The photochem. behavior of a no. of flyover-bridge iron complexes I (R = R1 = R2 = R3 = Me, Et, Ph; R = R3 = Me, R1 = R2 = Ph; R = R3 = Ph, R1 = R2 = Me; R = R2 = Ph, R1 = R3 = Me) is discussed with regard to their electronic structure. In the case of I (R-R1 = Ph) the overall photochem. event is the formation of an unsatd. species upon CO loss, which evolves, in the absence of any Lewis bases, the fragments of [Fe(CO)3{(PhC2Ph)2CO}], C4Ph4CO, and [Fe(CO)5]. Photosubstitution of CO by phosphine occurs very rapidly and proceeds stereospecifically in a pseudo-axial position as assessed by 13C NMR studies. I exhibit photocatalytic activity toward olefin isomerization and, interestingly, this reaction can be activated simply by sunlight exposure. The dienone chain clasps the metal-metal bond, preventing complex decompn. and acts as a good sensitizer for the sunlight.
Photochemical and photocatalytic behavior of 'flyover-bridge' complexes
BOTTA, Mauro;GOBETTO, Roberto;
1988-01-01
Abstract
The photochem. behavior of a no. of flyover-bridge iron complexes I (R = R1 = R2 = R3 = Me, Et, Ph; R = R3 = Me, R1 = R2 = Ph; R = R3 = Ph, R1 = R2 = Me; R = R2 = Ph, R1 = R3 = Me) is discussed with regard to their electronic structure. In the case of I (R-R1 = Ph) the overall photochem. event is the formation of an unsatd. species upon CO loss, which evolves, in the absence of any Lewis bases, the fragments of [Fe(CO)3{(PhC2Ph)2CO}], C4Ph4CO, and [Fe(CO)5]. Photosubstitution of CO by phosphine occurs very rapidly and proceeds stereospecifically in a pseudo-axial position as assessed by 13C NMR studies. I exhibit photocatalytic activity toward olefin isomerization and, interestingly, this reaction can be activated simply by sunlight exposure. The dienone chain clasps the metal-metal bond, preventing complex decompn. and acts as a good sensitizer for the sunlight.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.