A metal cyclopentadienyl complex has the formula:

##STR00001##

wherein m≥0; M is a Group I, II or III main group metal, alkali or transition metal; C.sub.5H.sub.4 represents a Cp ring where two hydrogens are substituted by M and R(F).sub.m; R(F).sub.m is connected to any one of the carbon atoms of the Cp and selected from a hydrocarbyl, fluorohydrocarbyl, silyl group [SiR′.sub.3], or amino group [—NR.sup.1R.sup.2]. The metal cyclopentadienyl complexes include Li(C.sub.5H.sub.4-2-C.sub.5H.sub.11) (CAS No: 2413046-23-6), K(C.sub.5H.sub.4-2-C.sub.5H.sub.11), Na(C.sub.5H.sub.4-2-C.sub.5H.sub.11), K(C.sub.5H.sub.4-1-F—C.sub.4H.sub.10), K(C.sub.5H.sub.4-1,1,1-3F—C.sub.4H.sub.6), Li(C.sub.5H.sub.4-2-C.sub.4H.sub.9), or In(C.sub.5H.sub.4-2-C.sub.5H.sub.11) (CAS No.: 2364634-67-1).

A mono-substituted cyclopentadiene has the formula:

##STR00002##

wherein m≥0; C.sub.5H.sub.5 represents the Cp ring where one hydrogen is substituted R(F).sub.m; R(F).sub.m is connected to any one of the carbon atoms of the Cp and selected from a hydrocarbyl, fluorohydrocarbyl, silyl group [SiR′.sub.3], or amino group [—NR.sup.1R.sup.2]. The mono-substituted cyclopentadienes include C.sub.5H.sub.5-1-F—C.sub.4H.sub.10, C.sub.5H.sub.5-2-C.sub.5H.sub.11, C.sub.5H.sub.5-2-C.sub.4H.sub.9, or C.sub.5H.sub.5-1,1,1-3F—C.sub.4H.sub.6.

The invention relates to a method for preparation of diesters from anhydrides of carboxylic acids.

The present invention provides a catalyst system for producing cyclic carbonates comprising: a pre-catalyst, which is BiCl.sub.3 having amounts in the range from 5 to 10% by weight of silica support; a compound having formula (I)

##STR00001## wherein: Y is selected from bromide (Br.sup.−) or iodide (I.sup.−); R.sup.1, R.sup.2, and R.sup.3 are methyl group or R.sup.1, R.sup.2, and R.sup.3 are taken together to form a heteroaryl ring having formula (II)

##STR00002##

and a silica (SiO.sub.2) support.

A catalyst system that may reduce polymeric fouling may include at least one titanate compound, at least one aluminum compound, and an antifouling agent. The antifouling agent may be chosen from one or more of a phosphonium or phosphonium salt; a sulfonate or a sulfonate salt; a sulfonium or sulfonium salt; an ester including a cyclic moiety; an anhydride; a polyether; and a long-chained amine-capped compound. The catalyst system may further include a non-polymeric ether compound.

A catalyst system that may reduce polymeric fouling may include at least one titanate compound, at least one aluminum compound, and an antifouling agent. The antifouling agent may be chosen from one or more of a phosphonium or phosphonium salt; a sulfonate or a sulfonate salt; a sulfonium or sulfonium salt; an ester including a cyclic moiety; an anhydride; a polyether; and a long-chained amine-capped compound. The catalyst system may further include a non-polymeric ether compound.

Provided are preparation methods for the chemical compound represented by formula (I) and an intermediate thereof. ##STR00001##

A catalyst system that may reduce polymeric fouling may include at least one titanate compound, at least one aluminum compound, and an antifouling agent. The antifouling agent may be chosen from one or more of a phosphonium or phosphonium salt; a sulfonate or a sulfonate salt; a sulfonium or sulfonium salt; an ester including a cyclic moiety; an anhydride; a polyether; and a long-chained amine-capped compound. The catalyst system may further include a non-polymeric ether compound.

A catalyst system that may reduce polymeric fouling may include at least one titanate compound, at least one aluminum compound, and an antifouling agent. The antifouling agent may be chosen from one or more of a phosphonium or phosphonium salt; a sulfonate or a sulfonate salt; a sulfonium or sulfonium salt; an ester including a cyclic moiety; an anhydride; a polyether; and a long-chained amine-capped compound. The catalyst system may further include a non-polymeric ether compound.

A method for preparing a homogenous catalyst for use in preparing a linear alpha olefin includes: preparing a first pre-catalyst solution by mixing a chromium source and a ligand in a first solvent, wherein the first pre-catalyst solution is stored in a first vessel; preparing a second pre-catalyst solution by mixing an organoaluminum compound and a modifier in a second solvent, wherein the second pre-catalyst solution is stored in a second vessel; and simultaneously feeding the first pre-catalyst solution and the second pre-catalyst solution directly into a reaction vessel, wherein the reaction vessel includes a third solvent.

Disclosed are mono-substituted cyclopentadienes, metal cyclopentadienyl complexes and methods for synthesizing them. The disclosed mono-substituted cyclopentadienes are synthesized by a selective catalytic carbon-carbon coupling reaction. The disclosed metal cyclopentadienyl complexes are synthesized from the disclosed mono-substituted cyclopentadienes. The disclosed metal cyclopentadienyl complexes include main group metal and transition metal cyclopentadienyl complexes, and may be used as deposition precursors contained in film forming compositions for film depositions in semiconductor industry, such as ALD, CVD, SOD, etc.