219609-65-1

Upstream product

• 109-72-8 n-butyllithium 
• 121-43-7 Trimethyl borate 
• 14162-95-9 4-bromo-2,2'-bipyridyl 
• 7647-01-0 hydrogenchloride 
• 5419-55-6 Triisopropyl borate 
• 14163-00-9 4-nitro-2,2'-bipyridine N-oxide 
• 14163-03-2 4-bromo-2,2’-bipyridine N-oxide 

Relevant academic research and scientific papers

Syntheses, characterization, and photochemical properties of amidate-bridged Pt(bpy) dimers tethered to Ru(bpy)32+ derivatives

Amidate-bridged diplatinum(ii) entities [Pt2(bpy) 2(μ-amidato)2]2+ (amidate = pivalamidate and/or benzamidate; bpy = 2,2′-bipyridine) were covalently linked to one or two Ru(bpy)32+-type derivatives. An amide group was introduced at the periphery of Ru(bpy)32+ derivatives to give metalloamide precursors [Ru(bpy)2(BnH)]2+ (abbreviated as RuBnH, n = 1 and 2), where deprotonation of amide BnH affords the corresponding amidate Bn, B1H = 4-(4-carbamoylphenyl)-2,2′-bipyridine, and B2H = ethyl 4′-[N-(4-carbamoylphenyl)carbamoyl]-2,2′- bipyridine-4-carboxylate. From a 1:1:1 reaction of [Pt2(bpy) 2(μ-OH)2](NO3)2, RuBnH, and pivalamide, trinuclear complexes [Pt2(bpy)2(μ-RuBn) (μ-pivalamidato)]4+ (abbreviated as RuBn-Pt2) were isolated and characterized. Tetranuclear complexes [Pt2(bpy) 2(μ-RuBn)2]6+ (abbreviated as (RuBn) 2-Pt2) were separately prepared and characterized in detail. The quenching of the triplet excited state of the Ru(bpy) 32+ derivative (i.e., Ru*(bpy)3 2+) upon tethering the Pt2(bpy)2(μ-amidato) 22+ moiety is strongly enhanced in RuB1-Pt2 and (RuB1)2-Pt2, while it is only slightly enhanced in RuB2-Pt2 and (RuB2)2-Pt2. These are partly explained by the driving forces for the electron transfer from the Ru*(bpy)32+ moiety to the Pt2(bpy) 2(μ-amidato)22+ moiety (ΔG° ET); the ΔG°ET values for RuB1-Pt2, (RuB1)2-Pt2, RuB2-Pt2, and (RuB2) 2-Pt2 are estimated as -0.01, 0.00, +0.22, and +0.28 eV, respectively. The considerable difference in the photochemical properties of the B1- and B2-bridged systems were further examined based on the emission decay and transient absorption measurements, which gave results consistent with the above conclusions.

A boronic acid-diol interaction is useful for chiroselective transcription of the sugar structure to the Δ- Versus Λ-[CoIII(bpy)3]3+ ratio

In order to apply boronic acid-saccharide interactions to the chiroselective synthesis of Δ- and Λ-[CoIII(bpy)3]3+ saccharide-binding ligands, 2,2′-bipyridine-4-boronic acid (bpymb) and 2,2′-bipyridine-4,4′-diboronic acid (bpydb) were newly synthesized. It was shown that most D-saccharides form cyclic 1:1 complexes with bpydb to afford the CD-active species. The positive exciton coupling band implies that two pyridine rings are twisted in a clockwise direction ((R)-chirality). In contrast, such a CD-active species was not yielded from bpymb. The treatment of the bpydb-D-saccharide complexes with Co(OAc)2 gave the substitution-active [CoII(bpyba)3]4--saccharide complexes, which were oxidized to the substitution-inactive [CoIII(bpyba)3]3--saccharide complexes. In this stage, the Δ vs. Λ ratio was fixed. The complexes were converted to [CoIII(bpy)]3+ by treatment with AgNO3 and the e.e. was determined by comparison with authentic Δ- or Λ-[CoIII(bpy)]3+. The Δ-isomer was obtained in excess from most D-saccharides but the Λ-isomer was also obtained from D-fructose and D-fucose. At 4°C, the largest e.e. for bpydb was attained with D-glucose (47% e.e.; Δ excess). Under the same reaction conditions the bpymb + D-glucose system gave 16% e.e. (Δ excess). The e.e. of the bpydb + D-glucose system increased with lowering the reaction temperature and at -25°C it reached 79% e.e. The foregoing results clearly establish that the saccharide-templated synthesis is useful as a new concept for the preparation of chiral tris(2,2′-bipyridine)-metal complexes. Furthermore, the Δ vs. Λ equilibrium can be shifted in either direction by the selection of saccharide enantiomers.