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A study of the oxidation of nitrite in aqueous solution and in H2O/CH3CN is conducted by a cationic trans-dioxoruthenium(VI) complex, trans-[[[Ru.sup.VI](L)(O)2].sup.2} (L= 1,12-dimethyl-3,4,9,10-dibenzo-1,12-diaza-5,8-dioxacyclopentadecane). The coordinated macrocyclic ligand L is resistant to oxidative degradation and ligand exchange.

The oxidation of a series of H(sub 2)Q-X compounds by trans-[Ru(super VI)(tmc)(O)(sub 2)](super 2+) in aqueous solutions and in CH(sub 3)CN, and by trans-[Ru(super IV) (tmc)(O)(CH(sub 3)CN)](super 2+) in CH(Sub 3)CN, occurs by initial, rate-limiting H-atom abstraction. The Marcus cross relation appears to hold well for these H-atom transfer reactions.

Research has been conducted on the pig purple acid phosphatase (uteroferrin). The involvement of Fe (super)II, Mn (super)II and Zn (super)II in naturally occutting forms of these phosphatases has been investigated and the details are reported.

Research is presented describing the use of oligopeptides to discover the radical cations of its molecules.

Research has been conducted on the osmium(VI) nitrido complexes that contain Schiff base ligands. The results of their synthesis in the presence of 2,6-dimethylpyridine are described.

The article explains the synthesis and the characterization of trans-[[[Os.sup.III](salen)[(CN).sub.2]].sup.-]. The complex is shown to be widely used as a new paramagnetic building block for the construction of molecule-based magnetic materials.

The oxidation of alkanes by various peroxides is efficiently catalyzed by [[[Os.sup.VI](N)[Cl.sub.4]].sup.-]/Lewis acid in C[H.sub.2][Cl.sub.2]/C[H.sub.3]C[O.sub.2]H to give alcohols and ketones. The new mechanism has involved initial O-atom transfer from ROOH to [[[Os.sup.VI](N)[Cl.sub.4]].sup.-]/Lewis acid to generate [[[Os.sup.VIII](N)(O)[Cl.sub.4]].sup.-]/Lewis acid, which has oxidized alkanes via H-atom abstraction.

A study was conducted to examine the kinetics and mechanisms of the oxidation iodide and bromide anion by trans-[[[Ru.sup.VI]([N.sub.2][O.sub.2])[(O).sub.2]].sup.2+] in aqueous solutions. The mechanism was observed to involve initial oxygen atom transfer from trans-[[[Ru.sup.VI]([N.sub.2][O.sub.2])[(O).sub.2]].sup.2+] to bromide to give trans-[[[Ru.sup.IV]([N.sub.2][O.sub.2])(O)(OBr)].sup.+] followed by parallel aquation and oxidation of bromide and both reactions are acid-catalyzed.

The article presents a new approach, which utilizes the N...N coupling of different (salen)ruthenium(VI) nitrides for the general synthesis of the (salen)ruthenium(III) complexes. These ruthenium salen complexes are shown to be widely used as the catalysts in different organic transformations.

The kinetics of the oxidation of trans-[[[Ru.sup.IV](tmc)(O)(solv)].sup.2+] to trans-[[[Ru.sup.VI](tmc)[(O).sub.2]].sup.2+] (tmc = 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane, a tetradentate macrocyclic tertiary amine ligand, solv = [H.sub.2]O or C[H.sub.3]CN) by Mn[O.sub.4.sup.-] is analyzed in aqueous solutions and in acetonitrile. Large deuterium and oxygen isotope effects are seen for reactions in water.

The design and synthesis of a novel tridentate C,N,[N.sub.pyrazolyl] cyclometalating ligand, 2-phenyl-6-(1H-pyrazol-3-yl)-pyridine (HL) is described. The pH dependence of luminescent properties of this system is attributed to the protonation/deprotonation of the 1-pyrazolyl-NH on the C,N,[N.sub.pyrazolyl] cyclometalated Pt(II) system.

(Salen)manganese (V) nitro species are activated by electrophiles such as trifluoroacetic anhydride (TFAA) or trifluoroacetic acid (TFA) to produce [N.sub.2]. Mechanistic studies suggest that the manganese(V) nitrido species first react with TFAA or TFA to produce an imido species, which then undergoes N...N coupling.

The kinetics and mechanistic study of the BF3-activated oxidation of alkanes and arylalkanes by KMnO4 are reported. The results have demonstrated that BF3 forms an adduct with MnO(sub 4)(super -) in CH3CN that oxidizes hydrocarbons at rates over 7 orders of magnitude faster than that by MnO(sub 4)(super -) alone.

The synthesis, structures, and magnetic properties of four cyano-bridged M(super II)Ru(super III)(sub 2) compounds prepared from the paramagnetic Ru(super III) building blocks, trans-[Ru(salen)(CN)2](super -) and trans-[Ru(acac)2(CN)2](super -) are described. The use of trans-[Ru(acac)2(CN)2](super -) and trans-[Ru(salen)-(CN)2](super -) as building blocks has produced a number of trinuclear, 2-D, and 3-D M(super II)Ru2(super III) compounds.

The synthesis and reactivities of a highly electrophillic, cationic ruthenium(VI) nitrido complex containing the cyclohexylene-bridged salen ligand, N,N'-bis(salicylidene) omicron-cyclohexyldiamine dianion is reported. The result indicates that the steric and electronic tunabality of slaen would be utilized to probe the mechanism of the aziridination reaction and reduction of Ru(sub IV) (AZ(-H) to RuIII(AZ).

A study of remarkable activating effects of FeCl3 on the oxidation of alkanes by the nitridoosmate(VIII) ion, [Os(N)(O)3](super -), is reported. Findings show that methane monooxygenase (MMO), which catalyzes the oxidation of methane to methanol by dioxygen, is believed to involve a bis(mu-oxo)-diiron(IV) species as the active oxidant.

Research has been conducted on alkylaromatic compounds. The study of the oxidation of these compounds in CH (sub)3 CN by trans-dioxoruthenium(VI) complex is presented.

Research has been conducted on three-dimensional malonate bridged networks. The authors describe the synthesis of these networks in H (sub)2 O -N,N-dimethylformamide solution.

Results suggest that oxidation of the phenolic compounds in water and acetonitrile by a cationic trans-dioxoruthenium(VI) complex occurs mostly through a hydrogen atom abstraction mechanism although an alternative mechanism is plausible. Data show that the correlation between rate constant and bond dissociation enthalpies is more consistent with the former mechanism.

The catalytic activities of the ruthenium(II) complex cis-[Ru(6,6-Cl2bpy)2(OH2)2](CF3SO3)2 (1) in organic oxidations using tert-butyl hydroperoxide (TBHP) as terminal oxidant are presented. Mechanistic studies showing a large primary kinetic isotope effect suggest a hydrogen-atom abstraction pathway for these oxidations. Data from these studies reveal that oxidations of saturated hydrocarbons by complex 2, the '1+TBHP' protocol and Gif-type systems are not similar from a mechanistic viewpoint.

The research shows that the nucleophilic addition to salophen and salen coordinated to a high-valent metal center could be very facile. The reason for the low turnovers of most (salen)-mangnese epoxidation catalysts could be due to attack at the (salen) manganese (V) oxo intermediates by nucleophiles in the reaction mixture, hence suitable modifications of the salen ligand to inhibit attack at the imine carbons could increase the lifetime of the epoxidation catalysts.

A series of cyano-bridged LnIIIRuIII2 coordination polymers, Ph4P{Ln(NO3)2[Ru(acac)2(CN)2]2} [Ln = Tb (1), Dy (2), Er (3), Gd (4); Hacac = acetylacetone] have been synthesized by the reaction of Ln(NO3)3 with trans-Ph4P[Ru- (acac)2(CN)2] in methanol. X-ray crystallographic determination reveals that these compounds are isostructural and have a wavy (4,4) layer structure with the Ln3+ ions bridged by trans-[Ru(acac)2(CN)2]. Magnetic studies shows that the magnetic coupling between the Ln(lll) and Ru(III) ions through the cyano bridges in 1-4 is negligibly weak. [ABSTRACT FROM AUTHOR]

Hydrogen-bridged dinuclear ruthenium carbene complexes supported by salen have been prepared and found to be active catalysts for the cyclopropanation of alkenes; electrochemical and theoretical studies suggest the existence of electronic communication between the Ru centers. [ABSTRACT FROM AUTHOR]

Examines the results of a study which used electrospray tandem mass spectrometry to examine nitrido and imido complexes. How the ionic complexes were delivered to the gas phase; Ionic complexes which were examined; Evidence showing that Os=bond is stronger than the Os=O bond.

The oxidation of alkanes by various peroxides (tBuOOH, H2O2, PhCH2C(CH3)2OOH) is efficiently catalyzed by [OsVI(N)Cl4]-/Lewis acid (FeCI3 or Sc(OTf)3) in CH2CI2/CH3CO2H to give alcohols and ketones. Oxidations occur rapidly at ambient conditions, and excellent yields and turnover numbers of over 7500 and 1000 can be achieved in the oxidation of cyclohexane with tBUOOH and H2O2, respectively. In particular, this catalytic system can utilize PhCH2C(CH3)2OOH (MPPH) efficiently as the terminal oxidant; good yields of cyclohexanol and cyclohexanone (>70%) and MPPOH (>90%) are obtained in the oxidation of cyclohexane. This suggests that the mechanism does not involve alkoxy radicals derived from homolytic cleavage of MPPH but is consistent with heterolytic cleavage of MPPH to produce a metal-based active intermediate. The following evidence also shows that no free alkyl radicals are produced in the catalytic oxidation of alkanes: (1) The product yields and distributions are only slightly affected by the presence of O2. (2) Addition of BrCCI3 does not affect the yields of cyclohexanol and cyclohexanone in the oxidation of cyclohexane. (3) A complete retention of stereochemistry occurs in the hydroxylation of cis- and trans-1,2-dimethylcyclohexane. The proposed mechanism involves initial O-atom transfer from ROOH to [OsVI(N)Cl4]-/Lewis acid to generate [OsVIII(N)(O)Cl4]-/Lewis acid, which then oxidizes alkanes via H-atom abstraction. [ABSTRACT FROM AUTHOR]

Highlights a study which focused on the conditions under which argentinated oligopeptides fragment yeild abundant argentinated product ions. What the Ag+ ion is used for; Details on the [b2 - H + Ag]= product ion of argentinated oligopeptides; Method used for the study; Results the study.

The kinetics of the oxidation of trans-[RuIV(tmc)(O)(soIv)]2+ to trans-[RuVI(tmc)(O)2]2+ (tmc is 1,4,8,-11-tetramethyl-1,4,8,11 -tetraazacyclotetradecane, a tetradentate macrocyclic tertiary amine ligand; solv = H2O or CH3CN) by MnO4- have been studied in aqueous solutions and in acetonitrile. In aqueous solutions the rate law is -d[MnO4]/dt= kH2O[RuIV][MnO4-] = (kx + (Ky)/(Ka)[H+])[RuIV][MnO4-], kx = (1.49 ± 0.09) × 101 M-1s-1 and ky = (5.72 ± 0.29) × 104 M-1 s-1 at 298.0 K and I = 0.1 M. The terms kx and ky are proposed to be the rate constants for the oxidation of RUIV by MnO4 and HMnO4, respectively, and Ka is the acid dissociation constant of HMnO4. At [H+] = I = 0.1 M, ΔH‡ and ΔS‡ are (9.6 ± 0.6) kcal mol-1 and -(18 ± 2) cal mol-1 K-1, respectively. The reaction is much slower in D2O, and the deuterium isotope effects are kx/kxD = 3.5 ± 0.1 and ky/kyD = 5.0 ± 0.3. The reaction is also noticeably slower in H218O, and the oxygen isotope effect is kH216o/kH218o = 1.30 ± 0.07. 18O-labeled studies indicate that the oxygen atom gained by RuIV comes from water and not from KMnO4. These results are consistent with a mechanism that involves initial rate-limiting hydrogen-atom abstraction by MnO4- from coordinated water on RuIV. In acetonitrile the rate law is -d[MnO4-]/dt= kCH3CN[RuIV][MnO4-], kCH3CN = 1.95 ± 0.08 M-1 s-1 at 298.0 K and I = 0.1 M. ΔH‡ and ΔS‡ are (12.0 ± 0.3) kcal mol-1 and -(17 ± 1) cal mol-1 K-1, respectively. 18O- labeled studies show that in this case the oxygen atom gained by RuIV comes from MnO4-1, consistent with an oxygen-atom transfer mechanism. [ABSTRACT FROM AUTHOR]