Synthesis and Physical Properties of Ferrocene Derivatives (XXIII) Phase Transition and Unique Molecular Structure of Monosubstituted Ferrocene Derivatives

Abstract

The monosubstituted ferrocene derivatives, x-[4-(4-methoxyphenoxycarbonyl) phenoxy]alkoxycarbonyl ferrocene, were synthesized in order to compare the liquid crystallinity to that of disubstituted ferrocene derivatives, 1,1 0 -bis[x-[4-(4-methoxyphenoxycarbonyl)phenoxy]alkoxycarbonyl]ferrocene. Some of the monosubstituted ferrocene derivatives containing relatively longer flexible spacer showed the liquid crystalline phase, nematic and=or smectic phases. The crystal structure of 2-[4-(4-methoxyphenoxycarbonyl)phenoxy]ethoxycarbonyl ferrocene was determined by X-ray diffraction method using a single crystal. The molecular structure revealed a bent structure that is almost a half of ''Z'' shaped molecular structure of 1,1 0 -bis[2-[4-(4-methoxyphenoxycarbonyl)phenoxy]ethoxycarbonyl]ferrocene.

Synthesis and physical properties of ferrocene derivatives XXIV: structural study of liquid crystalline mono-substituted ferrocene derivatives

“…27 The single crystals used for analyses were grown by slow evaporation from a solution in a mixed solvent system: chloroform, 1,4-dioxane, and acetonitrile (1:1:1) for mMAF-3, benzene and n-heptane (1:1) for mMAF-4, 1,4-dioxane and n-heptane (1:1) for mMAF-5, benzene and nheptane (1:4) for mMAF-6, chloroform and n-hexane (1:3) for mMAF-7, benzene and ethanol (2:1) for mMAF-8, 1,4-dioxane and n-heptane (1:1) for mMAF-11.…”

“…Packing coefficient 30 Figure 2 shows the molecular structure of mMAF-n (n = 2, 27 3-8, 11) together with the atom numbering. Selected torsion angles of mMAF-n (n = 2, 27 [3][4][5][6][7][8]11) are listed in Table 3.…”

“…Secondary extinction corrections 29 were also applied. Other details are summarized in Table 2, together with the data of mMAF-2 previously analyzed 27 and details of the software used.…”

“…Selected torsion angles of mMAF-n (n = 2, 27 [3][4][5][6][7][8]11) are listed in Table 3. These structures are divided into three groups from the molecular shapes depending on a conformational pattern in the alkyl spacer, i.e.…”

“…Recently, we have synthesized a series of mono-substituted ferrocene derivatives composed of the same substituent of bMAF-n (n = 2-12), ω- [4-(4-methoxyphenoxycarbonyl)phenoxy]alkoxycarbonyl ferrocene (abbreviated hereafter as mMAF-n, n = 2-12, where n is the number of carbon atoms in the alkyl spacer, see *nakamura@sk.ritsumei.ac.jp; phone 81 77 561-2779; fax 81 77 561-2659 Figure 1b), in order to elucidate the correlation of the number of substituent with the liquid crystallinity and the crystal structure. 27 In the phase-transition behavior of mMAF-n (n = 2-12), it was revealed that the longer members of mMAF-n (n = 9-12) showed monotropic nematic and smectic phases (Table 1). In addition, the crystal structure of mMAF-2 was determined.…”