Two bis(mu-methoxo)dichromium(III) complexes, [(L2Cr2)-Cr-Se(mu-OCH3)(2)(CH3OH)(2)] 1 and [(L2Cr2)-Cr-Se(mu-OCH3)(2)(CH3OH)(CH3O)](-) 2, where L-Se represents the dianion of 2,2'-selenobis(4,6-di-tertbutylphenol), have been reported to demonstrate the effect of hydrogen bonding on the exchange coupling interactions between the chromium(Ill) centers. The corresponding sulfur analogue of the ligand, i.e., 2,2'-thiobis(4,6-di-tert-butylphenol), also yields the analogous [(L2Cr2)-Cr-S(Umu-OCH3)(2)(CH3OH)(2)] 3 and [(L2Cr2)-Cr-S(mu-OCH3)(2)(CH3O)(CH3OH)](-) 4, which exhibit similar exchange coupling parameters. An acid-base dependent equilibrium between I and 2 or 3 and 4 has been established by electronic spectral measurements.