Mixed ligand complexes of β-diketonates: synthesis, characterization, and FAB mass spectral analysis

• Published in: Journal of coordination chemistry 2009-09, Vol.62 (18), p.2983-2994
• Main Authors: Prasad, Ram Lakhan, Kushwaha, Anita, Gautam, Bhanu Pratap S.
• Format: Article
• Language: English
• Subjects: ESR spectra of mixed ligand complexes; FAB mass spectra of β-diketonates; Mixed ligand complexes; β-diketonates
• ISSN: 0095-8972; 1029-0389
• DOI: 10.1080/00958970902954102

Complexes of the type MLL′ · nB (where M = Ni(II) and Cu(II); LH and L′H = 2,4-pentanedione (acacH), 1-phenyl-1,3-butanedione (bacH), and 1,3-diphenyl-1,3-propanedione (dbmH); n = 0 to 2 and B = water or pyridine) have been synthesized and characterized. IR spectra are consistent with uninegative bidentate ligands. Magnetic moments and electronic spectral studies reveal high-spin octahedral geometry for nickel(II) complexes and distorted octahedral stereochemistry for copper(II) complexes. Frozen chloroform solution ESR spectra of the copper(II) complexes display significant Jahn-Teller distortion and dimeric behavior of the complexes in solution. FAB mass spectra of the copper(II) complexes also exhibit peaks corresponding to dimers. Molecular, pseudo-molecular, dimeric pseudo-molecular, and fragment ion peaks in unit resolution mass spectra have been identified with the help of their isotope distribution pattern expected due to natural abundances of the 63 Cu and 65 Cu isotopes. All the FAB mass spectral peaks from the fragment ions containing copper have been interpreted on the basis of isotope distribution pattern.