An iridium-based luminescent or electrochemiluminescent compound of Formula I wherein R1-R12 is hydrogen, halide, cyano- or nitro-group, a hydrophilic group, or R19, wherein R19 is aryl, substituted aryl, alkyl, substituted alkyl branched alkyl, substituted branched alkyl, arylalkyl, substituted arylalkyl,alkylaryl, substituted alkylaryl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, wherein the substituent is selected from hydrogen, halide, cyano- or nitro-group, a hydrophilic group, wherein R13-R16 is hydrogen, halide, cyano- or nitro-group, a hydrophilic group, -Q-Y, or R19, wherein R19 is aryl, substituted aryl, alkyl, substituted alkyl branched alkyl, substituted branched alkyl, arylalkyl, substituted arylalkyl,alkylaryl, substituted alkylaryl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, wherein the substituent is selected from hydrogen, halide, cyano- or nitro-group, a hydrophilic group, wherein R17-R18 represents hydrogen, alkyl, aryl, substituted aryl and alkyl, heteroaromatic ring system, non-aromatic ring or ring system, imidazolium, cyclodextrin or Q-Y, or wherein within R1-R12 or/and within R13-R16, respectively, two adjacent Rs can form an aromatic ring or a substituted aromatic ring, wherein the substituent is selected from hydrogen, halide, cyano- or nitro-group, a hydrophilic group, or wherein within R1-R12 or/and within R13-R16, respectively, two adjacent Rs can form an aliphatic ring or a substituted aliphatic ring, wherein the substituent is selected from hydrogen, halide, cyano- or nitro-group, a hydrophilic group, wherein X represents C or N, wherein Y represents C or N, wherein at least one of R13-R18 is -Q-Y, wherein Q represents a linker and Y is a functional group and, wherein said functional group Y is selected from the group consisting of carboxylic acid, N-hydroxysuccinimide ester, amino group, halogen, sulflrydryl, maleimido, alkynyl, azide and phosphoramidite. wherein R1-R12 is hydrogen, halide, cyano- or nitro-group, a hydrophilic group, or R19, wherein R19 is aryl, substituted aryl, alkyl, substituted alkyl branched alkyl, substituted branched alkyl, arylalkyl, substituted arylalkyl,alkylaryl, substituted alkylaryl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, wherein the substituent is selected from hydrogen, halide, cyano- or nitro-group, a hydrophilic group, wherein R13-R16 is hydrogen, halide, cyano- or nitro-group, a hydrophilic group, -Q-Y, or R19, wherein R19 is aryl, substituted aryl, alkyl, substituted alkyl branched alkyl, substituted branched alkyl, arylalkyl, substituted arylalkyl,alkylaryl, substituted alkylaryl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, wherein the substituent is selected from hydrogen, halide, cyano- or nitro-group, a hydrophilic group, wherein R17-R18 represents hydrogen, alkyl, aryl, substituted aryl and alkyl, heteroaromatic ring system, non-aromatic ring or ring system, imidazolium, cyclodextrin or Q-Y, or wherein within R1-R12 or/and within R13-R16, respectively, two adjacent Rs can form an aromatic ring or a substituted aromatic ring, wherein the substituent is selected from hydrogen, halide, cyano- or nitro-group, a hydrophilic group, or wherein within R1-R12 or/and within R13-R16, respectively, two adjacent Rs can form an aliphatic ring or a substituted aliphatic ring, wherein the substituent is selected from hydrogen, halide, cyano- or nitro-group, a hydrophilic group, wherein X represents C or N, wherein Y represents C or N, wherein at least one of R13-R18 is -Q-Y, wherein Q represents a linker and Y is a functional group and, wherein said functional group Y is selected from the group consisting of carboxylic acid, N-hydroxysuccinimide ester, amino group, halogen, sulflrydryl, maleimido, alkynyl, azide and phosphoramidite.