2,3,4-tetraphenyl-5-p-tolyl-1,3-cyclopentadiene (4a), 1,4-diphenyl-2,3,5-tri-p-tolyl-1,3- cyclopentadiene (4b), 1,2,3,4,5-penta-p-tolyl-1,3-cyclopentadiene (4c), 1,2,3,4-tetraphenyl-5-pbromphenyl- 1,3-cyclopentadiene (4d), and 1,2,3,4-tetraphenyl-5-p-anisyl-1,3-cyclopentadiene (4e). The compounds have been characterized by elemental analysis, IR, NMR, and mass spectra, and, in the case of 2c, by 13 C-CPMAS spectroscopy and X-ray powder diffractometry

Complexes [Bi(phen) 2 (NO 3 )(NCS) 2 (MeOH)] and [Bi(phen) 2 (NO 3 ) 2 (NCS)] have been synthesized and characterized by their IR spectra and elemental analyses. The structure of the [Bi(phen) 2 (NO 3 )(NCS) 2 (MeOH)] complex has been confirmed by X-ray crystallography. The Bi atoms are unsymmetrically eight-coordinated, N 6 O 2 . The arrangement of the ligands does not show a gap in the coordination geometry around the Bi(III) ion, indicating that its lone pair of electrons is not active. The thiocyanate ligands are coordinated to the bismuth atom via the nitrogen atom. There is π-π stacking interactions between the parallel aromatic rings belonging to adjacent chains

The binary cubic Laves phases EuPt 2 , GdPt 2 , and TmNi 2 form extended solid solutions Eu 1−x Pt 2 In x , Gd 1−x Pt 2 In x , and Tm 1−x Ni 2 In x . Samples within these homogeneity ranges have been prepared from the elements by arc-melting on water-cooled copper chills or by induction melting in sealed tantalum tubes and subsequent annealing. The indides were characterized by X-ray powder and single crystal diffraction: MgCu 2 type, Fd3̅m, a = 770.68(6) pm, wR2 = 0.0251, 67 F 2 values, 6 variables for Eu 0.94(3) Pt 2 In 0.06(3) , a = 769.16(6) pm, wR2 = 0.0244, 67 F 2 values, 6 variables for Eu 0.85(2) Pt 2 In 0.15(2) , a = 760.12(9) pm, wR2 = 0.0693, 65 F 2 values, 6 variables for Gd 0.79(5) Pt 2 In 0.21(5) , and MgCu 4 Sn type, F 4̅3m, a=700.27(6) pm, wR2=0.0368, BASF=0.13(2), 175 F 2 values, 8 variables for TmNi 4 In. The platinum and nickel atoms build up three-dimensional networks of corner-sharing Pt 4/2 and Ni 4/2 tetrahedra. These networks leave larger voids of coordination number 16 that are filled with the rare earth (RE) and the indium atoms. While the thulium and indium atoms are ordered in TmNi 4 In, one observes mixed RE/In occupancies in Eu 0.94(3) Pt 2 In 0.06(3) , Eu 0.85(2) Pt 2 In 0.15(2) , and Gd 0.79(5) Pt 2 In 0.21(5)

2,2-Dimethyl-4,6-dioxo-5-pyridinomethyl-1,3-dioxan-5-yl-pyridinium ylide (9) reacts with 2,3-dihydro- 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene (1; R 1 = i Pr, R 2 = Me) to give the zwitterionic imidazolium derivative 2,2-dimethyl-4,6-dioxo-5-(1,3-diisopropyl-4,5-dimethylimidazoliomethyl)- 1,3-dioxan-5-yl-imidazolium ylide (4) in good yield. Similarly, the phosphonium compound 2,2-dimethyl-4,6-dioxo-5-triphenylphosphoniomethyl-1,3-dioxan-5-yl-phosphonium ylide (5) is obtained from 9 and PPh 3 . The crystal structures of 4 and 5 are reported

The reactions of N-(2-aminoethyl)piperazine (aeppz) with tetraaqua-bis(saccharinato)zinc(II) and -cadmium(II) in ethanol solution yield the new complexes trans-[Zn(sac) 2 (aeppz) 2 ] (1), and trans- [Cd(sac) 2 (aeppz) 2 ] (2) (sac = saccharinate), respectively. The complexes were characterized by elemental analyses, IR spectroscopy and X-ray crystallography. Both complexes 1 and 2 are mononuclear of Ci symmetry. The zinc(II) and cadmium(II) ions are coordinated by two neutral aeppz ligands and two sac anions in an elongated distorted octahedral environment. The aeppz ligand acts as a bidentate N, N’ donor through the central heterocyclic N atom and the N atom of the aminoethyl group, while the sac ligand is O-coordinated via the carbonyl O atom. The packing of the molecules in the crystals in both complexes is consolidated by arene π −π stacking interactions between the sac rings and by intermolecular hydrogen bonds involving the amine groups of aeppz and the sulfonyl oxygen atoms of the sac ligands

The synthesis of novel di- and tricarboxylic acids is described. Starting from diethanolamine, a series of N-substituted diethanol derivatives were prepared which were converted in the subsequent reaction step into the corresponding carboxylic acids by treatment with chloroacetic acid. N,N-bis[2- (carboxymethoxy)ethyl]glycine was obtained by N-alkylation of glycine ethylester with ethyl 2-(2- bromoethoxy)acetate

Benzene solutions of Me 3 SnCl when exposed to moisture yield the adduct Me 3 SnCl·Me 3 SnOH·H 2 O. This adduct represents an intermediate in Me 3 SnCl hydrolysis. The structure of Me 3 SnCl·Me 3 SnOH·H 2 O features an array of Me 3 Sn units connected alternatingly by bridging Cl and OH ligands

Bromonitromethane adds to aliphatic aldehydes in the presence of tin(II) chloride to yield β -nitro alcohols via a Reformatsky-type reaction in high yields, while aromatic aldehydes give low yields. The products were characterized by IR, NMR, and mass spectroscopy and by elemental analysis

The crystal structures of the title compounds, which were synthesized at temperatures between 500 and 850 °C via reaction of Al 2 O 3 , M 2 O 3 and M 2 O 5 (M = As, Sb) with the respective elemental alkaline and alkaline earth elements, have been determined by single crystal X-ray diffraction. The two isotypic compounds A I 2 Sb 2 Al 2 O 7 (K 2 Sb 2 Al 2 O 7 structure type, A I =Rb/Cs; trigonal, space group P3̄̅m1, a = 566.04(10)/570.23(8), c = 836.8(2)/888.0(2) pm, Z = 1, R1 = 0.0511/0.0461) contain double layers consisting of vertex-sharing tetrahedra [Al 2 O 7 ], which are connected to ψ- tetrahedra SbO 3 via common vertices. These double layers are stacked in identical orientation (AA sequence), while in the barium compound BaSb 2 Al 2 O 7 (trigonal, space group R32, a = 545.5(7), c = 2377.3(12) pm, Z = 3, R1 = 0.0427) similar layers [Sb 2 Al 2 O 7 ] are stacked in an ABC sequence. In the arsenic(III) aluminate Cs 2 As 2 Al 2 O 7 (orthorhombic, space group Imm2, a = 546.9(3), b = 1003.81(16), c = 888.5(3) pm, Z = 2, R1 = 0.0313) the Al 2 O 7 moieties are similarly connected via [AsO 3 ] units, in this case not only forming layers, but a three-dimensional network. In the three antimonates, the A cations are not coordinated by the lone electron pairs of M(III), which are oriented towards the interior of the sheets, whereas in the arsenate the lone electron pairs play a significant role in the coordination of one of the two crystallographically independent Cs sites

Strontium ozonide has been synthesised, starting from caesium ozonide, via cation exchange in liquid ammonia. From these solutions, if kept at −78 °C for 14 days, an ammoniate, Sr(O 3 ) 2 · 9 NH 3 , crystallises. The coarse, ruby red crystals decompose above the boiling temperature of ammonia and are extremely sensitive to moisture. According to a single crystal structure determination (P4/nmm; a = 7.597(1), c = 13.496(2) Å , Z = 2; R1 = 7.50%; 254 independent reflections) Sr(O 3 ) 2 · 9 NH 3 consists of ozonide anions and strontium cations. The complex cations form an approximately cubic close packing, where the octahedral and half of the tetrahedral interstices are occupied by ozonide anions. The anions are orientationally disordered

Colourless single crystals of KBaPS 4 (a = 11.587(2), b = 6.700(1), c = 10.118(2) Å ), and pale orange ones of KBaPSe 4 (a = 11.972(2), b = 6.973(1), c = 10.388(2) Å ) were obtained by reactions of Ba 3 (PS 4 ) 2 and Ba 3 (PSe 4 ) 2 , respectively, with KCl (790 °C; 30 h). The isotypic compounds crystallize with a slightly modified TlEuPS 4 type structure (Pnma, Z = 4); that is, the characteristic units are distorted discrete PX 4 tetrahedra (X: S, Se) interconnected by K + and Ba 2+ . However, due to the strong distortion of the trigonal X 6 prisms along [001] the coordination numbers increase from 8 to 9 for the barium atoms and from 8 to 11 for the potassium atoms. Orange crystals of Ba 3 PO 4 PSe 4 (a= 6.779(1), b =7.108(1), c =12.727(3)Å ; α = 82.45(3)°, β =78.88(3)°, γ =81.34(3)°) resulted as a by-product of the synthesis of Ba 3 (PSe 4 ) 2 . The compound crystallizes in a new type of structure (P1̅; Z = 2) and is the first chalcogenophosphate with discrete PO 4 and PSe 4 tetrahedra. The coordination polyhedra of the barium atoms are formed by both chalcogen atoms

The family of quasi-binary cyanamides/carbodiimides of general formula M(NCN) containing divalent 3d transition metals (M = Mn, Fe, Co, Ni and Cu) has been studied by density-functional means; until now, such light transition-metal compounds have not yet been prepared. Twenty-eight structural models have been considered based on known compounds having NCN 2− and other triatomic anionic entities (e. g., thiocyanates). After performing LDA geometry optimizations, the relative energetic orderings are interpreted in terms of geometrical factors such as molar volumes and effective coordination numbers; dense structures with octahedral metal coordinations and highspin electronic configurations are to be expected, especially for the earlier metals (Mn and Fe). Based on GGA total-energy calculations, there is a chance to synthesize these enthalpically unstable compounds, not from the elements but via appropriate exchange reactions employing fairly stable cyanamide/carbodiimide precursors and yielding stable or volatile metal halides which can be removed from the chemical equilibria

New protoilludane sequiterpenoids, echinocidins C (3) and D (4) have been isolated from liquid culture of Echinodontium tsugicola. Their structures have been established on the basis of spectral analysis. The biological activities of 3 and 4 were examined by bioassay with lettuce seedlings

NaBH 4 in the presence of sodium bisulfate (NaHSO 4 ·H 2 O), a weakly acidic reagent, efficiently reduces a variety of carbonyl compounds such as aldehydes, ketones, α,β -unsaturated aldehydes and ketones, α-diketones and acyloins to their corresponding alcohols in acetonitrile under heterogeneous condition. Reduction reactions were accomplished at room temperature or under reflux condition

Three complex 7-oxygenated-8-prenylflavones, (-)-semiglabrin and (-)-pseudosemiglabrin, which are diastereoisomers, and lanceolatin A have been isolated from the root of Tephrosia apollinea (Del.) Link (Leguminosae) growing in Southern Egypt, together with two phytosterols, stigmasterol and sitosterol. The structures of the isolated compounds have been elucidated by means of physical and several spectroscopic methods including UV, IR, 1 H, 13 C NMR, DEPT, 2D 1 H- 1 H COSY, HSQC, HMBC experiments, and high resolution mass spectrometry (HR-MS), as well as some chemical transformations. The stereochemistry of the structures of (-)-semiglabrin and lanceolatin A have been confirmed by X-ray crystal structure analysis. The anticarcinogenic properties of the isolated compounds showed no inhibitory mechanisms concerning the initiation, promotion, and progression stage of carcinogenesis. Moreover, the in vitro antimicrobial activities of the root ethanolic extract are discussed

Certain adamantylated heterocycles were previously shown to enhance the secretion of tumor necrosis factor alpha (TNF-α) by murine melanoma cells that have been transduced with the gene for human TNF-α and constitutively expressed this cytokine. The stimulatory potency of those compounds depended, among other factors, on the structure of the linker between the adamantyl residue and the heterocyclic core. In the present study, a series of (1-adamantyl)alkylsulfanyl derivatives of heterocyclic compounds was prepared by alkylation of the corresponding thioheterocyles. Of the novel adamantylalkylthio compounds tested in the aforementioned cell line, 2-(2-adamantan-1-ylethylsulfanyl)- 4-methyl-pyrimidine was found to be the most active

Aluminium maltolate shows a longest-wavelength absorption at λ max = 314 nm which is of the intraligand (IL) type. IL excitation leads to a photodecomposition of the ligand (φ = 0.04 at λ irr = 313 nm, in ethanol). While a fluorescence is not observed, Al maltolate displays a phosphorescence in low-temperature glasses (λ max =510 nm at 77 K, in ethanol)