An acetylacetone derivative is useful for capturing a metal element by complexation. A convenient and very versatile synthesis method can be used to synthesize the derivative. The derivative can have the following formula: ##STR00001##

An acetylacetone derivative is useful for capturing a metal element by complexation. A convenient and very versatile synthesis method can be used to synthesize the derivative. The derivative can have the following formula: ##STR00001##

To provide europium complexes having high photostability.

A europium complex expressed with the following formula (A):

##STR00001##

{wherein, R.sup.A and R.sup.B are independently a cyclic alkyl group with 3 to 10 carbons, respectively, and R.sup.C is a cyclic alkyl group with 3 to 10 carbons or a phenyl group expressed with the following formula (B):

##STR00002##

(wherein, X.sup.A, X.sup.B, A.sup.C, X.sup.D and X.sup.E independently represent a hydrogen atom; a fluorine atom; an alkyl group with 1 to 3 carbon(s); an alkyloxy group with 1 to 3 carbon(s); an aryloxy group with 6 to 10 carbons; a fluoroalkyl group with 1 to 3 carbon(s); a fluoroalkyloxy group with 1 to 3 carbon(s); or a phenyl group that may be substituted with a fluorine atom, an alkyl group with 1 to 3 carbon(s), an alkyloxy group with 1 to 3 carbon(s), a fluoroalkyl group with 1 to 3 carbon(s), a fluoroalkyloxy group with 1 to 3 carbon(s), a fluorophenyl group, a hydroxyl group or a cyano group, respectively); R.sup.A is a cyclic alkyl group with 3 to 10 carbons; R.sup.B and R.sup.C are a phenyl group expressed with the formula (B), provided, however, that a case where R.sup.A a cyclohexyl group, and, R.sup.B and R.sup.C are a phenyl group is excluded; or R.sup.A, R.sup.B and R.sup.C independently represent an ortho-substituted phenyl group expressed with the following formula (Ba):

##STR00003##

(wherein, X.sup.E represents a hydrogen atom, an alkyl group with 1 to 3 carbon(s), an alkyloxy group with 1 to 3 carbon(s), a fluoroalkyl group with 1 to 3 carbon(s), a fluoroalkyloxy group with 1 to 3 carbon(s), a naphthyl group that may be substituted with a fluorine atom, a pyridyl group that may be substituted with a fluorine atom, or a phenyl group that is expressed with a formula (C):

##STR00004##

[wherein, Z.sup.A, Z.sup.C and Z.sup.E independently represent a hydrogen atom, a fluorine atom, an alkyl group with 1 to 3 carbon(s), an alkyloxy group with 1 to 3 carbon(s), a fluoroalkyl group with 1 to 3 carbon(s), a fluoroalkyloxy group with 1 to 3 carbon(s), a phenyl group that may be substituted with a fluorine atom, a hydroxyl group or a cyano group; Z.sup.B and Z.sup.D independently represent a hydrogen atom or a fluorine atom, respectively], provided, however, that a case where R.sup.A, R.sup.B and R.sup.C are all a phenyl group is excluded), respectively; R.sup.D represents a hydrogen atom, a deuterium atom or a fluorine atom; W.sup.A and W.sup.B independently represent an alkyl group with 1 to 6 carbon(s), a fluoroalkyl group with 1 to 6 carbon(s), a phenyl group, a 2-thienyl group or a 3-thienyl group; and n represents an integer of 1 t

An object of the present invention is to provide an organic EL element which has a shorter maximum luminescent wavelength, a long luminous lifespan, a low driving voltage, a small time-dependent change in driving voltage, and a small change in external extraction quantum efficiency even when being used at a high temperature. In addition, an object of the present invention is to provide a lighting device and a display device including the organic EL element. The organic EL element of the present invention is an organic EL element including: at least one luminous layer sandwiched between a positive electrode and a negative electrode, wherein the luminous layer contains at least one kind of phosphorescent organometallic complex having a structure represented by the following Formula (1): ##STR00001##

An object of the present invention is to provide an organic EL element which has a shorter maximum luminescent wavelength, a long luminous lifespan, a low driving voltage, a small time-dependent change in driving voltage, and a small change in external extraction quantum efficiency even when being used at a high temperature. In addition, an object of the present invention is to provide a lighting device and a display device including the organic EL element. The organic EL element of the present invention is an organic EL element including: at least one luminous layer sandwiched between a positive electrode and a negative electrode, wherein the luminous layer contains at least one kind of phosphorescent organometallic complex having a structure represented by the following Formula (1): ##STR00001##

Disclosed is a rare-earth complex polymer including trivalent rare-earth ions and a phosphine oxide bidentate ligand represented by the formula (1). One phosphine oxide bidentate ligand is coordinated to the two rare-earth ions, and crosslinks the same. ##STR00001##

Disclosed is a rare-earth complex polymer including trivalent rare-earth ions and a phosphine oxide bidentate ligand represented by the formula (1). One phosphine oxide bidentate ligand is coordinated to the two rare-earth ions, and crosslinks the same. ##STR00001##

The present invention provides an iridium compound useful as a raw material compound for producing a cyclometalated iridium complex, the iridium compound being represented by the following General Formula (1). The iridium compound of the present invention is particularly useful as a raw material for imidazole-based cyclometalated iridium complexes among cyclometalated iridium complexes.

##STR00001##

(In General Formula (1), Ir represents an iridium atom, O represents an oxygen atom, X represents a halogen atom, and Y represents a counter cation; and R.sup.1 and R.sup.2 each independently represent an alkyl group with a carbon number of 1 or more and 10 or less, with the proviso that only one of R.sup.1 and R.sup.2 is a branched alkyl group.)

Methods are provided for synthesizing W(IV) beta-diketonate precursors. Additionally, methods are provided for forming W containing thin films, such as WS.sub.2, WN.sub.x, WO.sub.3, and W via vapor deposition processes, such as atomic layer deposition (ALD) type processes and chemical vapor deposition (CVD) type processes. Methods are also provided for forming 2D materials containing W.

Methods are provided for synthesizing W(IV) beta-diketonate precursors. Additionally, methods are provided for forming W containing thin films, such as WS.sub.2, WN.sub.x, WO.sub.3, and W via vapor deposition processes, such as atomic layer deposition (ALD) type processes and chemical vapor deposition (CVD) type processes. Methods are also provided for forming 2D materials containing W.