As described above, the aforementioned radicals may be substituted by E and/or, if desired, interrupted by D. Interruptions are of course possible only in the case of radicals containing at least 2 carbon atoms connected to one another by single bonds; C₆-C₁₈aryl is not interrupted; interrupted arylalkyl or alkylaryl contains the unit D in the alkyl moiety. C₁-C₂₄alkyl substituted by one or more E and/or interrupted by one or more units D is, for example, (CH₂CH₂O)_(n)—R^(x), where n is a number from the range 1-9 and R^(x) is H or C₁-C₁₀alkyl or C₂-C₁₀alkanoyl (e.g. CO—CH(C₂H₅)C₄H₉), CH₂—CH(OR^(y′))—CH₂—O—R^(y), where R^(y) is C₁-C₂₄alkyl, C₅-C₁₂cycloalkyl, phenyl, C₇-C₁₅phenylalkyl, and R^(y′) embraces the same definitions as R^(y) or is H; C₁-C₈alkylene-COO—R^(z), e.g. CH₂COOR^(z), CH(CH₃)COOR^(z), C(CH₃)₂COOR^(z), where R^(z) is H, C₁-C₂₄alkyl, (CH₂CH₂O)₁₋₉—R^(x), and R^(x) embraces the definitions indicated above; CH₂CH₂—O—CO—CH═CH₂; CH₂CH(OH)CH₂—O—CO—C(CH₃)═CH₂.
The blue-emitting 2H-benzotriazoles of this invention emit light below about 520 nm, for example between about 380 nm and about 520 nm. For example, the blue-emitting 2H-benzotriazoles of this invention have a NTSC coordinate of about (0.14, 0.08), where the first coordinate is between about 0.12 and about 0.16, and the second coordinate is between about 0.05 and about 0.10.
The present compounds of formula I, Including those of formulae II, III, IV, V and VI, as well as the ortho-hydrocarbyloxyphenyl-2H-benzotriazoles, may also function as other than a blue-emitting organic compound, for example they may also function as a hole-injecting, hole-transporting, and electron-injecting or an electron-transporting material.
The organic EL device of the present Invention has significant industrial values since it can be adapted for a flat panel display of an on-wall television set, a flat light-emitting device, a light source for a copying machine or a printer, a light source for a liquid crystal display or counter, a display signboard and a signal light.

### Language ###
English

### Assessment ###
The text mentions specific wavelength range for blue light emission, which could be of interest to someone looking for technical specifications.

### Query ###
What is the wavelength range for blue light emission?
What is the wavelength range for blue light emission?