IAC (iodoacetamide azobenzene)

thiol-reactive reversible photoswitchable cross-linker, trans form stable in the dark, trans absorbs UV (λmax 370 nm;ε370=24000M-1cm-1)
https://www.ncbi.nlm.nih.gov/pubmed/10760254

bis-sulfonato-bis-chloroacetamido-azobenzene (BSBCA)

water-soluble, thiol reactive cross-linker, UV, ε370=29000M-1cm-1
https://www.ncbi.nlm.nih.gov/pubmed/17406582

tetra-ortho-methoxyazobenzene-chloroaceamide (TOM)

green/red, λmax=490nm, photoswitchable cross-linker

https://www.ncbi.nlm.nih.gov/pubmed/22082305

tetra-ortho-methoxy azonium (PIP)

red-light photoswitch, ε600 = ~20,000 M-1cm-1 in pH7.0 buffer; trans azonium form
apparent pKa of 7.2
https://www.ncbi.nlm.nih.gov/pubmed/24214131