Spectroscopically distinct geometrical isomers in a single crystal. Characterization of the eight-coordinate adducts of tris(dipivaloylmetanato)lanthanide(III) with 2,9-dimethyl-1,10-phenanthroline
- Univ. of Minnesota, Duluth, MN (United States)
Tris(dipivaloylmethanato)(2,9-dimethyl-1,10-phenanthroline)lanthanide(III), [Ln(DPM)[sub 3][center dot]DMOP], complexes (Ln = La, Eu, Tb, Ho) were synthesized from [Ln(DPM)[sub 3]] and 2,9-dimethyl-1,10-phenanthroline in carbon tetrachloride. The Eu[sup 3+] and Tb[sup 3+] complexes were characterized spectroscopically by infrared and luminescence techniques. The luminescence spectra of the Eu[sup 3+] and Tb[sup 3+] adducts were recorded at 77 K. For Eu[sup 3+], two transitions in the [sup 5]D[sub 0] [yields] [sup 7]Fo region are observed which are separated by an unprecedented 35 cm[sup [minus]1]. The [sup 5]D[sub 0] [yields] [sup 7]F[sub 1] and [sup 5]D[sub 0] [yields] [sup 7]F[sub 2] spectral regions contain six and eight bands, respectively, indicating two distinct Eu[sup 3+] environments. The Eu[sup 3+] luminescence spectrum indicates that both Eu[sup 3+] environments have local site symmetry C[sub 1]. The crystal structure of [Eu(DPM)[sub 3][center dot]DMOP] was solved by single-crystal X-ray diffraction methods. Two geometrical isomers were found to exist in the unit cell with the ligating atoms forming an eight-coordinate distorted square antiprism. The two isomers differ only in the way the chelate rings span the lateral (1) and square (s) edges of a square antiprism with occupancy factors of 59 and 41%. X-ray crystallographic occupancy factors were determined for [La(DPM)[sub 3][center dot]DMOP], [Tb(DPM)[sub 3][center dot]DMOP], and [Ho(DPM)[sub 3][center dot]DMOP], and each complex was found to crystallize in the monoclinic space group P2[sub 1]/n. Each of these adducts contain isomers which exist in 57 to 43%, 58 to 42%, and 55 to 45% ratios for La[sup 3+], Tb[sup 3+], and Ho[sup 3+], respectively. The isomer found more often in each case has all four chelate rings spanning the l edges of a square antiprism while the remaining isomer has two [beta]-diketonate rings spanning s edges and a [beta]-diketonate and a DMOP chelate ring spanning l edges.
- OSTI ID:
- 5042185
- Journal Information:
- Inorganic Chemistry; (United States), Vol. 32:23; ISSN 0020-1669
- Country of Publication:
- United States
- Language:
- English
Similar Records
Syntheses, structures and luminescent properties of lanthanide coordination polymers assembled from imidazophenanthroline derivative and oxalate ligands
Exploring the Promotion of Synthons of Choice: Halogen Bonding in Molecular Lanthanide Complexes Characterized via X-ray Diffraction, Luminescence Spectroscopy, and Magnetic Measurements
Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
EUROPIUM COMPLEXES
MOLECULAR STRUCTURE
HOLMIUM COMPLEXES
LANTHANUM COMPLEXES
TERBIUM COMPLEXES
ABSORPTION SPECTROSCOPY
CHELATES
LUMINESCENCE
MONOCLINIC LATTICES
COMPLEXES
CRYSTAL LATTICES
CRYSTAL STRUCTURE
RARE EARTH COMPLEXES
SPECTROSCOPY
400201* - Chemical & Physicochemical Properties