Brilliant red crystals from colorless solution: Re-examination of the cause of the solid-state effect in bis(dimethylglyoximato)nickel(II)

INOR 433

Ronald L. Musselman, RMusselm@cas.usf.edu, Department of Chemistry, Franklin and Marshall College and University of South Florida, 4202 E. Fowler Avenue, Tampa, FL 33620 and Asher A. Miller, Department of Chemistry, Franklin and Marshall College, Lancaster, PA 17603.
The quantitative precipitation of Ni(dmg)2 when dimethylglyoxime is in the presence of nickel ions is a classic reaction for the wet analytical determination of Ni. The brilliant red color of the crystals developing from an essentially colorless solution was cited several decades ago in a specular reflectance study as an excellent example of a dramatic spectral change upon stacking of planar molecules. We recently re-examined the polarized specular reflectance spectra of Ni(dmg)2 with a greatly improved instrument and found the early experimental data to be essentially correct. Upon calculating a simulation of the solid-state perturbation with a Zerner-modified INDO technique that has proven successful for both simpler and more complex similar molecules, however, we found that the earlier interpretation of a dz2 → pz single molecule transition red-shifting some 10 kcm-1 upon crystallization may need reinterpretation.
 

Spectroscopy --> Electronic Structure --> Reactivity
7:00 PM-10:00 PM, Sunday, March 25, 2007 Hyatt Regency Chicago -- Riverside Center, Poster

Sci-Mix
8:00 PM-10:00 PM, Monday, March 26, 2007 Hyatt Regency Chicago -- Riverside Center, Sci-Mix

Division of Inorganic Chemistry

The 233rd ACS National Meeting, Chicago, IL, March 25-29, 2007