Young-Inn Kim

Blue phosphorescent iridium(III) complexes containing carbazole-functionalized phenylpyridine for organic light-emitting diodes: energy transfer from carbazolyl moieties to iridium(III) cores

By introducing a hexylcarbazolyl substituent into a phenylpyridine-based ligand, a Forster energy transfer from the carbazole moieties to the Ir(III) cores was observed in the heteroleptic cyclometalated Ir(III) complexes, resulting in an enhancement of luminescent efficiency. The phosphorescent OLED gave CIE coordinates of (0.21, 0.55) with a maximum external quantum efficiency of 7.16%.

Nicotinium tetra­chloro­cuprate(II)

The structure of the title compound, (C10H16N2)[CuCl4], comprises two crystallographically non-equivalent tetrahedral [CuCl4]2− anions, each of which is linked to two doubly protonated nicotinium cations via hydrogen bonds. There are two different types of hydrogen-bonding interactions present, namely (i) the protonated pyridinium groups exclusively form bifurcated hydrogen bonds to two cis-Cl atoms of both [CuCl4]2− units and (ii) the protonated pyrrolidinium groups exclusively form a two-center hydrogen bond with a chloride of both [CuCl4]2− units.

Di-μ-chlorido-bis­{[2-(benzyl­imino­meth­yl)pyridine-κ2 N,N′]chloridomercury(II)} dichloridomercury(II)

The HgII ion in the title centrosymmetric dinuclear complex, [Hg2Cl4(C13H12N2)2]·[HgCl2], adopts a distorted square-pyramidal geometry, being coordinated by the bis-chelating N-heterocyclic ligand, two bridging Cl atoms and one terminal Cl atom. One of the bridging Hg—Cl bonds [2.8428 (11) Å] is significantly longer than the other [2.5327 (10) Å]. In the crystal, there are weak π–π interactions [centroid–centroid distance = 3.630 (3) Å] between the aromatic rings of the discrete units. The HgCl2 adduct molecule is located on an inversion centre and has an Hg—Cl bond length of 2.2875 (11) Å.

[Benz­yl(2-pyridyl­methyl­idene)amine]­dichloridomercury(II)

The HgII ion in the title complex, [HgCl2(C13H12N2)], adopts a distorted tetrahedral geometry being coordinated by two Cl anions and by two N atoms of the benzyl(2-pyridylmethylene)amine ligand. The Cl—Hg—Cl plane is twisted at 70.1 (1)° from the mean plane of the chelate ring. In the crystal structure, intermolecular π–π interactions [centroid–centroid distance = 3.793 (3) Å] between the aromatic rings link the molecules into zigzag chains extending along [010].

Detection and prediction of local recurrence of maxillary sinus cancer using F-18 FDG PET/CT

PURPOSE The aim of the current study was to investigate the role of F-18 FDG PET/CT in the detection and prediction of local recurrence of maxillary sinus cancer. METHODS Retrospectively, we analyzed F-18 FDG PET/CT images of maxillary sinus cancer patients for the surveillance after treatment. Twenty-two consecutive patients with maxillary sinus cancer, who underwent maxillectomy followed by adjuvant radiation treatment, were included in the study. F-18 FDG PET/CT images were analyzed visually and quantitatively. RESULTS The median age of the patients included in the current study population was 54.5 years (range, 35-78). Seven patients (29.1%) had local recurrent diseases. Recurrent diseases show statistically significant higher values in SUV(max) (recurrent: 5.09 +/- 3.3, non-recurrent; 3.05 +/- 0.7, p < 0.05), L/NL (recurrent: 2.95 +/- 0.9, non-recurrent; 1.86 +/- 0.5, p < 0.05), L/Ao (recurrent: 3.37 +/- 2.1: non-recurrent; 1.88 +/- 0.4, p < 0.05), and L/Cbr (recurrent: 1.06 +/- 0.7: non-recurrent; 0.46 +/- 0.1, p < 0.05) than those of non-recurrent disease of maxillary sinus cancer. There were no statistical differences between visual assessment and quantitative indices for the detection of local recurrence. The visual assessment was the potent predictor by logistic regression analysis for prediction of local recurrence. CONCLUSION The visual assessment of F-18 FDG uptake pattern was potential predictor for local recurrence of maxillary sinus cancer. However, the diagnostic performances were similar between visual assessment and quantitative indices. Further studies are needed to confirm these results and improve statistical accuracy.

Bis(2-{[(9H-fluoren-2-yl)methyl­idene]amino}­phenolato-κ2N,O)zinc methanol disolvate

In the title compound, [Zn(C20H14NO)2]·2CH3OH, the ZnII atom lies on a crystallographic twofold rotation axis and is coordinated by two O atoms and two N atoms from two bidentate 2-{[(9H-fluoren-2-yl)methylidene]amino}phenolate ligands within a distorted tetrahedral geometry. The dihedral angle between the two chelate rings is 82.92 (5)°. In the coordinated ligand, the phenol ring is twisted at 30.22 (9)° from the mean plane of the fluorene ring. In the crystal, O—H⋯O hydrogen bonds link the complex molecules to the methanol solvent molecules.

Bis(3-methyl­pyridinium) tetra­chlorido­cuprate(II)

The title compound, (C6H8N)2[CuCl4], is composed of two 3-methylpyridinium cation and one tetrachloridocuprate(II) anion. The geometry around the copper(II) ion is that of a distorted tetrahedron. In the crystal structure, the anions and cations are linked by three different N—H⋯Cl hydrogen bonds. In addition, the crystal structure exhibits aromatic π–π interactions between the pyridinium rings of two discrete units [centroid–centroid distance = 3.704 (2) Å].

[Benzyl(2-pyridylmeth­yl)amine]dichloridomercury(II)

The Hg atom in the title compound, [HgCl2(C13H14N2)], adopts a distorted tetrahedral geometry, being ligated by two N atoms of the benzyl(2-pyridylmethyl)amine (bpma) ligand and two Cl atoms. The dihedral angle between the least-squares planes through the chelate ring and Cl—Hg—Cl atoms is 85.4 (1)°. The phenyl ring on the bpma ligand is twisted out of the pyridine plane, forming a dihedral angle of 76.0 (3)°. Disorder in this ring is also noted with two coplanar conformations having equal site occupancies.

Magnetic properties and coordination environments of oxovanadium(IV) within VO(IV)N2S2 and VO(IV)S4 chromophores

Abstract Oxovanadium(IV) complexes of the 2-amino-1-cyclopentene-1-dithiocarboxylate (acdc) and 2-methylamino-1-cyclopentene-1-dithiocarboxylate (NCH 3 acdc) anion have been synthesized and characterized by using IR, EPR, magnetic susceptibility and XPS measurements to elucidate the coordination environment of oxovanadium(IV) complexes of the acdc ligand and its derivative. The corresponding spin-Hamiltonian parameters, 〈 g 〉 values and hyperfine coupling constants, 〈 A 〉 have been examined for the prepared complexes having VO(IV)N 2 S 2 and VO(IV)S 4 chromophore. The EPR data confirm its usefulness in the characterization of the coordination environments of these compounds. The XPS studies have also provided us with valuable information on the binding properties of VO(acdc) 2 and VO(NCH 3 acdc) 2 . The magnetic susceptibility, coupled with the VO stretching frequency suggest the presence of some degree of magnetic interaction in these compounds.

(5-Methyl­pyrazine-2-carboxyl­ato-κ2N1,O)bis­[2-(4-methyl­pyridin-2-yl-κN)-3,5-bis­(tri­fluoro­meth­yl)phenyl-κC1]iridium(III) chloro­form hemisolvate

In the title complex, [Ir(C14H8F6N)2(C6H5N2O2)]·0.5CHCl3, the IrIII atom adopts a distorted octahedral geometry, being coordinated by three N atoms (arranged meridionally), two C atoms and one O atom of three bidentate ligands. The complex molecules pack with no specific intermolecular interactions between them. The SQUEEZE procedure in PLATON [Spek (2009 ▶). Acta Cryst. D65, 148–155] was used to model a disordered chloroform solvent molecule; the calculated unit-cell data allow for the presence of half of this molecule in the asymmetric unit.