James Takemoto

METAL ISOTOPE EFFECT ON METAL-LIGAND VIBRATIONS. V. CIS AND TRANS Ni(II) PHOSPHINE--HALIDE COMPLEXES.

Abstract Infrared spectra (4000–200 cm−1) have been reported for Ni(DPE)X2 where X is Cl, Br and I and DPE is 1,2-bis(diphenylphosphino)ethane. The Ni[sbnd]X and Ni[sbnd]P stretching bands have been assigned based on the observed isotopic shifts due to the 58Ni-62Ni substitution. The Ni[sbnd]X stretching frequencies are always lower and the Ni[sbnd]P stretching frequencies are always higher in the cis-complexes such as Ni(DPE)X2 than in the corresponding trans-complexes such as Ni(PEt3)2X2. These differences between cis and trans configurations have been attributed to the strong trans-effect of phosphine ligands.

Metal Isotope Effect on Raman Spectrum of [Zn(NH3)4]I2 Crystals

The Raman spectra of [64Zn(NH3)4]I2 and its 68Zn analog have been measured in the crystalline state. The Zn–N stretching vibrations have been assigned based on the observed metal isotope shifts. These shifts have been compared with theoretical values obtained from a complete normal coordinate analysis on the [Zn(NH3)4]2+ ion.

Effect of changing oxidation state on the metal–ligand vibrations of [Cr(2,2′-bipyridyl)3]n+ type complexes

In the series of tris-(2,2′-bipyridyl) complexes of chromium, the Cr–N stretching frequencies change very little by changing the oxidation state of chromium from III to 0, this unexpected result indicating that the strength of the Cr–N bond does not change appreciably over a wide change in the oxidation state of chromium.

Metal isotope effect on the Raman spectrum of solid [Zn(NH3)4]I2

The A1 and F2 Zn–N stretching vibrations of the Raman spectrum of solid [Zn(NH3)4]I2 have been assigned by using the metal isotope technique: the A1 mode shows almost no dependence on the isotopic substitution of the central metal atom, whereas the F2 mode is metal isotope-sensitive.