156818-63-2

Upstream product

• 612-28-2 2-nitro-N-methylaniline 
• 589-93-5 2,5-dimethylpyridine 
• 55876-82-9 5-methyl-2-pyridinecarboxylic acid-ethyl ester 
• 88-73-3 2-Chloronitrobenzene 
• 4434-13-3 2-carboxy-5-methylpyridine 
• 100974-85-4 4,4’-methylene-2,2’-dinitro-bis(N-methyl-aniniline) 
• 128073-07-4 5-methylpyridine-2-carboxylic acid chloride 

Downstream Products

• 156818-73-4 N,N'-5,5'-tetramethyl,N,N'-(3-nitrophen-4,1-ylene)methylene(2-nitrophen-4,1-ylene)>>bis 
• 179468-76-9 Pyridine-2,6-dicarboxylic acid 2-diethylamide 6-[methyl-(4-{4-[methyl-(5-methyl-pyridine-2-carbonyl)-amino]-3-nitro-benzyl}-2-nitro-phenyl)-amide] 

Relevant academic research and scientific papers

Smaller than a nanoparticle with the design of discrete polynuclear molecular complexes displaying near-infrared to visible upconversion

This work shows that the operation of near-infrared to visible light-upconversion in a discrete molecule is not limited to non-linear optical processes, but may result from superexcitation processes using linear optics. The design of nine-coordinate metallic sites made up of neutral N-heterocyclic donor atoms in kinetically inert dinuclear [GaEr(L1)3]6+ and trinuclear [GaErGa(L2)3]9+ helicates leads to [ErN9] chromophores displaying unprecedented dual visible nanosecond Er(4S3/2→4I15/2) and near-infrared microsecond Er(4I13/2→4I15/2) emissive components. Attempts to induce one ion excited-state absorption (ESA) upconversion upon near-infrared excitation of these complexes failed because of the too-faint Er-centred absorption cross sections. The replacement of the trivalent gallium cation with a photophysically-tailored pseudo-octahedral [CrN6] chromophore working as a sensitizer for trivalent erbium in [CrEr(L1)3]6+ improves the near-infrared excitation efficiency, leading to the observation of a weak energy transfer upconversion (ETU). The connection of a second sensitizer in [CrErCr(L2)3]9+ generates a novel mechanism for upconversion, in which the superexcitation process is based on the CrIII-sensitizers. Two successive Cr→Er energy transfer processes (concerted-ETU) compete with a standard Er-centred ETU, and a gain in upconverted luminescence by a factor larger than statistical values is predicted and observed.

Syntheses of Segmental Heteroleptic Ligands for the Self-Assembly of Heteronuclear Helical Supramolecular Complexes

The development of a modified Phillips reaction allows the synthesis of complicated heteroleptic ligands based on pyridine and 1H-benzimidazole moieties.The key-step formation of aromatic 1H-benzimidazole rings from N-(2-nitroaryl)arenecarboxamides significantly improves the possibilities of the classical intermolecular Phillips reactions and can be applied to the synthesis of large oligo-multidentate units.Segmental heteroleptic ligands containing two different bidentate coordinating units (see 14) or bidentate and terdentate sites connected by 'diphenylmethane' (= methylenebis(phenylene)) spacers (see 15 and 16) were obtained in fair to good yield by using multistep syntheses following this strategy.Heterotrileptic ligands (bidentate-terdentate-bidentate, see 19 and 20; terdentate-terdentate-terdentate, see 23) requiring the simultaneous formation of four 1H-benzimidazole rings in one step were prepared and demonstrate the extended possibilities of this methodology.Data are presented to show that the milder conditions used for this modified Phillips reaction together with its flexibility are essential for the development of ligands adapted for the self-assembly of heteronuclear helical complexes.