Preparation of new (η5-C5H4CH3)Mn(NO)(PPh3) and (η7-C7H7)Mo(CO)-(PPh3) complexes

The complex (η⁵-C₅H₄CH₃)Mn(NO)(PPh₃)I has been prepared by the reaction of NaI with [(η⁵-C₅H₄CH₃)Mn(NO)(CO)(PPh₃)]⁺ and also by the reaction of [(η⁵-C₅H₄CH₃)Mn(NO)(CO)₂]⁺ with NaI followed by PPh₃. This iodide compound reacts with NaCN to yield (η⁵-C₅H₄CH₃)Mn(NO)(PPh₃)CN which is ethylated by [(C₂H₅)₃O]BF₄ to yield [(η⁵-C₅H₄CH₃)Mn(NO)(PPh₃)(CNC₂H₅)]⁺. Both [(η⁵-C₅H₄CH₃)Mn(NO)(CO)₂]⁺ and [(η⁵-C₅H₄CH₃)Mn(NO)(PPh₃)(CO)]⁺ react with NaCN to yield [(η⁵-C₅H₄CH₃)Mn(NO)(CN)₂]^?. This anion reacts with Ph₃SnCl to yield cis-(η⁵-C₅H₄CH₃)Mn(NO)(CN)₂SnPh₃ and with [(C₂-H₅)₃O]BF₄ to yield [(η⁵-C₅H₄CH₃)Mn(NO)(CNC₂H₅)₂]⁺. The reaction of (η⁵-C₅-H₄CH₃)Mn(NO)(PPh₃)I with AgBF₄ in acetonitrile yields [(η⁵-C₅H₄CH₃)Mn-(NO)(PPh₃)(NCCH₃)]⁺. The complex (η⁵-C₅H₄CH₃)Mn(NO)(CO)I, produced in the reaction of [(η⁵-C₅H₄CH₃)Mn(NO)(CO)₂]⁺ with NaI, is not stable and decomposes to the dimeric complex (η⁵-C₅H₄CH₃)₂Mn₂(NO)₃I for which a reasonable structure is proposed. Similar dimers can be prepared from the other halide salts. The reaction of (η⁷-C₇H₇)Mo(CO)(PPh₃)I with NaCN yields (η⁷-C₇-H₇)Mo(CO)(PPh₃)CN which is ethylated by [(C₂H₅)₃O]BF₄ to yield [(η⁷-C₇H₇)-Mo(CO)(PPh₃)(CNC₂H₅)]⁺. The interaction of this molybdenum halide complex with AgBF₄ in acetonitrile and pyridine yields [(η⁷-C₇H₇)Mo(CO)(PPh₃)-(NCCH₃)]⁺ and [(η⁷-C₇H₇)Mo(CO)(PPh₃)(NC₅H₅)]⁺, respectively. Both (η⁵-C₅-H₄CH₃)Mn(NO)(PPh₃)I and (η⁷-C₇H₇)Mo(CO)(PPh₃)I are oxidized by NOPF₆ to the respective 17-electron cations in acetonitrile at ?78°C but revert to the neutral halide complex at room temperature. This result is supported by electrochemical data.     

Formation and Reactivity of Organo‐Functionalized Tin Selenide Clusters

Reactions of R¹SnCl₃ (R¹=CMe₂CH₂C(O)Me) with (SiMe₃)₂Se yield a series of organo‐functionalized tin selenide clusters, [(SnR¹)₂SeCl₄] ( 1 ), [(SnR¹)₂Se₂Cl₂] ( 2 ), [(SnR¹)₃Se₄Cl] ( 3 ), and [(SnR¹)₄Se₆] ( 4 ), depending on the solvent and ratio of the reactants used. NMR experiments clearly suggest a stepwise formation of 1 through 4 by subsequent condensation steps with the concomitant release of Me₃SiCl. Furthermore, addition of hydrazines to the keto‐functionalized clusters leads to the formation of hydrazone derivatives, [(Sn₂(μ‐R³)(μ‐Se)Cl₄] ( 5 , R³=[CMe₂CH₂CMe(NH)]₂), [(SnR²)₃Se₄Cl] ( 6 , R²=CMe₂CH₂C(NNH₂)Me), [(SnR⁴)₃Se₄][SnCl₃] ( 7 , R⁴=CMe₂CH₂C(NNHPh)Me), [(SnR²)₄Se₆] ( 8 ), and [(SnR⁴)₄Se₆] ( 9 ). Upon treatment of 4 with [Cu(PPh₃)₃Cl] and excess (SiMe₃)₂Se, the cluster fragments to form [(R¹Sn)₂Se₂(CuPPh₃)₂Se₂] ( 10 ), the first discrete Sn/Se/Cu cluster compound reported in the literature. The derivatization reactions indicate fundamental differences between organotin sulfide and organotin selenide chemistry.     

Heteroleptic rhodium complexes containing both the dipyrrin/cyclooctadiene ligands and application of [(η-C8H12)Rh(4-pyrdpm)] in the construction of homo-/hetero-bimetallic complexes

Heteroleptic rhodium(I) complexes with the general formulations [(η⁴-C₈H₁₂)Rh(L)] [η⁴-C₈H₁₂ = 1,5-cyclooctadiene; L = 5-(4-cyanophenyl)dipyrromethene, cydpm; 5-(4-nitrophenyl)dipyrromethene, ndpm; and 5-(4-benzyloxyphenyl)dipyrromethene, bdpm; 5-(4-pyridyl)dipyrromethene, 4-pyrdpm; 5-(3-pyridyl)dipyrromethene, 3-pyrdpm] have been synthesized. The complex [(η⁴-C₈H₁₂)Rh(4-pyrdpm)] have been used as a synthon in the construction of homo-bimetallic complex [(η⁴-C₈H₁₂)Rh(μ-4-pyrdpm)Rh(η⁵-C₅Me₅)Cl₂] and hetero-bimetallic complexes [(η⁴-C₈H₁₂)Rh(μ-4-pyrdpm)Ir(η⁵-C₅Me₅)Cl₂], [(η⁴-C₈H₁₂)Rh(μ-4-pyrdpm)Ru(η⁶-C₁₀H₁₄)Cl₂] and [(η⁴-C₈H₁₂)Rh(μ-4-pyrdpm)Ru(η⁶-C₆H₆)Cl₂]. Resulting complexes have been characterized by elemental analyses and spectral studies. Molecular structures of the representative mononuclear complexes [(η⁴-C₈H₁₂)Rh(ndpm)] and [(η⁴-C₈H₁₂)Rh(4-pyrdpm)] have been authenticated crystallographically.     

Metabolism of Deuterated threo‐Dihydroxy Fatty Acids in Saccharomyces cerevisiae: Enantioselective Formation and Characterization of Hydroxylactones and γ‐Lactones

Biotransformation of (±)‐threo‐7,8‐dihydroxy(7,8‐²H₂)tetradecanoic acids (threo‐(7,8‐²H₂)‐ 3 ) in Saccharomyces cerevisiae afforded 5,6‐dihydroxy(5,6‐²H₂)dodecanoic acids (threo‐(5,6‐²H₂)‐ 4 ), which were converted to (5S,6S)‐6‐hydroxy(5,6‐²H₂)dodecano‐5‐lactone ((5S,6S)‐(5,6‐²H₂)‐ 7 ) with 80% e.e. and (5S,6S)‐5‐hydroxy(5,6‐²H₂)dodecano‐6‐lactone ((5S,6S)‐5,6‐²H₂)‐ 8 ). Further β‐oxidation of threo‐(5,6‐²H₂)‐ 4 yielded 3,4‐dihydroxy(3,4‐²H₂)decanoic acids (threo‐(3,4‐²H₂)‐ 5 ), which were converted to (3R,4R)‐3‐hydroxy(3,4‐²H₂)decano‐4‐lactone ((3R,4R)‐ 9 ) with 44% e.e. and converted to ²H‐labeled decano‐4‐lactones ((4R)‐(3‐²H₁)‐ and (4R)‐(2,3‐²H₂)‐ 6 ) with 96% e.e. These results were confirmed by experiments in which (±)‐threo‐3,4‐dihydroxy(3,4‐²H₂)decanoic acids (threo‐(3,4‐²H₂)‐ 5 ) were incubated with yeast. From incubations of methyl (5S,6S)‐ and (5R,6R)‐5,6‐dihydroxy(5,6‐²H₂)dodecanoates ((5S,6S)‐ and (5R,6R)‐(5,6‐²H₂)‐ 4a ), the (5S,6S)‐enantiomer was identified as the precursor of (4R)‐(3‐²H₁)‐ and (2,3‐²H₂)‐ 6 ). Therefore, (4R)‐ 6 is synthesized from (3S,4S)‐ 5 by an oxidation/keto acid reduction pathway involving hydrogen transfer from C(4) to C(2). In an analogous experiment, methyl (9S,10S)‐9,10‐dihydroxyoctadecanoate ((9S,10S)‐ 10a ) was metabolized to (3S,4S)‐3,4‐dihydroxydodecanoic acid ((3S,4S)‐ 15 ) and converted to (4R)‐dodecano‐4‐lactone ((4R)‐ 18 ).     

[(η5-C5HR4)CuCO] (R = CHMe2) – A Remarkably Stable Copper Carbonyl Complex and its Reaction with P4

Carbonyl(tetraisopropylcyclopentadienyl)copper has been synthesized and isolated and can be stored at room temperature for several days. [(C₅HR₄)Cu(CO)] (R = CHMe₂) has been characterized by ¹H and ¹³C NMR, C,H analysis, mass spectrometry, and IR spectroscopy. Its reaction with white phosphorus yields a mixture of [(C₅HR₄)Cu(η²-P₄)] with edge-opened P₄ coordinated to a Cu^III atom and [(C₅HR₄)Cu(μ,η^2:1-P₄)Cu(C₅HR₄)] with an additional Cu(C₅HR₄) fragment coordinated to one atom of the P₄ ligand (R = CHMe₂).     

Vibrational spectra and structure of complexes containing the hydrogen dinitrate ion

Infrared and Raman spectra of solid hydrogen dinitrate complexes with K⁺, Rb⁺, Cs⁺, (CH₃)₄N⁺, trans-(Co py₄Cl₂)⁺, Ph₄As⁺, Ph₄P⁺, (C₂H₅)₄N⁺ and (C₄H₉)N⁺ have been recorded and analyzed. The assignments were assisted by deuteration and, in the case of the Cs⁺, (CH₃)₄N⁺, and Ph₄As⁺ complexes, by ¹⁵N substitution. Infrared spectra at 50 kbar of the (CH₃)₄N⁺ complex were also recorded. The salient features of the i.r. spectra are the lack of fundamental OH bands above 1800 cm⁻¹ and the appearance of a strong absorption centered at about 600 cm⁻¹, both indicating very strong hydrogen bonding. The i.r. and Raman spectra permit the differentiation between the planar and nonplanar types of the hydrogen dinitrate ion.     

Triple Helicates with Golden Strands: Self‐Assembly of M2Au6 Complexes from Gold(I) Metallaligands and Iron(II), Cobalt(II) or Zinc(II) Cations

Alkynyl gold(I) metallaligands [(AuC≡Cbpyl)₂(μ‐diphosphine)] (bpyl=2,2′‐bipyridin‐5‐yl; diphosphine=Ph₂P(CH₂)_nPPh₂, [n=3 (L^Pr), 4 (L^Bu), 5 (L^Pent), 6 (L^Hex)], dppf (L^Fc), Binap (L^Binap) and Diop (L^Diop)) react with MX₂ (M=Fe, Zn, X=ClO₄; M=Co, X=BF₄) to give triple helicates [M₂(L^R)₃]X₄. These complexes, except those containing the semirigid L^Binap metallaligand, present similar hydrodynamic radii (determined by diffusion NMR spectroscopy measurements) and a similar pattern in the aromatic region of their ¹H NMR spectra, which suggests that in solution they adopt a compact structure where the long and flexible organometallic strands are folded. The diastereoselectivity of the self‐assembly process was studied by using chiral metallaligands, and the absolute configuration of the iron(II) complexes with L^Binap and L^Diop was determined by circular dichroism spectroscopy (CD). Thus, (R)‐L^Binap or (S)‐L^Binap specifically induce the formation of (Δ,Δ)‐[Fe₂((R)‐L^Binap)₃](ClO₄)₄ or (Λ,Λ)‐[Fe₂((S)‐L^Binap)₃](ClO₄)₄, respectively, whereas (R,R)‐ or (S,S)‐L^Diop give mixtures of the ΔΔ‐ and ΛΛ‐diastereomers. The ΔΔ helicate diastereomer is dominant in the reaction of Fe^II with (R,R)‐L^Diop, whereas the ΛΛ isomer predominates in the analogous reaction with (S,S)‐L^Diop. The photophysical properties of the new dinuclear alkynyl complexes and the helicates have been studied. The new metallaligands and the [Zn₂(L^R)₃]⁴⁺ helicates present luminescence from [π→π*] excited states mainly located in the C≡Cbpyl units.     

K2Au(IO3)5 and β‐KAu(IO3)4: Polar Materials with Strong SHG Responses Originating from Synergistic Effect of AuO4 and IO3 Units

Two new polar potassium gold iodates, namely, K₂Au(IO₃)₅ (Cmc2₁) and β‐KAu(IO₃)₄ (C2), have been synthesized and structurally characterized. Both compounds feature zero‐dimensional polar [Au(IO₃)₄]^? units composed of an AuO₄ square‐planar unit coordinated by four IO₃^? ions in a monodentate fashion. In β‐KAu(IO₃)₄, isolated [Au(IO₃)₄]^? ions are separated by K⁺ ions, whereas in K₂Au(IO₃)₅, isolated [Au(IO₃)₄]^? ions and non‐coordinated IO₃^? units are separated by K⁺ ions. Both compounds are thermally stable up to 400 °C and exhibit high transmittance in the NIR region (λ=800–2500 nm) with measured optical band gaps of 2.65 eV for K₂Au(IO₃)₅ and 2.75 eV for β‐KAu(IO₃)₄. Powder second‐harmonic generation measurements by using λ=2.05 μm laser radiation indicate that K₂Au(IO₃)₅ and β‐KAu(IO₃)₄ are both phase‐matchable materials with strong SHG responses of approximately 1.0 and 1.3 times that of KTiOPO₄, respectively. Theoretical calculations based on DFT methods confirm that such strong SHG responses originate from a synergistic effect of the AuO₄ and IO₃ units.     

Synthesis and Characterization of Iron,Cobalt, and Nickel [PNP] Pincer Amido Complexes by N–H Activation

The N–H bond activation product [PNP]‐Fe^I(PMe₃)₂ ( 2 ) was obtained at room temperature by the reaction of diphosphinito [PNP] pincer ligand ((Ph₂P(C₆H₄))₂NH ( 1 )) with Fe(PMe₃)₄. Treatment of 1 with Co(PMe₃)₄, CoCl(PMe₃)₃ and CoMe(PMe₃)₄ afforded the same N–H bond activation product [PNP]‐Co^I(PMe₃)₂ ( 3 ). In order to have a better understanding of the mechanism of formation of 3 , in situ IR and ¹H NMR spectroscopic investigations were conducted.The reaction of 1 with Ni(PMe₃)₄ afforded the ligand replacement complex 4 while a [PNP]‐Ni^IIMe complex 5 was obtained via deprotonation through the reaction of 1 with NiMe₂(PMe₃)₃. The molecular structures of 2 – 4 were confirmed by X‐ray diffraction analysis.     

Synthesis and Reactivity of an End‐Deck cyclo‐P4 Iron Complex

Reduction of the Fe^II complex [(^PhPP₂^Cy)FeCl₂] ( 2 ) generated an electron‐rich and unsaturated Fe⁰ species, which was reacted with white phosphorus. The resulting new complex, [(^PhPP₂^Cy)Fe(η⁴‐P₄)] ( 3 ), is the first iron cyclo‐P₄ complex and the only known stable end‐deck cyclo‐P₄ complex outside Group V. Complex 3 features an Fe^II center, as shown by Mössbauer spectroscopy, associated to a P₄^2? fragment. The distinct reactivity of complex 3 was rationalized by analysis of the molecular orbitals. Reaction of complex 3 with H⁺ afforded the unstable complex [(^PhPP₂^Cy)Fe(η⁴‐P₄)(H)]⁺ ( 4 ), whereas with CuCl and BCF, the complexes [(^PhPP₂^Cy)Fe(η⁴:η¹‐P₄)(μ‐CuCl)]₂ ( 5 ) and [(^PhPP₂^Cy)Fe(η⁴:η¹‐P₄)B(C₆F₅)₃] ( 6 ) were formed.     

Preparation and Reactivity of Mo(NCMe)(η2‐C2Ph2)2(η4‐C4Ph4)

Reaction of Mo(CO)(η²‐C₂Ph₂)₂(η⁴‐C₄Ph₄) and Me₃NO in acetonitrile solvent affords Mo(NCMe)(η²‐C₂Ph₂)₂(η⁴‐C₄Ph₄) 1 . Compound 1 reacts with trimethylphosphine to produce Mo(PMe₃)(η²‐C₂Ph₂)₂(η⁴‐C₄Ph₄) 2 , or reacts with diphenylacetylene to produce (η⁵‐C₅Ph₅)₂Mo 3 and Mo(η²‐O₂CPh)(η⁴‐C₄Ph₄H)(η⁴‐C₄Ph₄) 4 . The molecular structures of 1, 2 and 4 have been determined by an X‐ray diffraction study.     

Neue phosphidoverbrückte Mehrkernkomplexe des Ag und Zn. Die Kristallstrukturen von [Ag3(PPh2)3(PnBu2tBu)3], [Ag4(PPh2)4(PR3)4] (PR3 = PMenPr2, PnPr3), [Ag4(PPh2)4(PEt3)4]n, [Zn4(PPh2)4Cl4(PRR2)2] (PRR′2 = PMenPr2, PnBu3, PEt2Ph), [Zn4(PhPSiMe3)4Cl4(C4H8O)2] und [Zn4(PtBu2)4Cl4]

New Phosphido-bridged Multinuclear Complexes of Ag and Zn. The Crystal Structures of [Ag₃(PPh₂)₃(PⁿBu₂^tBu)₃], [Ag₄(PPh₂)₄(PR₃)₄] (PR₃ = PMeⁿPr₂, PⁿPr₃), [Ag₄(PPh₂)₄(PEt₃)₄]_n, [Zn₄(PPh₂)₄Cl₄(PRR′₂)₂] (PRR′₂ = PMeⁿPr₂, PⁿBu₃, PEt₂Ph), [Zn₄(PhPSiMe₃)₄Cl₄(C₄H₈O)₂] and [Zn₄(P^tBu₂)₄Cl₄] AgCl reacts with Ph₂PSiMe₃ in the presence of tertiary Phosphines (PⁿBu₂^tBu, PMeⁿPr₂, PⁿPr₃ and PEt₃) to form the multinuclear complexes [Ag₃(PPh₂)₃(PⁿBu₂^tBu)₃] 1 , [Ag₄(PPh₂)₄(PR₃)₄] (PR₃ = PMeⁿPr₂ 2 , PⁿPr₃ 3 ) and [Ag₄(PPh₂)₄(PEt₃)₄]_n 4 . In analogy to that ZnCl₂ reacts with Ph₂PSiMe₃ and PRR′₂ to form the multinuclear complexes [Zn₄(PPh₂)₄Cl₄(PRR′₂)₂] (PRR′₂ = PMeⁿPr₂ 5 , PⁿBu₃ 6 , PEt₂Ph 7 ). Further it was possible to obtain the compounds [Zn₄(PhPSiMe₃)₄Cl₄(C₄H₈O)₂] 8 and [Zn₄(P^tBu₂)₄Cl₄] 9 by reaction of ZnCl₂ with PhP(SiMe₃)₂ and ^tBu₂PSiMe₃, respectively. The structures were characterized by X-ray single crystal structure analysis. Crystallographic data see “Inhaltsübersicht”.     

The metathesis reactions of [SNS][SbF6] and [SN][AsF6] with Li[Al(OC(CF3)3)4] in liquid SO2

The small di- and triatomic molecules [SN]⁺ and [SNS]⁺ have shown versatile chemistries and [SNS]⁺ is an important starting reagent for many sulfur-nitrogen radicals. However, their chemistry is limited to the more polar solvents (e.g. SO₂). In this work an attempt is made to increase their solubility in less polar solvents by exchange of the usual [MF₆]⁻ (M = As, Sb) anions by the large and weakly coordinating [Al(OC(CF₃)₃)₄]⁻. As expected the metathesis reactions of [SN][AsF₆] and [SNS][SbF₆] with Li[Al(OC(CF₃)₃)₄] in liquid sulfur dioxide resulted in the formation of the insoluble Li[SbF₆], which is the driving force for these metathesis reactions. The characterization of the compounds by IR and multinuclear NMR revealed that [SNS]⁺ formed a [Al(OC(CF₃)₃)₄]⁻ salt in a clean reaction. A preliminary crystal structure of [SNS][Al(OC(CF₃)₃)₄] is presented. The solubility of [SNS][Al(OC(CF₃)₃)₄] in CH₂Cl₂ is significantly increased with respect to the corresponding [MF₆]⁻ salts, and potentially opens up new areas of [SNS]⁺ chemistry. The reaction of the more reactive [SN]⁺ with Li[Al(OC(CF₃)₃)₄] was less clear. Multinuclear NMR and IR spectra were consistent with the formation of [SN][Al(OC(CF₃)₃)₄], which also showed significant decomposition.     

Synthesis,Structure, and Reactivity of RuII Complexes with Trimethylsilylethinylamidinate Ligands

The mononuclear amidinate complexes [(η⁶‐cymene)‐RuCl( 1a )] ( 2 ) and [(η⁶‐C₆H₆)RuCl( 1b )] ( 3 ), with the trimethylsilyl‐ethinylamidinate ligands [Me₃SiC≡CC(N‐c‐C₆H₁₁)₂]^– ( 1a^– ) and[Me₃SiC≡CC(N‐i‐C₃H₇)₂]^– ( 1b^– ) were synthesized in high yields by salt metathesis. In addition, the related phosphane complexes[(η⁵‐C₅H₅)Ru(PPh₃)( 1b )] ( 4a ) [(η⁵‐C₅Me₅)Ru(PPh₃)( 1b )] ( 4b ), and [(η⁶‐C₆H₆)Ru(PPh₃)( 1b )](BF₄) ( 5 ‐BF₄) were prepared by ligand exchange reactions. Investigations on the removal of the trimethyl‐silyl group using [Bu₄N]F resulted in the isolation of [(η⁶‐C₆H₆)Ru(PPh₃){(N‐i‐C₃H₇)₂CC≡CH}](BF₄) ( 6 ‐BF₄) bearing a terminal alkynyl hydrogen atom, while 2 and 3 revealed to yield intricate reaction mixtures. Compounds 1a / b to 6 ‐BF₄ were characterized by multinuclear NMR (¹H, ¹³C, ³¹P) and IR spectroscopy and elemental analyses, including X‐ray diffraction analysis of 1b , 2 , and 3 .     

Einfache Trithio- und Perthiocarbonatokomplexe mit interessanter Koordinationschemie: [E(CS3)2]2− (E = Sn,Zn, Cd), [E(CS3)3]3− (E = As,Sb, Bi,Co), {Cu(CS3)−}∞ und [Zn(CS4)2]2−

Simple Trithio- and Perthiocarbonato Complexes with Interesting Bond Properties: [E(CS₃)₂]^2? (E = Sn, Zn, Cd), [E(CS₃)₃]^3? (E = As, Sb, Bi, Co), {Cu(CS₃)^?}_∞ and [Zn(CS₄)₂]^2? By reactions of potassium trithiocarbonate ( 1 ) with solutions of zinc(II)- acetylacetonate, cadmium(II)-chloride, tin(II)-chloride, arsenic(III)-sulfide (suspension), antimony(III)-chloride, bismuth(III)-chloride and copper(II)-chloride in dimethyl sulfoxide, as well as of trisodium hexanitrito cobaltate(III) in water, and the precipitation of the complexes with an aqueous solution of tetraphenylphosphonium chloride the compounds (PPh₄)₂[Zn(CS₃)₂] ( 2 ), (PPh₄)₂[Cd(CS₃)₂] ( 3 ), (PPh₄)₂[Sn(CS₃)₂] ( 4 ), (PPh₄)₃[As(CS₃)₃] ( 5 ), (PPh₄)₃[Sb(CS₃)₃] ( 6 ), (PPh₄)₃[Bi(CS₃)₃] ( 7 ), (PPh₄)₃[Co(CS₃)₃] ( 8 ) and (PPh₄)Cu(CS₃) ( 9 ) have been isolated. (PPh₄)₂[Zn(CS₄)₂] · CH₃NO₂ ( 10 ) has been prepared by heating a solution of 2 in nitromethane to 60--70°C in presence of air. The reaction of 1 in dimethyl sulfoxide with an aqueous tetraphenylphosphonium chloride solution in presence of oxygen leads to (PPh₄)₂[C₂S₆] ( 11 ). The compounds have been characterized by spectroscopical studies (IR, Raman, UV/Vis, ¹¹³Cd/⁵⁹Co-NMR), magnetic susceptibility measurements, powder diffractometry, elemental analyses and single crystal X-ray structure analysis ( 4 – 7 , 10 and 11 ). The difficult growing of single crystals has been reported in detail. For crystal data see Inhaltsübersicht.     

The Isotopomeric (Z)- and (E)-2,3-Dimethyl(1,1,1,4,4,4-2H6)but-2-enes: Mechanistic Probes for Stereospecific Epoxidation

By unambiguous methods, (Z)- and (E)-2, 3-dimethyl(1, 1, 1, 4, 4, 4-²H₆)but-2-enes ( 3 ) were synthesized and transformed to the epoxides 4 with 3-chloroperbenzoic acids. Both the isotopomeric olefins and the epoxides are detected separately by ¹H-NMR at 400 MHz. Epoxidation of (Z)- 3 with [Rh^ICl(PPh₃)₃]/cumene hydroperoxide resulted in a 1: 1 mixture of (Z)- and (E)- 4 , while reaction of (Z)- 3 with [Fe^III(tpp)]Cl/PhIO gave only (Z)- 4 (tpp = tetraphenylporphyrin).     

Phosphanstabilisierte organyltellurenylkationen, [RTe(PR′3)]+

Diorganyl ditellurides, RTeTeR (R = CH₃, p-FC₆H₄) are oxidized by nitrosyl salts, NO⁺X⁻ (X⁻ = BF₄⁻, ClO₄⁻) with formation of the respective organyl tellurenyl cations, RTe⁺ which can be stabilized with tri(n-butyl)phosphine as organyl tellurophosphonium cations, [RTe(P(n-C₄H₉)₃)]⁺.     

Synthesis,crystal structure,DNA binding,and oxidative cleavage activity of copper(II)-bipyridyl complexes containing tetraalkylammonium groups

Two copper(II) complexes of disubstituted 2,2′-bipyridine (bpy = 2, 2′-bipyridine) with tetraalkylammonium groups, [Cu(L¹)₂Br](ClO₄)₅·2H₂O (1) and [Cu(L²)₂Br](ClO₄)₅·H₂O (2) (L¹ = [4, 4′-(Et₃NCH₂)₂-bpy]²⁺, L² = [4, 4′-((n-Bu)₃NCH₂)₂-bpy]²⁺), have been synthesized and characterized. X-ray crystallographic study of 1 indicates that Cu(II) is a distorted trigonal bipyramidal or square pyramid. DNA binding of both complexes was studied by UV spectroscopic titration. In the presence of reducing reagents, the cleavage of plasmid pBR322 DNA mediated by both complexes was investigated and efficient oxidative cleavage of DNA was observed. Mechanistic study with reactive oxygen scavengers indicates that hydrogen peroxide and singlet oxygen participate in DNA cleavage.     

Wave mechanics - the first fifty years : edited by W.C. Price,S.S. Chissick and T. Ravensdale,Butterworths, London, 1973, pp. 435, price £12.00

The free NH₃ molecule and the [Zn(NH₃)₄]²⁺ ion were studied by the kinematic coupling approach. The pure effects of this coupling were found to be small, and some modifications had to be introduced in order to get a reasonable force field. The force constants deduced for the skeletal vibrations are comparable with those of a quasi-exact force field. Calculated frequencies for [⁶⁸Zn(NH₃)₄]²⁺ and [⁶⁴Zn(ND₃)₄]²⁺ are reported in addition to those of [⁶⁴Zn(NH₃)₄]²⁺. Mean amplitudes of vibration for [⁶⁴Zn(NH₃)₄]²⁺ are given.     

Studies of η5-cyclichydrocarbon ruthenium(II) complexes containing para-amino-N-(pyrid-2-ylmethylene)phenylamine ligand: molecular structure of [(η5-C5H5)Ru(PPh3)(C5H4NCH=N-C6H4-p-NH2)]BF4

Reaction of [(η⁵-Cp)Ru(PPh₃)₂Cl] (1) with excess para-amino-N-(pyrid-2-ylmethylene)-phenylamine ligand (app) in methanol in the presence of NH₄BF₄ leads to the formation of [η⁵-CpRu(PPh₃)(aap)]BF₄ (6BF₄). Similarly, [(η⁵-ind)Ru(PPh₃)₂(CH₃CN)]BF₄ (4BF₄) and [(η⁵-Cp*)Ru(PPh₃)₂(CH₃CN)]BF₄ (5BF₄) react with app to yield the cationic complexes [(η⁵-ind)Ru(PPh₃)(app)]BF₄ (7BF₄) and [(η⁵-Cp*)Ru(PPh₃)(app)]BF₄ (8BF₄), respectively. The complexes were characterized by analysis and spectroscopic data. The structure of a representative complex (6BF₄) was established by single-crystal X-ray methods.