N. Aurangzeb et al., CRYSTALLOGRAPHIC CHARACTERIZATION OF A POSSIBLE MODEL FOR PHOTOSYSTEM-II, Journal of the Chemical Society, Chemical Communications, (9), 1994, pp. 1153-1155
An X-ray crystal study of [Mn(3,5,Cl-salen)(H2O)(2)](2)(ClO4)(2) [3,5,
Cl-salen = N,N'-3,5-dichloro(salicylidene)1,2-diaminoethane] reveals i
t to be a hydrogen-bonded di-aquabridged dimer; a combination of the s
teric bulk of the ligand and a hydrogen bonding system creates a coord
ination cleft which can allow the approach of p-benzoquinone and water
photolysis to occur on irradiation with visible light (no such photol
ysis occurs when sterically bulky 2,5-tert-butyl-p-benzoquinone is emp
loyed).