David H. White

Synthesis and characterization of technetium complexes with phosphoruscontaining ligands. The homoleptic trimethylphosphite, dimethylmethylphosphonite and methyldiethylphosphinite technetium(I) cations

Abstract Technetium(I) complexes of trimethylphosphite (tmp), dimethylmethylphosphonite (dmmp) and methyldiethylphosphinite (mdep) have been synthesized through direct interaction of the ligand with sodium pertechnetate. The homoeleptic, hexakis (ligand), cationic complexes can be isolated as tetraphenylborate salts. Characterization using multinuclear NMR of 99 Tc (−422 and −248 ppm versus TcO 4 − for the tmp and dmmp complexes, respectively) and 31 P (158.5 and 248 ppm versus 85% H 3 PO 4 for the tmp and dmmp complexes, respectively) gives chemical shift values which compare favorably with previous data on Tc-phosphine and transition-metal-phosphite complexes. Mass spectra (fast atom bombardment and plasma desorption) of the tmp and dmmp complexes exhibit the expected parent peaks and show series of peaks attributed to stepwise loss of ligand molecules or possible decompositon products. X-ray photoelectron spectra of the tmp and dmmp complexes are consistent with formulation as the Tc(I) oxidation state when referenced to well-characterized complexes in known oxidation states.

Purification of X-ray contrast agent, magnetic resonance imaging agent, or radiopharmaceuticals using reverse osmosis

The use of reverse osmosis as an alternative or substitute method for the purification of a crude diagnostic agent. X-ray contrast agent, magnetic resonance imaging agent, or radiopharmaceuticals are purified by passing through a cross-linked reverse osmosis membrane.

Trifluoromethyl analogs of X-ray contrast media for magnetic resonance imaging

Methods and compositions are disclosed for enhancing 19 F magnetic resonance imaging which utilize trifluoromethyl derivatives of iodinated X-ray contrast media. Typical magnetic resonance contrast media within the scope of the present invention include bis(trifluoromethyl)benzene derivatives, tris(trifluoromethyl)benzene derivatives, tetrakis(trifluoromethyl)benzene derivatives, and other related trifluoromethylated benzene derivatives.