Characterization of the relevant excited states in the photodissociation of CO-ligated hemoglobin and myoglobin.
The relevant excited states in the rapid photodissociation process of hemoglobin and myoglobin are examined by means of time-dependent density functional theory. Our calculations clearly show that the photodissociation is mediated by two repulsive states (5 A' ' and 3 A') which cross the lowest excited states (1 A' and 1 A' ') at an internuclear Fe-C distance of about 2 A. Electron detachment/attachment density plots nicely explain the repulsive nature of the 5 A' ' and 3 A' states.
Dreuw
Andreas
A
Department of Chemistry, University of California, Berkeley, and Chemical Science Division, Lawrence Berkeley National Laboratory, California 94720, USA.
Dunietz
Barry D
BD
Head-Gordon
Martin
M
D002248:Carbon Monoxide / Q000737:chemistry*; D002263:Carboxyhemoglobin / Q000737:chemistry*; D006454:Hemoglobins / Q000737:chemistry*; D006639:Histidine / Q000737:chemistry; D006801:Humans; D007093:Imidazoles / Q000737:chemistry; D008956:Models, Chemical; D008958:Models, Molecular; D018716:Molecular Mimicry; D009211:Myoglobin / Q000737:chemistry*; D010777:Photochemistry; D011166:Porphyrins / Q000737:chemistry; D013816:Thermodynamics
D006454:Hemoglobins; D007093:Imidazoles; D009211:Myoglobin; D011166:Porphyrins; D006639:Histidine; D002248:Carbon Monoxide; D002263:Carboxyhemoglobin