Musa A. Said

The reactivity of trimethylsilyliminophosphines towards titanium and zirconium halides

Zirconium tetrachloride reacted with C2H4(Ph2PNSiMe3)2-1,2 1 under C–H activation to give the NCN chelate complex ZrCl3{κ3-N,C,N′-C2H3(Ph2PNSiMe3)2}, while the reaction with C5H3N(Ph2PNSiMe3)2-2,6 gave an N-donor adduct. Cp*TiCl3 reacts with trimethylsilyliminophosphines under dehalosilylation in all cases. In contrast to 1, the potentially C–N chelating benzylphosphinimine (4-ButC6H4CH2)Ph2PNSiMe3 undergoes dehalosilylation with TiCl4 in preference to C–H activation, while prolonged reflux with ZrCl4 affords the salt [4-ButC6H4CH2P(Ph)2NHSiMe3]2[Zr2Cl10]. The molecular structures of the latter, ZrCl3{C2H3(Ph2PNSiMe3)2}, C5H3N(Ph2PNTiCl2Cp*)2-2,6, and TiCl2Cp*{NPPh2CH2C6H4But-4} have been determined by X-ray diffraction.

Synthesis and crystal structure of a new pyridinium bromide salt: 4-methyl-1-(3-phen­oxy­prop­yl)pyridinium bromide

The simple synthesis and crystal structure of a new pyridinium bromide salt, 4-methyl-1-(3-phenoxy propyl)pyridinium bromide, are reported. The C–H⋯Br− interactions have an effect on the NMR signals of the ortho- and meta-pyridinium protons.

Titanium and zirconium complexes with sterically hindered aryl-substituted iminophosphoranato ligands

The benzyliminophosphorane 4-ButC6H4CH2P(Ph)2NC6H2Me3-2,4,6 reacted with TiCl4 or ZrCl4 to give the N-donor adducts, MCl4{4-ButC6H4CH2P(Ph)2NC6H2Me3-2,4,6}. Whereas the zirconium compound proved unreactive, solutions of the titanium analogue at 10–20xa0°C slowly underwent C–H activation to give the phosphoranato complex TiCl3{4-ButC6H4CHP(Ph)2NC6H2Me3-2,4,6}. The trichloro complexes MCl3{4-ButC6H4CHP(Ph)2NC6H2Me3-2,4,6} were also accessible from Li[4-ButC6H4CHP(Ph)2NC6H2Me3-2,4,6] and MCl4 (Mxa0=xa0Ti or Zr). The reaction of 4-ButC6H4CH2P(Ph)2NC6H2Me3-2,4,6 with Zr(NMe2)4 in refluxing toluene led to Zr(NMe2)3{4-ButC6H4CHP(Ph)2NC6H2Me3-2,4,6}. The compound is fluxional in solution. Treatment with an excess of Me3SiCl led to silylation of the ligand to give ZrCl4{4-ButC6H4CH(SiMe3)P(Ph)2NC6H2Me3-2,4,6}. The structures of 4-ButC6H4CH2P(Ph)2NC6H2Me3-2,4,6 and Zr(NMe2)3{4-ButC6H4CHP(Ph)2NC6H2Me3-2,4,6} were determined by X-ray diffraction.

Synthesis and crystal structure of bis(furan-2-ylmethanaminium)-catena-[bis(μ2-phthalato-κ2O:O′)cobalt(II)], C26H24CoN2O10

Abstract C26H24CoN2O10, monoclinic, F2/d (equiv. to no. 15), a = 23.7125(7) Å, b = 10.7325(4) Å, c = 39.5740(15) Å, β = 90.324(3)°, V = 10071.2(6) Å3, Z = 16, Rgt(F) = 0.0514, wRref(F2) = 0.1048, T = 140(1) K.

Crystal structure of 1-heptylpyridazin-1-ium iodide, C11H19N2I

Abstract C11H19N2I, triclinic, P1̄ (no. 2), a = 5.7074(3) Å, b = 8.9811(5) Å, c = 14.4312(8) Å, α = 100.989(4)°, β = 94.768(4)°, γ = 97.327(4)°, V = 715.83(7) Å3, Z = 2, Rgt(F) = 0.0386, wRref(F2) = 0.0913, T = 295(2) K.

Antimicrobial and antioxidant studies of novel mixed-metal complexes of benzoyl-aminoethanoic acid-nicotinamide: Microwave-assisted green synthesis, spectroscopic characterization and molecular modeling

Purpose : To enhance the antimicrobial and antioxidant activities ofxa0 benzoylaminoethanoic acid (BAEA) and nicotinamide (NA). Methods: Complexes of benzoylaminoethanoic acid (BAEA) and nicotinamide (NA)xa0 were prepared in a microwave oven. These metal complexes were evaluated byxa0 various techniques including 1H and 13C nuclear magnetic resonance spectrometry (NMR), infrared spectrometry (IR), ultraviolet-visible spectrometry (UV), mass spectrometry (MS), thermogravemetric analysis (TGA) and molar conductivity. The synthesized compounds were screened for both antibacterial and antifungalxa0 activities using disc diffusion technique. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging method was used to assess the antioxidant activity of the complexes. Results: Based on the results of spectroscopic techniques and physicochemicalxa0 characterization, these complexes have been named [Cu(NA)2(BAEA)Cl2],xa0 [Co(NA)2(BAEA)Cl2], and [Ni(NA)2](BAEA)Cl2], respectively. A model structure with a distorted octahedron was proposed based on the outcome of the magnetic, analytical and spectral analyses. Synthesized metal complexes were more effective and efficient than nicotinamide and benzoylaminoethanoic acid. Conclusion: Efficiently synthesized mixed metal complexes were prepared using a simple, eco-friendly rapid green chemistry methodology. The newly synthesized complexes have significant antimicrobial activities against the test bacterial and fungal strains. Keywords: Antimicrobial agents, Antioxidant, Nicotinamide, Benzoylaminoethanoic acid, Mixed ligand complexes, Eco-friendly

Crystal structure of (E)-1-{2-[(5,5-dimethyl-1,3,2-dioxaphosphinan-2-yl)-oxy]naphthalen-1-yl}-N-(4-fluoro-phen-yl)methanimine.

In the title compound, the six-membered ring which includes the P atom has a chair conformation and three O atoms are bonded in a trigonal–pyramidal manner to the P atom. In the crystal, molecules are linked via C—H⋯π interactions, forming slabs lying parallel to (10).

A new route for the synthesis of phosphate esters: 2,2'-[benzene-1,2-diylbis(­oxy)]bis­(5,5-dimethyl-1,3,2-dioxaphosphinane) 2,2'-dioxide

Podand-type ligands are an interesting class of acyclic ligands which can form host-guest complexes with many transition metals and can undergo conformational changes. Organic phosphates are components of many biological molecules. A new route for the synthesis of phosphate esters with a retained six-membered ring has been used to prepare 2,2-[benzene-1,2-diylbis(oxy)]bis(5,5-dimethyl-1,3,2-dioxaphosphinane) 2,2-dioxide, C6H4{O[cyclo-P(O)OCH2CMe2CH2O]}2 or C16H24O8P2, (1), 2-[(2-hydroxybiphenyl-2-yl)oxy]-5,5-dimethyl-1,3,2-dioxaphosphinane 2-oxide, [cyclo-P(O)OCH2CMe2CH2O](2,2-OC6H4-C6H4OH), (2), and oxybis(5,5-dimethyl-1,3,2-dioxaphosphinane) 2,2-dioxide, O[cyclo-P(O)OCH2CMe2CH2O]2, (3). Compound (1) is novel, whereas the results for compounds (2) and (3) have been reported previously, but we record here our results for compound (3), which we find are more precise and accurate than those currently reported in the literature. In (1), two cyclo-P(O)OCH2CMe2CH2O groups are linked through a catechol group. The conformations about the two catechol O atoms are quite different, viz. one C-C-O-P torsion angle is -169.11 (11)° and indicates a trans arrangement, whereas the other C-C-O-P torsion angle is 92.48 (16)°, showing a gauche conformation. Both six-membered POCCCO rings have good chair-shape conformations. In both the trans and gauche conformations, the catechol O atoms are in the axial sites and the short P=O bonds are equatorially bound.

Synthesis and catalytic activity of binuclear titanium imido complexes

Treatment of the N-P ligand ArPN(SiMe3)2 with TiCl4 affords the imido-bridged binuclear titanium complex [TiCl2(THF)(micro-NArP)]2 (ArP = m-C6H4PR2) which reacts with Ni(0) or Pd(ii) to give heterotrinuclear compounds, while activation with methylaluminoxane generates a new type of imido-based ethene polymerisation catalyst that is tolerant of -PR2 functional groups.