Volume 36, Issue 9

Reaction of triirondodecacarbonyl (1) with the dinuclear chloroiridium complex [(η 5 -C 5 Me 5 )Ir(μ-Cl)Cl] 2 (2) in benzene at 50 °C yields the novel mixed iron iridium cluster of composition (η 5 -C 5 Me 5 )IrFe 2 (CO) 9 (8) the molecular structure of which has been established by X-ray diffraction methods. The mononuclear half-sandwich complex (η 5 -C 5 Me 5 )Ir(CO) 2 (4) present in the reaction mixture was found to represent the immediate precursor of the cluster compound 8.

Rhenium Carbonyl Olefin Complexes Re 2 (CO)io has been photolyzed in the presence of cyclooctatetraene, 1,3-butadiene and 1,4-pentadiene, respectively. In pentane solutions the species (CO) 4 Re-μ-(η 3 :η 1 -C 4 H 6 )Re(CO) 5 , (CO) 4 Re-μ-(η 2 :η 2 -C 4 H 6 ]Re(CO) 4 (11) and HRe 3 (CO) 14 could be isolated with 1,3-butadiene. C 8 H 8 yielded several compounds of which the following could be unequivocally characterized (CO) 4 Re-μ-(η 3 :η 1 -C 8 H 8 )Re(CO) 5 (14), (η 2 -C 8 H 8 )Re(CO) 4 -μ-(1,2,8-η 3 :5-η 1 -C 8 H 8 )-Re(CO) 4 and (CO) 3 Re-μ-(η 4 :η 4 -C 8 H 8 )Re(CO) 3 .11 and 14 have been characterized by X-ray structure analysis.

In benzene HgSe reacts with H 2 SiI 2 at 120 °C to yield a polymer, which on heating in benzene depolimerizes to form (H 2 SiSe) 3 . 1 H, 29 Si, 77 Se, NMR, IR and MS data are presented.

The 2-amino-4,4,5,5-tetrakis(trifluoromethyl)-1,3,2λ 3 -dioxaphospholanes 1 a - c are synthesized by reacting halogenoaminophosphines with dilithiumperfluoropinacolate, whereas 1 d-f are obtained from 2-chloro-4,4,5,5-tetrakis(trifluoromethy 1) -1,3, 2λ 3 -dioxaphospholane and the aminosilanes RNH(SiMe 3 ) (R = t-Bu, SiMe 3 ) or the amide (Me 3 Si) 2 NLi, respectively. Addition of chlorine to 1 a-f yields the covalent 2,2-dichloro-1,3,2 λ 5 -dioxaphospholanes 2 a-f which furnish the spirophosphoranes 3 a-f upon reaction with dilithiumperfluoropinacolate. The X-ray structure analysis of 3 a exhibits an almost ideal trigonal bipyramid having a very short P-N bond distance (1.590 Å) and H ··· O distance (2.34 Å).

Alkylidenearsines, Aminomethylidenearsines, Barrier of Rotation In the absence of a catalyst phenyl-bis(trimethylsilyl)arsine (1 a) reacts only very slowly with excess dimethylformamide (4) to give (dimethylaminomethylidene)-phenylarsine (8 a) and hexamethyldisiloxane (5). In the presence of small amounts of solid sodium hydroxide, however, the reaction is already finished after four days at + 20 °C. Similarly, lithium phenyltrimethylsilylarsenide · DME (2 a), which can easily be obtained from la and methyllithium in 1,2-dimethoxyethane (DME), and dimethylformamide (4) also form the alkylidenearsine (3 a) and lithium trimethylsilanolate. The NMR spectra of 3 a show the rotation of the dimethylamino group to be hindered with a barrier of about 63 kJ · mol -1 .

Dissolution of crystalline Se 8 or extraction of glassy or red amorphous selenium, prepared from aqueous SeO 2 by reduction, by organic solvents yields solutions containing Se 6 , Se 7 and Se 8 in equilibrium as shown by HPLC. The equilibrium explains the concentration dependence of the molar absorbance of such solutions observed earlier. Since the Raman spectrum of red amorphous selenium does not show any lines due to Se 6 Se 7 and Se 8 a rapid interconversion of selenium molecules in solution at 20 °C is postulated. Red amorphous selenium may consist of a mixture of small and medium sized ring molecules

The inhibition effect of tri-n-octylphosphine oxide (TOPO), triphenylarsine oxide (TAsO), triphenylphosphine oxide (TPO), triphenylarsine (TPAs) and triphenylphosphine (TPP) on the polarographic reduction of Cd 2+ , Zn 2+ and Co 2+ ions in aqueous methanolic and methanolic solutions has been studied. A different action of the inhibitors was obtained for each reducible ion. No change in the mechanism of the cathodic reductions has been observed. In all systems TOPO appeared to be the strongest inhibitor.

At room temperature in the presence of CsF sulfur-oxide-chloride-fluoride-imides R f NSOFCl (8) (R f = CF 3 , C 2 F 5 , i-C 3 F 7 , C 6 F 5 ) are formed from N-perfluoroalkyl-sulfinyl-imides and Cl 2 . At prolonged reaction times or higher temperatures the chloride is ex-changed and the difluorides R f NSOF 2 are isolated in high yields. In the same way (CF 3 ) 2 CFNS(O)ClCF 3 (12) and (CF 3 ) 2 CClNS(O)ClCF 3 (13) are obtained from (CF 3 ) 2 C = N-S(O)CF 3 (9) and Cl 2 /CsF. 12 can be fluorinated by CsF to give (CF 3 )2CFNS(O)FCF 3 (14). 14 is also observed, when fluorine is added to 9 via XeF 2 in the presence of BF 3 , but mainly C-S-bond cleavage occurs. SF 5 NS(O)FCF(CF 3 ) 2 (19) was identified by spectroscopic methods from the reaction of SF 5 NSOF 2 and CF 3 CF = CF 2 in the presence of CsF.

The new compounds Ca 9 Cd 4 Bi 9 , Sr 9 Cd 4 Bi 9 and Ca 9 Zn 4 Sb 9 crystallize in the orthorhombic system (Pbam) in the Ca 9 Mn 4 Bi 9 structure with the following constants: Ca 9 Cd 4 Bi 9 : a = 2258 ± 2 pm, b = 1278 ± 1 pm, c = 474 ± 1 pm. Sr 9 Cd 4 Bi 9 : a = 2347 ± 2 pm, b = 1327 ± 1 pm, c = 489 ± 1 pm. Ca 9 Zn 4 Sb 9 : a = 2192 ± 2 pm, b = 1250 ± 1 pm, c = 454 ± 1 pm.

The reactions of di-tert-butylantimony chloride with sodium hydroxide or sodium sulfide yield new anhydrides or thioanhydrides of tert-butylstibinous acids, which have structures with bridging oxygen or sulfur atoms. Analogous reactions of tert-butylantimonydichloride produce the first examples of anhydrides or thioanhydrides of tertbutylstibonous acids, which have cyclic structures (t-BuSbE) n E = O, n = 3, 4; E = S, n = 2, 3, 4, 5. Structural evidence is based on IR, 1 H NMR and MS data.

The diphenyls MPh 2 (M = Be, Mg, Zn, Cd, Hg) have been reacted with pyrazine (Pz) in tetrahydrofuran. Only the magnesium derivative undergoes electron transfer to yield the 1:1 radical complex [Pz(MgPh)] · . However, in the presence of sodium or potassium persistent 1:2 complexes [Pz(MPh) 2 ] + . are formed with M = Be, Mg, Zn. Use of the higher homologues CdPh 2 and HgPh 2 leads to reduction to the metals. The 1:2 complexes have been characterized by ESR spectroscopy; metal coupling constants of 9 Be, 25 Mg and 67 Zn could be determined in natural isotopic abundance.

Thiocarbamoylphosphine sulfides 1 a-c and oxides 2 a-c are ambidentate chelating ligands which may form monomeric or dimeric complexes with carbonylmetal halides. The reaction of 1 a-c with ClMn(CO) 5 and ClRe(CO) 5 yields the monomeric cw-tetracarbonyl complexes 3 a-c and 4 a-c with S,S'-coordination. The phosphine oxides 2 a-c first form tetracarbonyl complexes which dimerize spontaneously under loss of CO to give the anfi-fac-tricarbonyl complexes 6 a-c and 6 a with bridging three-coordinate sulfur. On refluxing in n-hexane solution, 8 a-c and 4b, c are converted into the corresponding dimers 7 a-c and 8 b, c. Dissolving of 7 b, c in CH 2 Cl 2 leads to re-formation of 8 b, c, the free ligands 1 b, c and inorganic manganese compounds.

The title compound has been prepared in high yield from K 2 [PtCl 4 ] and 1,5-bis(diphenylphosphano) pentane in dry CH 2 Cl 2 . The crystals are monoclinic, space group P2 1 /c with lattice parameters a = 11.733(3), b = 17.229(5), c = 13.743(4) Å, and β= 92.37(3)°; Z = 4. An X-ray analysis shows that the complex is monomeric and that it has a planar cis-configuration.

1 C 4 H 9 N = V(OSiMe 3 ) 3 has been prepared by reaction of NH 4 VO 3 with HNSiMe 3 ( t C 4 H 9 ). This compound is the starting material for the synthesis of C 6 H 5 N = V(OSiMe 3 ) 3 and t G 4 H 9 N = VCl 3 by transamination with aniline or redistribution with VOCl 3 , respectively. The properties of the trichloride are studied by chemical reactions such as redistribution, complex formation and substitution with silver carboxylates. All compounds are mono-meric in solution, probably containing a nitrogen vanadium triple bond. The structure of 2,2'-dipyridyl complexes [ t C 4 H 9 N = VX 3 · C 10 H 8 N 2 ] (X = Cl, CH 3 COO) has been found to be octahedral with meridional arrangement of chloride or acetate ligands.

Changes in motional properties of the -SH group environment in sarcoplasmic reticulum ATPase [1] induced by addition of specific ligands to sarcoplasmic reticulum membrane vesicles were investigated systematically by electron spin resonance (e.p.r.) spectroscopy. Alternatively, two kinds of iodoacetamide analog spin labels, 4-(2-iodoacetamido)- 2,2,5,5-tetramethyl-1-pyrrolidinyl-N-oxyl (label I) and 4-(2-iodoacetamido)-2,2,6,6-tetramethyl- 1-piperidinyl-N-oxyl (label II) were used. The labeling conditions were chosen such that less than three moles of -SH groups per mole of ATPase reacted with the spin labels. A marked increase in isotropic motion of either spin label was observed on addition of calcium in millimolar concentrations plus ATP or β-γ-methylene ATP. Qualitatively similar but smaller changes were also observed with inosine 5'-triphosphate (ITP), acetylphosphate, or ADP in the presence of calcium. These effects were independent of added magnesium. The spectral changes induced by β-γ-methylene ATP, which binds to the ATPase but is not hydrolyzed, and those of calcium plus ADP suggest a conformational change due to simultaneous binding of these ligands in the absence of enzyme phosphorylation. These changes in e.p.r. spectra were different in quality and magnitude from those observed upon separate binding of calcium or adenine nucleotides. The two spin labels, differing only in their numbers of heterocyclic ring atoms, were found to reflect environmental changes in different ways. This demonstrates the usefulness of employing different spin labels to detect and interpret structural transitions in macromolecular assemblies.

Tris[norbornyl-2]methanol The structure of the reaction product of the hydroboration oxidation of norbornene is determined by use of carbon-13 NMR spectroscopy. The conformers distribution of the resulting 1:3 mixture of the two stereoisomere 4 and 5 is analysed by addition of the paramagnetic shift reagent Eu(fod) 3 .

Reaction of the title compound 1 with o-phenylenediamine afforded either the diaze-pinones (2) or the amides (3). Treatment of 1 with thiourea gave the thiouracils (4). The indazoles (5) gave diacetyl or diphenylsulphonyl derivatives (6, 7) on treatment with acetic anhydride or benzenesulphonyl chloride, respectively. Condensation of 1 with benzenesulphonhydrazide gave the 2-substituted indazole (8). Michael condensation of 1 with anisalcyclohexanone gave 9.

Polymer anchored sulfonylazide is compared with its efficiency in the diazogroup transfer reaction of tosylazide. The resulting yields with the polymeric reaction are slightly lower than with tosylazide. However the greater thermostability of polymeric sulfonyl azide and its workup procedure make this alternative very attractive for synthesis. The reaction of polymeric sulfonyl azide with cyclic polyenes gives very small yields compared with the monomeric reaction. The attempt to generate diazocyclononatetraene by an alternative route leads only to the secondary product namely indene. At low temperature, and intermediate diazo-compound is, however, observed, which is tentatively assigned to structure 12.

From the extract of Catharanthus roseus tissue cultures 16 different indole alkaloids have been isolated belonging to heteroyohimbane, aspidosperma and iboga types. The structures were deduced by UV, NMR and mass spectrometry. Ajmalicine (1) and catharanthine (16) were found to be the major constituents, tetra-hydroalstonine (2), akuammigine (3), 3-isoajmalicine (4), pleiocarpamine (6), akuammiline (6), tabersonine (7), 20-hydroxytabersonine (8), lochnericine (9), horhammericine (10), minovincinine (11), vindolinine (12), 20-epivindolinine (13), vindolinine -N b -oxide (14) and 20-epivindolinine-N b -oxide (15) could be determined as minor or trace alkaloids.

From aspergillus oryzae extracts via 100 g preparations each 80 mg pure ribonuclease T 2 were obtained. The enzyme contains 16-17% carbohydrate (12-13% neutralsugars and 4% glucosamine). G. c. analysis results mannose, glucose, fucose, glucosamine, galactose and xylose in ratio 14:8:6:6:4:1. Proteolytic degradation of the enzyme gave a glyco-peptide with a uniform heteropolysaccharide containing the total carbohydrate amount.

From Ruta chalepensis L. (Rutaceae) a new alkaloid, taifine, has been isolated. Its structure has been determined as 9-ethyl-7-methoxyfuro[2,3-b]quinolone-4.

By X ray and NMR techniques the flavone structure for an extractive from Helichrysum graveolens has been confirmed. An extractive from an Artemisia sp. previously assigned the same structure must therefore have a different constitution.

The preparation and properties of N 6 -2,2,2 -trichloro -tert-butoxycarbonyl -adenosine axe described as a model of a new protecting group technique for amino groups in oligo-nucleotide syntheses.

A simple synthesis of khaplofoline (lb) and dihydroflindersine (4) has been reported. PTC-prenylation of 4-hydroxy-2-quinolone (8 a) gave a mixture of C-, O-and C/O-prenylated compounds (2a, 8b, 8c, 3d, 3e and 8f), 2a being the major product. N-prenylation of 8h gave 3i which yielded 8k after following treatment with aqueous HCl. Acid catalysed cyclisation of 2 a gave a mixture of 4 and 1 b in a ratio of 3:1.

From the trank heartwood of Morinda lucida four new anthraquinones, 3-hydroxy-anthraquinone-2-carbaldehyde, morindone-5-methyl ether, munjistin methyl ester, damna-canthol-ѡ-methyl ether and two glycosides, soranjidiol 6-0-β-primveroside and lucidin 3-0-β-primveroside were isolated and identified by spectroscopic and chemical methods.

N-Bromo-N-sodiocarbamidate, Trimethylbromostannane, Triphenylchloroplumbane N-bromo-N-sodiocarbamidate can be prep-ared by the reaction of N-bromo-carbamidate with sodium hydride. The salt, a white crys-talline compound, decomposes above 140 °C. It reacts with (CH 3 )3SnBr and (C 6 H 5 ) 3 PbCl to give the new N-halogeno-N-metallo compounds C 2 H 5 OC(o)NBr-Sn(CH 3 ) 3 (dec. 104 °C) and C 2 H 5 OC(O)NBr-Pb(C 6 H 5 ) 3 (dec. 126 °C).

One-dimensional Conductors, Linear Chain Structures (C9H7INO · C12H4N4) triclinic PT, a = 7.161(5) Å, b = 8.639(5) Å, c = 17.392(6) Å, α -64.96(4)°, β = 80.64(3)°, γ = 76.99(3)°, V = 1075.6 Å 3 , Z = 2, d c = 1.47 Mgm -3 . The structure was refined to R - 0.114 for 2022 reflections. It consists of segregated diadic stacks of TCNQ and 4-oxo-iodoquinolinium ions. Inter-planar distances in the TCNQ stack are 3.09(1) Å and 3.32(1) Å; 3.37(1) Å and 3.55(1) Å in the quinolinium stack.

The distortive effects produced by the sub-stitution of Ca(II) for Sr(II) upon the PO 4 3- ions in the Ca 10 (PO 4 ) 6 (OH) 2 and Ca 10 (PO 4 ) 6 F 2 lattices have been investigated. The study is based on the behaviour of the symmetric stretching frequency of the anion in series of solid solutions containing both cations.

Ten new compounds were synthesized. They crystallize with a Ni 2 In-type structure (space group P 6 3 /mmc-D 4 6h ). Their magnetic behaviour was investigated in the temperature range from 80 to 290 K.

The magnetic susceptibilities of ternary rare earth compounds with the CaAl 2 Si 2 structure were measured in the temperature range of 80 to 290 K. YbZn 2 Sb 2 and the compounds YbZn 2-x ;Cu x X 2 (X = P, As) with x < 1 show intermediate valence behaviour, that is a nonintegral occupancy of the 4f shell. Of the compounds EuZn 2 X 2 (X = P, As, Sb) the results for those with X = P or Sb show good agreement with the theoretical values for Eu(II). In LuZnCuAs 2 and RELi 2 X 2 (RE = Ce, Pr, Nd, Tb; X = P, As, Sb, Bi) the trivalent state of the rare earth atoms can be established. With the exception of LuZnCuAs 2 the susceptibilities of all of the investigated compounds follow the CURIEWEISS law.

1,3-Dienes react with bis(η 3 -allyl)palladium-ligand systems to give the title compounds which are believed to be involved, as intermediates, in the palladium-catalyzed oligomeriation of dienes.

The tetrabutylammonium salt of 2-thioxo-1,3-dithiol-4,5-dithiolate (TDD) was isolated and new one-dimensional conducting solids of the donor-acceptor type with TDD as a ligand were prepared.

Coupling of various protected amino acids or small peptides on an isocyano polymer and in the presence of 1 -methyl-3-formylindole demonstrates the feasibility of peptide formation by four component condensation on a polymer support, and the final peptide is detached from the resin by 50% trifluoroacetic acid in aceto-nitrile at room temperature.