MPI für bioanorganische Chemie / MPI für bioanorganische Chemie |
|Electronic Structures of Octahedral Ni(II) Complexes with "Click" Derived Triazole Ligands: A Combined Structural, Magnetometric, Spectroscopic, and Theoretical Study|
|Authors:||Schweinfurth, David; Krzystek, J.; Schapiro, Igor; Demeshko, Serhiy; Klein, Johannes; Telser, Joshua; Ozarowski, Andrew; Su, Cheng-Yong; Meyer, Franc; Atanasov, Mihail; Neese, Frank; Sarkar, B.|
|Date of Publication (YYYY-MM-DD):||2013|
|Title of Journal:||Inorganic Chemistry|
|Journal Abbrev.:||Inorg. Chem.|
|Abstract / Description:||The coordination complexes of Ni(II) with the tripodal ligands tpta (tris[(1-phenyl-1H-1,2,3-triazol-4-yl)methyl]amine), tbta ([(1-benzyl-1H-1,2,3-triazol-4-yl)methyl]amine), and tdta (tris[(1-(2,6-diisopropyl-phenyl)-1H-1,2,3-triazol-4-yl)methyl]amine) and the bidentate ligand pyta (1-(2,6-diisopropylphenyl)-4-(2-pyridyl)-1,2,3-triazole), [Ni(tpta)(2)](BF4)(2) (1), [Ni(tbta)(2)](BF4)(2) (2), [Ni(tdta)(2)](BF4)(2) (3), and [Ni(pyta)(3)](BF4)(2) (4), were synthesized from Ni(BF4)(2)center dot 6H(2)O and the corresponding ligands. Complexes 2 and 4 were also characterized structurally using X-ray diffraction and magnetically via susceptibility measurements. Structural characterization of 2 that contains the potentially tetradentate, tripodal tbta ligand revealed that the Ni(II) center in that complex is in a distorted octahedral environment, being surrounded by two of the tripodal ligands. Each of those ligands coordinate to the Ni(II) center through the central amine nitrogen atom and two of the triazole nitrogen donors; the Ni-N(amine) distances being longer than Ni-N(triazole) distances. In case of 4, three of the bidentate ligands pyta bind to the Ni(II) center with the binding of the triazole nitrogen atoms being stronger than those of the pyridine. Temperature dependent susceptibility measurements on 2 and 4 revealed a room temperature chi T-M value of 1.18 and 1.20 cm(3) K mol(-1), respectively, indicative of S = 1 systems. High-frequency and field EPR (HFEPR) measurements were performed on all the complexes to accurately determine their g-tensors and the all-important zero-field splitting (zfs) parameters D and E. Interpretation of the optical d-d absorption spectra using ligand field theory revealed the B and Dq values for these complexes. Quantum chemical calculations based on the X-ray and DFT optimized geometries and their ligand field analysis have been used to characterize the metal-ligand bonding and its influence on the magnitude and sign of the zfs parameters. This is the first time that such extensive HFEPR, LFT, and advanced computational studies are being reported on a series of mononuclear, distorted octahedral Ni(II) complexes containing different kinds of nitrogen donating ligands in the same complex.|
|External Publication Status:||published|
|Communicated by:||N. N.|
|Affiliations:||MPI für bioanorganische Chemie|
|External Affiliations:||Schweinfurth, D.; Sarkar, B.; Free Univ Berlin, Inst Chem & Biochem, D-14195 Berlin, Germany.
Krzystek, J.; Ozarowski, A.; Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32310 USA.
Demeshko, S.; Meyer, F.; Univ Göttingen, Inst Anorgan Chem, D-37077 Gottingen, Germany.
Klein, J.; Univ Stuttgart, Inst Anorgan Chem, D-70569 Stuttgart, Germany.
Telser, J.;Roosevelt Univ, Dept Biol Chem & Phys Sci, Chicago, IL 60605 USA.
Su, C.-Y.; Sun Yat Sen Univ, Sch Chem & Chem Engn, Lehn Inst Funct Mat, Guangzhou 510275, Guangdong, Peoples R China.
|Identifiers:||ISI:000320689200015 [ID No:1] |
ISSN:0020-1669 [ID No:2]
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