D. Andrew Knight

Surface modification using phosphonic acids and esters.

Cleḿence Queffeĺec,† Marc Petit,†,‡ Pascal Janvier,† D. Andrew Knight, and Bruno Bujoli*,† †LUNAM Universite,́ CNRS, UMR 6230, Chimie Et Interdisciplinarite:́ Synthes̀e Analyse Modeĺisation (CEISAM), UFR Sciences et Techniques, 2, rue de la Houssinier̀e, BP 92208, 44322 NANTES Cedex 3, France ‡Universite ́ Pierre et Marie Curie (UPMC), CNRS, UMR7201, Institut Parisien De Chimie Molećulaire (IPCM), 4 place Jussieu, 75252 Paris Cedex 05, France Chemistry Department, Florida Institute of Technology, 150 West University Boulevard, Melbourne, Florida 32901, United States

Cobalt Complexes as Antiviral and Antibacterial Agents

Metal ion complexes are playing an increasing role in the development of antimicrobials. We review here the antimicrobial properties of cobalt coordination complexes in oxidation state 3+. In addition to reviewing the cobalt complexes containing polydentate donor ligands, we also focus on the antimicrobial activity of the homoleptic [Co(NH3)6]3+ ion.

Oxidation of Trimethoprim by Ferrate(VI): Kinetics, Products, and Antibacterial Activity

Kinetics, stoichiometry, and products of the oxidation of trimethoprim (TMP), one of the most commonly detected antibacterial agents in surface waters and municipal wastewaters, by ferrate(VI) (Fe(VI)) were determined. The pH dependent second-order rate constants of the reactions of Fe(VI) with TMP were examined using acid-base properties of Fe(VI) and TMP. The kinetics of reactions of diaminopyrimidine (DAP) and trimethoxytoluene (TMT) with Fe(VI) were also determined to understand the reactivity of Fe(VI) with TMP. Oxidation products of the reactions of Fe(VI) with TMP and DAP were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Reaction pathways of oxidation of TMP by Fe(VI) are proposed to demonstrate the cleavage of the TMP molecule to ultimately result in 3,4,5,-trimethoxybenzaldehyde and 2,4-dinitropyrimidine as among the final identified products. The oxidized products mixture exhibited no antibacterial activity against E. coli after complete consumption of TMP. Removal of TMP in the secondary effluent by Fe(VI) was achieved.

Rhodium catalyzed allylic isomerization in water

Abstract A water-soluble rhodium bis-phosphine complex was used for the aqueous phase isomerization of three allylic alcohols. For the isomerization of cinnamyl alcohol, the catalyst was recycled with slight loss of activity and the optimum phosphine:rhodium ratio was found to be 6:1.

The first examples of an aryl ring substituted by both phosphine and phosphonate moieties: synthesis and characterization of the new highly water-soluble phosphine ligand Na2[Ph2P(C6H4-p-PO3)]·1.5H2O and platinum(II) complexes

The highly water-soluble phosphine Na2[TPPMP]·1.5H2O (TPPMP =‘triphenylphosphine monophosphonate’) represents the first example of a compound containing an aryl ring which is substituted by both phosphine and anionic phosphonate moieties; the preparation and spectroscopic characterisation of the platinum(II) complexes (trans-and cis-Na4[PtCl2(TPPMP)2]·3H2O is described.

NEW CHIRAL PHOSPHINE-PHOSPHONITES DERIVED FROM (2R, 3R)-DIMETHYL TARTRATE,(S)-BINAPHTHOL AND (1R, 2S)-EPHEDRINE

Abstract The reaction of 2-lithiophenyldiphenylphosphine with phosphorus trichloride afforded the new unsymmetric phosphine, dichloro(2-diphenylphosphinophenyl)phosphine (4). Condensation of 4 with (a) (2R,3R)-dimethyl tartrate or (b) (S)-binaphthol in the presence of triethylamine gave new chiral phosphine-phosphonite ligands, (2R,3R)-[2-(2′-(diphenylphosphino)phenyl)-4,5-bis(carbomethoxy)-1,3,2-dioxaphospholane] ((2R,3R)-5) and (S)-[2-(diphenylphosphino)benzene][1,1′-binaphthalen-2,2′-diyl]phosphonite] ((S)-6). The analogous reaction of 4 with (1R,2S)-ephedrine using N-methylmorpholine as the base, gave [2-(2′-(diphenylphosphino)phenyl)-3,4-dimethyl-5-phenyl-1,3,2-oxazaphospholidine] (7) as a 95:5 mixture of diastereoisomers.

Accelerating the initial rate of hydrolysis of methyl parathion with laser excitation using monolayer protected 10 nm Au nanoparticles capped with a Cu(bpy) catalyst

Using a low power green laser, we have demonstrated a rate acceleration of ~2-fold for the hydrolysis of methyl parathion by irradiating the plasmon absorption band of Au nanoparticles capped with a Cu(bpy) catalyst.

Ethoxycarbonyl-, cyano- and methoxy-methyl complexes of nickel(II) and their carbonylation reactions

The oxidative addition of ClCH2CO2Et, ClCH2CN and BrCH2OMe to [Ni(cod)2](cod = cycloocta-1,5-diene), in the presence of 2 equivalents of PMe3, affords the β-functionalized nickel(II) methyl derivatives trans-[Ni(CH2R)X(PMe3)2](R = CO2Et, X = Cl 1; R = CN, X = Cl 2; R = OMe, X = Br 3). The interaction of these complexes with carbon monoxide has been studied. The methoxymethyl derivative 3 forms a stable acyl of composition trans-[Ni{C(O)CH2OMe}Br(PMe3)2]7, but for the ethoxycarbonylmethyl complex 1 the corresponding acyl 8 forms reversibly and, although stable as a solid, only exists in solution under an atmosphere of carbon monoxide. No stable acyl has been observed from the reaction of 2 with CO; only decomposition occurs. Stable 18-electron alkyl and acyl cyclopentadienyl derivatives of composition [Ni(CH2R)(η-C5H5)(PMe3)](R = CO2Et 4; CN 5, or OMe 6) and [Ni{C(O)CH2R}(η-C5H5)(PMe3)](R = OMe 9 or CO2Et 10) are easily obtained upon reaction of the above 16-electron complexes with Na(C5H5). The new compounds have been fully characterized by analytical and spectroscopic (IR and 1H, 13C and 31P NMR) methods.

An organometallic sol–gel route to layered zinc phenylphosphonate and encapsulation studies with η6-(C6H6)Cr(CO)3

Phenylphosphonic acid reacts with diethylzinc in toluene/THF to give a white gel. The gel was dried in air at room temperature for 8 h to give the layered compound [ZnC6H5PO3]·H2O (1). This process represents a convenient non-aqueous organometallic sol–gel route to a layered metal phosphonate material. Zinc phenylphosphonate synthesized using the sol–gel method is identical to that prepared using the conventional aqueous precipitation technique as determined by IR spectroscopy, thermal gravimetric analysis and powder X-ray diffraction. η6-(C6H6)Cr(CO)3 can be incorporated into the gel during the condensation reaction.

Camphor-derived β-ketophosphine complexes of palladium(II) and platinum(II)

Reaction of chlorodiphenylphosphine with the lithium enolate derived from the treatment of (1R)-endo-(+)-3-bromocamphor (camphor = bornan-2-one) with n-butyl-lithium gives (1R)-endo-(+)-3-diphenylphosphinocamphor (L). This new chiral β-ketophosphine ligand reacts with [Pd(CH3CN)2Cl2] to give trans-[PdL2Cl2], and in a 1 : 1 ratio to give the chloro-bridged dimer [{PdL(µ-Cl)Cl}2]. The ligand L reacts with [Pt(CH3CN)2Cl2] to give trans-[PtL2Cl2]. Thermolysis of [ML2Cl2](M = Pd or Pt) in refluxing xylene gives mixed phosphine–phosphinite complexes with mutually cis chlorides. The complex [PdL2Cl2] reacts with an excess of AgBF4 to give [PdL2][BF4]2 which is shown to contain bidentate binding through the phosphorus and keto-oxygen atoms. All complexes are characterised by i.r., 1H and 31P n.m.r. spectroscopy.