Robert Erik Sammelson

Structure and vibrational assignment of beryllium acetylacetonate

The structure of beryllium acetylacetonate, Be(acac)(2), was fully optimized at the B3LYP (using the 6-31G*, 6-311G*, and 6-311++G(3df,2p) basis sets), Hartree-Fock, and the Möller-Plesset (using the 6-31G* basis set) levels. The frequency and intensity of the vibrational bands of Be(acac)(2) and its 1,3,5-(13)C; 2,4-(13)C; 3-(2)H; 3-(2)H-2,4-(18)O derivatives were obtained at the B3LYP level using 6-311G* basis set. We also calculated the anharmonic frequencies at the B3LYP/6-311G* level of theory for Be(acac). The calculated frequencies are compared with the experimental Fourier transform IR and Raman spectra. All of the measured IR and Raman bands were interpreted in terms of the calculated vibrational modes. The scaled theoretical frequencies and the structural parameters are in excellent agreement with the experimental data. Analysis of the vibrational spectra indicates a strong coupling between the chelated ring modes. Four bands at the 1042, 826, 748, and 480cm(-1) are found to be mainly due to the metal-oxygen stretching motions.

X-ray diffraction and vibrational spectroscopic study of trans-bis(acetylacetonato)-bis(4-methylpyridine)cobalt(III)

Trans-bis(acetylacetonato)-bis(4-methylpyridine)cobalt(III)hexafluorophosphate, [AMPC]PF6, was synthesized and characterized by X-ray diffraction and vibrational spectroscopy. The title compound C22H28N2O4Co crystallizes with Z=2 in space group P-1 (#2). The molecular structure and vibrational spectra of this compound were investigated by means of density functional theory (DFT) calculations and the results were compared with the experimental data. The measured IR bands were interpreted in terms of the calculated vibrational normal modes and compared with the tris(acetylacetonate)Co(III) (Co(acac)3) and 4-methylpyridine (4-Mepy) vibrational spectra. The scaled theoretical wavenumbers and the structural parameters were in excellent agreement with the experimental data.