The present invention aims to provide a polymerizable compound that has high storage stability without causing crystal precipitation when added to a polymerizable composition and to provide a polymerizable composition containing the polymerizable compound. A polymer film produced by polymerization of the polymerizable composition has a low haze, high thickness uniformity, low occurrence of nonuniform orientation, high surface hardness, high adhesiveness, and good appearances and fewer orientation defects even after ultraviolet irradiation. The present invention also aims to provide a polymer produced by polymerization of the polymerizable composition and an optically anisotropic body produced from the polymer.

A monomer capable forming a polymer through ring-opening metathesis polymerization and capable of depolymerization thereafter through ring-closing metathesis, wherein the monomer comprises a cycloalkene having a fused ring attached thereto to form a cycloalkene-fused ring monomer, wherein the fused ring decreases the ring strain energy of the cycloalkene to a lower ring strain energy state of 5.3 kcal/mol or lower as compared to the same cycloalkene without the fused ring having a ring strain energy above 5.3 kcal/mol and wherein the cycloalkene-fused ring monomer is capable of isomerization into a higher ring strain energy state before polymerization and method of synthesizing the monomer. The monomer is further capable of forming chemically recyclable to monomers block copolymers.

A monomer capable forming a polymer through ring-opening metathesis polymerization and capable of depolymerization thereafter through ring-closing metathesis, wherein the monomer comprises a cycloalkene having a fused ring attached thereto to form a cycloalkene-fused ring monomer, wherein the fused ring decreases the ring strain energy of the cycloalkene to a lower ring strain energy state of 5.3 kcal/mol or lower as compared to the same cycloalkene without the fused ring having a ring strain energy above 5.3 kcal/mol and wherein the cycloalkene-fused ring monomer is capable of isomerization into a higher ring strain energy state before polymerization and method of synthesizing the monomer. The monomer is further capable of forming chemically recyclable to monomers block copolymers.

A carboxylic acid onium salt of formula (1) exerts a satisfactory acid diffusion control (or quencher) function. A resist composition comprising the carboxylic acid onium salt can be processed by DUV or EUV lithography to form a resist pattern with improved resolution, reduced LWR and minimal defects after development.

##STR00001##

A carboxylic acid onium salt of formula (1) exerts a satisfactory acid diffusion control (or quencher) function. A resist composition comprising the carboxylic acid onium salt can be processed by DUV or EUV lithography to form a resist pattern with improved resolution, reduced LWR and minimal defects after development.

##STR00001##

A tetracarboxylic dianhydride includes: at least one acid dianhydride (A) selected from the group consisting of compounds each having an endo/exo type three-dimensional structure represented by a particular general formula and their enantiomeric compounds each having an exo/endo type three-dimensional structure; and/or an acid dianhydride (B) having an endo/endo type three-dimensional structure represented by a particular general formula, wherein a content of the acid dianhydride (B) in a total amount of the acid dianhydrides (A) and (B) is 30 to 100% by mole in a mole ratio.

A tetracarboxylic dianhydride includes: at least one acid dianhydride (A) selected from the group consisting of compounds each having an endo/exo type three-dimensional structure represented by a particular general formula and their enantiomeric compounds each having an exo/endo type three-dimensional structure; and/or an acid dianhydride (B) having an endo/endo type three-dimensional structure represented by a particular general formula, wherein a content of the acid dianhydride (B) in a total amount of the acid dianhydrides (A) and (B) is 30 to 100% by mole in a mole ratio.

A compound having a group represented by the formula (Ia): ##STR00001##
wherein R.sup.1 represents a C.sub.1 to C.sub.8 fluorinated alkyl group, R.sup.2 represents a group having an optionally substituted C.sub.5 to C.sub.18 alicyclic hydrocarbon group, and * represents a binding site.

A compound having a group represented by the formula (Ia): ##STR00001##
wherein R.sup.1 represents a C.sub.1 to C.sub.8 fluorinated alkyl group, R.sup.2 represents a group having an optionally substituted C.sub.5 to C.sub.18 alicyclic hydrocarbon group, and * represents a binding site.

The present invention relates to novel cyclopropane derivatives represented by Formula I:

##STR00001##

wherein R represents a hydrocarbon group containing 1-20 carbon atoms or an ester containing 1-20 carbon atoms;

wherein R′ represents a C.sub.1-C.sub.6 acyclic carboxylic acid ester, a C.sub.4-C.sub.6 cyclic carboxylic acid ester or —OR″, and R″ is selected from the group consisting of H, a C.sub.1-C.sub.6 acyclic hydrocarbon group, a C.sub.3-C.sub.6 carbocyclic ring and a C.sub.4-C.sub.5 heterocyclic ring; and

wherein the composition is selected from the group consisting of a flavor composition and a fragrance composition.