geoscience.net logo
+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Bis(alpha-diimine)nickel complexes: molecular and electronic structure of three members of the electron-transfer series [Ni(L)(2)](z)() (z = 0, 1+, 2+) (L = 2-Phenyl-1,4-bis(isopropyl)-1,4-diazabutadiene). A combined experimental and theoretical study


, : Bis(alpha-diimine)nickel complexes: molecular and electronic structure of three members of the electron-transfer series [Ni(L)(2)](z)() (z = 0, 1+, 2+) (L = 2-Phenyl-1,4-bis(isopropyl)-1,4-diazabutadiene). A combined experimental and theoretical study. Inorganic Chemistry 46(13): 5327-5337

From the reaction of Ni(COD)(2) (COD = cyclooctadiene) in dry diethylether with 2 equiv of 2-phenyl-1,4-bis(isopropyl)-1,4-diazabutadiene (L(Ox))(0) under an Ar atmosphere, dark red, diamagnetic microcrystals of [Ni(II)(L*)(2)] (1) were obtained where (L*)(1-) represents the pi radical anion of neutral (L(Ox))(0) and (L(Red))(2-) is the closed shell, doubly reduced form of (L(Ox))(0). Oxidation of 1 with 1 equiv of ferrocenium hexafluorophosphate in CH(2)Cl(2) yields a paramagnetic (S = 1/2), dark violet precipitate of [Ni(I)(L(Ox))(2)](PF(6)) (2) which represents an oxidatively induced reduction of the central nickel ion. From the same reaction but with 2 equiv of [Fc](PF(6)) in CH(2)Cl(2), light green crystals of [Ni(II)(L(Ox))(2)(FPF(5))](PF(6)) (3) (S = 1) were obtained. If the same reaction was carried out in tetrahydrofuran, crystals of [Ni(II)(L(Ox))(2)(THF)(FPF(5))](PF(6)) x THF (4) (S = 1) were obtained. Compounds 1, 2, 3, and 4 were structurally characterized by X-ray crystallography: 1 and 2 contain a tetrahedral neutral complex and a tetrahedral monocation, respectively, whereas 3 contains the five-coordinate cation [Ni(II)(L(Ox))(2)(FPF(5))](+) with a weakly coordinated PF(6)(-) anion and in 4 the six-coordinate monocation [Ni(II)(L(Ox))(2)(THF)(FPF(5))](+) is present. The electro- and magnetochemistry of 1-4 has been investigated by cyclic voltammetry and SQUID measurements. UV-vis and EPR spectroscopic data for all compounds are reported. The experimental results have been confirmed by broken symmetry DFT calculations of [Ni(II)(L*)(2)](0), [Ni(I)(L(Ox))(2)](+), and [Ni(II)(L(Ox))(2)](2+) in comparison with calculations of the corresponding Zn complexes: [Zn(II)((t)L(Ox))(2)](2+), [Zn(II)((t)L(Ox))((t)L*)](+), [Zn(II)((t)L*)(2)](0), and [Zn(II)((t)L*)((t)L(Red))](-) where ((t)L(Ox))(0) represents the neutral ligand 1,4-di-tert-butyl-1,4-diaza-1,3-butadiene and ((t)L*)(1-) and ((t)L(Red))(2-) are the corresponding one- and two-electron reduced forms. It is clearly established that the electronic structures of both paramagnetic monocations [Ni(I)(L(Ox))(2)](+) (S = 1/2) and [Zn(II)((t)L(Ox))((t)(L*)](+) (S = 1/2) are different.

US$19.90

PMID: 17530843

DOI: 10.1021/ic700407m


Other references

Reeb, R.M.; McFarland, S.T., 1995: Emergency baptism. Journal of Christian Nursing 12(2): 27-27

Lane, C., 2005: Witch hazels. This book aims to authenticate and describe all known selections, varieties and species of witch hazels. The first 2 chapters cover the nomenclature and taxonomy, and morphology and distribution of these winter-flowering shrubs. This is followed b...

Slatopolsky, E.; Finch, J.; Denda, M.; Ritter, C.; Zhong, M.; Dusso, A.; Macdonald, P.; Brown, A., 1995: Phosphate restriction prevents parathyroid cell growth in uremic rats and high phosphate directly stimulates PTH secretion in tissue culture. Journal of the American Society of Nephrology 6(3): 971

Zhang GuoFang; Storozhenko, S.; Straeten, D. van der; Lambert, W.E., 2005: Investigation of the extraction behavior of the main monoglutamate folates from spinach by liquid chromatography-electrospray ionization tandem mass spectrometry. An LC-MS/MS method has been developed for the determination of main monoglutamate folates in spinach with folic acid as an internal standard. A sample preparation with ultrafiltration (molecular weight cut-off membrane, 5 kDa) was followed by a ch...

Singh D.D.; Rastogi B.K., 1984: Source mechanism studies in Himalaya and nearby regions. Pages 11 1984

Zagorska, N.; Palakarcheva, M.; Shabanov, D.; Popristev, V., 1978: Homo zygous tobacco lines produced by induced androgenesis. More than 700 haploid plants were produced by induced androgenesis in anther cultures from 3 regenerants and 13 hybrids. Their diploidization was achieved by callus cultures of leaves, leaf pedicels and stem pith parenchyma of young haploid plants...

Ginsburg, L.; Bulot, C., 2000: The stratigraphic context. One of the interests of Sansan is that the fossiliferous layer is interbedded in the large series of the Molasses de l'Armagnac, which has yielded several famous sites for fossils. So the relative age of these different sites is known directl...

Wong, HA.; Fernando, MA., 1981: Effects of temperature and glucose concentration on glycogen synthesis in Ancylostoma caninum. The glycogen content of starved Ancylostoma caninum incubated in Krebs-Ringer bicarbonate, ox serum or dog serum, increased with increasing glucose concentrations. A maximum of worm glycogen content was reached at a much lower glucose concentratio...

Pomarede, M., 1986: Les minuscules parasites des cages et des volieres (deuxieme partie). Journal des Oiseaux, 26-29 No. 199

Able, J.A.; Rathus, C.; Gray, S.; Nguyen, T.V.; Godwin, I.D., 1998: Transformation of sorghum using the Particle Inflow Gun (PIG). Optimum parameters for the genetic transformation of sorghum (Sorghum bicolor) tissues with GUS [uidA] using a PIG were investigated. The highest mean number of GUS spots/leaf of callus piece was obtained under a pressure of 2200 kPa and a shelf d...