Intermolecular interactions in cyanodimethylarsine and cyanodimethylstibine.

Cyanodimethylarsine, [As(CH(3))(2)(CN)], and cyanodimethylstibine, [Sb(CH(3))(2)(CN)], have closely related, but not isomorphous, crystal structures containing XCN.XCN. chains.

Structure Determination of the Products from the Acid-Catalyzed Condensation of Indole with Acetone.

Four of the previously reported compounds obtained from the acid-catalyzed condensation of indole with acetone are now assigned the following structures: cis-4,4a,9,9a-tetrahydro-2-(1H-indol-3-yl)-4,4-dimethyl-3H-carbazole (2a), 1,1',4,4'-tetrahydro-1,1,1',1'-tetramethyl-3,3'(2H,2'H)-spirobi[cyclopent[b]indole] (4), 4,4a-dihydro-2-(3-1H-indolyl)-4,4-dimethyl-3H-carbazol-4a-ol (7), and 5-(2-aminophenyl)-1,3,4,5-tetrahydro-1,1,4,4-tetramethylcyclopent[kl]acridine (8). The structure of the novel rearrangement product 8 was solved by an X-ray crystal structure determination. The two previously reported autoxidation products of 4 are now assigned the following structures: 1,3',4,4'-tetrahydro-1,1,4',4'-tetramethyl-cis-dispiro[cyclopent[b]indole-3(2H),2'(5'H)-furan-5',3"-[3H]-indol]-2"(1"H)-one (5) and 1,4-dihydro-1,1,5',5'-tetramethylspiro[cyclopent[b]indole-3(2H),3'(4'H)-1-benzazocine]-2'(1'H),6'(5'H)-dione (6).

An Rh-105 complex of tetrathiacyclohexadecane diol with potential for formulating bifunctional chelates.

1,5,9,13-Tetrathiacyclohexane-3,11-diol (16S4-diol), a sulfur crown ether analog, was studied as a potential chelating agent to complex no-carrier-added (NCA) grade 105Rh(III) in high yield at low ligand concentrations. trans-[RhCl2(16S4-diol)]chi (chi = Cl, PF6) was prepared using nonradioactive RhCl3.3H2O and characterized by UV-Vis, nuclear magnetic resonance (NMR) and X-ray crystallography.

Some observations on the instability of 99mTc-complexes of propylene amine oxime (PnAO).

When eluates from expired 99mMo/99mTc generators were used to form the neutral lipophilic complexes of PnAO and its derivatives, degradation of these chelates occurred on standing to form secondary 99mTc-species. It was determined that the conversion of the primary complexes to secondary complexes was due to the impurities present in the 99mTcO4- eluate. The stability was found to be improved by extraction of the complexes into CHCl3 and reconstituting in buffer after evaporation of CHCl3, indicating that the impurities are non extractable into CHCl3.

Synthesis, characterization and biodistribution of a new hexadentate aminethiol ligand labeled with Tc-99m.

A new hexadentate aminethiol ligand (TACNS) derived from triazacyclononane was synthesized and characterized for the development of technetium radiopharmaceuticals. The ligand formed a neutral, lipophilic and stable complex with [99mTc]pertechnetate in the presence of tin(II)tartarate as a reducing agent. The biodistribution of [99mTc]TACNS indicates slight uptake in brain (0.