An aromatic amine derivative represented by formula (1): ##STR00001##
wherein R.sup.1, R.sup.2, R.sup.3, L, Ar.sup.1, Ar.sup.2, k, m, and n are the same as defined in the specification, is useful as a material for an organic EL device and realizes an organic EL device with a high efficiency and a long lifetime even when driving it at a low voltage.

An aromatic amine derivative represented by formula (1): ##STR00001##
wherein R.sup.1, R.sup.2, R.sup.3, L, Ar.sup.1, Ar.sup.2, k, m, and n are the same as defined in the specification, is useful as a material for an organic EL device and realizes an organic EL device with a high efficiency and a long lifetime even when driving it at a low voltage.

The present invention relates to a compound of the following formula (I): ##STR00001## The invention also relates to uses thereof as dye or pigment, notably as a luster pigment. The invention relates also to a reflective or photonic or nanophotonic or optoelectronic device comprising a compound of the invention. The invention relates also to a metal-like reflective coating, a metal-like particle or an organic-based metal-like liquid film comprising a compound of the invention.

Provided are: a composition for forming a hole transporting layer for perovskite solar cells, which is inexpensive and does not need to be used together with a dopant; and a compound which can be contained in a composition for forming a hole transporting layer. A compound represented by general formula (I) (wherein Ar represents an aryl group; A represents a structure represented by formula (II); Z's independently represent a hydrogen atom, a structure represented by general formula (III), or a structure represented by formula (IV), and maybe the same as or different from each other, wherein a case where each of Z's is a hydrogen atom is excluded; Y's independently represents at least one member selected from the group mentioned below; R.sup.1 and R.sup.2 independently represents a hydrogen atom, an alkyl group or an alkoxy group, or R.sup.1 and R.sup.2 may together form a ring having one or two oxygen atoms; ×'s independently represent an alkyl group, an alkoxy group, an alkylthio group, a monoalkylamino group or a dialkylamino group each of which may be substituted by a halogen atom; k represents 0 or 1; l represents 2 or 3; m represents an integer of 1 to 6; and r represents 1 or 2; wherein, when k is 0, 1 is 3, m is 1 and all of three bonds of A are bonded to Z.

##STR00001##

Provided are: a composition for forming a hole transporting layer for perovskite solar cells, which is inexpensive and does not need to be used together with a dopant; and a compound which can be contained in a composition for forming a hole transporting layer. A compound represented by general formula (I) (wherein Ar represents an aryl group; A represents a structure represented by formula (II); Z's independently represent a hydrogen atom, a structure represented by general formula (III), or a structure represented by formula (IV), and maybe the same as or different from each other, wherein a case where each of Z's is a hydrogen atom is excluded; Y's independently represents at least one member selected from the group mentioned below; R.sup.1 and R.sup.2 independently represents a hydrogen atom, an alkyl group or an alkoxy group, or R.sup.1 and R.sup.2 may together form a ring having one or two oxygen atoms; ×'s independently represent an alkyl group, an alkoxy group, an alkylthio group, a monoalkylamino group or a dialkylamino group each of which may be substituted by a halogen atom; k represents 0 or 1; l represents 2 or 3; m represents an integer of 1 to 6; and r represents 1 or 2; wherein, when k is 0, 1 is 3, m is 1 and all of three bonds of A are bonded to Z.

##STR00001##

A method for producing a nitroso compound of the following formula (3), comprising reacting a compound of the following formula (1) with a compound of the following formula (2) by using a tertiary alcohol and a base.

##STR00001## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.8, and R.sup.9 are each independently a hydrogen atom, a halogen atom, a (C1-C4) alkyl, or a (C1-C4) alkoxy.

A method for producing a nitroso compound of the following formula (3), comprising reacting a compound of the following formula (1) with a compound of the following formula (2) by using a tertiary alcohol and a base.

##STR00001## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.8, and R.sup.9 are each independently a hydrogen atom, a halogen atom, a (C1-C4) alkyl, or a (C1-C4) alkoxy.

An electrochromic element including a first electrode, second electrode facing the first electrode with gap, electrolyte layer between the first and second electrodes, and layer including a compound represented by General Formula (1) where the layer is on or above the first electrode,

##STR00001##

where R.sub.1 to R.sub.4 are each a monovalent organic group wherein no hydrogen atom is at a benzyl site where the monovalent group may include a polymerizable functional group; and R.sub.5 to R.sub.28 are each a hydrogen atom, alkyl or alkoxy group where R.sub.25 and R.sub.28, or R.sub.26 and R.sub.27 may be bonded to form a structure represented by General Formula (2),

##STR00002##

where R.sub.29 and R.sub.30 are each an alkyl, alkoxy or aryl group, and R.sub.29 and R.sub.30 may be bonded via a common bond to form a cyclic structure when R.sub.29 and R.sub.30 are aryl groups.

The present invention relates to certain fluorenes, to the use of the compounds in an electronic device, and to an electronic device comprising at least one of these compounds. The present invention furthermore relates to a process for the preparation of the compounds and to a formulation and composition comprising one or more of the compounds.

The present invention relates to certain fluorenes, to the use of the compounds in an electronic device, and to an electronic device comprising at least one of these compounds. The present invention furthermore relates to a process for the preparation of the compounds and to a formulation and composition comprising one or more of the compounds.