Volume 48, Issue 6

Structural properties for Cu—In—Se thin-films for solar cell applications formed by electrochemical deposition at room temperature were studied using Raman-scattering. Reactions among Cu, In and Se to binary compounds and CuInSe 2 , respectively, were observed. It is concluded that Raman scattering spectroscopy only at low temperature conditions shows the real composition of the electrochemically deposited Cu—In—Se layer. It was also found by Raman spectroscopy that the CuInSe, phase is formed by annealing as-deposited Cu—In—Se thin films preferentially at temperatures around 400°C under selenium vapour pressure.

The reaction of Ph(R)PSiMe 3 with an excess of CpFe(CO) 2 Cl results in the elimination of Me 3 SiCl to give the open diferriophosphonium halides [{CpFe(CO) 2 } 2 P(Ph)R]Cl (R = H, Ph, CH 2 SiMe 3 , Me) (1 a—d). The deprotonation reaction of 1 a with KOBu t at —78°C results in the formation of the unstable diferriophosphane {CpFe(CO) 2 } 2 PPh (3), which reacts with alkylating reagents RX (R = Me, CH 2 Ph, CH 2 COOEt; X = Cl, I) to give the P-functionalized diferriophosphonium halides [{CpFe(CO) 2 } 2 P(Ph)R]X (1 d’—f). The light-sensitive compounds 1b—f are found to eliminate readily a CO ligand upon photolysis to give the corresponding closed P-functionalized diferriophosphonium salts [{µ-CO(CpFeCO) 2 }P(Ph)R]X (2b—f) with a bridging CO ligand and a Fe— Fe bond. The mass, IR and NMR spectra of 1, 2 and the results of a crystal structure determination of [{ μ -CO(CpFeCO) 2 }PPh 2 ]BPh 4 (2b’) are reported and discussed.

The first crystal structure analysis of a 1,4-dihydroquinoxaline is described by example of the 1,4-bis(tert-butyldimethylsilyl) derivative. In the solid state, this molecule exhibits a nonplanar heterocycle with a dihedral angle of 156.3° along the N—N axis in the boat-shaped 8π electron ring system. The alkyl groups of the Si(tert-Bu)Me 2 substituents are arranged as to minimize steric repulsion. Despite the reduced π electron conjugation due to non-planarity, the compound is oxidized reversibly to an EPR detectable radical cation at —0.59 V vs. ferrocene in dichloromethane. However, the second oxidation to the fully aromatic dication is electrochemically irreversible. A comparison with previously obtained results illustrates the structural flexibility of the non-aromatic 1,4-dihydro-1,4-diazine ring system which is strongly affected by rather weak non-bonded interactions.

Diboron tetrachloride reacts with bis(trimethylgermyl)acetylene to give 1,1-bis(chlormethylboryl)-2,2-bis(chlordimethylgermyl)ethene (2 b). With 1,2-dichlor-1,2-di-t-butyldiborane(4) the corresponding 1,1-bis(chlor-t-butylboryl)-2,2-bis(trimethylgermyl)ethene (2c) is obtained. Substitution of chlorine atoms in 2b with trimethylsilyldimethylamin leads to the corresponding 1,1-bis(dimethylaminomethylboryl)-2,2-bis(chlordimethylgermyl)acetylene (2 d). The constitution of 2c—2e is derived from NMR and MS data, and confirmed for 2d by an X-ray structure analysis.

Depending on the H + concentration and solvent, reaction of [RuCl 3 (NO)(PPh 3 ) 2 ] with 'S 2 N 2 H 2 ′2- - alternatively yields either [Ru(NO)PPh 3 (′S 2 N 2 H 2 ′)]Cl 1 or [Ru(NO)(′S 2 N 2 H′)] 2 2. 1 gives 2 upon treatment with base, 2 yields 1 when reacted with HC1 and PPh 3 in THF. In MeOH, 2 is completely insoluble, but reacts with HC1 to give [Ru(NO)(′S 2 N 2 H 2 ′)] 2 Cl 2 , 4a, which is converted into [RuCl(NO)(′S 2 N 2 H 2 ′)] 3 when dissolved in THF. Reactions of 2 with phosphines such as PMe 3 , PPr 3 or PBu 3 in THF yield the corresponding [Ru(NO)PR 3 (′S 2 N 2 H′)] complexes, which is proof that not a protonation of the amido donor in 2, but sufficient solubility of 2 in the respective solvent and a subsequent dissociation into mononuclear complex fragments are decisive for cleavage of 2. Protonation or deprotonation of the N donors are more likely to influence the fine-tuning of the Ru center in [Ru(NO)(′S 2 N 2 H 2 ′)] fragments with respect to coordination of hard or soft co-ligands.

has been prepared by the reaction of Li(DME)[P(t-Bu)2] with benzonitrile in 1,2-dimethoxyethan solution. The compound forms violet, moisture sensitive crystals, which were characterized by an X-ray structure determination [Space group P2 1 /n, Z = 4, 3282 observed unique reflections, R = 0.082. Lattice dimensions at -40°C: a = 851.0(5), b = 1238.0(3), c = 3029.2(4) pm, β = 90.53(4)°]. The compound forms an ion pair, in which the lithium atom is coordinated by two oxygen atoms of a chelating DME molecule, by an oxygen atom of a nonchelating DME molecule, and by the nitrogen atom of the planar diazaphosphole ring in 1-position. The phenyl groups are nearly coplanar with the diazaphosphole ring. is the product of the reaction of the lithium complex with methanol. It forms colourless crystals [Space group Ρ2 1 /n, Ζ = 4, 2015 observed unique reflections, R = 0.068. Lattice dimensions at -80°C: a = 1458.3(2), b = 824.8(1), c = 1716.9(2) pm, β = 105.37(9)°]. The molecules have planar 5 H-diazaphosphole rings.

o-Methylbenzyldifluorophosphite 2 was obtained by the reaction of o-methylbenzyltrimethyl silyl ether 1 with chlorodifluorophosphine PF 2 Cl. The reaction of 2 with the palladium(II) complex 3 led to the tetrakis(difluorophosphonato)palladate(II) complex 7. The X-ray structure analysis of 7 confirmed the nearly exact square planar structure at the metal atom of the tetrakis(difluorophosphonato)palladate(II) dianion. Minimal deviations from the ideal geometry at palladium and phosphorus are mainly the result of thermal motion or disorder phenomena in the crystal. In the reaction of the platinum(II) complex 8 with chlorodifluorophosphine the binuclear tetrakis(chlorodifluorophosphine)platinum(II)chloro complex 9 was obtained. In acetonitrile, 9 was cleaved to form the mononuclear complex 10. Similar results were obtained in the oxidative addition reactions of the platinum(0) complex 11 with sulfuryl chloride fluoride, 12, sulfuryl fluoride, 13, and phosphorus pentafluoride. Tetrakis-(triphenylphosphine)-μ-dichlorodiplatinum(II) hexafluorophosphate 14 was isolated. In acetonitrile the mononuclear acetonitrile-bis(triphenylphosphine)chloroplatinum(II) hexafluorophosphate complex 15 was isolated.

All components of the two series [Os 35 Cl n I 6-n ] 2- and [Os 37 Cl n I 6-n ] 2- , n = 0-6, including the pairs of geometric isomers for n = 2, 3, 4, have been prepared and isolated by ion exchange chromatography on DEAE cellulose. The highly resolved low temperature (80 K) IR and Raman spectra of the pure isotopomers show distinct isotopic shifts for different vibrational modes up to 10 cm -1 . Normal coordinate analyses have been performed, based on a general valence force field. Due to the stronger trans influence of I as compared to Cl in all asymmetric Cl˙—Os—I′ axes the Os—I′ bonds are strengthened and the Os—Cl˙ bonds are weakened, as indicated by valence force constants for Os—I′ approximately 9% higher, for Os—Cl˙ 7% lower, as compared with the values calculated for symmetric axes.

The isotypic compounds K 8 In 11 , Rb 8 In 11 , K 8 Tl 11 , and Rb 8 Tl 11 were prepared from the elements. The crystal structures were determined by single crystal X-ray diffraction methods. (K 8 In 11 : a = 1002.1(3), c = 5089.1(8) pm; Rb 8 In 11 : a = 1030.1(3), c = 5236.7(7) pm; Κ 8 Τl 11 : a = 999.1(3), c = 5084.8(7) pm; Rb 8 Tl 11 : a = 1028.0(3), c = 5230.5(7) pm, R3̄c, Z = 6). The crystal structures contain In 11 - and Tl 11 -clusters, respectively, of pentacapped trigonal prisms. Band structure calculations on K 8 In 11 confirm an [In 11 ] 7 -“anion”, with one excess electron per In 11 -cluster involved in alkalimetal-earthmetal bonding.

Phenylamine has been oxidized by radiolytically generated hydroxyl and sulfate radicals, the ensuing intermediates and their reactions have been studied by pulse radiolysis and product analysis in the absence and presence of oxidants such as Fe(CN) 6 3- and O 2 . Upon OH radical attack, hydroxycyclohexadienyl-type radicals are mainly formed while Η-abstraction reactions can be neglected. In the presence of Fe(CN) 6 3- these radicals are for the most part oxidized to the corresponding tyrosines (80%), except for the ipso-OH-adduct radicals (≈ 20%). It is concluded that ˙OH-addition is almost random, but with a slight avoidance of the metaposition relative to the ortho-, para- and ipso-positions. Oxygen adds reversibly to the OH-adduct radicals (k f = 1.8 × 10 8 dm 3 mol -1 s -1 , k r = 5.4 × 10 4 s -1 ). In this case, tyrosine formation occurs by HO 2 ˙-elimination. However, due to side reactions, tyrosine formation only reaches 52% of the OH radical yield. The tyrosine yield drops to 10% in the absence of an oxidant. Upon SO 4 ˙⁻-attack, decarboxylation becomes a major process (33% of SO 4 ˙⁻) alongside the production of tyrosines (43%). Here, with Fe(CN) 6 3- as the oxidant the formation of p-Tyr (18.5%) and m-Tyr (16.5%) is preferred over o-Tyr formation (8.5%). It is believed that in analogy to other systems a radical cation is formed immediately upon SO 4 ˙⁻-attack which either reacts with water under the formation of hydroxycyclohexadienyl-type (“OH-adduct”) radicals, or decarboxylates after intramolecular electron transfer. The radical cation can also arise indirectly through H + -catalysed water elimination from the ˙OH-adduct radicals. At pH 2 and a dose rate of 0.0046 Gy s -1 CO 2 formation matches the OH radical yield when ˙OH is the attacking radical. Below pH 2, G(CO 2 ) decreases with falling pH. This indicates the occurrence of another, unimolecular, pathway under these conditions competing effectively with decarboxylation. This appears to be a relatively slow deprotonation reaction of the carboxylprotonated phenylalanine radical cation which gives rise to the benzyl-type radical.

Novel rhenium complexes with terminal thiocarbonyl groups have been synthesized from ReCl 3 (Me 2 PhP) 3 and sodium diethyldithiocarbamate. mer-(Diethyldithiocarbamato)tris-(dimethylphenylphosphine)(thiocarbonyl)rhenium(I), mer-[Re(CS)(Me 2 PhP) 3 (Et 2 dtc)], and tris(diethyldithiocarbamato)(thiocarbonyl)rhenium(III), [Re(CS)(Et 2 dtc) 3 ] have been studied by infrared and NMR spectroscopy, mass spectrometry and X-ray diffraction. mer-[Re(CS)(Me 2 PhP) 3 (Et 2 dtc)] crystallizes orthorhombic in the space group Pna21 with a = 1516.1(2), b = 2189.8(2) and c = 1035.6(1) pm. Structure solution and refinement converged at R = 0.042. The coordination geometry is a distorted octahedron. The Re—C bond length is found to be 184(2) pm. [Re(CS)(Et 2 dtc) 3 ] crystallizes monoclinic in the space group P21/c with a = 962.2(6), b = 1744.0(2), c = 1537.4(6) pm and β = 96.21(1)°. The final R value is 0.028. In the monomeric complex the rhenium atom is seven-coordinate with an approximate pentagonal-bipyramidal coordination sphere and a rhenium-carbon distance of 181(1) pm.

Mononuclear compounds CpCo(η 2 -azobenzene)(PMe 3 ) (1) or ortho-metallated (2) are obtained from azobenzene and CpCo(PMe 3 ) 2 or CoMe(PMe 3 ) 4 , respectively. With 4-acetoxo-azobenzene the ortho-metallation reaction gives isomers , (3A) and (3B) in a 1:1 ratio. Carbonylation of 2 gives (4). Benzo[c]cinnoline affords CoCH 3 (η 2 -C 12 H 8 N 2 )(PMe 3 ) 3 (5) and μ 2 -(N ,N′)-C 12 H 8 N 2 (CoCp)[CoCp(PMe3)] (6). The coordination mode of the diazene ligands in 1 and 6 has been shown by X-ray crystal structure determinations. Dynamic N M R spectroscopy indicates intramolecular hopping of trimethylphosphine across the CoCo bond in 6.

Mononuclear cobalt(0) complexes Co(η 2 -azaolefin)(PMe 3 ) 3 (azaolefin = benzo[c]cinnoline (1), p-dimethylamino-phenyl(phenyl)diazene (2), 1/2 diazobenzene (3), bis(p-tolyl)diazene (4), bis(p-fluorphenyl)diazene (5), bis(p-trifluoromethyl-phenyl)diazene (6), phenylisocyanate (7)) are obtained from Co(cyclo-C 5 H 8 )(PMe 3 ) 3 by substitution of the olefin. X-ray crystal structure determinations of 1 and 7 show tetrahedral arrangements of ligands around the cobalt atom. By reaction with carbon monoxide carbonyl(phosphine)cobalt(0) complexes are formed. 7 catalyses the cyclotrimerization of phenylisocyanate, while with CoCl(PMe 3 ) 3 as a catalyst the cyclic dimer of phenylisocyanate is selectively formed. A convenient synthesis for CoCl(PMe 3 ) 3 is described.

Sr 3 [MnN 3 ] (hexag. P6 3 /m (Nr. 176); a = 764.2(1) pm, c = 529.8(1) pm; Z = 2) and Ba 3 [MnN 3 ] (hexag. P6 3 /m (Nr. 176); a = 805.0(2) pm, c = 558.6(1) pm; Z = 2) are isotypes of the Ba 3 [FeN 3 ] crystal structure and contain trigonal-planar anions [MnN 3 ] 6- with D 3h -symmetry (Mn—N: 174.1(13) pm/173.7(12) pm). The compounds were prepared by reaction of mixtures of Li, Sr/Ba and Mn (molar ratio 2:1:1) in tungsten crucibles with nitrogen (1 atm) at 850°C.

TaFe 1.14 Te 3 is obtained from the elements in sealed quartz ampoules at 600°C. It crystallizes in the monoclinic space group P2 1 /m with a = 7.4262(8), b = 3.6374(5), c = 9.9925(5) Å, and β = 109.166(8)°. The structure is built up from TaFeTe 3 layers. Fe atoms with fractional occupancy are situated at the Te surfaces of the TaFeTe 3 slabs giving rise to a 3 D connectivity of the TaFeTe 3 layers in space. TaFe 1.14 Te 3 exhibits metallic properties and shows an antiferromagnetic ordering at 215 K. Tight-binding band structure calculations show that Fe–Fe and Ta–Fe interactions are important for the electronic stability of TaFe 1.14 Te 3 ; replacing Fe by more electron-rich transition metals such as Co or Ni may lead to compounds of composition TaM 2 Te 3 . A possible structure is derived from that of TaFe 1.14 Te 3 by filling tetrahedral voids within the TaMTe 3 layers with additional 3d metal atoms.

Sixteen new designs of antagonists of the luteinizing hormone releasing hormone (LHRH) with histidine in position 8 were synthesized, because this position is critical both for antiovulatory activity and the side effect of histamine release. The most potent antagonist was NAcDQal-DpClPhe–D 3 Pal– Ser–cPzACAla–DPicLys– Leu– His – Pro –DAlaNH 2 , which showed 33% AOA at 0.25 μg. The histamine release was remarkably negligible by an ED 50 of 308 μg/ml which is superior to 186 μg/ml for LHRH and comparable to 300 for Antide. The relative basicities of His, Arg, and ILys in position 8 of antagonists appear to influence both the level of potency of AOA and a negligible to a significant release of histamine. The least basic His 8 -analogs can have the lowest AOA and the highest ED 50 . The very basic Arg 8 -analogs can have the highest AOA and the lowest ED 50 . The moderately basic ILys 8 -analogs can be a compromise for acceptable levels of potency and safety.

The ternary condensation of terphthalaldehyde with malononitrile and some active methylene, and methyl group reagents are reported. Structures and different pathways are described.

The crystal structure of the title compound was determined to obtain structural information on asymmetric tetrapyrroles bearing an sp 3 -hybridized meso-oxygen atom. These types of compounds serve as models for the enol-form of oxophlorins, which often are obtained in crystalline form only with rotational disordering of the oxofunction, making conformational analyses difficult. C 37 H 42 CuN 4 O 5 , monoclinic, P2 1 /n, a = 15.025(7), b = 9.204(3), c = 23.544(9) Å, β = 94.33(4)°, V = 3246.7(13) Å 3 , 130 K, Z = 4, R = 0.075 for 3186 reflections with I > 2.0 σ(I). The structure is characterized by a planar tetracoordinated copper(II) and an almost planar macrocycle.

Compounds which have two mesogenic groups with and without terminal alkyl chains containing thiophene systems, were prepared from α.ω-bis(5-formyl-2-thienyl)alkanes (3a-3n) and various aromatic amines or 2-fluorenyl-Wittig-salt (10). The liquid crystalline properties of these compounds were characterized by differential scanning calorimetry (DSC) and polarizing microscopy. Only the series of α.ω-bis{5-[N-(4′-butyloxybiphenyl-4-yl)imino]formyl-2-thienyl}alkanes (7a-71) showed enantiotropic smectic and nematic mesophases. The series of E,E-α.ω-bis[5-(2-fluorenylvinyl)-2-thienyl]alkanes (8a-81) showed enantiotropic nematic mesophases for the compounds with 4 and 6 methylene groups, monotropic nematic mesophases for the compounds with 7—12 methylene groups and no liquid crystalline phases for compounds with 3, 5, 16 methylene groups in the connecting alkylene chain. In contrast to the compounds 8a-81, E-l-(5-butyl-2-thienyl)-2-(2-fluorenyl)ethylene has a smectic mesophase.

The new compound CaPtGa 2 crystallizes in a MgCuAl 2 type structure, orthorhombic system, space group C mcm (No. 63) with the lattice constants: a = 425,8(1), b = 1025,1(2), c = 698,8(1) pm.

Palladium and platinum powder dissolve at room temperature in oxygen saturated solutions of α-amino acids, peptides, nucleosides and ATP. The resulting mass concentrations of dissolved palladium and platinum were in the range from 10 to 100 μg/ml.

Transesterification or acylation method has been used for the preparation of three novel hydroxy-substituted aromatic aminoxyl esters 4, 5, and 8 from which three new spin-labelled azo compounds 10,13, and 14 have been synthesized.