Probing 1J(C-F) and nJ(F-F) Spin-Spin Coupling Constants for Fluoroazines: An Ab Initio Theoretical Investigation was written by Del Bene, Janet E.;Alkorta, Ibon;Elguero, Jose. And the article was included in Journal of Physical Chemistry A in 2010.HPLC of Formula: 33097-39-1 This article mentions the following:
Ab initio equation-of-motion coupled cluster singles and doubles calculations have been carried out to evaluate one-bond C-F coupling constants 1J(C-F) and three-, four-, and five-bond F-F coupling constants nJ(F-F) for a series of mono-, di-, and trifluoroazines. The computed 1J(C-F) and nJ(F-F) values for these are in good agreement with available exptl. coupling constants The values of 1J(C-F) vary as the number and positions of N atoms and the number and relative positions of C-F bonds change, but it is difficult to discern general patterns for these changes due to opposing effects of the Fermi contact and paramagnetic spin-orbit terms. The majority of 1J(C-F) values lie in a range that includes the three monosubstituted pyridines. For trifluoroazines, 1J(C-F) for a C-F bond that is ortho to two other C-F bonds is greater than 1J(C-F) for the other two bonds. F-F coupling constants arise in these mols. when the two C-F bonds are ortho, meta, or para. Values of 3J(F-F) are relatively large and neg., whereas values of 5J(F-F) are relatively large and pos. 4J(F-F) may be pos. or neg. and large or small. The value of this coupling constant depends on the nature of the atom that links the two C-F bonds and the number and positions of N atoms in the ring. The calculations carried out in this study at a reliable level of theory give values for one-bond C-F and n-bond F-F spin-spin coupling constants for the fluoroazines that are not available exptl. In addition, the patterns that describe the changes that occur in these mols. provide a basis for predicting their values in larger, related systems in the absence of exptl. data and direct calculations In the experiment, the researchers used many compounds, for example, 3,6-Difluoropyridazine (cas: 33097-39-1HPLC of Formula: 33097-39-1).
3,6-Difluoropyridazine (cas: 33097-39-1) belongs to pyridazine derivatives. Pyridazine and phthalazine have quite different spectroscopic properties compared with their isomers, pyrazine and quinoxaline. Pyridazine and derivatives coordinate readily with transition metals to form complexes and catalysts with synthetic utility.HPLC of Formula: 33097-39-1
Referemce:
Pyridazine – Wikipedia,
Pyridazine | C4H4N2 – PubChem