Volume 59, Issue 8

The reaction of CuCl[P(C 7 H 7 ) 3 ] (1a) with sodium hexafluoroacetylacetonate, Na(hfac), leads to (hfac)Cu[P(C 7 H 7 ) 3 ] (2a), which in the presence of excess P(C 7 H 7 ) 3 (a) gives (hfac)Cu[P(C 7 H 7 ) 3 ] 2 (3a). Whereas the 1:2 compound 3a is a pseudo-tetrahedral copper(I) complex with relatively long Cu-P (224.85(10) and 223.75(10) pm) and Cu-O (212.7(3) and 212.0(3) pm) distances, the 1:1 complex 2a may be described as having a distorted pseudo-trigonal coordination sphere (Cu-P 214.32(11) pm, Cu-O 196.6(3) and 208.1(3) pm), although one of the cyclohepta-2,4,6-trienyl substituents develops a weak additional interaction with the metal through its central C=C double bond (Cu-C 275.1 and 272.9 pm). The molecular geometries of the tri(1-cyclohepta-2,4,6-trienyl) complexes 2a and 3a are compared with those of the known tri(cyclohexyl)phosphane complexes, (hfac)Cu[P(C 6 H 11 ) 3 ] n (n = 1 (2b) and 2 (3b)), and related compounds.

The tetrakis(phenyl isocyanide)nickel(0) complexes [Ni(CNR) 4 ](R = C 6 H 5 , 1; R= C 6 H 3 -2,6-Me 2 , 2; R = C 6 H 4 -2-NO 2 , 3) have been synthesized from [Ni(COD) 2 ] and the corresponding phenyl isocyanides in toluene. Complexes 1 - 3 were characterized by X-ray diffraction. All three complexes contain a nickel atom which is coordinated in a slightly distorted tetrahedral fashion.

The coordination chemistry of the unsymmetric, aliphatic, tetradentate tripodal ligand N[(CH 2 CH 2 NH 2 )(CH 2 CH 2 OH)(CH 2 CH 2 CH 2 OH)] H 4 -1 with iron chlorides was investigated. The disodium salt of the deprotonated ligand Na 2 (H 2 -1) reacts with FeCl 3 to yield a yellow precipitate which upon recrystallization from DMSO/CH 2 Cl 2 gives red crystals of the octanuclear iron(III) complex [{Fe III Cl(H 2 -1)} 4 Fe III 4 (μ 4 -O) 4 Cl 4 ] 2 ・ 4CH 2 Cl 2 containing a central Fe 4 (μ 4 -O) 4 cubane core. Crystals of 2 ・4DMF were obtained by slow oxidation of the green iron(II) complex obtained from ferrous chloride and Na 2 (H 2 -1) after recrystallization from DMF. The structure determination of 2 ・4CH 2 Cl 2 also revealed the presence of the iron(III) oxo cubane core. The core is surrounded by four iron atoms each coordinated by η 4 -(H 2 -1) 2- and Cl - ligands.

Light-yellow crystals of a second modification of mercury(I) orthoarsenate(V), β-(Hg 2 ) 3 (AsO 4 ) 2 , were obtained during a diffusion-controlled precipitation reaction starting from diluted solutions of Hg 2 (NO 3 ) 2 , Hg(NO 3 ) 2 , and H 3 AsO 4 . The crystal structure was determined from a single crystal X-ray diffraction data set. The previously reported crystal structure of synthetic chursinite, α-(Hg 2 ) 3 (AsO 4 ) 2 , has also been re-investigated and refined with better accuracy and precision. Both phases crystallize in space group type P2 1 /c (no. 14) [α- (β -): Z = 2 (4), a = 8.7915(6) (10.2034(18)), b = 5.0699(4) (8.5875(14)), c = 15.6839(10) (13.5172(19)) Å , β = 128.761(1) (101.016(3))°, 1661 (3528) structure factors, 74 (146) parameters, RF 2 > 2σ (F 2 )] = 0.0195 (0.0492)] and are made up from Hg 2 2+ dumbbells and AsO 4 3− tetrahedra as the main building units, but the topologies of the structures are quite different.

The benzoyl protected 4-ethynyl-L-phenylalanine methyl ester gives with octacarbonyldicobalt and ethylene-bis(triphenylphosphine)platinum(0) the complexes Co 2 (CO) 6 (HC≡CR) and (Ph 3 P) 2 Pt(HC≡CR) (R = p-C 6 H 4 CH 2 CH(CO 2 Me)N(HCOPh). The heterocumulene [Cp(Ph 3 P) 2 Ru=C=C(H)R]+BF 4 − (R = p-C 6 H 4 CH 2 C(H)N(H)-Boc is formed from [Cp(Ph 3 P) 2 Ru] + BF 4 − and N-t-Boc-4-ethynylphenylalanine methyl ester. The alkynyl bridged tetraamino acid with a tetraphenylmethane backbone C[p-C 6 H 4 C≡C-p-C 6 H 4 -CH 2 CH(CO 2 Me)NH-t- Boc] 4 was synthesized from tetrakis(4-iodophenyl)methane and N-Boc-4-ethynylphenylalanine methyl ester by Sonogashira coupling.

The two new compounds Mn 2 (L)Sb 2 S 5 (L = diethylenetriamine = DIEN, N-methyl-1,3- diaminopropane = MDAP) were prepared under solvothermal conditions using the elements as starting materials. Both compounds crystallise in the monoclinic space group P2 1 /c with the lattice parameters a=10.669(7), b=12.805(2), c=12.072(1)Å , β =115.786(7)°,V =1485.1(4) Å 3 for L = DIEN and a = 10.1859(7), b = 12.7806(6), c = 12.1256(8)Å , β = 110.173(8)°, V = 1481.7(2) Å 3 for L = MDAP and Z = 4. The primary building units are SbS 3 pyramids, MnS 6 and MnS 4 N 2 distorted octahedra. These primary building blocks are interconnected to form Mn2Sb2S4 hetero-cubane units. The hetero-cubanes share common corners, edges and faces thus forming a second heterocubane. These secondary building units are joined to form layers within the (100) plane. The connection mode yields ellipsoidal pores within the layers. The amines are exclusively bound to one of the two crystallographically independent Mn 2+ cations and they point into the pores and between the layers separating the layers from each other. The interlayer separation and the size of the pores depend on the sterical requirements of the amine incorporated into the network. A pronounced distortion of the MnS 4 N 2 octahedron results from a significant elongation of one Mn-S distance from 2.866 Å (L = methylamine, MA) to 3.185 Å for L = MDAP. The magnetic susceptibility curves are typical for low-dimensional antiferromagnetic materials and the large negative values for the Weiss constant Θ indicate strong antiferromagnetic exchange interactions. The magnetic properties are significantly influenced by the change of the Mn-S bonds introduced by the different amines. The compounds decompose at elevated temperatures with a two step reaction for L = MA and ethylenediamine and in a one step reaction for the bidentate acting amine molecules.

A solid-state pH sensor was fabricated using a transparent conductive tin oxide film on a glass substrate. The coating of the glass substrate was achieved by a novel simple chemical vapor deposition (CVD) procedure. The response time of the pH sensor was substantially reduced when a thin graphite film was deposited onto the tin oxide conductive film. The sensor slope was found to increase as the temperature of the solution was increased. The performance of the sensor was investigated in the pH range from 0.3 to 11.0. A straight-line calibration graph was achieved throughout the whole range tested, especially when the solution temperature was 80 ℃. The working pH range was found to decrease on the expense of the lower range as the temperature was decreased. Results obtained by the suggested sensor compares very well with conventional pH electrodes where the square of the correlation coefficient was 0.999.

The present work is the first comprehensive account of the knowledge acquired from single crystals of the isotopic series M 2 Te 4 O 11 (M = La - Nd, Sm - Yb). In the crystal structure, the M 3+ cation is coordinated by eight oxygen atoms in the shape of a distorted square antiprism. Out of these polyhedra a mesh-like [M 2 O 16 ] 14− layer parallel to the (001) plane is built via three common edges. The [Te 4 O 11 ] 6− double layers in turn build two tellurium-oxygen chains crosswise to each other. The construction of the tellurium-oxygen partial structure is, however, only possible taking the secondary Te-O contacts into consideration. In most oxotellurates(IV), three oxygen atoms are covalently bound to the Te atoms (d(Te-O) ≈ 180−200 pm; ψ 1 tetrahedron). Another oxygen atom is found in the near vicinity at a distance of 230 to 280 pm. The significance of such secondary interactions for the stability of the crystal structures was recognized recently in theoretical as well as experimental investigations. All oxygen atoms with distances smaller than 280 pm are counted to the secondary coordination sphere. This limit may seem somewhat arbitrary but it accounts very well for the Te-O partial structure. The coordination sphere for the tellurium center is a ψ 1 trigonal bipyramid including the stereochemically active electron pair (“lone pair”). A description of the crystal structure is also possible without this partial structure, however in the [TeO 3+1 ] 4− polyhedra above and below the meshes of [M 2 O 10 ] 14− layers are linked via Te 2 -O 6 -Te 2 contacts only.

Reaction of (η 6 -C 6 H 5 CH 3 )Mo(CO) 3 with the easily accessible chiral chelate ligand P,P,Pʹ-tris- [(+)-9-phenyldeltacyclan-8-yl]-1,2-bis(phosphanyl)benzene P-P’ afforded the octahedral molybdenum carbonyl derivate (P-P’)Mo(CO) 4 1 as a diastereomer mixture 1a (74%) and 1b (26%). Crystallization gave single crystals of (SP)-(P-P’)Mo(CO) 4 1a. The X-ray structure analysis of compound 1a revealed the formation of an unusual triple-decker π-stack in the solid state.

The thulium nickel indide TmNiIn forms solid solutions TmNi 1−x−y In 1+x . Several samples have been prepared by arc-melting of the elements under argon. The structure of TmNiIn contains two crystallographically different nickel sites. The Ni1 atoms have a trigonal prismatic coordination by indium, while the Ni2 sites have six thulium neighbors in a trigonal prismatic arrangement. The Ni1 sites show defects in the solid solution, while the Ni2 sites have Ni2/In mixing with a maximal occupancy of 32 at.-% indium. The structures of three single crystals of solid solutions have been refined, leading to the compositions TmNi 0.88 In 1.10 (a =747.06(7), c = 367.8(1) pm, wR2 =0.0342, 323 F 2 values, 16 variables), TmNi 0.80 In 1.16 (a= 752.94(7), c =366.5(1) pm, wR2=0.0475, 503 F 2 values, 16 variables), and TmNi 0.76 In 1.21 (a = 758.4(1), c = 366.68(7) pm, wR2 = 0.0949, 226 F 2 values, 16 variables). The crystal chemical peculiarities and the differences in chemical bonding are briefly discussed.

The title compound [Ni 2 (L)(3,5 prz)], prz = pyrazolate with the formally pentadentate ligand L = 1,3-bis(salicylideneamino)propan-2-olate, was synthesized and identified using elemental analysis and IR spectroscopy. It crystallizes in the monoclinic space group P2 1 /c with cell parameters a = 29.873(4), b = 11.131(2), c = 13.166(3) Å , β = 107.770(10)°, V = 4169.0(13) Å 3 , Z = 4, D cal = 1.618 Mg/m 3 . The nickel ions are bridged by the alkoxo group of the ligand and the N atoms of the μ-pyrazolate group. Each nickel(II) ion is coordinated by two N atoms and two O atoms, forming a square with trans-N 2 O 2 geometry. The Ni···Ni distance and the Ni−O−Ni angle are 3.371(1) Å and 126.4(1)°, respectively.

From aqueous solutions containing acetylenedicarboxylic acid and Na 2 CO 3 or KOH single crystals of Na 2 (C 2 (COO) 2 )(H 2 O) 4 (P2 1 /n, Z = 2) and K 2 (C 2 (COO) 2 )(H 2 O) (P1̅, Z = 2) were obtained by slow evaporation of the solvent. In Na 2 (C 2 (COO) 2 )(H 2 O) 4 the sodium atom is co-ordinated almost octahedrally by three water molecules and three oxygen atoms of the carboxylate ligands. These octahedra are connected to layers, which are held together by hydrogen bonds. In K 2 (C 2 (COO) 2 )(H 2 O) two crystallographic distinct potassium ions exist both seven co-ordinate by oxygen atoms stemming from water molecules and carboxylate ligands. These KO 7 polyhedra are linked to a threedimensional structure by the bifunctional carboxylate anions and the water molecules.

N,N’-Disubstituted hydrazinecarbothioamides 6a - c and substituted thioureidoethylthioureas 12a - c react with ethenetetracarbonitrile (TCNE) in ethyl acetate or chlorobenzene to form the derivatives of pyrazole 7, 8; thiadiazole 10, 11 thiadiazepine 9, thiadiazepane 13, imidazolidine 14 and diazepine 15.

Treatment of the dilithiated dibenzotetraethyleneglycol reagent [(o-C 6 H 4 OLi)-(OCH 2 CH 2 ) 2 O- (o-C 6 H 4 OLi)] (5) with TiCl 4 · 2 THF gave the corresponding metal complex [{(o-C 6 H 4 O-) - (OCH 2 CH 2 ) 2 O-(o-C 6 H 4 O-)}TiCl 2 ] (6). The X-ray crystal structure analysis of 6 revealed that all five oxygen atoms are located in one plane and bonded to titanium in a pentagonal-dipyramidal geometry with the two chloride ligands being oriented trans to each other in the apical positions.

A new eremophilenolide 1β ,10β -epoxy-6β -acetoxy-3β -angeloyloxy-8β -hydrox y-eremophil- 7(11)-en-8,12α-olide (1), together with liguhodgsonal (2), esculetin (3) and β -sitosterol (4), was isolated from the aerial parts of Ligularia sagitta. The structure of the new constituent (1) was elucidated by spectroscopic methods and confirmed by single-crystal X-ray diffraction.

Two novel protoilludane sesquiterpenoids, echinocidins A (3) and B, (4) have been isolated from an artificial liquid culture of the basidiomycetous fungus Echinodontium tsugicola and their structures clarified spectroscopically. Echinocidin A (3) accelerated primary root growth to 117% and echinocidin B to 180% of controls at a concentration of 100 ppm.

γ -Aminobutyric acid (GABA) adds onto nitrile imine 1,3-dipolar species (generated in situ from their N-arylhydrazonoyl chloride precursors 1a-c ) to deliver the corresponding acyclic amidrazone adducts 10a-c. In the presence of 1,1’-carbonyldiimidazole, the latter adducts undergo cyclocondensation involving the activated carboxyl and the amidrazone-CH 2 NH groups to afford the respective N-[1-(arylhydrazono)-2-oxopropan-1-yl] pyrrolidin-2-ones (11a-c). The constitution of 10 and 11 is evidenced from analytical and spectral (IR , MS and NMR) data.

(11Z)-11,19-Icosadienyl acetate (1) has been shown to be an efficient repellent against the ant Myrmica rubra whereas its corresponding (11E) stereoisomer 2 does not exhibit any repellent activity at all. Several synthetic strategies for these two compounds have been evaluated.

The hexagonal Laves phase MgIr 2 was synthesized from the elements in a sealed tantalum tube in an induction furnace. MgIr 2 was investigated by powder and single crystal X-ray data: P6 3 /mmc, a = 516.9(1), c = 838.5(2) pm, wR2 = 0.0771, 135 F 2 values, and 11 variable parameters. The magnesium atoms have coordination number (CN) 16 (12 Ir + 4 Mg), while the smaller iridium atoms, Ir1 and Ir2, both have CN 12 (6 Ir + 6 Mg). The Ir-Ir distances within the three-dimensional network of face- and corner-sharing Ir 4/2 tetrahedra range from 250 to 267 pm. The magnesium atoms have one shorter (306 pm) and three longer (319 pm) magnesium contacts. The crystal chemistry of MgIr 2 is briefly discussed and compared with the other binary Mg-Ir intermetallics.