Preparation, Structure, and Properties of Tetranuclear Vanadium(III) and (IV) Complexes Bridged by Diphenyl Phosphate or Phosphate

Three novel tetranuclear vanadium­(III) or (IV) complexes bridged by diphenyl phosphate or phosphate were prepared and their structures characterized by X-ray crystallography. The novel complexes are [{V­(III)₂(μ-hpnbpda)}₂{μ-(C₆H₅O)₂PO₂}₂(μ-O)₂]·6CH₃OH (<b>1</b>), [{V­(III)₂(μ-tphpn)­(μ-η³-HPO₄)}₂(μ-η⁴-PO₄)]­(ClO₄)₃·4.5H₂O (<b>2</b>), and [{(V­(IV)­O)₂(μ-tphpn)}₂(μ-η⁴-PO₄)]­(ClO₄)₃·H₂O (<b>3</b>), where hpnbpda and tphpn are alkoxo-bridging dinucleating ligands. H₃hpnbpda represents 2-hydroxypropane-1,3-diamino-<i>N,N′</i>-bis­(2-pyridylmethyl)-<i>N,N′</i>-diacetic acid, and Htphpn represents <i>N,N,N′,N′</i>-tetrakis­(2-pyridylmethyl)-2-hydroxy-1,3-propanediamine. A dinuclear vanadium­(IV) complex without a phosphate bridge, [(VO)₂(μ-tphpn)­(H₂O)₂]­(ClO₄)₃·2H₂O (<b>4</b>), was also prepared and structurally characterized for comparison. The vanadium­(III) center in <b>1</b> adopts a hexacoordinate structure while that in <b>2</b> adopts a heptacoordinate structure. In <b>1</b>, the two dinuclear vanadium­(III) units bridged by the alkoxo group of hpnbpda are further linked by two diphenylphosphato and two oxo groups, resulting in a dimer-of-dimers. In <b>2</b>, the two vanadium­(III) units bridged by tphpn are further bridged by three phosphate ions with two different coordination modes. Complex <b>2</b> is oxidized in aerobic solution to yield complex <b>3</b>, in which two of the three phosphate groups in <b>2</b> are substituted by oxo groups

Preparation, Structure, and Properties of Tetranuclear Vanadium(III) and (IV) Complexes Bridged by Diphenyl Phosphate or Phosphate

Three novel tetranuclear vanadium­(III) or (IV) complexes bridged by diphenyl phosphate or phosphate were prepared and their structures characterized by X-ray crystallography. The novel complexes are [{V­(III)₂(μ-hpnbpda)}₂{μ-(C₆H₅O)₂PO₂}₂(μ-O)₂]·6CH₃OH (<b>1</b>), [{V­(III)₂(μ-tphpn)­(μ-η³-HPO₄)}₂(μ-η⁴-PO₄)]­(ClO₄)₃·4.5H₂O (<b>2</b>), and [{(V­(IV)­O)₂(μ-tphpn)}₂(μ-η⁴-PO₄)]­(ClO₄)₃·H₂O (<b>3</b>), where hpnbpda and tphpn are alkoxo-bridging dinucleating ligands. H₃hpnbpda represents 2-hydroxypropane-1,3-diamino-<i>N,N′</i>-bis­(2-pyridylmethyl)-<i>N,N′</i>-diacetic acid, and Htphpn represents <i>N,N,N′,N′</i>-tetrakis­(2-pyridylmethyl)-2-hydroxy-1,3-propanediamine. A dinuclear vanadium­(IV) complex without a phosphate bridge, [(VO)₂(μ-tphpn)­(H₂O)₂]­(ClO₄)₃·2H₂O (<b>4</b>), was also prepared and structurally characterized for comparison. The vanadium­(III) center in <b>1</b> adopts a hexacoordinate structure while that in <b>2</b> adopts a heptacoordinate structure. In <b>1</b>, the two dinuclear vanadium­(III) units bridged by the alkoxo group of hpnbpda are further linked by two diphenylphosphato and two oxo groups, resulting in a dimer-of-dimers. In <b>2</b>, the two vanadium­(III) units bridged by tphpn are further bridged by three phosphate ions with two different coordination modes. Complex <b>2</b> is oxidized in aerobic solution to yield complex <b>3</b>, in which two of the three phosphate groups in <b>2</b> are substituted by oxo groups

Preparation, Structure, and Properties of Tetranuclear Vanadium(III) and (IV) Complexes Bridged by Diphenyl Phosphate or Phosphate

Three novel tetranuclear vanadium­(III) or (IV) complexes bridged by diphenyl phosphate or phosphate were prepared and their structures characterized by X-ray crystallography. The novel complexes are [{V­(III)₂(μ-hpnbpda)}₂{μ-(C₆H₅O)₂PO₂}₂(μ-O)₂]·6CH₃OH (<b>1</b>), [{V­(III)₂(μ-tphpn)­(μ-η³-HPO₄)}₂(μ-η⁴-PO₄)]­(ClO₄)₃·4.5H₂O (<b>2</b>), and [{(V­(IV)­O)₂(μ-tphpn)}₂(μ-η⁴-PO₄)]­(ClO₄)₃·H₂O (<b>3</b>), where hpnbpda and tphpn are alkoxo-bridging dinucleating ligands. H₃hpnbpda represents 2-hydroxypropane-1,3-diamino-<i>N,N′</i>-bis­(2-pyridylmethyl)-<i>N,N′</i>-diacetic acid, and Htphpn represents <i>N,N,N′,N′</i>-tetrakis­(2-pyridylmethyl)-2-hydroxy-1,3-propanediamine. A dinuclear vanadium­(IV) complex without a phosphate bridge, [(VO)₂(μ-tphpn)­(H₂O)₂]­(ClO₄)₃·2H₂O (<b>4</b>), was also prepared and structurally characterized for comparison. The vanadium­(III) center in <b>1</b> adopts a hexacoordinate structure while that in <b>2</b> adopts a heptacoordinate structure. In <b>1</b>, the two dinuclear vanadium­(III) units bridged by the alkoxo group of hpnbpda are further linked by two diphenylphosphato and two oxo groups, resulting in a dimer-of-dimers. In <b>2</b>, the two vanadium­(III) units bridged by tphpn are further bridged by three phosphate ions with two different coordination modes. Complex <b>2</b> is oxidized in aerobic solution to yield complex <b>3</b>, in which two of the three phosphate groups in <b>2</b> are substituted by oxo groups

Preparation, Structure, and Properties of Tetranuclear Vanadium(III) and (IV) Complexes Bridged by Diphenyl Phosphate or Phosphate

Three novel tetranuclear vanadium­(III) or (IV) complexes bridged by diphenyl phosphate or phosphate were prepared and their structures characterized by X-ray crystallography. The novel complexes are [{V­(III)₂(μ-hpnbpda)}₂{μ-(C₆H₅O)₂PO₂}₂(μ-O)₂]·6CH₃OH (<b>1</b>), [{V­(III)₂(μ-tphpn)­(μ-η³-HPO₄)}₂(μ-η⁴-PO₄)]­(ClO₄)₃·4.5H₂O (<b>2</b>), and [{(V­(IV)­O)₂(μ-tphpn)}₂(μ-η⁴-PO₄)]­(ClO₄)₃·H₂O (<b>3</b>), where hpnbpda and tphpn are alkoxo-bridging dinucleating ligands. H₃hpnbpda represents 2-hydroxypropane-1,3-diamino-<i>N,N′</i>-bis­(2-pyridylmethyl)-<i>N,N′</i>-diacetic acid, and Htphpn represents <i>N,N,N′,N′</i>-tetrakis­(2-pyridylmethyl)-2-hydroxy-1,3-propanediamine. A dinuclear vanadium­(IV) complex without a phosphate bridge, [(VO)₂(μ-tphpn)­(H₂O)₂]­(ClO₄)₃·2H₂O (<b>4</b>), was also prepared and structurally characterized for comparison. The vanadium­(III) center in <b>1</b> adopts a hexacoordinate structure while that in <b>2</b> adopts a heptacoordinate structure. In <b>1</b>, the two dinuclear vanadium­(III) units bridged by the alkoxo group of hpnbpda are further linked by two diphenylphosphato and two oxo groups, resulting in a dimer-of-dimers. In <b>2</b>, the two vanadium­(III) units bridged by tphpn are further bridged by three phosphate ions with two different coordination modes. Complex <b>2</b> is oxidized in aerobic solution to yield complex <b>3</b>, in which two of the three phosphate groups in <b>2</b> are substituted by oxo groups

Preparation, Structure, and Properties of Tetranuclear Vanadium(III) and (IV) Complexes Bridged by Diphenyl Phosphate or Phosphate

Three novel tetranuclear vanadium­(III) or (IV) complexes bridged by diphenyl phosphate or phosphate were prepared and their structures characterized by X-ray crystallography. The novel complexes are [{V­(III)₂(μ-hpnbpda)}₂{μ-(C₆H₅O)₂PO₂}₂(μ-O)₂]·6CH₃OH (<b>1</b>), [{V­(III)₂(μ-tphpn)­(μ-η³-HPO₄)}₂(μ-η⁴-PO₄)]­(ClO₄)₃·4.5H₂O (<b>2</b>), and [{(V­(IV)­O)₂(μ-tphpn)}₂(μ-η⁴-PO₄)]­(ClO₄)₃·H₂O (<b>3</b>), where hpnbpda and tphpn are alkoxo-bridging dinucleating ligands. H₃hpnbpda represents 2-hydroxypropane-1,3-diamino-<i>N,N′</i>-bis­(2-pyridylmethyl)-<i>N,N′</i>-diacetic acid, and Htphpn represents <i>N,N,N′,N′</i>-tetrakis­(2-pyridylmethyl)-2-hydroxy-1,3-propanediamine. A dinuclear vanadium­(IV) complex without a phosphate bridge, [(VO)₂(μ-tphpn)­(H₂O)₂]­(ClO₄)₃·2H₂O (<b>4</b>), was also prepared and structurally characterized for comparison. The vanadium­(III) center in <b>1</b> adopts a hexacoordinate structure while that in <b>2</b> adopts a heptacoordinate structure. In <b>1</b>, the two dinuclear vanadium­(III) units bridged by the alkoxo group of hpnbpda are further linked by two diphenylphosphato and two oxo groups, resulting in a dimer-of-dimers. In <b>2</b>, the two vanadium­(III) units bridged by tphpn are further bridged by three phosphate ions with two different coordination modes. Complex <b>2</b> is oxidized in aerobic solution to yield complex <b>3</b>, in which two of the three phosphate groups in <b>2</b> are substituted by oxo groups

Preparation, Structure, and Properties of Tetranuclear Vanadium(III) and (IV) Complexes Bridged by Diphenyl Phosphate or Phosphate

Three novel tetranuclear vanadium­(III) or (IV) complexes bridged by diphenyl phosphate or phosphate were prepared and their structures characterized by X-ray crystallography. The novel complexes are [{V­(III)₂(μ-hpnbpda)}₂{μ-(C₆H₅O)₂PO₂}₂(μ-O)₂]·6CH₃OH (<b>1</b>), [{V­(III)₂(μ-tphpn)­(μ-η³-HPO₄)}₂(μ-η⁴-PO₄)]­(ClO₄)₃·4.5H₂O (<b>2</b>), and [{(V­(IV)­O)₂(μ-tphpn)}₂(μ-η⁴-PO₄)]­(ClO₄)₃·H₂O (<b>3</b>), where hpnbpda and tphpn are alkoxo-bridging dinucleating ligands. H₃hpnbpda represents 2-hydroxypropane-1,3-diamino-<i>N,N′</i>-bis­(2-pyridylmethyl)-<i>N,N′</i>-diacetic acid, and Htphpn represents <i>N,N,N′,N′</i>-tetrakis­(2-pyridylmethyl)-2-hydroxy-1,3-propanediamine. A dinuclear vanadium­(IV) complex without a phosphate bridge, [(VO)₂(μ-tphpn)­(H₂O)₂]­(ClO₄)₃·2H₂O (<b>4</b>), was also prepared and structurally characterized for comparison. The vanadium­(III) center in <b>1</b> adopts a hexacoordinate structure while that in <b>2</b> adopts a heptacoordinate structure. In <b>1</b>, the two dinuclear vanadium­(III) units bridged by the alkoxo group of hpnbpda are further linked by two diphenylphosphato and two oxo groups, resulting in a dimer-of-dimers. In <b>2</b>, the two vanadium­(III) units bridged by tphpn are further bridged by three phosphate ions with two different coordination modes. Complex <b>2</b> is oxidized in aerobic solution to yield complex <b>3</b>, in which two of the three phosphate groups in <b>2</b> are substituted by oxo groups

Preparation, Structure, and Properties of Tetranuclear Vanadium(III) and (IV) Complexes Bridged by Diphenyl Phosphate or Phosphate

Three novel tetranuclear vanadium­(III) or (IV) complexes bridged by diphenyl phosphate or phosphate were prepared and their structures characterized by X-ray crystallography. The novel complexes are [{V­(III)₂(μ-hpnbpda)}₂{μ-(C₆H₅O)₂PO₂}₂(μ-O)₂]·6CH₃OH (<b>1</b>), [{V­(III)₂(μ-tphpn)­(μ-η³-HPO₄)}₂(μ-η⁴-PO₄)]­(ClO₄)₃·4.5H₂O (<b>2</b>), and [{(V­(IV)­O)₂(μ-tphpn)}₂(μ-η⁴-PO₄)]­(ClO₄)₃·H₂O (<b>3</b>), where hpnbpda and tphpn are alkoxo-bridging dinucleating ligands. H₃hpnbpda represents 2-hydroxypropane-1,3-diamino-<i>N,N′</i>-bis­(2-pyridylmethyl)-<i>N,N′</i>-diacetic acid, and Htphpn represents <i>N,N,N′,N′</i>-tetrakis­(2-pyridylmethyl)-2-hydroxy-1,3-propanediamine. A dinuclear vanadium­(IV) complex without a phosphate bridge, [(VO)₂(μ-tphpn)­(H₂O)₂]­(ClO₄)₃·2H₂O (<b>4</b>), was also prepared and structurally characterized for comparison. The vanadium­(III) center in <b>1</b> adopts a hexacoordinate structure while that in <b>2</b> adopts a heptacoordinate structure. In <b>1</b>, the two dinuclear vanadium­(III) units bridged by the alkoxo group of hpnbpda are further linked by two diphenylphosphato and two oxo groups, resulting in a dimer-of-dimers. In <b>2</b>, the two vanadium­(III) units bridged by tphpn are further bridged by three phosphate ions with two different coordination modes. Complex <b>2</b> is oxidized in aerobic solution to yield complex <b>3</b>, in which two of the three phosphate groups in <b>2</b> are substituted by oxo groups

Preparation, Structure, and Properties of Tetranuclear Vanadium(III) and (IV) Complexes Bridged by Diphenyl Phosphate or Phosphate

Three novel tetranuclear vanadium­(III) or (IV) complexes bridged by diphenyl phosphate or phosphate were prepared and their structures characterized by X-ray crystallography. The novel complexes are [{V­(III)₂(μ-hpnbpda)}₂{μ-(C₆H₅O)₂PO₂}₂(μ-O)₂]·6CH₃OH (<b>1</b>), [{V­(III)₂(μ-tphpn)­(μ-η³-HPO₄)}₂(μ-η⁴-PO₄)]­(ClO₄)₃·4.5H₂O (<b>2</b>), and [{(V­(IV)­O)₂(μ-tphpn)}₂(μ-η⁴-PO₄)]­(ClO₄)₃·H₂O (<b>3</b>), where hpnbpda and tphpn are alkoxo-bridging dinucleating ligands. H₃hpnbpda represents 2-hydroxypropane-1,3-diamino-<i>N,N′</i>-bis­(2-pyridylmethyl)-<i>N,N′</i>-diacetic acid, and Htphpn represents <i>N,N,N′,N′</i>-tetrakis­(2-pyridylmethyl)-2-hydroxy-1,3-propanediamine. A dinuclear vanadium­(IV) complex without a phosphate bridge, [(VO)₂(μ-tphpn)­(H₂O)₂]­(ClO₄)₃·2H₂O (<b>4</b>), was also prepared and structurally characterized for comparison. The vanadium­(III) center in <b>1</b> adopts a hexacoordinate structure while that in <b>2</b> adopts a heptacoordinate structure. In <b>1</b>, the two dinuclear vanadium­(III) units bridged by the alkoxo group of hpnbpda are further linked by two diphenylphosphato and two oxo groups, resulting in a dimer-of-dimers. In <b>2</b>, the two vanadium­(III) units bridged by tphpn are further bridged by three phosphate ions with two different coordination modes. Complex <b>2</b> is oxidized in aerobic solution to yield complex <b>3</b>, in which two of the three phosphate groups in <b>2</b> are substituted by oxo groups

Efficient Synthesis of Tris-Heteroleptic Iridium(III) Complexes Based on the Zn²⁺-Promoted Degradation of Tris-Cyclometalated Iridium(III) Complexes and Their Photophysical Properties

We report on the efficient synthesis of tris-heteroleptic iridium (Ir) complexes based on the degradation of tris-cyclometalated Ir complexes (IrL₃, L: cyclometalating ligand) in the presence of Brønsted and Lewis acids such as HCl (in 1,4-dioxane), AlCl₃, TMSCl, and ZnX₂ (X = Br or Cl), which affords the corresponding halogen-bridged Ir dimers (μ-complexes). Tris-cyclometalated Ir complexes containing electron-withdrawing groups such as fluorine, nitro, or CF₃ moieties on the ligands were less reactive. This different reactivity was applied to the selective degradation of heteroleptic Ir complexes such as <i>fac</i>-Ir­(tpy)₂(F₂ppy) (<i><b>fac</b></i><b>-12</b>) (tpy: 2-(4′-tolyl)­pyridine and F₂ppy: 2-(4′,6′-difluorophenyl)­pyridine), <i>mer</i>-Ir­(tpy)₂(F₂ppy) (<i><b>mer</b></i><b>-12</b>), and <i>mer</i>-Ir­(mpiq)₂(F₂ppy) (<i><b>mer</b></i><b>-15</b>) (mpiq: 1-(4′-methylphenyl)­isoquinoline). For example, the reaction of <i><b>mer</b></i><b>-12</b> with ZnBr₂ gave the heteroleptic μ-complex [{Ir­(tpy)­(F₂ppy)­(μ-Br)}₂] <b>27b</b> as a major product, resulting from the selective elimination of the tpy ligand of <i><b>mer</b></i><b>-12</b>, and treatment of <b>27b</b> with acetylacetone (acacH) afforded the corresponding tris-heteroleptic Ir complex Ir­(tpy)­(F₂ppy)­(acac)<b>18</b>. In addition, another tris-heteroleptic Ir complex <b>35a</b> having 8-benzene­sulfonyl­amido­quinoline (8BSQ) ligand was synthesized. Mechanistic studies of this degradation reaction and the photochemical properties, especially a dual emission, of these newly synthesized tris-heteroleptic Ir complexes are also reported

Stereospecific Synthesis of Tris-heteroleptic Tris-cyclometalated Iridium(III) Complexes via Different Heteroleptic Halogen-Bridged Iridium(III) Dimers and Their Photophysical Properties

Herein, we report on the stereospecific synthesis of two single isomers of tris-heteroleptic tris-cyclometalated iridium­(III) (Ir­(III)) complexes composed of three different nonsymmetric cyclometalating ligands via heteroleptic halogen-bridged Ir dimers [Ir­(tpy)­(F₂ppy)­(μ-Br)]₂ <b>17b</b> and [Ir­(mpiq)­(F₂ppy)­(μ-Br)]₂ <b>27b</b> (tpyH: (2-(4′-tolyl)­pyri­dine) and F₂ppyH: (2-(4′,6′-di­fluoro­phenyl)­pyridine), and mpiqH: (1-(4′-methyl­phenyl)­iso­quinoline)) prepared by Zn²⁺-promoted degradation of Ir­(tpy)₂­(F₂ppy) <b>21</b> and Ir­(mpiq)₂­(F₂ppy) <b>26</b>, as reported by us. Subsequently, <b>17b</b> and <b>27b</b> were converted to the tris-heteroleptic tris-cyclometalated Ir complexes Ir­(tpy)­(F₂ppy)­(mpiq) <b>25</b> consisting of tpy, F₂ppy, and mpiq, as confirmed by spectroscopic data and X-ray crystal structure analysis. The first important point in this work is the selective synthesis of specific isomers among eight possible stereoisomers of Ir complexes having the same combination of three cyclometalating ligands. Namely, two meridional forms of <b>25</b> were synthesized and isolated. The second finding is that the different stereoisomers of <b>25</b> have different stability. Finally, different stereoisomers exhibit different emission spectra. Namely, one of its stereoisomers <b>25a</b> exhibits a single broad emission from <i>ca</i>. 550 nm to <i>ca</i>. 650 nm (orange emission), while stereoisomer <b>25c</b> emits dual emission at <i>ca</i>. 509 nm and <i>ca</i>. 600 nm (pale pink emission), as supported by time-dependent density functional theory calculation. To the best of our knowledge, this is the first report of the selective and efficient synthesis of different stereoisomers of tris-heteroleptic tris-cyclometalated Ir­(III) complexes that have different stabilities and different photophysical properties