142593-07-5Relevant articles and documents
Insights on the synthesis and organisational phenomena of twisted pyrazine-pyridine hybrids
Heirtzler, Fenton,Neuburger, Markus,Kulike, Klaus
, p. 809 - 820 (2002)
Pyrazine-pyridine hybrids containing two different oligopyridyl chains, 2,3-disubstituted onto the pyrazine ring nucleus are prepared from appropriate mixed α-diketone precursors. The latter were obtained by epoxidation of the enols of corresponding 1,2-disubstituted ethanones. The structures of the pyrazine derivatives were investigated by detailed proton NMR spectroscopic and X-ray crystallographic methods. These indicated a twisting of the oligopyridyl chains about one another to result in a pre-double helical topology. This phenomenon occurred up to two pyridin-2,6-diyl groupings from the pyrazine ring and is accompanied by edge-on-face stacking of spatially proximate pyridyl rings. Parallel stacking of pyrazine and weak C-H···N acid interactions are significant in their crystal lattices and may also figure in their metallosupramolecular self-assembly behaviour patterns.
Spectroscopic characterization of dipicolinic acid and its photoproducts as thymine photosensitizers
Lhiaubet-Vallet, Virginie,Lineros-Rosa, Mauricio,Miranda, Miguel A.,Nardi, Giacomo,Palumbo, Fabrizio
, (2021)
Dipicolinic acid (DPA), present in large amount in bacterial spores, has been proposed to act as an endogenous photosensitizer in spore photoproduct formation. The proposed mechanism involves a triplet-triplet energy transfer from DPA to thymine. However, up to now, no spectroscopic studies have been performed to determine the interaction between the endogenous compound and the nucleobase, probably due to its photolability in aqueous solutions. Here, triplet excited state properties of DPA are reported together with its bimolecular quenching rate constant by thymidine, kq of ca. 5.3 × 109 M?1 s?1. To run more reliable studies, a stable methyl ester derivative of DPA, which exhibits the same spectroscopic properties as the parent compound, is also described. Finally, DPA photoproducts are characterized. Studies of their triplet excited state properties have demonstrated that, interestingly, one of them is able to photosensitize thymidine triplet excited state formation.
Convergent access to bis-1,2,4-triazinyl-2,2′-bipyridines (BTBPs) and 2,2′-bipyridines: Via a Pd-catalyzed Ullman-type reaction
Carrick, Jesse D.,Waters, Gabrielle D.
, p. 10807 - 10815 (2020/03/27)
Multidentate, soft-Lewis basic, complexant scaffolds have displayed significant potential in the discrete speciation of the minor actinides from the neutron-absorbing lanthanides resident in spent nuclear fuel. Efforts to devise convergent synthetic strategies to targets of interest to improve liquid-liquid separation outcomes continue, but significant challenges to improve solubility in process-relevant diluents to effectively define meaningful structure-activity relationships remain. In the current work, a synthetic method to achieve the challenging 2,2′-bipyridine bond of the bis-1,2,4-triazinyl-2,2′-bipyridine (BTBP) complexant class leveraging a Pd-catalyzed Ullman-type coupling is reported. This convergent strategy improves upon earlier work focused on linear synthetic access to the BTBP complexant moiety. Method optimization, relevant substrate scope and application, as well as a preliminary mechanistic interrogation are reported herein.
