On iodido bismuthates, bismuth complexes and polyiodides with bismuth in the system BiI3/18-crown-6/I2

The iodido bismuthates [Bi(18-crown-6)I2][BiI4] (1) and [Bi(18-crown-6)I2][Bi3I10] (2), the neutral complex [Bi(C6H14O4)I3](18-crown-6) (3) as well as the polyiodides [Bi(18-crown-6)I2][I5](18-crown-6) (4), [Bi(18-crown-6)I2]2[I14] (5) and [Bi(18-crown-6)I2]2[I19] (6) were prepared by reaction of BiI3, 18-crown-6, and I2 at T = 60–120 °C. The compounds 1–5 were prepared in [n-Bu3MeN][N(Tf)2] as an ionic liquid ([n-Bu3MeN]: tributylmethylammonium, [N(Tf)2]: bis(trifluoromethylsulfonyl)imide), whereas 6 was obtained only by direct reaction of the starting materials. The title compounds exhibit two different constitutions of the [Bi(18-crown-6)I2]+ cation as well as a non-charged, molecular [Bi(C6H14O4)I3] unit with a triethylene glycol ligand generated in situ by cleavage of the crown ether. Infinite chain-like [ BiI 2 / 1 I 4 / 2 ] − ∞ 1 ${}_{\infty }{}^{1}[{{\text{BiI}}_{2/1}{\text{I}}_{4/2}]}^{-}$ and [ Bi 6 I 18 / 1 I 4 / 2 ∞ 1 ] − ${{}_{\infty }{}^{1}[{\text{Bi}}_{6}{\text{I}}_{18/1}{\text{I}}_{4/2}]}^{-}$ anions occur in 1 and 2, whereas various polyiodide anions (e.g. [I3]−, [I5]−, [I7]−, [I9]−) with partly complex interaction are observed in 4, 5, and 6. The title compounds were characterized by single-crystal X-ray diffraction analysis and infrared spectroscopy. In the case of 1 and 2, the optical band gap was determined to be E g = 1.91 and 1.62 eV, respectively. Especially, the ionic-liquid-based synthesis affords the different metastable compounds with variable composition and structure in a narrow temperature range.

A Photolabile Fe Catalyst for Light-Triggered Alkyd Paint Curing

In search for cobalt replacements for alkyd paint curing we show that the photo-active complex [(Cp)Fe(C₆H₆)]+ (Cp = cyclopentadienyl) acts as a latent catalytic drier that allows for photochemical control over the onset of curing, without the need for anti-skinning agents such as the volatile MEKO normally used to prevent curing during paint storage. The highly soluble neutral complex [(Cp)Fe(Ch)] (Ch = cyclohexadienyl) readily converts to the photo-active complex [(Cp)Fe(C₆H₆)]⁺ upon oxidation in alkyd, allowing the latter to be dosed in a wide range of concentrations. Infrared and Raman studies show similar spectral changes of the alkyd paint matrix as have been observed in alkyd curing mediated by the known commercial cobalt- and manganese-based driers Durham NUODEX® Cobalt 10 Neo and NUODEX® DryCoat. The new [(Cp)Fe(Ch)] / [(Cp)Fe(C₆H₆)]⁺ system performs equally well as both commercial paint driers in terms of drying time, and outperforms NUODEX® DryCoat by showing a hardness development (increase) similar to the cobalt-based drier. Based on an observed light-dark on/off effect and EPR studies we propose that photolysis of [(Cp)Fe(C₆H₆)]+ generates short-lived active Fe^II species, explaining the excellent latency. The novel alkyd curing system [(Cp)Fe(Ch)] / [(Cp)Fe(C₆H₆)]⁺ presented herein is the first example of an intrinsically latent paint curing catalyst that is: (1) based on an abundant and harmless transition metal (Fe), (2) doesn’t require any anti-skinning agents, and (3) shows excellent performance in terms of drying times and hardness development. <br>

A Photolabile Fe Catalyst for Light-Triggered Alkyd Paint Curing

In search for cobalt replacements for alkyd paint curing we show that the photo-active complex [(Cp)Fe(C₆H₆)]+ (Cp = cyclopentadienyl) acts as a latent catalytic drier that allows for photochemical control over the onset of curing, without the need for anti-skinning agents such as the volatile MEKO normally used to prevent curing during paint storage. The highly soluble neutral complex [(Cp)Fe(Ch)] (Ch = cyclohexadienyl) readily converts to the photo-active complex [(Cp)Fe(C₆H₆)]⁺ upon oxidation in alkyd, allowing the latter to be dosed in a wide range of concentrations. Infrared and Raman studies show similar spectral changes of the alkyd paint matrix as have been observed in alkyd curing mediated by the known commercial cobalt- and manganese-based driers Durham NUODEX® Cobalt 10 Neo and NUODEX® DryCoat. The new [(Cp)Fe(Ch)] / [(Cp)Fe(C₆H₆)]⁺ system performs equally well as both commercial paint driers in terms of drying time, and outperforms NUODEX® DryCoat by showing a hardness development (increase) similar to the cobalt-based drier. Based on an observed light-dark on/off effect and EPR studies we propose that photolysis of [(Cp)Fe(C₆H₆)]+ generates short-lived active Fe^II species, explaining the excellent latency. The novel alkyd curing system [(Cp)Fe(Ch)] / [(Cp)Fe(C₆H₆)]⁺ presented herein is the first example of an intrinsically latent paint curing catalyst that is: (1) based on an abundant and harmless transition metal (Fe), (2) doesn’t require any anti-skinning agents, and (3) shows excellent performance in terms of drying times and hardness development. <br>

Crystal structure of {N 1,N 3-bis[(1-tert-butyl-1H-1,2,3-triazol-4-yl)methylidene]-2,2-dimethylpropane-1,3-diamine}bis(thiocyanato)iron(II)

The unit cell of the title compound, [FeII(NCS)2(C19H32N8)], consists of two charge-neutral complex molecules. In the complex molecule, the tetradentate ligand N 1 ,N 3-bis[(1-tert-butyl-1H-1,2,3-triazol-4-yl)methylene]-2,2-dimethylpropane-1,3-diamine coordinates to the FeII ion through the N atoms of the 1,2,3-triazole and aldimine groups. Two thiocyanate anions, also coordinated through their N atoms, complete the coordination sphere of the central Fe ion. In the crystal, neighbouring molecules are linked through weak C—H...C/S/N interactions into a three-dimensional network. The intermolecular contacts were quantified using Hirshfeld surface analysis and two-dimensional fingerprint plots, revealing the relative contributions of the contacts to the crystal packing to be H...H 50.8%, H...C/C...H 14.3%, H...S/S...H 20.5% and H...N/N...H 12.1%. The average Fe—N bond distance is 2.170 Å, indicating the high-spin state of the FeII ion, which does not change upon cooling, as demonstrated by low-temperature magnetic susceptibility measurements. DFT calculations of energy frameworks at the B3LYP/6–31 G(d,p) theory level were performed to account for the interactions involved in the crystal structure.

Crystal structure of (N 1,N 3-bis{[1-(4-methoxybenzyl)-1H-1,2,3-triazol-4-yl]methylidene}-2,2-dimethylpropane-1,3-diamine)bis(thiocyanato)iron(II)

The unit cell of the title compound, [FeII(NCS)2(C29H32N8O2)], consists of eight charge-neutral complex molecules. In the complex molecule, the tetradentate ligand N 1,N 3-bis{[1-(4-methoxybenzyl)-1H-1,2,3-triazol-4-yl]methylene}-2,2-dimethylpropane-1,3-diamine coordinates to the FeII ion through the N atoms of the 1,2,3-triazole and aldimine groups. Two thiocyanate anions, coordinated through their N atoms, complete the coordination sphere of the central Fe ion. In the crystal, neighbouring molecules are linked through weak C...C, C...N and C...S interactions into a one-dimensional chain running parallel to [010]. The intermolecular contacts were quantified using Hirshfeld surface analysis and two-dimensional fingerprint plots, revealing the relative contributions of the contacts to the crystal packing to be H...H (37.5%), H...C/C...H (24.7%), H...S/S...H (15.7%) and H...N/N...H (11.7%). The average Fe—N bond distance is 2.167 Å, indicating the high-spin state of the FeII ion, which does not change upon cooling, as demonstrated by low-temperature magnetic susceptibility measurements.

Crystal structure and Hirshfeld surface analysis of [2-(1H-benzimidazol-2-yl-κN 3)aniline-κN]dichloridozinc(II) N,N-dimethylformamide monosolvate

The title compound, [ZnCl2(C13H11N3)]·C3H7NO, crystallized in the monoclinic crystal system in space group P21/n. The asymmetric unit contains one neutral complex molecule, which consists of a zinc ion, a bidentate ligand, and two chlorido ligands with dimethylformamide monosolvate. The ligand has two moieties, a benzimidazole and an aniline group. The benzimidazole and aniline planes are not coplanar, subtending a dihedral angle of 18.24 (8)°. The Zn(II) ion shows distorted tetrahedral geometry, being coordinated by an imidazole N atom, the aniline N atom, and two chlorido ligands. The packing features N—H...O, N—H...Cl, C—H...Cl hydrogen bonding.

Substrate mediated interaction of Terbium(III) double-deckers with the TiO2(110) surface.

Terbium(III)-bis(phthalocyaninato) neutral complex was deposited on the rutile TiO2(110) surface, and their interaction was studied by Scanning Tunneling Microscopy (STM) and X-ray Photoelectron Spectroscopy (XPS). At variance with many non-metal...

Synthesis, structural characterization and catalytic activity of chlororuthenium(II) complexes with substituted Schiff base/phosphine ancillary ligands

Treatment of [(η6-p-cymene)RuCl2]2 with one equivalent of chlorodiphenylphosphine in tetrahydrofuran at reflux afforded a neutral complex [(η6-p-cymene)RuCl2(κ1-P-PPh2OH)] (1). Similarly, the reaction of [Ru(bpy)2Cl2·2H2O] (bpy = 2,2′-bipyridine) and chlorodiphenylphosphine in methanol gave a cationic complex [Ru(bpy)2Cl(κ1-P-PPh2OCH3)](PF6) (2), while treatment of [RuCl2(PPh3)3] with [2-(C5H4N)CH=N(CH2)2N(CH3)2] (L1) in tetrahydrofuran at room temperature afforded a ruthenium(II) complex [Ru(PPh3)Cl2(κ3-N,N,N-L1)] (3). Interaction of the chloro-bridged complex [Ru(CO)2Cl2]n with one equivalent of [Ph2P(o-C6H4)CH=N(CH2)2N(CH3)2] (L2) led to the isolation of [Ru(CO)Cl2(κ3-P,N,N-L2)] (4). The molecular structures of the ruthenium(II) complexes 1–4 have been determined by single-crystal X-ray crystallography. The properties of the ruthenium(II) complex 4 as a hydrogenation catalyst for acetophenone were also tested.