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.

Crystal structures of mono-substituted ferrocene derivatives,ω-[4-(4-methoxyphenoxycarbonyl)phenoxy]alkoxycarbonyl ferrocene (mMAF-n, n = 3-8, 11, where n is the number of carbon atoms in the alkyl spacer), are newly determined. The molecular structures of mMAF-n are divided into three groups; (i) a bent shape containing a doublegauche conformation (n = 2, 4, 6), (ii) a linear shape containing a kink (n = 3, 5, 7), and (iii) an extended linear shape adopting an all-trans conformation (n = 8, 11). The difference of the molecular shape between group (i) and (ii) is highly correlated with the parity of the number of carbon atoms in the alkyl spacer (odd-even effects). In both group (i) and (ii), the high entropic contribution of gauche conformations is introduced in the alkyl spacer, which is consistent with the non-liquid crystallinity of mMAF-n (n = 2-7). In group (iii), it is found out that there is a border at mMAF-8 on the mesomorphism of mMAF-n (n = 2-12).

the intralayer Mn-Mn distance. The magnetic ordering of the Mn layers along the c-axis is antiferromagnetic for the smaller value than the critic intralayer Mn-Mn distance or ferromagnetic for the bigger than that value [1 and the references therein]. Since the intralayer Mn-Mn distance of the SmMn 2 Ge 2 compounds is very close to the critic distance, the multiple magnetic phase transitions are observed as a function of the temperature. Because of the multiple magnetic phase transitions, this compound is very good candidate to investigate the magnetoresistance and magnetocaloric effect. SmMn 2-x Fe x Ge 2 (x=0.05 and 0.1) and SmMn 2-x Co x Ge 2 (x=0.05 and 0.15) compounds are prepared by using arc melting under argon atmosphere. All compounds crystallize in ThCr 2 Si 2-type tetragonal structure. The temperature and magnetic field dependence of magnetization are measured in an applied field up to 5 T between 10 and 350 K. The magnetocaloric effect-MCE is calculated by using Maxwell's relation and Landau theory. Both calculated MCE values are good accordance. For the SmMn 1.95 Fe 0.05 Ge 2 and SmMn 1.85 Co 0.15 Ge 2 compounds, the positive and negative MCE are observed. Resistivity measurements are performed by a four probe method as function of temperature (between 70 and 350K) and magnetic field (up to 7 T). The magnetoresistance effect is also observed at the metamagnetic transition. At T C Sm , the magnetoresistance effect Δρ/ρ is about-%20 and-%12, respectively.