Iridium(III) coordination compounds based on organophosphorus ancillary ligands showing cytotoxicity against breast cancer cells and Fe(III) luminescent sensing.

Three phosphorescent iridium(III) complexes consisting bis-diphosphine ligands were prepared and characterized by single-crystal XRD, CHN analysis, spectroscopic techniques, cyclic voltammetry, and DFT. The synthesized complexes were the three monomeric [Ir(ppy)(L)Cl] (1), [Ir(ppy)(L)]Cl (2) and [Ir(ppy)(L)]Cl (3) where L = bis-(diphenylphosphino)methane (dppm), L = bis-(diphenylphosphino)propane (dppp) and L = bis-(diphenylphosphino)benzene (dppbe). Complexes 1-3 gave an absorption band between 240 to 380 nm in both CHCl and DMSO, which is assigned as a charge transfer transition based on theoretical calculation.

Synthesis, crystal structure and Hirshfeld surface analysis of [bis-(di-phenyl-phosphan-yl)methane-κ]chloridobis-[2-(pyridin-2-yl)phenyl-κ , ]iridium(III).

The title Ir complex, [Ir(CHN)Cl(CHP)], was synthesized from the substitution reaction between the (ppy)Ir(μ-Cl)Ir(ppy) (ppy = deprotonated 2-phenyl-pyridine, CHN) dimer and 1,1-bis-(di-phenyl-phosphan-yl)methane (dppm, CHP) under an argon gas atmosphere for 20 h. The Ir atom is coordinated by two C,-bidentate ppy anions, a unidentate dppm ligand and a chloride anion in a distorted octa-hedral IrCNPCl arrangement. The N donor atoms of the ppy ligands are mutually while the C atoms are .

Crystal structure of di-chlorido-bis-[2-(phenyl-diazen-yl)pyridine-κN (1)]zinc.

The structure of the title complex, [ZnCl2(C11H9N3)2], comprises two 2-(phenyl-diazen-yl)pyridine ligands coordin-ating to a central Zn(II) dichloride unit via the pyridyl N-atom donors, resulting in a slightly distorted tetra-hedral geometry. The complex exhibits twofold rotation symmetry, with the rotation axis bis-ecting the zinc cation. The structure is stabilized by weak inter-molecular C-H⋯Cl inter-actions [C⋯Cl = 3.

2-Amino-5-bromo-pyridin-1-ium (2-amino-5-bromo-pyridine-κN (1))trichloridozincate.

The structure of the title salt, (C5H6BrN2)[ZnCl3(C5H5BrN2)], consists of discrete 2-amino-5-bromo-pyridin-1-ium cations and distorted tetra-hedral (2-amino-5-bromo-pyridine)-tri-chlorido-zincate anions. In the crystal, the complex anions and cations are linked via N-H⋯Cl hydrogen bonds into layers parallel to (101). Short Br⋯Cl contacts of 3.

2-{2-[4-(Dimethyl-amino)-phen-yl]diazen-1-ium-1-yl}pyridinium tetra-chlorido-zincate.

The title compound, (C(13)H(16)N(4))[ZnCl(4)], consists of a tetra-hedral [ZnCl(4)](2-) anion and a 2-{2-[4-(dimethyl-amino)-phen-yl]diazen-1-ium-1-yl}pyridinium dication. The pyridinium-N atom is syn to the azo bond which allows for the formation of an intramolecular N-H⋯N hydrogen bond. In the crystal, the cation and anion are held together by N-H⋯Cl hydrogen-bond inter-actions involving the pyridinium and diazen-1-ium N atoms.

Bis[5-chloro-2-(phenyl-diazenyl-κN(2))pyridine-κN]bis-(thio-cyanato-κN)iron(II).

In the title complex, [Fe(NCS)(2)(C(11)H(8)ClN(3))(2)], the Fe(II) atom is coordinated by two N atoms from the thio-cyanate ligands and four N atoms from two chelating 5-chloro-2-(phenyl-diazen-yl)pyridine ligands, generating a fairly regular FeN(6) octa-hedral coordination geometry. The thio-cyanate ions are in a cis disposition and the pyridine N atoms are in a trans orientation. In the crystal, a short inter-molecular Cl⋯S contact [3.

A new screening method for flunitrazepam in vodka and tequila by fluorescence spectroscopy.

A new screening method for flunitrazepam in colourless alcoholic beverages based on a spectroscopic technique is proposed. Absorption and steady-state fluorescence of flunitrazepam and its protonated form with various acids were investigated. The redshift of the wavelength of maximum absorption was distinctively observed in protonated flunitrazepam.

Photoactive azoimine dyes: 4-(2-pyridylazo)-N,N-diethylaniline and 4-(2-pyridylazo)-N,N-dimethylaniline: computational and experimental investigation.

4-(2-Pyridylazo)-N,N-dimethylaniline and 4-(2-pyridylazo)-N,N-diethylaniline, two photoactive azoimine dyes, were prepared from the reaction of 2-aminopyridine with N,N-dialkyl-1,4-nitrosoaniline at room temperature. Structural characterizations of these dyes using single crystal X-ray diffraction, (1)H NMR, elemental analysis, mass spectroscopy and IR spectroscopy have been carried out. The X-ray structure indicates a trans configuration around the azo group.

Dichloridobis{N,N-diethyl-4-[(pyridin-2-yl-κN)diazen-yl]aniline}zinc.

In the title complex, [ZnCl(2)(C(15)H(18)N(4))(2)], the Zn(II) cation is coordinated by two N atoms from the pyridine rings of two unidentate N,N-diethyl-4-[(pyridin-2-yl)diazen-yl]aniline ligands and two Cl atoms, resulting in a distorted tetra-hedral geometry. The ligands are mutually transoid with respect to the metal atom. Weak inter-molecular C-H⋯Cl hydrogen bonds and π-π inter-actions, with centroid-centroid distances of 3.

N,N-Dimethyl-4-[(2-pyrid-yl)diazen-yl]aniline.

The title compound, C(13)H(14)N(4), adopts a trans configuration about the azo bond. There is a dihedral angle of 12.18 (7)° between the pyridine and benzene rings and the mean plane of the dimethyl-amino substituent is twisted by 6.