To develop an improved synthetic route to [3(6)](1,2,3,4,5,6)cyclophane (CP) 2, a more practical synthetic route to [3(5)](1,2,3,4,5)CP 3 than the original one was developed, which started from [3(2)](1,3)CP 7 via [3(4)](1,2,4,5)CP 5. The fundamental structural parameters of [3(n)]CPs (n = 3-6) in the solid state were elucidated, and the observed structures were in good agreement with the most stable conformers in solution and those predicted by the theoretical calculations. In the case of [3(6)]CP 2, the most stable C(6)(h) structure was observed in the crystal structure of the 2-TCNQ-F(4) (1:1) complex, whereas the highly strained structure with a D(6)(h) symmetry was observed in the crystal structure of 2 and the 2:TCNQ:benzene (1:1:1) complex because of a severe disorder problem. [3(n)]CPs (n > 3) showed reversible redox processes, and 2 (+0.39 V vs F(c)/F(c)(+), Cl(2)CHCHCl(2)) showed the lowest first half-wave oxidation potential [E(1/2) (I)] in [3(n)]CPs. The E(1/2) (I) data support the strong donating ability of 2 and its lower homologues. This is attributed to their molecular structures where effective hyperconjugation between the benzyl hydrogens and benzene ring is possible. By taking advantage of the strong electron-donating ability of [3(n)]CPs, their CT complexes with TCNE, TCNQ, and TCNQ-F(4) were prepared, and their crystal structural properties were examined. The single-crystal conductivity data of the CT complexes indicated that the TCNQ-F(4) complexes showed higher conductivities than the corresponding TCNQ complexes mainly due to a larger charge separation. Among the [3(n)]CP-TCNQ complexes, the [3(3)](1,3,5)CP 6-TCNQ-F(4) (1:1) complex showed the highest conductivity (10(-)(4) S cm(-)(1)), and this was ascribed to the formation of an infinite column of partially overlapped acceptors with a short acceptor-acceptor distance, while the formation of such a column was not observed in the 2-TCNQ-F(4) complex. Although the conductivities of the cyclophane-CT complexes are much lower than those of the TTF related complexes, this study successfully provides the basic knowledge for understanding the CT interactions in the solid state.

2,3 : 6,7-Dibenzobicyclo[3.3.1]nona-2,6-diene-4,8-diol was synthesized and resolved via (−)-menthoxyacetate. Several kinds of optically active derivatives with the same absolute configuration were prepared from the (−)-diol and their chiroptical properties were recorded. The absolute configuration of this series of compounds was determined to be 1R, 5R by a chemical correlation with (R)-(−)-3-phenylbutanoic acid via (−)-1,3-diphenylglutaric acid and (−)-2,4-diphenylpentane.

Synthesis of two new acceptors, i.e., dibenzo- and naphtho-TCNQ, is described. Their redox potentials suggest that benzo and naphtho annelations to TCNQ lower the acceptor strength. Both compounds gave no CT complex with TTT, TTF, etc.

Laser photolysis studies at 355 nm have been carried out on the intramolecular hydrogen atom transfer (intra-HT) reaction of [(hydroxynaphthyl)propyl] benzophenone, BP-(CH&-ROH, and the proton-induced intramolecular ionization (intra-pion) reaction of [ (methoxynaphth yl)propyl]benzophenone, BP-(CH2)3-ROMe, in acetonitrilewater (4:l v/v) at 295 K. After 355-nm laser pulsing to BP-(CH&-ROH and BP-(CH2)3-ROMe, the intramolecular triplet energy transfer (intra-ET) reactions from the triplet moiety (3BP*) to the naphthol (ROH) and methoxynaphthalene (ROMe) moieties occur to yield BP-(CH2)3-3ROH* and BP-( C H Z )~-~R O M~* on a nanosecond time scale. The former triplet molecule (BP-(CH2)3-3ROH*) undergoes intramolecular hydrogen atom transfer (intra-HT) with an efficiency (&T) of unity to yield a biradical molecule with benzophenone ketyl radical (>COH-) and naphthoxy radical (ROO) moieties (>C0H-(CH2)3-ROo). The rate constant (~H T ) for intra-HT was determined to be 9.8 X lo5 s-l and independent of [BP-(CH2)3-ROH]. The deuterium isotope effect on intra-HT was examined by using BP-(CH&-ROD. The rate constant (~D T ) for intra-DT was determined to be 5.1 X lo5 s-l. In the presence of protons, the rate constant of intra-HT is enhanced proportional to the acid concentration though the value of r#Jm (=1.0) is independent of the acid concentration. The triplet molecule (BP-(CH2)s-3ROMe*) undergoes ionization only in the presence of protons (intra-pion) to yield a biradical molecule with >COH-and methoxynaphthalene cation radical (-ROMe'+) moieties (>C0H-(CH2)3-ROMeo+) with efficiencies (&I) of 0.3 for [H2S04] = 0.005 M and 1.0 for [H2S04] = 0.5 M in acetonitrilewater (4:l v/v) at 295 K. The rate constant for intra-pion increases with an increaseof the acid concentration. The mechanisms for intra-HT and intra-p-ion were interpreted by considering the intramolecular triplet exciplexes, 3(>CO-(CH2)3-ROH)* and 3(>CO-(CH2)3-ROMe)*, and the intramolecular protonated triplet exciplexes, 3(>+COH-(CH2)3-ROH)* and 3(>+COH-(CH2)3-ROMe)*, respectively. On the basis of the mechanism for intra-HT and intra-pion of the two chromophores linked with a propyrene chain, the structures of the triplet exciplex and protonated triplet exciplex are suggested to be sandwichlike with weak charge-transfer character.

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The compound P4Q4Q’, where a porphyrin chromophore is covalently linked in series to two different quinones, was incorporated into planar bilayer lipid membranes. Upon irradiation a transmembrane photocurrent due to the intramolecular, multistep electron transfer was observed.