A tale of hydrogen abstraction, initially detected via X-ray diffraction

作者：Hui Alice K; Chen Chun Hsing; Terwilliger Adam M; Lord Richard L^*; Caulton Kenneth G

来源：Acta Crystallographica Section C-Crystal Structure Communications, 2014, 70(3): 250-+.

DOI：10.1107/S2053229614003234

• crystal structure
• vanadium
• hydrogen bonding
• non-innocent
• tetrazine
• hydrogen abstraction
• redox

Reaction of a bis-tetrazinyl pyridine pincer ligand, btzp, with a vanadium(III) reagent gives not a simple adduct but dichlorido{3-methyl-6-[6-(6-methyl-1,2,4,5-tetrazin-3-yl-kappa N-2)pyridin-2-yl-kappa N]-1,4-dihydro-1,2,4,5-tetrazin-1-yl-kappa N-1}oxidovanadium(IV) acetonitrile 2.5-solvate, [V(C11H10N9)Cl2O]center dot 2.5CH(3)CN, a species which X-ray diffraction reveals to have one H atom added to one of the two tetrazinyl rings. This H atom was first revealed by a short intermolecular N center dot center dot center dot Cl contact in the unit cell and subsequently established, from difference maps, to be associated with a hydrogen bond. One chloride ligand has also been replaced by an oxide ligand in this synthetic reaction. This formula for the complex, [V(Hbtzp)Cl2O], leaves open the question of both ligand oxidation state and spin state. A computational study of all isomeric locations of the H atom shows the similarity of their energies, which is subject to perturbation by intermolecular hydrogen bonding found in X-ray work on the solid state. These density functional calculations reveal that the isomer with the H atom located as found in the solid state contains a neutral radical Hbtzp ligand and tetravalent d(1) V center, but that these two unpaired electrons are more stable as an open-shell singlet and hence antiferromagnetically coupled.

• 出版日期2014-3