Band 72, Heft 6

Triethynylphenylsilane ( 1 ), trivinylphenylsilane ( 2 ), diethynyldiphenylsilane ( 3 ) and diphenyldivinylsilane ( 4 ) were reacted with chlorodimethylsilane yielding the corresponding hydrosilylation products. To increase their Lewis acidity, the Si–Cl functions were directly transferred into Si–C 6 F 5 units by salt elimination reactions leading to the (semi-) flexible molecules 5–8 bearing two or three Lewis-acidic sidearms. With the aim of providing host-guest complexes, the air-stable and readily soluble compounds 5–8 were converted with N- and O-Lewis bases of different size and geometry. In all cases, NMR spectroscopic investigations reveal no formation of Lewis acid-base complexes. X-ray diffraction experiments of host compounds 5–7 show intermolecular aryl…perfluoroaryl interactions of dispersion nature in the solid state. By hydrosilylation of 1 with trichlorosilane the more Lewis-acidic all- trans -tris[(trichlorosilyl)vinyl]phenylsilane ( 9 ) was obtained. Its Lewis acidity was further increased by fluorination to yield all- trans -tris[(trifluorosilyl)vinyl]phenylsilane ( 10 ); the conversion with nitrogen containing Lewis bases ends up in the formation of insoluble precipitates.

Two new defensive constituents, solatuberenol A ( 1 ) and 3-O- β - d -glucopyranosyl stigmasta-5(6),24(28)-diene ( 2 ), were isolated from the potato tubers ( Solanum tuberosum ) infected with late blight disease. Their structures were identified by extensive spectroscopic analysis, including HRMS, IR, UV, 1D/2D NMR, ECD and quantum chemical calculations. Compounds 1 and 2 showed moderate activity against Phytophthora infestans with mycelia-growth inhibition of 30.1% and 52.4%, respectively, at the concentration of 500 ppm.

The reaction of CoCl 2 ·6H 2 O with mixed ligands of 2,2′-oxybis(benzoic acid) (2,2′-H2oba) and trans -1,2-bis(4-pyridyl)ethylene (bpe) under hydrothermal conditions produced a new 3D cobalt(II) supramolecular architecture {[Co(oba)(bpe)(H 2 O)]·1/2bpe} n ( 1 ), which was structurally characterized by elemental analysis, infrared spectroscopy, thermogravimetric analyses, and single-crystal X-ray diffraction. The results show that the Co(II) ions are connected to form an infinite polymeric chain by bpe ligands in complex 1 . Due to strong intermolecular O–H···O hydrogen bonds, the adjacent chains are connected to generate a double-chain structure. These double chains are joined by O–H···N hydrogen bonding to produce a 2D supramolecular architecture. Furthermore, through intermolecular C–H···O hydrogen bonds, the layers are linked into a 3D supramolecular structure. Magnetic susceptibility measurements have indicated that complex 1 shows weak antiferromagnetic interactions between adjacent Co(II) ions.

A series of 2-substituted 2,3-dihydroquinazolin-4(1 H )-ones were oxidized to quinazolin-4(3 H )-ones using tetrabutylammonium peroxydisulfate. The rate and the outcome of the reaction are dependent on the type and nature of 2-substitution. An electron transfer mechanism is proposed for this study, which is supported by the retention or elimination of 2-substitution during the oxidation process.

A new compound [C 3 H 5 NH 3 ][Mn(N 3 ) 3 ] has been synthesized, in which the Mn 2+ ions are connected by the end-to-end azide anions to form the 3D architecture, while the C 3 H 5 NH 3 + cations reside in the cavities of the Mn 2+ –N 3 − network, forming rich N−H···N hydrogen bonds with the terminal N atoms of the azide anions. The complex has been characterized by IR spectroscopy, elemental analyses, and magnetic measurements. Magnetic susceptibility data indicate antiferromagnetic interaction among the Mn II ions.

A new dinuclear Ni(II) complex, [{Ni(L)(C 5 H 5 N)} 2 ], has been synthesized with 4-chloro-4′,6′-dibromo-2,2′-[ethylenedioxybis(nitrilomethylidyne)]diphenol (H 2 L), and characterized by elemental analyses, FT-IR, UV/Vis, molar conductance and X-ray crystallographic analysis. Each Ni(II) atom is located at a N 2 O 2 coordination site of a completely deprotonated (L) 2− unit. Two μ -phenoxo oxygen atoms from two [Ni(L)] units and two pyridine nitrogen atoms coordinate with two Ni(II) atoms. The two hexa-coordinated Ni(II) atoms have slightly distorted octahedral geometries. The μ -phenoxo bridges play important roles in assembling Ni 2+ and (L) 2− units. This 2:2 (Ni 2+ :(L) 2− ) structure is different from that of other Salamo-type Ni(II) complexes reported earlier.

Chemokines (chemoattractant cytokines) together with their receptors represent key players in inflammatory processes. In order to develop novel chemokine CCR2 and CCR5 receptor antagonists, 2-benz-azepin-1-one 5 was prepared, which showed promising CCR2 affinity. During the synthesis, regioisomeric bromo substituted β -keto esters 4a and 4b had to be separated. A crystal structure determination of the regioisomer 4b displayed unequivocally the bromine atom in the 7-position and the existence of 4b as the enol ester tautomer. Although the 7-membered azepine ring is rather flat, it is distorted around the 3-methylene moiety.

Two new dialkyammonium selenate salts [ i -Pr 2 NH 2 ] 2 [SeO 4 ] ( 1) and [ n -Bu 2 NH 2 ][HSeO 4 ] ( 2 ) have been isolated and characterized by single-crystal X-ray diffraction. Salt 1 crystallizes in the monoclinic system, space group P 2 1 / n with a =8.7190(5), b =8.8500(4), c =22.5953(9) Å, β =94.6290(17)°, V =1737.84(14) Å 3 and Z=4. Salt 2 crystallizes in the monoclinic system space group P 2 1 / n with a =10.9328(9), b =8.1700(6), c =13.8095(11) Å, β =97.130(3)°, V =1223.94(17) Å 3 and Z =4. In both salts, dialkylammonium cations and selenate anions are connected through NH···O and OH···O hydrogen bonds. In the crystal structure, 1 and 2 are organized in layer-like arrangements. Structural characterizations were completed by infrared and 1 H, 13 C{ 1 H} and 77 Se NMR spectroscopy and elemental analysis which corroborate the X-ray elucidations.

The nitridoborates Mg 3 [BN 2 ]N ( P 6 3 / mmc ) and Ca 3 [BN 2 ]N ( P 4/ mmm ) are electron-precise compounds with discrete linear [BN 2 ] 3− and isolated N 3− anions. Electronic structure calculations reveal pronounced B–N bonding within the [BN 2 ] 3− units with more covalent Mg–N vs. Ca–N bonding. Total energy calculation for hexagonal normal-pressure Mg 3 [BN 2 ]N, orthorhombic high-pressure Mg 3 [BN 2 ]N and a hypothetical Ca 3 [BN 2 ]N-type tetragonal Mg 3 [BN 2 ]N modification revealed that the hexagonal modification is the ground state structure. The band structure for orthorhombic high-pressure Mg 3 [BN 2 ]N indicates a substantial metallization (delocalization in the high-pressure regime). This peculiar result calls for a reinvestigation of high-pressure Mg 3 [BN 2 ]N under different high-pressure high-temperature conditions along with physical property studies.

The adducts urea:pyrazine (1:1) ( 1 ), thiourea:pyrazine (2:1) ( 2 ), and thiourea:piperazine (2:1) ( 3 ) were prepared and their structures determined. Adduct 1 forms a layer structure, in which urea chains of graph set C(4)[R21${\rm{R}}_{\rm{2}}^{\rm{1}}$(6)] run parallel to the b axis and are crosslinked by N–H···N hydrogen bonding to the pyrazine residues. Adduct 2 is a variant of the well-known R22${\rm{R}}_{\rm{2}}^{\rm{2}}$(8) ribbon substructure for urea/thiourea adducts, with the pyrazine molecules attached to the remaining thiourea NH groups via bifurcated hydrogen bonds (N–H···) 2 S; the more distant end of the pyrazine molecules is crosslinked to another symmetry-equivalent but perpendicular ribbon system, thus creating a three-dimensional packing. The packing of adduct 3 involves thiourea layers parallel to the ab plane; the piperazine molecules occupy the regions between these layers and are linked to the thiourea molecules by two hydrogen bonds (one as donor, one as acceptor) at each piperazine nitrogen atom.

Eight new intermetallic rare earth-ruthenium-magnesium compounds have been synthesized from the elements in sealed niobium ampoules using different annealing sequences in muffle furnaces. The compounds have been characterized by powder and single crystal X-ray diffraction. Sm 9.2 Ru 6 Mg 17.8 ( a =939.6(2), c =1779(1) pm), Gd 11 Ru 6 Mg 16 ( a =951.9(2), c =1756.8(8) pm), and Tb 10.5 Ru 6 Mg 16.5 ( a =942.5(1), c =1758.3(4) pm) crystallize with the tetragonal Nd 9.34 Ru 6 Mg 17.66 type structure, space group I 4/ mmm . This structure exhibits a complex condensation pattern of square-prisms and square-antiprisms around the magnesium and ruthenium atoms, respectively. Y 2 RuMg 2 ( a =344.0(1), c =2019(1) pm) and Tb 2 RuMg 2 ( a =341.43(6), c =2054.2(7) pm) adopt the Er 2 RuMg 2 structure and Tm 3 Ru 2 Mg ( a =337.72(9), c =1129.8(4) pm) is isotypic with Sc 3 Ru 2 Mg. Tm 3 Ru 2 Mg 2 ( a =337.35(9), c =2671(1) pm) and Lu 3 Ru 2 Mg 2 ( a =335.83(5), c =2652.2(5) pm) are the first ternary ordered variants of the Ti 3 Cu 4 type, space group I 4/ mmm . These five compounds belong to a large family of intermetallics which are completely ordered superstructures of the bcc subcell. The group-subgroup scheme for Lu 3 Ru 2 Mg 2 is presented. The common structural motif of all three structure types are ruthenium-centered rare earth cubes reminicent of the CsCl type. Magnetic susceptibility measurements of Y 2 RuMg 2 and Lu 3 Ru 2 Mg 2 samples revealed Pauli paramagnetism of the conduction electrons.

Reactions of the Collman reagent, Na 2 [Fe(CO) 4 ]·1.5 dioxane, towards the nitrosyl carbonyls [CoNO(CO) 3 ] and [Fe(NO) 2 (CO) 2 ] in THF as the solvent at room temperature were investigated. Thereby a quick transfer of one nitrosyl ligand from the nitrosyl carbonyl molecule to the iron carbonyl metalate was observed. The reaction with the cobalt compound afforded in high yields the well-known species [Co(CO) 4 ] − and [FeNO(CO) 3 ] − isolated by addition of two equivalents of [PPN] + Cl − ([PPN] + = bis(triphenylphosphane)iminium cation) and characterized by their known IR spectra, by elemental analysis and their characteristic colors and melting points. In the reaction of the Collman reagent with [Fe(NO) 2 (CO) 2 ] a clean transformation to the tricarbonylnitrosylferrate(1−) as the only formed product was observed.