Nickel structural data

SiH3)2C6H4 (H2L) leads to the nickel(iv) complex Ni(dmpe-P,.f, )(L-6V,6V )2. 31P NMR spectroscopic studies of the reaction indicate the presence of the intermediates Ni(dmpe-.P,.P )(dmpe-P)(L-Structural data have confirmed the unusual Ni2Si2 core. Starting from Ni(depe)2 (depe = l,2-bis(diethylphosphino)ethane), reaction with... 

The approach to pyrazino[2,3-, ]quinoxalines shown in Equation (114) has now been used to prepare pyrazino[2,3-, ]pyrazines <2007EJ01237>, whose nickel complexes have also been prepared. The same publication also describes the formation of 172 by treatment of conjugated system 173 with sodium thiosulfate. The former is reconverted to the latter on exposure to air and, on further aerial oxidation at 130 °C, 173 eventually forms the highly condensed system 174. Detailed studies of the formation of the tetrahydropyrazinopyrazine 101 have been reported, along with theoretical studies, and structural data for the trans isomer <2007T6915>. 

Relevant structural data for selected mixed phosphine carbonyl complexes are shown in Table 5. In all these complexes the nickel(O) atom is four-coordinate in a pseudotetrahedral geometry with the Ni—CO linkage essentially linear, the Ni—C—O angles being in the range 173-178°. In complex (14) the np3 ligand bonds through the three phosphorus atoms and the r. kel is in a pseudotetrahedral environment.103... 

A number of X-ray crystal structures of nickel(O) complexes containing both alkenes and phosphines have been reported to date with the aim of gaining more information on the bonding in metal alkene complexes. Structural data for the most relevant nickel(O) phosphine alkene complexes are reported in Table 9. 

Table 9 Structural Data for some Nickel(0) Phosphine Alkene Mixed Complexes and Related...

Table 17 Structural Data for some Complexes Containing the CjPh3 Fragment Coordinated to the Nickel...

Hundreds of nickel(II) complexes with monodentate phosphines have been reported. Selected complexes are reported in Table 59 together with some of their physicochemical properties. A selection of structural data is shown in Table 60. 

A few representative examples of simple organometallic compounds of nickel(II) including carbonyl and hydrido compounds are reported here. A more complete listing of such types of compound is given in Comprehensive Organometallic Chemistry (vol. 6, p. 37) and references therein. Selected structural data for organometallic nickel(II) complexes with monodentate phosphines are reported in Table 61. 

Table 82 Structural Data for Representative Nickel(II) Complexes Containing Coordinated Nitrite...

Dithiolenes have been found to stabilize nickel(III) and a number of structural investigations have been performed on nickel(III) dithiolene complexes. Structural data and physical properties of selected compounds are collected in Table 120. The EPR spectra of the [NiS4] unit have been extensively studied in order to decide whether the unpaired electron resides mainly on the metal or on the ligand3202,3203,3210,3212-3217 giving rise to a true nickel(III) complex (422) or to a nickel(II)-stabilized ligand radical complex (423). 

Structural Data for Binary Nickel Xanthates, Ni(S2COR)2... 

Structural Data for Nickel Xanthate Adducts of the General Formula Ni(S2COR)2(NnN)... 

Table 12. Structural data for selected unoxidized small-ring nickel porphyrin systems...

An electron-diffraction experiment in the gas phase and an X-ray diffraction study at low temperature on solid Ni(CO)4 have shown the compound to have a regular tetrahedral geometry. An accurate refinement of the structural data has established the carbonyl ligands to be C-bonded to nickel. ... 

Auf der Heyde, T. P. E., and Nassimbeni, L. R. Reaction pathways from structural data dynamic stereochemistry of nickel compounds. Inorg. Chem. 23, 4525-4532 (1984). 

In recent years Ishikawa and coworkers have described some very complex photochemical rearrangements of compounds derived from nickel-catalyzed reactions of silacyclopropenes with silylalkynes. As depicted in equation 93, it was shown that the disilacyclohexadiene A could be photochemically converted to the same products as were formed from the silacyclobutene B. In the absence of a trapping reagent the silaindene C was formed as a major product, via the proposed intermediates shown141. In the presence of methanol, two adducts were isolated whose structures can be understood in terms of the reaction of methanol with one of the proposed intermediates. While the structures of the products are confirmed by the X-ray crystal structure data, the mechanisms of the reactions observed must be considered speculative at this time. 

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