A salt made of 4-N,N-dimethylaminopyridine (DMAP) and saccharin as an efficient recyclable acylation catalyst: a new bridge between heterogeneous and homogeneous catalysis.

Here, we report insights into the new recyclable catalyst 1, (DMAP·saccharin). The DMAP·saccharin-catalysed acylation of alcohols has been successfully carried out more than 8 times. Only 1 mol% of catalyst 1 efficiently promotes acylation with almost equimolar amounts of acid anhydrides, under both base-free and solvent-free conditions.

5,5'-Bis[(2,2,2-trifluoro-eth-oxy)meth-yl]-2,2'-bipyridine.

The complete molecule of the title compound, C(16)H(14)F(6)N(2)O(2), is generated by crystallographic inversion symmetry, which results in two short intramolecular C-H⋯N hydrogen-bond contacts per molecule. In the crystal, aromatic π-π stacking [centroid-centroid distance = 3.457 (2) Å] and weak C-H⋯π inter-actions occur. A short H⋯H [2.32 (3) Å] contact is present.

Novel fluorous amphiphilic heteroleptic Ru-based complexes for a dye-sensitized solar cell: the first fluorous bis-ponytailed amphiphilic Ru complexes.

A new series of amphiphilic heteroleptic ruthenium(II) sensitizers with a fluorous bis-ponytailed bipyridine ancillary ligand, [Ru(H(2)dcbpy)(4,4'-bis(R(f)CH(2)OCH(2))-2,2'-bpy)(NCS)(2)] [where R(f) = HCF(2)CF(2) (CT4), C(3)F(7) (CT7), and HCF(2)CF(2)CF(2)CF(2) (CT8)], have been synthesized and fully characterized by UV/vis, visible emission, NMR, fast atom bombardment mass spectrometry, and cyclic voltammetric studies. Dye-sensitized solar cells (DSCs) based on these dyes exhibit efficiencies comparable with that of the standard cell based on N719. The conversion efficiency of a CT7- or CT8-based DSC is ~9% higher than that of Z907 with a nonfluorous bis-ponytailed bipyridine ancillary ligand. The fluorous chains were found to increase the dye density on TiO(2) and to help to suppress the dye desorption.

4,4'-Bis(2,2,2-trifluoroethoxymethyl)-2,2'-bipyridine.

As part of a homologous series of novel polyfluorinated bipyridyl (bpy) ligands, the title compound, C(16)H(14)F(6)N(2)O(2), contains the smallest fluorinated group, viz. CF(3). The molecule resides on a crystallographic inversion centre at the mid-point of the pyridine C(ipso)-C(ipso) bond. Therefore, the bpy skeleton lies in an anti conformation to avoid repulsion between the two pyridyl N atoms. Weak intramolecular C-H...N and C-H...O interactions are observed, similar to those in related polyfluorinated bpy-metal complexes. A pi-pi interaction is observed between the bpy rings of adjacent molecules and this is probably a primary driving force in crystallization. Weak intermolecular C-H...N hydrogen bonding is present between one of the CF(3)CH(2)- methylene H atoms and a pyridyl N atom related by translation along the [010] direction, in addition to weak benzyl-type C-H...F interactions to atoms of the terminal CF(3) group. It is of note that the O-CH(2)CF(3) bond is almost perpendicular to the bpy plane.