The present invention relates to a compound represented by the chemical formula 1, a catalyst system for olefin oligomerization comprising the same, and a method for oligomerizign olefins using the same, and the catalyst system for olefin oligomerization according to the present invention has excellent catalytic activity as well as high selectivity for 1-hexene or 1-octene, thereby enabling more efficient preparation of alpha-olefins.

One aspect of the present invention is a method for producing a compound represented by following general formula (1), the method being characterized by including a step of mixing ethylene, a compound represented by following general formula (2), and a compound represented by following general formula (3) to react with each other to give a compound represented by following general formula (4):

##STR00001## A.sup.1 to A.sup.4 each independently represent an aromatic group, and Z.sup.1 and Z.sup.2 each independently represent an oxygen atom, a sulfur atom, or a borane (BH.sub.3), Z.sup.3 represents an oxygen atom or a sulfur atom, n.sup.1 to n.sup.3 each independently represent 0 or 1, and X represents a halogen atom.

A heteroleptic binuclear copper(I) complex of the Cu.sub.2X.sub.2(E?N*)L.sub.2 form, having a structure of formula A: ##STR00001##
The copper(I) complex may be used in optoelectronic components, particularly for use in organic light emitting diodes (OLEDs).

The present invention provides a stabilized form of Tetrofosmin, which is stable at room temperature as well as in contact with oxygen, and a non-radioactive kit containing a stabilized form of Tetrofosmin for the preparation of a radiopharmaceutical composition in the field of diagnostic radiopharmaceuticals, especially for myocardial perfusion studies in patients with coronary artery diseases and in oncology.

Materials and methods for improving the stability of perovskites are described.

An organometallic compound represented by Formula 1

##STR00001## wherein, M.sub.1 to M.sub.4 are each independently a first-row transition metal, a second-row transition metal, or a third-row transition metal; X.sub.1 and X.sub.2 are each independently C(R.sub.5)(R.sub.6), Si(R.sub.5)(R.sub.6), N(R.sub.5), O, S, Se, or Te; W.sub.1 to W.sub.4 are each independently N(R.sub.7)(R.sub.8), P(R.sub.7)(R.sub.8), S(R.sub.7), a C.sub.5-C.sub.60 carbocyclic group unsubstituted or substituted with at least one R.sub.10a, or a C.sub.1-C.sub.60 heterocyclic group unsubstituted or substituted with at least one R.sub.10a; L.sub.1 to L.sub.6 are each independently a C.sub.1-C.sub.30 alkylene group unsubstituted or substituted with at least one R.sub.10a, a C.sub.5-C.sub.60 carbocyclic group unsubstituted or substituted with at least one R.sub.10a, or a C.sub.1-C.sub.60 heterocyclic group unsubstituted or substituted with at least one R.sub.10a, a3 to a6 are each independently an integer from 0 to 3, and R.sub.1 to R.sub.8 and R.sub.10a in Formula 1 are as described herein.

The present invention provides a method of efficiently producing an optically active 6-(3-aminopiperidin-1-yl)-2,4-dioxo-1,2,3,4-tetrahydropyrimidine derivative. The optically active piperidine-3-carboxamide or a derivative thereof, which is obtained by subjecting 1,4,5,6-tetrahydropyridine-3-carboxamide or a derivative thereof to an asymmetric reduction in the presence of a catalyst, is used as an intermediate.

The present invention provides a method of efficiently producing an optically active 6-(3-aminopiperidin-1-yl)-2,4-dioxo -1,2,3,4-tetrahydropyrimidine derivative. The optically active piperidine-3-carboxamide or a derivative thereof, which is obtained by subjecting 1,4,5,6-tetrahydropyridine -3-carboxamide or a derivative thereof to an asymmetric reduction in the presence of a catalyst, is used as an intermediate.

P-chirogenic organophosphorus compounds of general formula (I), a process for the synthesis of the compounds of formula (I), and intermediate products of general formulae (II), (III) and (IV), as shown below, are involved in the synthesis of compounds (I). ##STR00001## Metal complexes comprising compounds (I) as ligands are also described. The compounds and complexes are useful in asymmetric catalysis by transition metal complexes or organocatalysis, especially for asymmetric hydrogenation or allylation. Compounds of general formula (I) may be useful as agrochemical and therapeutic substances, or as reagents or intermediates for fine chemistry.

A new stable, catalytically active, tetradentate organophosphorus modified rhodium hydroformylation catalyst has been discovered that is capable of producing aldehyde products with a high linear/branched product ratio from linear olefins. The tetradentate organophosphorus modifier is a tetrasubstituted 2,2,2,5-tetramethyl-1,1:4-1-terphenyl, whereby, each methyl group has one hydrogen substituted by an R, R-diorganophosphine moiety. The R, R may comprise aromatic, alkyl, arylalkyl and alkylaryl groups. The precursor 2,2,2,5-tetramethyl-1,1:4,1-terphenyl hydrocarbon may be prepared from para-xylene and toluene derivatives.