|Budget Amount *help
¥2,000,000 (Direct Cost : ¥2,000,000)
Fiscal Year 1993 : ¥400,000 (Direct Cost : ¥400,000)
Fiscal Year 1992 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1991 : ¥1,000,000 (Direct Cost : ¥1,000,000)
I have found that the transannular interaction between multi heteroatoms of cyclic chalcogenides can produce the dications and the hypervalent species. The results are summarized as follows.
The chemistry of hypervalent selenuranes is much less developed than that of sulfuranes, and sulfuranes with apical nitrogen ligands are little known. The three-center transannular interaction betwee selenium and two-nitrogen atoms of new N-benzyl derivatives of 1,11-(methanoaminomethano)-5H, 7H-dibenzo[b, g][1,5]selenazocine provides the stable aminoammonioselenurane which is a new type of an isolable cyclic diazaselenurane with two unsymmetrical apical nitrogen ligands of tertiary alkylamino and quaternary alkylammonio groups. Generally, selenuranes have two symmetrical electronegative groups such as oxygen or halogen atoms at the apical positions.
Much less is known about the chemistry of bis-hypervalent bouns with two adjacent hypervalent bonding species. Cyclic bis-telluride, 1,5-ditelluracyclo-octane reacted with halogens to give new dihalogenoditelluranes with a Te(IV)-Te(IV) bond. Reduction of the latter with aqueous NaOH, PhSH and SmI2 gave the neutral bis-telluride.