Synthesis, spectroscopy, and structural characterization of five-coordinate, bis(aryldiazenido)technetium complexes and their protonation reactions. X-ray structure of (TcCl(PPh sub 3 ) sub 2 (NNC sub 6 H sub 4 Br) sub 2 )
- Massachusetts Institute of Technology, Cambridge (USA)
- Harvard Medical School, Boston, MA (USA)
The reaction of (TcCl{sub 4}(PPh{sub 3}){sub 2}) with arylhydrazines in methanol yields (TcCl(PPh{sub 3}){sub 2}(NNPh){sub 2}) (1). Complex 1 displays trigonal-bipyramidal geometry with phosphine ligands occupying axial sites. The technetium-aryldiazenido moieties are nearly equivalent, with Tc-N-N bond angles of 166.2 (6) and 170.7 (7){degree} and multiple bonding throughout. The chloride ligand occupies the remaining equatorial coordination site. The addition of HCl(g) to complex 1 in methanol gives the neutral, six-coordinate hydrazido(2-) complex (TcCl{sub 2}(PPh{sub 3}){sub 2}(NNPh)(NNHPh)). The reaction of complex 1 with HBr(g) gives the doubly protonated, cationic species (TcBr{sub 2}(PPh{sub 3}){sub 2}(NNPh)(NHNHPh))(Br). The {sup 99}Tc NMR spectra for these species are presented, which suggest that the metals exhibit considerable Tc(V) character and that the formal oxidation states of {minus}1 and +1 are not accurate ddescriptions of the electron density on the technetium. The {sup 1}H NMR, mass, and electronic spectroscopic data are also presented for the various species, along with the crystal structure of the five-coordinate bis(aryldiazenido) precursor. Crystal data for C{sub 48}H{sub 38}N{sub 4}P{sub 2}ClBr{sub 2}Tc are presented.
- OSTI ID:
- 7108190
- Journal Information:
- Inorganic Chemistry; (USA), Journal Name: Inorganic Chemistry; (USA) Vol. 28:20; ISSN 0020-1669; ISSN INOCA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
400201* -- Chemical & Physicochemical Properties
AROMATICS
BROMINE COMPOUNDS
CHLORINE COMPOUNDS
COMPLEXES
CRYSTAL STRUCTURE
DATA
EXPERIMENTAL DATA
HALOGEN COMPOUNDS
INFORMATION
MOLECULAR STRUCTURE
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
SYNTHESIS
TECHNETIUM COMPLEXES
TRANSITION ELEMENT COMPLEXES