Abstract: Disclosed is a polycyclic compound represented by the following formula (I):R.sup.1 --X.sup.1 --[A.sup.1 --X.sup.2 ]--[A.sup.2 --X.sup.3 ]--R.sup.2 (I)wherein R.sup.1 is a (halogenated) alkyl group of 6 to 16 carbon atoms, X.sup.1 is --O-- group or a single bond, A.sup.1 is a biphenylene group, a phenylene group or the like, A.sup.2 is 1-fluoro-3,4-dihydronaphthalene or the like, X.sup.2 and X.sup.3 are each --COO--, a single bond or the like, and R.sup.2 is an optically active group of 4 to 20 carbon atoms which has at least one asymmetric carbon atom. Also disclosed are a liquid crystal material consisting of the polycyclic compound, a liquid crystal composition comprising the liquid crystal material, and a liquid crystal element. This novel polycyclic compound is optically active and capable of being in a smectic phase in a wide temperature range including room temperature. The polycyclic compound can be used as a ferroelectric liquid crystal material or an antiferroelectric liquid crystal material.

Abstract: A propylene polymer is excellent in rigidity, heat resistance, surface hardness, glossiness, transparency and impact resistance. A propylene copolymer (wherein the amount of monomer units derived from an .alpha.-olefin other than propylene is not more than 5% by mol) is excellent in transparency, rigidity, surface hardness, heat resistance, heat-sealing property, anti-blocking property, anti-bleedout property and impact strength. A propylene copolymer (wherein the amount of monomer units derived from an .alpha.-olefin other than propylene is not less than 5% by mol) is excellent in transparency, environmental aging property, and effective in improving heat-sealing property at low temperature and impact strength. A propylene elastomer is excellent in heat resistance, impact absorbing capacity, transparency, heat-sealing properties and anti-blocking properties.

Abstract: Disclosed is a novel transition metal compound represented by the following formula: ##STR1## wherein M is a transition metal, X is halogen or the like, R.sup.1 is a hydrocarbon group or the like, R.sup.2 is an aryl group substituted with a halogenated hydrocarbon group, and Y is a divalent silicon-containing group or the like.Also disclosed are an olefin polymerization catalyst component comprising the transition metal compound, an olefin polymerization catalyst comprising the olefin polymerization catalyst component, and a process for olefin polymerization using the olefin polymerization catalyst.An olefin polymerization catalyst component having high polymerization activity can be formed from the transition metal compound. By the use of the olefin polymerization catalyst or the process for olefin polymerization, polyolefins having a high melting point and a high molecular weight can be prepared with high polymerization activity.

Abstract: The novel transition metal compound of the invention is represented by the following formula (I): ##STR1## wherein M is a transition metal; R.sup.1 is a hydrocarbon group of 2 to 6 carbon atoms, R.sup.2 is an aryl group of 6 to 16 carbon atoms; X.sup.1 and X.sup.2 are each a halogen atom or the like; and Y is a divalent hydrocarbon group, a divalent silicon-containing group or the like. An olefin polymerization catalyst component of the present invention comprises the aforementioned transition metal compound.

Abstract: A process for polymerizing propylene utilizes a metallocene catalyst component of the formula (I) ##STR1## wherein M is a transition metal, R.sup.1 is a C.sub.2-6 hydrocarbon, R.sup.2 is a C.sub.6-16 aryl group, X.sup.1 and X.sup.2 are each a halogen atom and Y is a divalent hydrocarbon or a divalent silicon-containing group. Propylene polymers produced thereby have such properties that the triad tacticity of propylene units is high, the proportion of inversely inserted units based on the 2,1-insertion of propylene monomer is in a specific range and the intrinsic viscosity (.eta.), as measured in decahydronaphthalene at 135.degree. C., is in a specific range.

Abstract: The novel propylene homopolymer and copolymer produced by using a catalyst which is represented by the following formula (I): ##STR1## wherein M is a transition metal; R.sup.1 is a hydrocarbon group of 2 to 6 carbon atoms, R.sup.2 is an aryl group of 6 to 16 carbon atoms; X.sup.1 and X.sup.2 are each a halogen atom or the like; and Y is a divalent hydrocarbon group, a divalent silicon-containing group or the like.

Abstract: The novel transition metal compound of the invention is represented by the following formula (I): ##STR1## wherein M is a transition metal; R.sup.1 is a hydrocarbon group of 2 to 6 carbon atoms, R.sup.2 is an aryl group of 6 to 16 carbon atoms; X.sup.1 and X.sup.2 are each a halogen atom or the like; and Y is a divalent hydrocarbon group, a divalent silicon-containing group or the like. An olefin polymerization catalyst component of the present invention comprises the aforementioned transition metal compound. An olefin polymerization catalyst of the present invention comprises the aforementioned olefin polymerization catalyst component. The propylene homopolymer, the propylene copolymer and the propylene elastomer according to the present invention have such properties that the triad tacticity of propylene units chain is high, a proportion of the inversely units based on the 2,1-insertion of propylene monomer is in the specific range, and the intrinsic viscosity [.eta.

Abstract: The novel transition metal catalyst of the invention is represented by the following formula (I): ##STR1## wherein M is a zirconium or hafnium; R.sup.1 is a hydrocarbon group of 2 to 6 carbon atoms, R.sup.2 is an aryl group of 6 to 16 carbon atoms; X.sup.1 and X.sup.2 are each a halogen atom; and Y is a divalent hydrocarbon group, a divalent silicon-containing group.

Abstract: Disclosed is a novel transition metal compound represented by the following formula: ##STR1## wherein M is a transition metal, X is halogen or the like, R.sup.1 is a hydrocarbon group or the like, R.sup.2 is an aryl group substituted with a halogenated hydrocarbon group, and Y is a divalent silicon-containing group or the like.Also disclosed are an olefin polymerization catalyst component comprising the transition metal compound, an olefin polymerization catalyst comprising the olefin polymerization catalyst component, and a process for olefin polymerization using the olefin polymerization catalyst.An olefin polymerization catalyst component having high polymerization activity can be formed from the transition metal compound. By the use of the olefin polymerization catalyst or the process for olefin polymerization, polyolefins having a high melting point and a high molecular weight can be prepared with high polymerization activity.

Abstract: Disclosed is a process for preparing a cyclopentadienyl group-containing silicon compound or a cyclopentadienyl group-containing germanium compound, comprising reacting (i) a lithium, sodium or potassium salt of a cyclopentadiene derivative with (ii) a silicon halide compound or a germanium halide compound in the presence of a cyanide or a thiocyanate. The cyanide or the thiocyanate is preferably a copper salt. According to the process of the invention, a cyclopentadienyl group-containing silicon compound or a cyclopentadienyl group-containing germanium compound, which is very useful for the preparation of a metallocene complex catalyst component, can be prepared in a high yield for a short period of time.