Metal carbene complexes comprising at least one imidazo-quinoxaline ligand, organic electronic devices, especially OLEDs (Organic Light-Emitting Diodes) which comprise such complexes, a light-emitting layer comprising at least one inventive metal carbene complex, an apparatus selected from the group consisting of illuminating elements, stationary visual display units and mobile visual display units comprising such an OLED, the use of such a metal carbene complex for electrophotographic photoreceptors, photoelectric converters, organic solar cells (organic photovoltaics), switching elements, organic light emitting field effect transistors (OLEFETs), image sensors, dye lasers and electroluminescent devices and a process for preparing such metal carbene complexes.

Pt.sub.2M heterotrinuclear metal-organic alkynyl complexes have a structure of formula (I): [Pt.sub.2M(-PR.sub.2CH.sub.2PRCH.sub.2PR.sub.2).sub.2(CCR).sub.2(CCR).sub.2].sup.+.sub.mA.sup.m. In formula (I), represents a bridging ligand; PR.sub.2CH.sub.2PRCH.sub.2PR.sub.2 is a type of tridentate phosphine ligands; the subscript number of each letter represents the number of each group. The complexes present phosphorescent emission, and the color distribution of the emitted light is relatively broad from blue-green to orange-red. The complexes can be used as photoluminescent materials in the fields of displays, lighting, sensors and biomarkers. Among the complexes, Cu complexes also exhibit reversible self-recovery photochromic performance. Under UV irradiation, the complexes change from a colorless or light color state to a dark color state rapidly, and after stopping UV irradiation, they gradually return to the light color state.

Pt.sub.2M heterotrinuclear metal-organic alkynyl complexes have a structure of formula (I): [Pt.sub.2M(-PR.sub.2CH.sub.2PRCH.sub.2PR.sub.2).sub.2(CCR).sub.2(CCR).sub.2].sup.+.sub.mA.sup.m. In formula (I), represents a bridging ligand; PR.sub.2CH.sub.2PRCH.sub.2PR.sub.2 is a type of tridentate phosphine ligands; the subscript number of each letter represents the number of each group. The complexes present phosphorescent emission, and the color distribution of the emitted light is relatively broad from blue-green to orange-red. The complexes can be used as photoluminescent materials in the fields of displays, lighting, sensors and biomarkers. Among the complexes, Cu complexes also exhibit reversible self-recovery photochromic performance. Under UV irradiation, the complexes change from a colorless or light color state to a dark color state rapidly, and after stopping UV irradiation, they gradually return to the light color state.

The present invention provides a luminogenic, in particular a phosphorogenic transition metal-based pyridyl complex containing a nitrone moiety, which nitrone moiety acts as a bioorthogonal functional group and an emission quencher, and can undergo cycloaddition reaction with a complementary bioorthogonal functional group coupled to a substrate. The transition metal is can be selected from iridium or ruthenium. Also disclosed is a method for preparing the transition metal-based pyridyl complex and a pharmaceutical composition comprising it. Still further provided is a method for bioorthogonal labeling of a biomolecule, a method for staining of a cell structure, a method for in vivo imaging of an organism, and a kit for in vivo imaging of an organism. The luminogenic properties and high reactivity of the complexes are highly advantageous for bioorthogonal labeling and imaging of biomolecules in their native biological environments at much lower costs than those of the existing commercial products.

The present invention provides a luminogenic, in particular a phosphorogenic transition metal-based pyridyl complex containing a nitrone moiety, which nitrone moiety acts as a bioorthogonal functional group and an emission quencher, and can undergo cycloaddition reaction with a complementary bioorthogonal functional group coupled to a substrate. The transition metal is can be selected from iridium or ruthenium. Also disclosed is a method for preparing the transition metal-based pyridyl complex and a pharmaceutical composition comprising it. Still further provided is a method for bioorthogonal labeling of a biomolecule, a method for staining of a cell structure, a method for in vivo imaging of an organism, and a kit for in vivo imaging of an organism. The luminogenic properties and high reactivity of the complexes are highly advantageous for bioorthogonal labeling and imaging of biomolecules in their native biological environments at much lower costs than those of the existing commercial products.

Use of transition metal complexes of the formula (I) in organic light-emitting diodes

##STR00001## where: M.sup.1 is a metal atom; carbene is a carbene ligand; L is a monoanionic or dianionic ligand; K is an uncharged monodentate or bidentate ligand selected from the group consisting of phosphines; CO; pyridines; nitriles and conjugated dienes which form a complex with M.sup.1; n is the number of carbene ligands and is at least 1; m is the number of ligands L, where m can be 0 or 1; o is the number of ligands K, where o can be 0 or 1; where the sum n+m+o is dependent on the oxidation state and coordination number of the metal atom and on the denticity of the ligands carbene, L and K and also on the charge on the ligands carbene and L, with the proviso that n is at least 1, and also

an OLED comprising these transition metal complexes, a light-emitting layer comprising these transition metal complexes, OLEDs comprising this light-emitting layer, devices comprising an OLED according to the present invention, and specific transition metal complexes comprising atb least two carbene ligands.

Use of transition metal complexes of the formula (I) in organic light-emitting diodes

##STR00001## where: M.sup.1 is a metal atom; carbene is a carbene ligand; L is a monoanionic or dianionic ligand; K is an uncharged monodentate or bidentate ligand selected from the group consisting of phosphines; CO; pyridines; nitriles and conjugated dienes which form a complex with M.sup.1; n is the number of carbene ligands and is at least 1; m is the number of ligands L, where m can be 0 or 1; o is the number of ligands K, where o can be 0 or 1; where the sum n+m+o is dependent on the oxidation state and coordination number of the metal atom and on the denticity of the ligands carbene, L and K and also on the charge on the ligands carbene and L, with the proviso that n is at least 1, and also

an OLED comprising these transition metal complexes, a light-emitting layer comprising these transition metal complexes, OLEDs comprising this light-emitting layer, devices comprising an OLED according to the present invention, and specific transition metal complexes comprising atb least two carbene ligands.

Encrypted markers that are not readily detectable can be revealed by treatment with a specific reagent used as a developer to reveal a readily detectable physical property of the marker, such as a characteristic fluorescence emission after excitation with a particular excitation wavelength, or to reveal a visible color. The encrypted marker can be developed in situ, or a sample can be removed by brushing, scraping, swabbing or scratching the marked object or item and developing the encrypted marker or a sample thereof with the appropriate developer to reveal an overt marker or optical signal. The encrypted marker may include a DNA taggant.

Encrypted markers that are not readily detectable can be revealed by treatment with a specific reagent used as a developer to reveal a readily detectable physical property of the marker, such as a characteristic fluorescence emission after excitation with a particular excitation wavelength, or to reveal a visible color. The encrypted marker can be developed in situ, or a sample can be removed by brushing, scraping, swabbing or scratching the marked object or item and developing the encrypted marker or a sample thereof with the appropriate developer to reveal an overt marker or optical signal. The encrypted marker may include a DNA taggant.

The present invention relates to a method for the deposition of at least one layer of an organic material on a substrate by (a) providing a source of a solid organic material in an atmosphere at a pressure comprised between 50 and 200 kPa, (b) heating said organic material to a first temperature to produce a vapor of said organic material, (c) exposing at least one surface of a substrate having a second temperature lower than said first temperature to said vapor to deposit organic material from said vapor onto said at least one surface of said substrate.