significant differences to results obtained from those of conventional diffraction
studies of long-lived photoinduced high spin states. Ultra-fast spin-state
photoswitching in two crystalline polymorphs of the octahedral Fe(III) complex
[(TPA)Fe(TCC)] (TPA ¼ tris(2-pyridylmethyl)amine and TCC ¼ 3,4,5,6tetrachloroactecholate dianion) (Fig. 11) has been studied by femtosecond optical
spectroscopy and picosecond X-ray diffraction [39]. In these experiments the X-ray
pulses were generated by a fast chopper, and data was collected with a series of
different delay times between the laser pump and the X-ray probe. The time
Fig. 11 Photodifference maps obtained for the monoclinic polymorph with isosurfaces (red
positive, blue negative) of (a) Æ0.14 eÅ
3 for the 500 ps data and (b) Æ0.46 eÅ
3 for the 50 μs
data. Reproduced from Ref. [39] with permission from the Royal Society of Chemistry
262
P. R. Raithby
studies of long-lived photoinduced high spin states. Ultra-fast spin-state
photoswitching in two crystalline polymorphs of the octahedral Fe(III) complex
[(TPA)Fe(TCC)] (TPA ¼ tris(2-pyridylmethyl)amine and TCC ¼ 3,4,5,6tetrachloroactecholate dianion) (Fig. 11) has been studied by femtosecond optical
spectroscopy and picosecond X-ray diffraction [39]. In these experiments the X-ray
pulses were generated by a fast chopper, and data was collected with a series of
different delay times between the laser pump and the X-ray probe. The time
Fig. 11 Photodifference maps obtained for the monoclinic polymorph with isosurfaces (red
positive, blue negative) of (a) Æ0.14 eÅ
3 for the 500 ps data and (b) Æ0.46 eÅ
3 for the 50 μs
data. Reproduced from Ref. [39] with permission from the Royal Society of Chemistry
262
P. R. Raithby