of CCl4, CHCl3
, or CH2Cl2 leads to major absorption
bands peaked below 570 nm. Conversely, when CHBr3,
BrCH2CH2Br, or Br2CHCHBr2 is involved, broad and redshifted
absorption bands at 550−615 nm are observed.
Furthermore, when reacting with CH2I2 or 1,4-C6H4I2, the
photochromic response will be further bathochromically shifted
to 635 nm.