|Budget Amount *help
¥12,000,000 (Direct Cost : ¥12,000,000)
Fiscal Year 1998 : ¥2,600,000 (Direct Cost : ¥2,600,000)
Fiscal Year 1997 : ¥9,400,000 (Direct Cost : ¥9,400,000)
We have been studied transannular pi-pi interaction, conformational behavior, and photochemical properties of superphane 1 and its lower homologs, multibridged [3_n]cyclophanes (n=3-5). Despite much effort, hexaprismane 3 has eluded synthesis so far. We studied the formation of the hexa-prismane skeleton by irradiating multibridged [3_n]cyclophanes. irradiation of [3_3 (1,3,5)cyclophane 2 with a low pressure Hg lamp in a water-saturated CH_2Cl_2 solution gave a new cage compound with bishomopentaprismane skeleton. Similarly [3_3](1,2,4,5)cyclophane 4 afforded a nove1 cage diol, whose skeleton is similar to that of diamantane. In both cases, irradiation may first afford highly strained hexaprismane derivatives, but they are immediately protonated to give cations, which are rearranged to the less strained cations. The most stable cations are intercepted by an attack of water to give hydroxyl compounds.
The multibridged [3_n]cyclophanes formed crystalline charge transfer complexes with TCNQ.The relative dependence of the electric conductivity on the stacking mode of the donar and acceptor was studied. The conductivity of the 1 : TCNQ (1 : 1) complex was low and this was ascribed to the alternate stacking of the donar and acceptor. The mono-nuclear Ru^<2+> and 0s^<2+> complexes of multibridged [3_n]cyclophanes (n=2-4) were synthesized and their electrocchemical properties were studied. Then di- nuclear Ru(II) complexes of 4 were synthesized and characterized, and their mixed-valance ion Ru(II)- Ru(O) was formed by the electrochemical reduction. Measurement of the conductivity is in progress.
We also developed novel synthetic reactions of cyclophanes such as photodecarbonylation and CO_2 insertion reactions.