Synthesis and characterization of a pentadentate Schiff base N[sub 3]O[sub 2] ligand and its neutral technetium(V) complex. X-ray structure of (N,N[prime]-3-azapentane-1,5-diylbis(3-(1-iminoethyl)-6-methyl-2H-pyran-2,4(3H)-dionato)(3-)-O,O[prime],N,N[prime],N[double prime])oxotechnetium(V)

Journal Article · Wed Dec 25 04:00:00 EST 1991 · Inorganic Chemistry; (United States)

OSTI ID:6837251

Liu, Shuang; Rettig, S J; Orvig, C ^[1]

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1. Univ. of British Columbia, Vancouver (Canada)

Preparations of a potentially pentadentate ligand, N,N[prime]-3-azapentane-1,5-diylbis(3-(1-iminoethyl)-6-methyl-2H-pyran-2,4-(3H)-dione) (H[sub 3]apa), and its neutral technetium(V) complex, [TcO(apa)], are described. The [sup 13]C and [sup 1]H NMR, infrared, optical, and mass spectra of the pentadentate ligand and its technetium(V) complex are reported. The X-ray structure of [TcO(apa)] has been determined. Crystals are orthorhombic, space group Pbca, with a = 12.833 (2) [angstrom], b = 33.320 (5) [angstrom], c = 9.942(4) [angstrom], V = 4251 (2) [angstrom], and Z = 8. The structure was solved by Patterson and Fourier methods and was refined by full-matrix least-squares procedures to R = 0.028 and R[sub W] = 0.032 for 4054 reflections with I [ge] 3[sigma](I). The technetium(V) complex has a highly distorted octahedral coordination geometry comprising a [TcO][sup 3+] core and the triply deprotonated pentadentate ligand wrapping around the metal center. One of the two oxygen donor atoms of the pentadentate ligand is located trans to the Tc[double bond]O bond while the remaining four donor atoms, N[sub 3]O, occupy the equatorial sites. The distance between the deprotonated N(1) atom to the Tc center is significantly shorter than a normal Tc-N single bond length of 2.10 angstroms, but longer than that for a Tc-N triple bond. [sup 1]H NMR spectral data reveal a rigid solution structure for the complex, which undergoes no conformational and configurational exchange at temperatures up to 50C.

• OSTI ID: 6837251
• Journal Information: Inorganic Chemistry; (United States), Journal Name: Inorganic Chemistry; (United States) Vol. 30:26; ISSN 0020-1669; ISSN INOCAJ
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
CARBON 13
CARBON ISOTOPES
CHALCOGENIDES
CHEMICAL PREPARATION
COHERENT SCATTERING
COMPLEXES
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DIFFRACTION
EVEN-ODD NUCLEI
IMINES
ISOTOPES
LATTICE PARAMETERS
LIGHT NUCLEI
MAGNETIC RESONANCE
NITROGEN COMPOUNDS
NITROGEN OXIDES
NUCLEAR MAGNETIC RESONANCE
NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORTHORHOMBIC LATTICES
OXIDES
OXYGEN COMPOUNDS
RESONANCE
SCATTERING
SCHIFF BASES
STABLE ISOTOPES
SYNTHESIS
TECHNETIUM COMPLEXES
TRANSITION ELEMENT COMPLEXES
X-RAY DIFFRACTION