Browsing by Author "Fanna, DJ"

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    3d transition metal complexes with a julolidine–quinoline based ligand: structures, spectroscopy and optical properties
    (Royal Society of Chemistry, 2015-12-07) Fanna, DJ; Zhang, YJ; Li, L; Karatchevtseva, I; Shepherd, ND; Azim, A; Price, JR; Aldrich-Wright, JR; Reynolds, JK; Li, F
    A Schiff base type ligand with the combination of the julolidine and the quinoline groups has been reported as a potential chemosensor in detecting the cobalt(II) ion among other heavy and transition metal ions in solution. However, no crystal structure of such a ligand with any metal ions has been reported. In this work, its complexation with 3d transition metal ions (Mn(II), Co(II), Ni(II), Cu(II) and Zn(II)) has been investigated with five new complexes being synthesised, and spectroscopically and structurally characterised. [Mn2L2(CH3OH)2(CH3COO)2]•CH3OH (1) {HL (C22H21N3O) = ((E)-9-((quinolin-8-ylimino)methyl)-1,2,3,5,6,7-hexahydropyrido[3,2,1-ij]quinolin-8-ol)} shows a dinuclear structure with two Mn : L : acetate (1 : 1 : 1) units bridged by two methanol molecules. [CoL2(NO3)]•CH3OH•H2O (2) and [NiL2]•H2O (3) exhibit mononuclear structures with a Co : L or Ni : L ratio of 1 : 2. [CuL(CH3COO)]•1/3CH3OH (4) demonstrates a mononuclear structure and the Cu ion has a square planar coordination polyhedron with a L ligand and a highly non-symmetrical acetate anion. [Zn2L2(CH3COO)2]•CH3OH (5) has two types of dinuclear units, both with two ZnL units bridged by two acetate anions but in three different bridging coordination modes. Their vibrational modes, absorption and photoluminescence properties have also been investigated. © 2016 The Partner Organisations
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    Dinuclear complexes of europium(III) and gadolinium(III) ions with a julolidine–quinoline-based tridentate ligand
    (Taylor and Francis Online, 2016-06-13) Fanna, DJ; Zhang, YJ; Salih, A; Reynolds, JK; Li, F
    The reaction of europium(III) or gadolinium(III) acetates with a Schiff base ligand {HL (C22H21N3O) = ((E)-9-((quinolin-8-ylimino)methyl)-1,2,3,5,6,7-hexahydropyrido[3,2,1-ij]quinolin-8-ol)} in methanol affords two dinuclear complexes which have been characterized by powder X-ray diffraction, Raman spectroscopy, scanning electron microscope–electron dispersive spectroscopy, absorption and emission spectroscopies as well as single-crystal X-ray diffraction. [Eu2L2(CH3COO)4(CH3OH)2] (1) and [Gd2L2(CH3COO)4(CH3OH)2] (2) are iso-structures, each consisting of two M : L : CH3COO : CH3OH (1 : 1 : 1 : 1) units bridged by two acetate anions with the metal center in a distorted capped square antiprismatic coordination geometry. Their vibration modes, electronic structures, and photoluminescent properties are reported. © 2016 Taylor & Francis Group
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    Dioxo-vanadium(V), oxo-rhenium(V) and dioxo-uranium(VI) complexes with a tridentate Schiff base ligand
    (Royal Society of Chemistry, 2016-08-03) Zhang, YJ; Fanna, DJ; Shepherd, ND; Karatchevtseva, I; Lu, KT; Kong, L; Price, JR
    The complexation of a julolidine–quinoline based tridentate ligand with three oxo-metal ions, dioxo-vanadium(V), oxo-rhenium(V) and dioxo-uranium(VI), has been investigated with four new complexes being synthesised and structurally characterised. (VO2L)·2/3H2O (1) {HL (C22H21N3O) = ((E)-9-((quinolin-8-ylimino)methyl)-1,2,3,5,6,7-hexahydropyrido[3,2,1-ij]quinolin-8-ol)} has a VO2L neutral mononuclear structure with a five-fold coordinated vanadium metal centre in a distorted trigonal bipyramidal geometry. (ReOL2)2(ReCl6)·7DMF (2) [DMF = dimethylformamide] exhibits a mixed valent rhenium complex with a (ReOL2)+ cationic unit in a distorted octahedral metal coordination geometry, charge balanced with (ReCl6)2− anions. [(UO2)L(H2O)2]2·2(NO3)·HL·4H2O (3) and [(UO2)L(CH3OH)2](NO3)·CH3OH (4) both have (UO2L)+ cationic mononuclear structures with either coordinated water or methanol molecules in pentagonal bipyramidal coordination geometries for the uranium metal centres. Intra-/intermolecular interactions including hydrogen bonding and π–π interactions are common and have been discussed. In addition, optical absorption and photoluminescence properties have been investigated. © 2016 The Royal Society of Chemistry
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    Lanthanide mononuclear complexes with a tridentate Schiff base ligand: structures, spectroscopies and properties
    (Elsevier, 2019-03-21) Zhang, YJ; Avdeev, M; Price, JR; Karatchevtseva, I; Fanna, DJ; Chironi, I; Lu, KT
    A series of six lanthanide mononuclear complexes with a julolidine-quinoline based tridentate Schiff base ligand have been synthesized and structurally characterized. The complexes [NdL2(CH3OH)(NO3)]·CH3OH (1) and [LnL2(NO3)] [Ln = Eu (2), Gd (3), Dy (4), Ho (5), Lu (6)] {HL (C22H21N3O) = ((E)-9-((quinolin-8-ylimino)methyl)-1,2,3,5,6,7-hexahydropyrido[3,2,1-ij]quinolin-8-ol)} all have mononuclear structures with a metal to ligand ratio of 1:2. The Ln(III) ions are nine-fold coordinated by two tridentate Schiff base ligands and a bidentate nitrate anion except for complex 1 in which Nd(III) ion is ten-fold coordinated with an additional MeOH molecule. The coordination of a bidentate nitrate anion makes chirality to the complexes with equal enantiomers presence in the solid state. Lanthanide contraction has been observed with the average Ln–O/Ln–N bond lengths decreasing along the lanthanide series. Vibrational modes (2–5), electronic structures (1–3), thermal stability (2) and magnetic properties (3) have been further investigated and reported. Crown Copyright © 2019 Published by Elsevier Ltd.
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    A large spin-crossover [Fe4L4]8+ tetrahedral cage
    (Royal Society of Chemistry, 2015-05-20) Li, L; Saigo, N; Zhang, YJ; Fanna, DJ; Shepherd, ND; Clegg, JK; Zheng, RK; Hayami, S; Lindoy, LF; Aldrich-Wright, JR; Li, CG; Reynolds, JK; Harman, DG; Li, F
    A large discrete face-capped tetranuclear iron(II) cage, [Fe4L4](BF4)8·n(solvent), was synthesised via metal-ion directed self-assembly. The cage is formed from a rigid tritopic ligand that incorporates chelating imidazole-imine functional groups. The cage displays temperature induced spin-crossover and LIESST effects and is amongst the largest iron(II) tetrahedral cages with such properties reported. The synthesis, structure and magnetic properties of this new metallo-cage are presented. © 2015 The Royal Society of Chemistry
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    Solvothermal synthesis of uranium(VI) phases with aromatic carboxylate ligands: a dinuclear complex with 4-hydroxybenzoic acid and a 3D framework with terephthalic acid
    (Elsevier B.V., 2016-02-01) Zhang, YJ; Karatchevtseva, I; Bhadbhade, MM; Tran, TT; Aharonovich, I; Fanna, DJ; Shepherd, ND; Lu, KT; Li, F; Lumpkin, GR
    With the coordination of dimethylformamide (DMF), two new uranium(VI) complexes with either 4-hydroxybenzoic acid (H2phb) or terephthalic acid (H2tph) have been synthesized under solvothermal conditions and structurally characterized. [(UO2)2(Hphb)2(phb)(DMF)(H2O)3]·4H2O (1) has a dinuclear structure constructed with both pentagonal and hexagonal bipyramidal uranium polyhedra linked through a µ2-bridging ligand via both chelating carboxylate arm and alcohol oxygen bonding, first observation of such a coordination mode of 4-hydroxybenzoate for 5 f ions. [(UO2)(tph)(DMF)] (2) has a three-dimensional (3D) framework built with pentagonal bipyramidal uranium polyhedra linked with µ4-terephthalate ligands. The 3D channeled structure is facilitated by the unique carboxylate bonding with nearly linear C–O–U angles and the coordination of DMF molecules. The presence of phb ligands in different coordination modes, uranyl ions in diverse environments and DMF in complex 1, and tph ligand, DMF and uranyl ion in complex 2 has been confirmed by Raman spectroscopy. In addition, their thermal stability and photoluminescence properties have been investigated. © 2015 Elsevier Inc.
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    Synthesis and characterisation of two new tripodal metalloligands incorporating zinc(II)
    (Springer Nature, 2015-05-06) Fanna, DJ; Smith, A; Zhang, Y; Li, L; Shepherd, ND; Harman, DG; Li, F
    The in situ Schiff base condensation of 2-acetylpyrazine with tris(2-aminoethyl)amine in the presence of zinc(II) perchlorate was carried out in absolute ethanol and 95 % ethanol, respectively. Two new tripodal metalloligands, 1 and 2, were isolated. The formation of complexes 1 and 2 has been verified by NMR, mass spectral studies and X-ray (for 2), with the evidence indicating that a zinc ion is incorporated in the tripodal cavity defined by the tren backbone in each case. However the products differed in the number of Schiff base condensation reactions that had occurred. While the use of absolute ethanol resulted in condensation at all three primary amine sites of tris(2-aminoethyl)amine, employing 95 % ethanol yielded condensation at only one of the primary amine sites. These different outcomes can be ascribed, at least in part, to the effect of the different water contents in the respective reaction solvents resulting in a shift of the dynamic equilibrium involving imine formation towards the precursor amine and ketone reagents. In 1, steric considerations dictate that the three uncoordinated pyrazine nitrogen donors will have their coordination vectors oriented in a mutually divergent manner suitable for coordination to three different metal centres when acting as a metalloligand while for 2, the X-ray structure confirms that the single uncoordinated (pendent) pyrazine nitrogen is also oriented for ready coordination to a second metal centre. © 2015 Springer Science+Business Media Dordrecht